ext4: Add BUG_ON debugging checks to noalloc_get_block_write()
[safe/jmp/linux-2.6] / fs / ext4 / inode.c
index a6b800c..e6113c3 100644 (file)
@@ -34,6 +34,7 @@
 #include <linux/writeback.h>
 #include <linux/pagevec.h>
 #include <linux/mpage.h>
+#include <linux/namei.h>
 #include <linux/uio.h>
 #include <linux/bio.h>
 #include "ext4_jbd2.h"
 #include "acl.h"
 #include "ext4_extents.h"
 
+#define MPAGE_DA_EXTENT_TAIL 0x01
+
 static inline int ext4_begin_ordered_truncate(struct inode *inode,
                                              loff_t new_size)
 {
-       return jbd2_journal_begin_ordered_truncate(&EXT4_I(inode)->jinode,
-                                                  new_size);
+       return jbd2_journal_begin_ordered_truncate(
+                                       EXT4_SB(inode->i_sb)->s_journal,
+                                       &EXT4_I(inode)->jinode,
+                                       new_size);
 }
 
 static void ext4_invalidatepage(struct page *page, unsigned long offset);
@@ -69,12 +74,17 @@ static int ext4_inode_is_fast_symlink(struct inode *inode)
  * "bh" may be NULL: a metadata block may have been freed from memory
  * but there may still be a record of it in the journal, and that record
  * still needs to be revoked.
+ *
+ * If the handle isn't valid we're not journaling so there's nothing to do.
  */
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
                        struct buffer_head *bh, ext4_fsblk_t blocknr)
 {
        int err;
 
+       if (!ext4_handle_valid(handle))
+               return 0;
+
        might_sleep();
 
        BUFFER_TRACE(bh, "enter");
@@ -167,7 +177,9 @@ static handle_t *start_transaction(struct inode *inode)
  */
 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
 {
-       if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS)
+       if (!ext4_handle_valid(handle))
+               return 0;
+       if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
                return 0;
        if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
                return 0;
@@ -181,6 +193,7 @@ static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
  */
 static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
 {
+       BUG_ON(EXT4_JOURNAL(inode) == NULL);
        jbd_debug(2, "restarting handle %p\n", handle);
        return ext4_journal_restart(handle, blocks_for_truncate(inode));
 }
@@ -188,9 +201,10 @@ static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
 /*
  * Called at the last iput() if i_nlink is zero.
  */
-void ext4_delete_inode (struct inode * inode)
+void ext4_delete_inode(struct inode *inode)
 {
        handle_t *handle;
+       int err;
 
        if (ext4_should_order_data(inode))
                ext4_begin_ordered_truncate(inode, 0);
@@ -199,8 +213,9 @@ void ext4_delete_inode (struct inode * inode)
        if (is_bad_inode(inode))
                goto no_delete;
 
-       handle = start_transaction(inode);
+       handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3);
        if (IS_ERR(handle)) {
+               ext4_std_error(inode->i_sb, PTR_ERR(handle));
                /*
                 * If we're going to skip the normal cleanup, we still need to
                 * make sure that the in-core orphan linked list is properly
@@ -211,10 +226,36 @@ void ext4_delete_inode (struct inode * inode)
        }
 
        if (IS_SYNC(inode))
-               handle->h_sync = 1;
+               ext4_handle_sync(handle);
        inode->i_size = 0;
+       err = ext4_mark_inode_dirty(handle, inode);
+       if (err) {
+               ext4_warning(inode->i_sb, __func__,
+                            "couldn't mark inode dirty (err %d)", err);
+               goto stop_handle;
+       }
        if (inode->i_blocks)
                ext4_truncate(inode);
+
+       /*
+        * ext4_ext_truncate() doesn't reserve any slop when it
+        * restarts journal transactions; therefore there may not be
+        * enough credits left in the handle to remove the inode from
+        * the orphan list and set the dtime field.
+        */
+       if (!ext4_handle_has_enough_credits(handle, 3)) {
+               err = ext4_journal_extend(handle, 3);
+               if (err > 0)
+                       err = ext4_journal_restart(handle, 3);
+               if (err != 0) {
+                       ext4_warning(inode->i_sb, __func__,
+                                    "couldn't extend journal (err %d)", err);
+               stop_handle:
+                       ext4_journal_stop(handle);
+                       goto no_delete;
+               }
+       }
+
        /*
         * Kill off the orphan record which ext4_truncate created.
         * AKPM: I think this can be inside the above `if'.
@@ -300,11 +341,11 @@ static int ext4_block_to_path(struct inode *inode,
        int final = 0;
 
        if (i_block < 0) {
-               ext4_warning (inode->i_sb, "ext4_block_to_path", "block < 0");
+               ext4_warning(inode->i_sb, "ext4_block_to_path", "block < 0");
        } else if (i_block < direct_blocks) {
                offsets[n++] = i_block;
                final = direct_blocks;
-       } else if ( (i_block -= direct_blocks) < indirect_blocks) {
+       } else if ((i_block -= direct_blocks) < indirect_blocks) {
                offsets[n++] = EXT4_IND_BLOCK;
                offsets[n++] = i_block;
                final = ptrs;
@@ -321,15 +362,43 @@ static int ext4_block_to_path(struct inode *inode,
                final = ptrs;
        } else {
                ext4_warning(inode->i_sb, "ext4_block_to_path",
-                               "block %lu > max",
+                               "block %lu > max in inode %lu",
                                i_block + direct_blocks +
-                               indirect_blocks + double_blocks);
+                               indirect_blocks + double_blocks, inode->i_ino);
        }
        if (boundary)
                *boundary = final - 1 - (i_block & (ptrs - 1));
        return n;
 }
 
+static int __ext4_check_blockref(const char *function, struct inode *inode,
+                                __le32 *p, unsigned int max) {
+
+       unsigned int maxblocks = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es);
+       __le32 *bref = p;
+       while (bref < p+max) {
+               if (unlikely(le32_to_cpu(*bref) >= maxblocks)) {
+                       ext4_error(inode->i_sb, function,
+                                  "block reference %u >= max (%u) "
+                                  "in inode #%lu, offset=%d",
+                                  le32_to_cpu(*bref), maxblocks,
+                                  inode->i_ino, (int)(bref-p));
+                       return -EIO;
+               }
+               bref++;
+       }
+       return 0;
+}
+
+
+#define ext4_check_indirect_blockref(inode, bh)                         \
+        __ext4_check_blockref(__func__, inode, (__le32 *)(bh)->b_data,  \
+                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
+
+#define ext4_check_inode_blockref(inode)                                \
+        __ext4_check_blockref(__func__, inode, EXT4_I(inode)->i_data,   \
+                             EXT4_NDIR_BLOCKS)
+
 /**
  *     ext4_get_branch - read the chain of indirect blocks leading to data
  *     @inode: inode in question
@@ -370,14 +439,27 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth,
 
        *err = 0;
        /* i_data is not going away, no lock needed */
-       add_chain (chain, NULL, EXT4_I(inode)->i_data + *offsets);
+       add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
        if (!p->key)
                goto no_block;
        while (--depth) {
-               bh = sb_bread(sb, le32_to_cpu(p->key));
-               if (!bh)
+               bh = sb_getblk(sb, le32_to_cpu(p->key));
+               if (unlikely(!bh))
                        goto failure;
-               add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
+                  
+               if (!bh_uptodate_or_lock(bh)) {
+                       if (bh_submit_read(bh) < 0) {
+                               put_bh(bh);
+                               goto failure;
+                       }
+                       /* validate block references */
+                       if (ext4_check_indirect_blockref(inode, bh)) {
+                               put_bh(bh);
+                               goto failure;
+                       }
+               }
+               
+               add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
                /* Reader: end */
                if (!p->key)
                        goto no_block;
@@ -413,11 +495,13 @@ no_block:
 static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
 {
        struct ext4_inode_info *ei = EXT4_I(inode);
-       __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
+       __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
        __le32 *p;
        ext4_fsblk_t bg_start;
        ext4_fsblk_t last_block;
        ext4_grpblk_t colour;
+       ext4_group_t block_group;
+       int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
 
        /* Try to find previous block */
        for (p = ind->p - 1; p >= start; p--) {
@@ -433,9 +517,22 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
         * It is going to be referred to from the inode itself? OK, just put it
         * into the same cylinder group then.
         */
-       bg_start = ext4_group_first_block_no(inode->i_sb, ei->i_block_group);
+       block_group = ei->i_block_group;
+       if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
+               block_group &= ~(flex_size-1);
+               if (S_ISREG(inode->i_mode))
+                       block_group++;
+       }
+       bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
        last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
 
+       /*
+        * If we are doing delayed allocation, we don't need take
+        * colour into account.
+        */
+       if (test_opt(inode->i_sb, DELALLOC))
+               return bg_start;
+
        if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
                colour = (current->pid % 16) *
                        (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
@@ -456,18 +553,9 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
 static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
                Indirect *partial)
 {
-       struct ext4_block_alloc_info *block_i;
-
-       block_i =  EXT4_I(inode)->i_block_alloc_info;
-
        /*
-        * try the heuristic for sequential allocation,
-        * failing that at least try to get decent locality.
+        * XXX need to get goal block from mballoc's data structures
         */
-       if (block_i && (block == block_i->last_alloc_logical_block + 1)
-               && (block_i->last_alloc_physical_block != 0)) {
-               return block_i->last_alloc_physical_block + 1;
-       }
 
        return ext4_find_near(inode, partial);
 }
@@ -484,10 +572,10 @@ static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
  *     return the total number of blocks to be allocate, including the
  *     direct and indirect blocks.
  */
-static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
+static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
                int blocks_to_boundary)
 {
-       unsigned long count = 0;
+       unsigned int count = 0;
 
        /*
         * Simple case, [t,d]Indirect block(s) has not allocated yet
@@ -525,6 +613,7 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
                                int indirect_blks, int blks,
                                ext4_fsblk_t new_blocks[4], int *err)
 {
+       struct ext4_allocation_request ar;
        int target, i;
        unsigned long count = 0, blk_allocated = 0;
        int index = 0;
@@ -573,10 +662,17 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
        if (!target)
                goto allocated;
        /* Now allocate data blocks */
-       count = target;
-       /* allocating blocks for data blocks */
-       current_block = ext4_new_blocks(handle, inode, iblock,
-                                               goal, &count, err);
+       memset(&ar, 0, sizeof(ar));
+       ar.inode = inode;
+       ar.goal = goal;
+       ar.len = target;
+       ar.logical = iblock;
+       if (S_ISREG(inode->i_mode))
+               /* enable in-core preallocation only for regular files */
+               ar.flags = EXT4_MB_HINT_DATA;
+
+       current_block = ext4_mb_new_blocks(handle, &ar, err);
+
        if (*err && (target == blks)) {
                /*
                 * if the allocation failed and we didn't allocate
@@ -592,7 +688,7 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
                 */
                        new_blocks[index] = current_block;
                }
-               blk_allocated += count;
+               blk_allocated += ar.len;
        }
 allocated:
        /* total number of blocks allocated for direct blocks */
@@ -600,7 +696,7 @@ allocated:
        *err = 0;
        return ret;
 failed_out:
-       for (i = 0; i <index; i++)
+       for (i = 0; i < index; i++)
                ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
        return ret;
 }
@@ -673,7 +769,7 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
                branch[n].p = (__le32 *) bh->b_data + offsets[n];
                branch[n].key = cpu_to_le32(new_blocks[n]);
                *branch[n].p = branch[n].key;
-               if ( n == indirect_blks) {
+               if (n == indirect_blks) {
                        current_block = new_blocks[n];
                        /*
                         * End of chain, update the last new metablock of
@@ -687,8 +783,8 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
                set_buffer_uptodate(bh);
                unlock_buffer(bh);
 
-               BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-               err = ext4_journal_dirty_metadata(handle, bh);
+               BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+               err = ext4_handle_dirty_metadata(handle, inode, bh);
                if (err)
                        goto failed;
        }
@@ -700,7 +796,7 @@ failed:
                BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget");
                ext4_journal_forget(handle, branch[i].bh);
        }
-       for (i = 0; i <indirect_blks; i++)
+       for (i = 0; i < indirect_blks; i++)
                ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
 
        ext4_free_blocks(handle, inode, new_blocks[i], num, 0);
@@ -727,10 +823,8 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 {
        int i;
        int err = 0;
-       struct ext4_block_alloc_info *block_i;
        ext4_fsblk_t current_block;
 
-       block_i = EXT4_I(inode)->i_block_alloc_info;
        /*
         * If we're splicing into a [td]indirect block (as opposed to the
         * inode) then we need to get write access to the [td]indirect block
@@ -753,18 +847,7 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
        if (num == 0 && blks > 1) {
                current_block = le32_to_cpu(where->key) + 1;
                for (i = 1; i < blks; i++)
-                       *(where->p + i ) = cpu_to_le32(current_block++);
-       }
-
-       /*
-        * update the most recently allocated logical & physical block
-        * in i_block_alloc_info, to assist find the proper goal block for next
-        * allocation
-        */
-       if (block_i) {
-               block_i->last_alloc_logical_block = block + blks - 1;
-               block_i->last_alloc_physical_block =
-                               le32_to_cpu(where[num].key) + blks - 1;
+                       *(where->p + i) = cpu_to_le32(current_block++);
        }
 
        /* We are done with atomic stuff, now do the rest of housekeeping */
@@ -783,8 +866,8 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
                 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
                 */
                jbd_debug(5, "splicing indirect only\n");
-               BUFFER_TRACE(where->bh, "call ext4_journal_dirty_metadata");
-               err = ext4_journal_dirty_metadata(handle, where->bh);
+               BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
+               err = ext4_handle_dirty_metadata(handle, inode, where->bh);
                if (err)
                        goto err_out;
        } else {
@@ -809,6 +892,10 @@ err_out:
 }
 
 /*
+ * The ext4_ind_get_blocks() function handles non-extents inodes
+ * (i.e., using the traditional indirect/double-indirect i_blocks
+ * scheme) for ext4_get_blocks().
+ *
  * Allocation strategy is simple: if we have to allocate something, we will
  * have to go the whole way to leaf. So let's do it before attaching anything
  * to tree, set linkage between the newborn blocks, write them if sync is
@@ -826,15 +913,16 @@ err_out:
  * return = 0, if plain lookup failed.
  * return < 0, error case.
  *
- *
- * Need to be called with
- * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
- * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ * The ext4_ind_get_blocks() function should be called with
+ * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
+ * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
+ * blocks.
  */
-int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
-               ext4_lblk_t iblock, unsigned long maxblocks,
-               struct buffer_head *bh_result,
-               int create, int extend_disksize)
+static int ext4_ind_get_blocks(handle_t *handle, struct inode *inode,
+                                 ext4_lblk_t iblock, unsigned int maxblocks,
+                                 struct buffer_head *bh_result,
+                                 int flags)
 {
        int err = -EIO;
        ext4_lblk_t offsets[4];
@@ -847,10 +935,11 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
        struct ext4_inode_info *ei = EXT4_I(inode);
        int count = 0;
        ext4_fsblk_t first_block = 0;
+       loff_t disksize;
 
 
        J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
-       J_ASSERT(handle != NULL || create == 0);
+       J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
        depth = ext4_block_to_path(inode, iblock, offsets,
                                        &blocks_to_boundary);
 
@@ -879,16 +968,12 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
        }
 
        /* Next simple case - plain lookup or failed read of indirect block */
-       if (!create || err == -EIO)
+       if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
                goto cleanup;
 
        /*
-        * Okay, we need to do block allocation.  Lazily initialize the block
-        * allocation info here if necessary
+        * Okay, we need to do block allocation.
        */
-       if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
-               ext4_init_block_alloc_info(inode);
-
        goal = ext4_find_goal(inode, iblock, partial);
 
        /* the number of blocks need to allocate for [d,t]indirect blocks */
@@ -922,8 +1007,13 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
         * protect it if you're about to implement concurrent
         * ext4_get_block() -bzzz
        */
-       if (!err && extend_disksize && inode->i_size > ei->i_disksize)
-               ei->i_disksize = inode->i_size;
+       if (!err && (flags & EXT4_GET_BLOCKS_EXTEND_DISKSIZE)) {
+               disksize = ((loff_t) iblock + count) << inode->i_blkbits;
+               if (disksize > i_size_read(inode))
+                       disksize = i_size_read(inode);
+               if (disksize > ei->i_disksize)
+                       ei->i_disksize = disksize;
+       }
        if (err)
                goto cleanup;
 
@@ -946,29 +1036,105 @@ out:
        return err;
 }
 
-/* Maximum number of blocks we map for direct IO at once. */
-#define DIO_MAX_BLOCKS 4096
+qsize_t ext4_get_reserved_space(struct inode *inode)
+{
+       unsigned long long total;
+
+       spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+       total = EXT4_I(inode)->i_reserved_data_blocks +
+               EXT4_I(inode)->i_reserved_meta_blocks;
+       spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+       return total;
+}
+/*
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate @blocks for non extent file based file
+ */
+static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
+{
+       int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
+       int ind_blks, dind_blks, tind_blks;
+
+       /* number of new indirect blocks needed */
+       ind_blks = (blocks + icap - 1) / icap;
+
+       dind_blks = (ind_blks + icap - 1) / icap;
+
+       tind_blks = 1;
+
+       return ind_blks + dind_blks + tind_blks;
+}
+
 /*
- * Number of credits we need for writing DIO_MAX_BLOCKS:
- * We need sb + group descriptor + bitmap + inode -> 4
- * For B blocks with A block pointers per block we need:
- * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
- * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
+ * Calculate the number of metadata blocks need to reserve
+ * to allocate given number of blocks
  */
-#define DIO_CREDITS 25
+static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
+{
+       if (!blocks)
+               return 0;
+
+       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
+               return ext4_ext_calc_metadata_amount(inode, blocks);
+
+       return ext4_indirect_calc_metadata_amount(inode, blocks);
+}
 
+static void ext4_da_update_reserve_space(struct inode *inode, int used)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       int total, mdb, mdb_free;
+
+       spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+       /* recalculate the number of metablocks still need to be reserved */
+       total = EXT4_I(inode)->i_reserved_data_blocks - used;
+       mdb = ext4_calc_metadata_amount(inode, total);
+
+       /* figure out how many metablocks to release */
+       BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
+       mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
+
+       if (mdb_free) {
+               /* Account for allocated meta_blocks */
+               mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+
+               /* update fs dirty blocks counter */
+               percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
+               EXT4_I(inode)->i_allocated_meta_blocks = 0;
+               EXT4_I(inode)->i_reserved_meta_blocks = mdb;
+       }
+
+       /* update per-inode reservations */
+       BUG_ON(used  > EXT4_I(inode)->i_reserved_data_blocks);
+       EXT4_I(inode)->i_reserved_data_blocks -= used;
+       spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+       /*
+        * free those over-booking quota for metadata blocks
+        */
+       if (mdb_free)
+               vfs_dq_release_reservation_block(inode, mdb_free);
+
+       /*
+        * If we have done all the pending block allocations and if
+        * there aren't any writers on the inode, we can discard the
+        * inode's preallocations.
+        */
+       if (!total && (atomic_read(&inode->i_writecount) == 0))
+               ext4_discard_preallocations(inode);
+}
 
 /*
+ * The ext4_get_blocks() function tries to look up the requested blocks,
+ * and returns if the blocks are already mapped.
  *
- *
- * ext4_ext4 get_block() wrapper function
- * It will do a look up first, and returns if the blocks already mapped.
  * Otherwise it takes the write lock of the i_data_sem and allocate blocks
  * and store the allocated blocks in the result buffer head and mark it
  * mapped.
  *
  * If file type is extents based, it will call ext4_ext_get_blocks(),
- * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping
+ * Otherwise, call with ext4_ind_get_blocks() to handle indirect mapping
  * based files
  *
  * On success, it returns the number of blocks being mapped or allocate.
@@ -981,30 +1147,31 @@ out:
  *
  * It returns the error in case of allocation failure.
  */
-int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
-                       unsigned long max_blocks, struct buffer_head *bh,
-                       int create, int extend_disksize, int flag)
+int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
+                   unsigned int max_blocks, struct buffer_head *bh,
+                   int flags)
 {
        int retval;
 
        clear_buffer_mapped(bh);
+       clear_buffer_unwritten(bh);
 
        /*
-        * Try to see if we can get  the block without requesting
-        * for new file system block.
+        * Try to see if we can get the block without requesting a new
+        * file system block.
         */
        down_read((&EXT4_I(inode)->i_data_sem));
        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
-                               bh, 0, 0);
+                               bh, 0);
        } else {
-               retval = ext4_get_blocks_handle(handle,
-                               inode, block, max_blocks, bh, 0, 0);
+               retval = ext4_ind_get_blocks(handle, inode, block, max_blocks,
+                                            bh, 0);
        }
        up_read((&EXT4_I(inode)->i_data_sem));
 
        /* If it is only a block(s) look up */
-       if (!create)
+       if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
                return retval;
 
        /*
@@ -1018,6 +1185,18 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                return retval;
 
        /*
+        * When we call get_blocks without the create flag, the
+        * BH_Unwritten flag could have gotten set if the blocks
+        * requested were part of a uninitialized extent.  We need to
+        * clear this flag now that we are committed to convert all or
+        * part of the uninitialized extent to be an initialized
+        * extent.  This is because we need to avoid the combination
+        * of BH_Unwritten and BH_Mapped flags being simultaneously
+        * set on the buffer_head.
+        */
+       clear_buffer_unwritten(bh);
+
+       /*
         * New blocks allocate and/or writing to uninitialized extent
         * will possibly result in updating i_data, so we take
         * the write lock of i_data_sem, and call get_blocks()
@@ -1031,7 +1210,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
         * let the underlying get_block() function know to
         * avoid double accounting
         */
-       if (flag)
+       if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
                EXT4_I(inode)->i_delalloc_reserved_flag = 1;
        /*
         * We need to check for EXT4 here because migrate
@@ -1039,10 +1218,10 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
         */
        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
-                               bh, create, extend_disksize);
+                                             bh, flags);
        } else {
-               retval = ext4_get_blocks_handle(handle, inode, block,
-                               max_blocks, bh, create, extend_disksize);
+               retval = ext4_ind_get_blocks(handle, inode, block,
+                                            max_blocks, bh, flags);
 
                if (retval > 0 && buffer_new(bh)) {
                        /*
@@ -1055,7 +1234,7 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                }
        }
 
-       if (flag) {
+       if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
                EXT4_I(inode)->i_delalloc_reserved_flag = 0;
                /*
                 * Update reserved blocks/metadata blocks
@@ -1063,26 +1242,30 @@ int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
                 * which were deferred till now
                 */
                if ((retval > 0) && buffer_delay(bh))
-                       ext4_da_release_space(inode, retval, 0);
+                       ext4_da_update_reserve_space(inode, retval);
        }
 
        up_write((&EXT4_I(inode)->i_data_sem));
        return retval;
 }
 
-static int ext4_get_block(struct inode *inode, sector_t iblock,
-                       struct buffer_head *bh_result, int create)
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+
+int ext4_get_block(struct inode *inode, sector_t iblock,
+                  struct buffer_head *bh_result, int create)
 {
        handle_t *handle = ext4_journal_current_handle();
        int ret = 0, started = 0;
        unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+       int dio_credits;
 
        if (create && !handle) {
                /* Direct IO write... */
                if (max_blocks > DIO_MAX_BLOCKS)
                        max_blocks = DIO_MAX_BLOCKS;
-               handle = ext4_journal_start(inode, DIO_CREDITS +
-                             2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb));
+               dio_credits = ext4_chunk_trans_blocks(inode, max_blocks);
+               handle = ext4_journal_start(inode, dio_credits);
                if (IS_ERR(handle)) {
                        ret = PTR_ERR(handle);
                        goto out;
@@ -1090,8 +1273,8 @@ static int ext4_get_block(struct inode *inode, sector_t iblock,
                started = 1;
        }
 
-       ret = ext4_get_blocks_wrap(handle, inode, iblock,
-                                       max_blocks, bh_result, create, 0, 0);
+       ret = ext4_get_blocks(handle, inode, iblock, max_blocks, bh_result,
+                             create ? EXT4_GET_BLOCKS_CREATE : 0);
        if (ret > 0) {
                bh_result->b_size = (ret << inode->i_blkbits);
                ret = 0;
@@ -1110,17 +1293,19 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
 {
        struct buffer_head dummy;
        int fatal = 0, err;
+       int flags = EXT4_GET_BLOCKS_EXTEND_DISKSIZE;
 
        J_ASSERT(handle != NULL || create == 0);
 
        dummy.b_state = 0;
        dummy.b_blocknr = -1000;
        buffer_trace_init(&dummy.b_history);
-       err = ext4_get_blocks_wrap(handle, inode, block, 1,
-                                       &dummy, create, 1, 0);
+       if (create)
+               flags |= EXT4_GET_BLOCKS_CREATE;
+       err = ext4_get_blocks(handle, inode, block, 1, &dummy, flags);
        /*
-        * ext4_get_blocks_handle() returns number of blocks
-        * mapped. 0 in case of a HOLE.
+        * ext4_get_blocks() returns number of blocks mapped. 0 in
+        * case of a HOLE.
         */
        if (err > 0) {
                if (err > 1)
@@ -1150,12 +1335,12 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
                        BUFFER_TRACE(bh, "call get_create_access");
                        fatal = ext4_journal_get_create_access(handle, bh);
                        if (!fatal && !buffer_uptodate(bh)) {
-                               memset(bh->b_data,0,inode->i_sb->s_blocksize);
+                               memset(bh->b_data, 0, inode->i_sb->s_blocksize);
                                set_buffer_uptodate(bh);
                        }
                        unlock_buffer(bh);
-                       BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-                       err = ext4_journal_dirty_metadata(handle, bh);
+                       BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+                       err = ext4_handle_dirty_metadata(handle, inode, bh);
                        if (!fatal)
                                fatal = err;
                } else {
@@ -1175,7 +1360,7 @@ err:
 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
                               ext4_lblk_t block, int create, int *err)
 {
-       struct buffer_head * bh;
+       struct buffer_head *bh;
 
        bh = ext4_getblk(handle, inode, block, create, err);
        if (!bh)
@@ -1191,13 +1376,13 @@ struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
        return NULL;
 }
 
-static int walk_page_buffers(  handle_t *handle,
-                               struct buffer_head *head,
-                               unsigned from,
-                               unsigned to,
-                               int *partial,
-                               int (*fn)(      handle_t *handle,
-                                               struct buffer_head *bh))
+static int walk_page_buffers(handle_t *handle,
+                            struct buffer_head *head,
+                            unsigned from,
+                            unsigned to,
+                            int *partial,
+                            int (*fn)(handle_t *handle,
+                                      struct buffer_head *bh))
 {
        struct buffer_head *bh;
        unsigned block_start, block_end;
@@ -1205,9 +1390,9 @@ static int walk_page_buffers(     handle_t *handle,
        int err, ret = 0;
        struct buffer_head *next;
 
-       for (   bh = head, block_start = 0;
-               ret == 0 && (bh != head || !block_start);
-               block_start = block_end, bh = next)
+       for (bh = head, block_start = 0;
+            ret == 0 && (bh != head || !block_start);
+            block_start = block_end, bh = next)
        {
                next = bh->b_this_page;
                block_end = block_start + blocksize;
@@ -1260,26 +1445,34 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
                                loff_t pos, unsigned len, unsigned flags,
                                struct page **pagep, void **fsdata)
 {
-       struct inode *inode = mapping->host;
+       struct inode *inode = mapping->host;
        int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
        handle_t *handle;
        int retries = 0;
-       struct page *page;
+       struct page *page;
        pgoff_t index;
-       unsigned from, to;
+       unsigned from, to;
 
+       trace_mark(ext4_write_begin,
+                  "dev %s ino %lu pos %llu len %u flags %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, flags);
        index = pos >> PAGE_CACHE_SHIFT;
-       from = pos & (PAGE_CACHE_SIZE - 1);
-       to = from + len;
+       from = pos & (PAGE_CACHE_SIZE - 1);
+       to = from + len;
 
 retry:
-       handle = ext4_journal_start(inode, needed_blocks);
-       if (IS_ERR(handle)) {
-               ret = PTR_ERR(handle);
-               goto out;
+       handle = ext4_journal_start(inode, needed_blocks);
+       if (IS_ERR(handle)) {
+               ret = PTR_ERR(handle);
+               goto out;
        }
 
-       page = __grab_cache_page(mapping, index);
+       /* We cannot recurse into the filesystem as the transaction is already
+        * started */
+       flags |= AOP_FLAG_NOFS;
+
+       page = grab_cache_page_write_begin(mapping, index, flags);
        if (!page) {
                ext4_journal_stop(handle);
                ret = -ENOMEM;
@@ -1288,7 +1481,7 @@ retry:
        *pagep = page;
 
        ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-                                                       ext4_get_block);
+                               ext4_get_block);
 
        if (!ret && ext4_should_journal_data(inode)) {
                ret = walk_page_buffers(handle, page_buffers(page),
@@ -1296,9 +1489,16 @@ retry:
        }
 
        if (ret) {
-               unlock_page(page);
+               unlock_page(page);
                ext4_journal_stop(handle);
-               page_cache_release(page);
+               page_cache_release(page);
+               /*
+                * block_write_begin may have instantiated a few blocks
+                * outside i_size.  Trim these off again. Don't need
+                * i_size_read because we hold i_mutex.
+                */
+               if (pos + len > inode->i_size)
+                       vmtruncate(inode, inode->i_size);
        }
 
        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -1313,7 +1513,7 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
        if (!buffer_mapped(bh) || buffer_freed(bh))
                return 0;
        set_buffer_uptodate(bh);
-       return ext4_journal_dirty_metadata(handle, bh);
+       return ext4_handle_dirty_metadata(handle, NULL, bh);
 }
 
 /*
@@ -1330,25 +1530,27 @@ static int ext4_ordered_write_end(struct file *file,
 {
        handle_t *handle = ext4_journal_current_handle();
        struct inode *inode = mapping->host;
-       unsigned from, to;
        int ret = 0, ret2;
 
-       from = pos & (PAGE_CACHE_SIZE - 1);
-       to = from + len;
-
+       trace_mark(ext4_ordered_write_end,
+                  "dev %s ino %lu pos %llu len %u copied %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, copied);
        ret = ext4_jbd2_file_inode(handle, inode);
 
        if (ret == 0) {
-               /*
-                * generic_write_end() will run mark_inode_dirty() if i_size
-                * changes.  So let's piggyback the i_disksize mark_inode_dirty
-                * into that.
-                */
                loff_t new_i_size;
 
                new_i_size = pos + copied;
-               if (new_i_size > EXT4_I(inode)->i_disksize)
-                       EXT4_I(inode)->i_disksize = new_i_size;
+               if (new_i_size > EXT4_I(inode)->i_disksize) {
+                       ext4_update_i_disksize(inode, new_i_size);
+                       /* We need to mark inode dirty even if
+                        * new_i_size is less that inode->i_size
+                        * bu greater than i_disksize.(hint delalloc)
+                        */
+                       ext4_mark_inode_dirty(handle, inode);
+               }
+
                ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                        page, fsdata);
                copied = ret2;
@@ -1372,9 +1574,19 @@ static int ext4_writeback_write_end(struct file *file,
        int ret = 0, ret2;
        loff_t new_i_size;
 
+       trace_mark(ext4_writeback_write_end,
+                  "dev %s ino %lu pos %llu len %u copied %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, copied);
        new_i_size = pos + copied;
-       if (new_i_size > EXT4_I(inode)->i_disksize)
-               EXT4_I(inode)->i_disksize = new_i_size;
+       if (new_i_size > EXT4_I(inode)->i_disksize) {
+               ext4_update_i_disksize(inode, new_i_size);
+               /* We need to mark inode dirty even if
+                * new_i_size is less that inode->i_size
+                * bu greater than i_disksize.(hint delalloc)
+                */
+               ext4_mark_inode_dirty(handle, inode);
+       }
 
        ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                        page, fsdata);
@@ -1399,7 +1611,12 @@ static int ext4_journalled_write_end(struct file *file,
        int ret = 0, ret2;
        int partial = 0;
        unsigned from, to;
+       loff_t new_i_size;
 
+       trace_mark(ext4_journalled_write_end,
+                  "dev %s ino %lu pos %llu len %u copied %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, copied);
        from = pos & (PAGE_CACHE_SIZE - 1);
        to = from + len;
 
@@ -1413,11 +1630,12 @@ static int ext4_journalled_write_end(struct file *file,
                                to, &partial, write_end_fn);
        if (!partial)
                SetPageUptodate(page);
-       if (pos+copied > inode->i_size)
+       new_i_size = pos + copied;
+       if (new_i_size > inode->i_size)
                i_size_write(inode, pos+copied);
        EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
-       if (inode->i_size > EXT4_I(inode)->i_disksize) {
-               EXT4_I(inode)->i_disksize = inode->i_size;
+       if (new_i_size > EXT4_I(inode)->i_disksize) {
+               ext4_update_i_disksize(inode, new_i_size);
                ret2 = ext4_mark_inode_dirty(handle, inode);
                if (!ret)
                        ret = ret2;
@@ -1431,47 +1649,19 @@ static int ext4_journalled_write_end(struct file *file,
 
        return ret ? ret : copied;
 }
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate @blocks for non extent file based file
- */
-static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks)
-{
-       int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb);
-       int ind_blks, dind_blks, tind_blks;
-
-       /* number of new indirect blocks needed */
-       ind_blks = (blocks + icap - 1) / icap;
-
-       dind_blks = (ind_blks + icap - 1) / icap;
-
-       tind_blks = 1;
-
-       return ind_blks + dind_blks + tind_blks;
-}
-
-/*
- * Calculate the number of metadata blocks need to reserve
- * to allocate given number of blocks
- */
-static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
-{
-       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-               return ext4_ext_calc_metadata_amount(inode, blocks);
-
-       return ext4_indirect_calc_metadata_amount(inode, blocks);
-}
 
 static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
 {
-       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-       unsigned long md_needed, mdblocks, total = 0;
+       int retries = 0;
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       unsigned long md_needed, mdblocks, total = 0;
 
        /*
         * recalculate the amount of metadata blocks to reserve
         * in order to allocate nrblocks
         * worse case is one extent per block
         */
+repeat:
        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
        total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks;
        mdblocks = ext4_calc_metadata_amount(inode, total);
@@ -1480,14 +1670,25 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
        md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
        total = md_needed + nrblocks;
 
-       if (ext4_has_free_blocks(sbi, total) < total) {
+       /*
+        * Make quota reservation here to prevent quota overflow
+        * later. Real quota accounting is done at pages writeout
+        * time.
+        */
+       if (vfs_dq_reserve_block(inode, total)) {
+               spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+               return -EDQUOT;
+       }
+
+       if (ext4_claim_free_blocks(sbi, total)) {
                spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+               if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
+                       yield();
+                       goto repeat;
+               }
+               vfs_dq_release_reservation_block(inode, total);
                return -ENOSPC;
        }
-
-       /* reduce fs free blocks counter */
-       percpu_counter_sub(&sbi->s_freeblocks_counter, total);
-
        EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
        EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
 
@@ -1495,36 +1696,52 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
        return 0;       /* success */
 }
 
-void ext4_da_release_space(struct inode *inode, int used, int to_free)
+static void ext4_da_release_space(struct inode *inode, int to_free)
 {
        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
        int total, mdb, mdb_free, release;
 
+       if (!to_free)
+               return;         /* Nothing to release, exit */
+
        spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+
+       if (!EXT4_I(inode)->i_reserved_data_blocks) {
+               /*
+                * if there is no reserved blocks, but we try to free some
+                * then the counter is messed up somewhere.
+                * but since this function is called from invalidate
+                * page, it's harmless to return without any action
+                */
+               printk(KERN_INFO "ext4 delalloc try to release %d reserved "
+                           "blocks for inode %lu, but there is no reserved "
+                           "data blocks\n", to_free, inode->i_ino);
+               spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+               return;
+       }
+
        /* recalculate the number of metablocks still need to be reserved */
-       total = EXT4_I(inode)->i_reserved_data_blocks - used - to_free;
+       total = EXT4_I(inode)->i_reserved_data_blocks - to_free;
        mdb = ext4_calc_metadata_amount(inode, total);
 
        /* figure out how many metablocks to release */
        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
        mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb;
 
-       /* Account for allocated meta_blocks */
-       mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
-
        release = to_free + mdb_free;
 
-       /* update fs free blocks counter for truncate case */
-       percpu_counter_add(&sbi->s_freeblocks_counter, release);
+       /* update fs dirty blocks counter for truncate case */
+       percpu_counter_sub(&sbi->s_dirtyblocks_counter, release);
 
        /* update per-inode reservations */
-       BUG_ON(used + to_free > EXT4_I(inode)->i_reserved_data_blocks);
-       EXT4_I(inode)->i_reserved_data_blocks -= (used + to_free);
+       BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks);
+       EXT4_I(inode)->i_reserved_data_blocks -= to_free;
 
        BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
        EXT4_I(inode)->i_reserved_meta_blocks = mdb;
-       EXT4_I(inode)->i_allocated_meta_blocks = 0;
        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+       vfs_dq_release_reservation_block(inode, release);
 }
 
 static void ext4_da_page_release_reservation(struct page *page,
@@ -1545,7 +1762,7 @@ static void ext4_da_page_release_reservation(struct page *page,
                }
                curr_off = next_off;
        } while ((bh = bh->b_this_page) != head);
-       ext4_da_release_space(page->mapping->host, 0, to_release);
+       ext4_da_release_space(page->mapping->host, to_release);
 }
 
 /*
@@ -1554,20 +1771,23 @@ static void ext4_da_page_release_reservation(struct page *page,
 
 struct mpage_da_data {
        struct inode *inode;
-       struct buffer_head lbh;                 /* extent of blocks */
+       sector_t b_blocknr;             /* start block number of extent */
+       size_t b_size;                  /* size of extent */
+       unsigned long b_state;          /* state of the extent */
        unsigned long first_page, next_page;    /* extent of pages */
-       get_block_t *get_block;
        struct writeback_control *wbc;
+       int io_done;
+       int pages_written;
+       int retval;
 };
 
 /*
  * mpage_da_submit_io - walks through extent of pages and try to write
- * them with __mpage_writepage()
+ * them with writepage() call back
  *
  * @mpd->inode: inode
  * @mpd->first_page: first page of the extent
  * @mpd->next_page: page after the last page of the extent
- * @mpd->get_block: the filesystem's block mapper function
  *
  * By the time mpage_da_submit_io() is called we expect all blocks
  * to be allocated. this may be wrong if allocation failed.
@@ -1576,25 +1796,25 @@ struct mpage_da_data {
  */
 static int mpage_da_submit_io(struct mpage_da_data *mpd)
 {
-       struct address_space *mapping = mpd->inode->i_mapping;
-       struct mpage_data mpd_pp = {
-               .bio = NULL,
-               .last_block_in_bio = 0,
-               .get_block = mpd->get_block,
-               .use_writepage = 1,
-       };
-       int ret = 0, err, nr_pages, i;
-       unsigned long index, end;
+       long pages_skipped;
        struct pagevec pvec;
+       unsigned long index, end;
+       int ret = 0, err, nr_pages, i;
+       struct inode *inode = mpd->inode;
+       struct address_space *mapping = inode->i_mapping;
 
        BUG_ON(mpd->next_page <= mpd->first_page);
-
-       pagevec_init(&pvec, 0);
+       /*
+        * We need to start from the first_page to the next_page - 1
+        * to make sure we also write the mapped dirty buffer_heads.
+        * If we look at mpd->b_blocknr we would only be looking
+        * at the currently mapped buffer_heads.
+        */
        index = mpd->first_page;
        end = mpd->next_page - 1;
 
+       pagevec_init(&pvec, 0);
        while (index <= end) {
-               /* XXX: optimize tail */
                nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
                if (nr_pages == 0)
                        break;
@@ -1606,8 +1826,17 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
                                break;
                        index++;
 
-                       err = __mpage_writepage(page, mpd->wbc, &mpd_pp);
+                       BUG_ON(!PageLocked(page));
+                       BUG_ON(PageWriteback(page));
 
+                       pages_skipped = mpd->wbc->pages_skipped;
+                       err = mapping->a_ops->writepage(page, mpd->wbc);
+                       if (!err && (pages_skipped == mpd->wbc->pages_skipped))
+                               /*
+                                * have successfully written the page
+                                * without skipping the same
+                                */
+                               mpd->pages_written++;
                        /*
                         * In error case, we have to continue because
                         * remaining pages are still locked
@@ -1618,9 +1847,6 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
                }
                pagevec_release(&pvec);
        }
-       if (mpd_pp.bio)
-               mpage_bio_submit(WRITE, mpd_pp.bio);
-
        return ret;
 }
 
@@ -1633,7 +1859,7 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd)
  * @logical - first logical block to start assignment with
  *
  * the function goes through all passed space and put actual disk
- * block numbers into buffer heads, dropping BH_Delay
+ * block numbers into buffer heads, dropping BH_Delay and BH_Unwritten
  */
 static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
                                 struct buffer_head *exbh)
@@ -1643,7 +1869,7 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
        int blocks = exbh->b_size >> inode->i_blkbits;
        sector_t pblock = exbh->b_blocknr, cur_logical;
        struct buffer_head *head, *bh;
-       unsigned long index, end;
+       pgoff_t index, end;
        struct pagevec pvec;
        int nr_pages, i;
 
@@ -1684,12 +1910,25 @@ static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical,
                                if (cur_logical >= logical + blocks)
                                        break;
 
-                               if (buffer_delay(bh)) {
-                                       bh->b_blocknr = pblock;
-                                       clear_buffer_delay(bh);
-                               } else if (buffer_mapped(bh)) {
+                               if (buffer_delay(bh) ||
+                                               buffer_unwritten(bh)) {
+
+                                       BUG_ON(bh->b_bdev != inode->i_sb->s_bdev);
+
+                                       if (buffer_delay(bh)) {
+                                               clear_buffer_delay(bh);
+                                               bh->b_blocknr = pblock;
+                                       } else {
+                                               /*
+                                                * unwritten already should have
+                                                * blocknr assigned. Verify that
+                                                */
+                                               clear_buffer_unwritten(bh);
+                                               BUG_ON(bh->b_blocknr != pblock);
+                                       }
+
+                               } else if (buffer_mapped(bh))
                                        BUG_ON(bh->b_blocknr != pblock);
-                               }
 
                                cur_logical++;
                                pblock++;
@@ -1715,62 +1954,211 @@ static inline void __unmap_underlying_blocks(struct inode *inode,
                unmap_underlying_metadata(bdev, bh->b_blocknr + i);
 }
 
+static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd,
+                                       sector_t logical, long blk_cnt)
+{
+       int nr_pages, i;
+       pgoff_t index, end;
+       struct pagevec pvec;
+       struct inode *inode = mpd->inode;
+       struct address_space *mapping = inode->i_mapping;
+
+       index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
+       end   = (logical + blk_cnt - 1) >>
+                               (PAGE_CACHE_SHIFT - inode->i_blkbits);
+       while (index <= end) {
+               nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
+               if (nr_pages == 0)
+                       break;
+               for (i = 0; i < nr_pages; i++) {
+                       struct page *page = pvec.pages[i];
+                       index = page->index;
+                       if (index > end)
+                               break;
+                       index++;
+
+                       BUG_ON(!PageLocked(page));
+                       BUG_ON(PageWriteback(page));
+                       block_invalidatepage(page, 0);
+                       ClearPageUptodate(page);
+                       unlock_page(page);
+               }
+       }
+       return;
+}
+
+static void ext4_print_free_blocks(struct inode *inode)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+       printk(KERN_EMERG "Total free blocks count %lld\n",
+                       ext4_count_free_blocks(inode->i_sb));
+       printk(KERN_EMERG "Free/Dirty block details\n");
+       printk(KERN_EMERG "free_blocks=%lld\n",
+                       (long long)percpu_counter_sum(&sbi->s_freeblocks_counter));
+       printk(KERN_EMERG "dirty_blocks=%lld\n",
+                       (long long)percpu_counter_sum(&sbi->s_dirtyblocks_counter));
+       printk(KERN_EMERG "Block reservation details\n");
+       printk(KERN_EMERG "i_reserved_data_blocks=%u\n",
+                       EXT4_I(inode)->i_reserved_data_blocks);
+       printk(KERN_EMERG "i_reserved_meta_blocks=%u\n",
+                       EXT4_I(inode)->i_reserved_meta_blocks);
+       return;
+}
+
+/*
+ * This function is used by mpage_da_map_blocks().  We separate it out
+ * as a separate function just to make life easier, and because
+ * mpage_da_map_blocks() used to be a generic function that took a
+ * get_block_t.
+ */
+static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
+                                  struct buffer_head *bh_result)
+{
+       int ret;
+       unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
+       loff_t disksize = EXT4_I(inode)->i_disksize;
+       handle_t *handle = NULL;
+
+       handle = ext4_journal_current_handle();
+       BUG_ON(!handle);
+       ret = ext4_get_blocks(handle, inode, iblock, max_blocks,
+                             bh_result, EXT4_GET_BLOCKS_CREATE|
+                             EXT4_GET_BLOCKS_DELALLOC_RESERVE);
+       if (ret <= 0)
+               return ret;
+
+       bh_result->b_size = (ret << inode->i_blkbits);
+
+       if (ext4_should_order_data(inode)) {
+               int retval;
+               retval = ext4_jbd2_file_inode(handle, inode);
+               if (retval)
+                       /*
+                        * Failed to add inode for ordered mode. Don't
+                        * update file size
+                        */
+                       return retval;
+       }
+
+       /*
+        * Update on-disk size along with block allocation we don't
+        * use EXT4_GET_BLOCKS_EXTEND_DISKSIZE as size may change
+        * within already allocated block -bzzz
+        */
+       disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
+       if (disksize > i_size_read(inode))
+               disksize = i_size_read(inode);
+       if (disksize > EXT4_I(inode)->i_disksize) {
+               ext4_update_i_disksize(inode, disksize);
+               ret = ext4_mark_inode_dirty(handle, inode);
+               return ret;
+       }
+       return 0;
+}
+
 /*
  * mpage_da_map_blocks - go through given space
  *
- * @mpd->lbh - bh describing space
- * @mpd->get_block - the filesystem's block mapper function
+ * @mpd - bh describing space
  *
  * The function skips space we know is already mapped to disk blocks.
  *
- * The function ignores errors ->get_block() returns, thus real
- * error handling is postponed to __mpage_writepage()
  */
-static void mpage_da_map_blocks(struct mpage_da_data *mpd)
+static int mpage_da_map_blocks(struct mpage_da_data *mpd)
 {
-       struct buffer_head *lbh = &mpd->lbh;
-       int err = 0, remain = lbh->b_size;
-       sector_t next = lbh->b_blocknr;
+       int err = 0;
        struct buffer_head new;
+       sector_t next;
 
        /*
         * We consider only non-mapped and non-allocated blocks
         */
-       if (buffer_mapped(lbh) && !buffer_delay(lbh))
-               return;
+       if ((mpd->b_state  & (1 << BH_Mapped)) &&
+               !(mpd->b_state & (1 << BH_Delay)) &&
+               !(mpd->b_state & (1 << BH_Unwritten)))
+               return 0;
+       /*
+        * We need to make sure the BH_Delay flag is passed down to
+        * ext4_da_get_block_write(), since it calls ext4_get_blocks()
+        * with the EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.  This flag
+        * causes ext4_get_blocks() to call
+        * ext4_da_update_reserve_space() if the passed buffer head
+        * has the BH_Delay flag set.  In the future, once we clean up
+        * the interfaces to ext4_get_blocks(), we should pass in a
+        * separate flag which requests that the delayed allocation
+        * statistics should be updated, instead of depending on the
+        * state information getting passed down via the map_bh's
+        * state bitmasks plus the magic
+        * EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.
+        */
+       new.b_state = mpd->b_state & (1 << BH_Delay);
+       new.b_blocknr = 0;
+       new.b_size = mpd->b_size;
+       next = mpd->b_blocknr;
+       /*
+        * If we didn't accumulate anything
+        * to write simply return
+        */
+       if (!new.b_size)
+               return 0;
 
-       while (remain) {
-               new.b_state = lbh->b_state;
-               new.b_blocknr = 0;
-               new.b_size = remain;
-               err = mpd->get_block(mpd->inode, next, &new, 1);
-               if (err) {
-                       /*
-                        * Rather than implement own error handling
-                        * here, we just leave remaining blocks
-                        * unallocated and try again with ->writepage()
-                        */
-                       break;
-               }
-               BUG_ON(new.b_size == 0);
+       err = ext4_da_get_block_write(mpd->inode, next, &new);
+       if (err) {
+               /*
+                * If get block returns with error we simply
+                * return. Later writepage will redirty the page and
+                * writepages will find the dirty page again
+                */
+               if (err == -EAGAIN)
+                       return 0;
 
-               if (buffer_new(&new))
-                       __unmap_underlying_blocks(mpd->inode, &new);
+               if (err == -ENOSPC &&
+                   ext4_count_free_blocks(mpd->inode->i_sb)) {
+                       mpd->retval = err;
+                       return 0;
+               }
 
                /*
-                * If blocks are delayed marked, we need to
-                * put actual blocknr and drop delayed bit
+                * get block failure will cause us to loop in
+                * writepages, because a_ops->writepage won't be able
+                * to make progress. The page will be redirtied by
+                * writepage and writepages will again try to write
+                * the same.
                 */
-               if (buffer_delay(lbh))
-                       mpage_put_bnr_to_bhs(mpd, next, &new);
-
-                       /* go for the remaining blocks */
-                       next += new.b_size >> mpd->inode->i_blkbits;
-                       remain -= new.b_size;
+               printk(KERN_EMERG "%s block allocation failed for inode %lu "
+                                 "at logical offset %llu with max blocks "
+                                 "%zd with error %d\n",
+                                 __func__, mpd->inode->i_ino,
+                                 (unsigned long long)next,
+                                 mpd->b_size >> mpd->inode->i_blkbits, err);
+               printk(KERN_EMERG "This should not happen.!! "
+                                       "Data will be lost\n");
+               if (err == -ENOSPC) {
+                       ext4_print_free_blocks(mpd->inode);
                }
+               /* invlaidate all the pages */
+               ext4_da_block_invalidatepages(mpd, next,
+                               mpd->b_size >> mpd->inode->i_blkbits);
+               return err;
+       }
+       BUG_ON(new.b_size == 0);
+
+       if (buffer_new(&new))
+               __unmap_underlying_blocks(mpd->inode, &new);
+
+       /*
+        * If blocks are delayed marked, we need to
+        * put actual blocknr and drop delayed bit
+        */
+       if ((mpd->b_state & (1 << BH_Delay)) ||
+           (mpd->b_state & (1 << BH_Unwritten)))
+               mpage_put_bnr_to_bhs(mpd, next, &new);
+
+       return 0;
 }
 
-#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | (1 << BH_Delay))
+#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
+               (1 << BH_Delay) | (1 << BH_Unwritten))
 
 /*
  * mpage_add_bh_to_extent - try to add one more block to extent of blocks
@@ -1782,43 +2170,73 @@ static void mpage_da_map_blocks(struct mpage_da_data *mpd)
  * the function is used to collect contig. blocks in same state
  */
 static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
-                                  sector_t logical, struct buffer_head *bh)
+                                  sector_t logical, size_t b_size,
+                                  unsigned long b_state)
 {
-       struct buffer_head *lbh = &mpd->lbh;
        sector_t next;
+       int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
 
-       next = lbh->b_blocknr + (lbh->b_size >> mpd->inode->i_blkbits);
-
+       /* check if thereserved journal credits might overflow */
+       if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) {
+               if (nrblocks >= EXT4_MAX_TRANS_DATA) {
+                       /*
+                        * With non-extent format we are limited by the journal
+                        * credit available.  Total credit needed to insert
+                        * nrblocks contiguous blocks is dependent on the
+                        * nrblocks.  So limit nrblocks.
+                        */
+                       goto flush_it;
+               } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
+                               EXT4_MAX_TRANS_DATA) {
+                       /*
+                        * Adding the new buffer_head would make it cross the
+                        * allowed limit for which we have journal credit
+                        * reserved. So limit the new bh->b_size
+                        */
+                       b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
+                                               mpd->inode->i_blkbits;
+                       /* we will do mpage_da_submit_io in the next loop */
+               }
+       }
        /*
         * First block in the extent
         */
-       if (lbh->b_size == 0) {
-               lbh->b_blocknr = logical;
-               lbh->b_size = bh->b_size;
-               lbh->b_state = bh->b_state & BH_FLAGS;
+       if (mpd->b_size == 0) {
+               mpd->b_blocknr = logical;
+               mpd->b_size = b_size;
+               mpd->b_state = b_state & BH_FLAGS;
                return;
        }
 
+       next = mpd->b_blocknr + nrblocks;
        /*
         * Can we merge the block to our big extent?
         */
-       if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) {
-               lbh->b_size += bh->b_size;
+       if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
+               mpd->b_size += b_size;
                return;
        }
 
+flush_it:
        /*
         * We couldn't merge the block to our extent, so we
         * need to flush current  extent and start new one
         */
-       mpage_da_map_blocks(mpd);
+       if (mpage_da_map_blocks(mpd) == 0)
+               mpage_da_submit_io(mpd);
+       mpd->io_done = 1;
+       return;
+}
 
+static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+{
        /*
-        * Now start a new extent
+        * unmapped buffer is possible for holes.
+        * delay buffer is possible with delayed allocation.
+        * We also need to consider unwritten buffer as unmapped.
         */
-       lbh->b_size = bh->b_size;
-       lbh->b_state = bh->b_state & BH_FLAGS;
-       lbh->b_blocknr = logical;
+       return (!buffer_mapped(bh) || buffer_delay(bh) ||
+                               buffer_unwritten(bh)) && buffer_dirty(bh);
 }
 
 /*
@@ -1835,20 +2253,38 @@ static int __mpage_da_writepage(struct page *page,
 {
        struct mpage_da_data *mpd = data;
        struct inode *inode = mpd->inode;
-       struct buffer_head *bh, *head, fake;
+       struct buffer_head *bh, *head;
        sector_t logical;
 
+       if (mpd->io_done) {
+               /*
+                * Rest of the page in the page_vec
+                * redirty then and skip then. We will
+                * try to to write them again after
+                * starting a new transaction
+                */
+               redirty_page_for_writepage(wbc, page);
+               unlock_page(page);
+               return MPAGE_DA_EXTENT_TAIL;
+       }
        /*
         * Can we merge this page to current extent?
         */
        if (mpd->next_page != page->index) {
                /*
                 * Nope, we can't. So, we map non-allocated blocks
-                * and start IO on them using __mpage_writepage()
+                * and start IO on them using writepage()
                 */
                if (mpd->next_page != mpd->first_page) {
-                       mpage_da_map_blocks(mpd);
-                       mpage_da_submit_io(mpd);
+                       if (mpage_da_map_blocks(mpd) == 0)
+                               mpage_da_submit_io(mpd);
+                       /*
+                        * skip rest of the page in the page_vec
+                        */
+                       mpd->io_done = 1;
+                       redirty_page_for_writepage(wbc, page);
+                       unlock_page(page);
+                       return MPAGE_DA_EXTENT_TAIL;
                }
 
                /*
@@ -1859,9 +2295,9 @@ static int __mpage_da_writepage(struct page *page,
                /*
                 * ... and blocks
                 */
-               mpd->lbh.b_size = 0;
-               mpd->lbh.b_state = 0;
-               mpd->lbh.b_blocknr = 0;
+               mpd->b_size = 0;
+               mpd->b_state = 0;
+               mpd->b_blocknr = 0;
        }
 
        mpd->next_page = page->index + 1;
@@ -1869,16 +2305,10 @@ static int __mpage_da_writepage(struct page *page,
                  (PAGE_CACHE_SHIFT - inode->i_blkbits);
 
        if (!page_has_buffers(page)) {
-               /*
-                * There is no attached buffer heads yet (mmap?)
-                * we treat the page asfull of dirty blocks
-                */
-               bh = &fake;
-               bh->b_size = PAGE_CACHE_SIZE;
-               bh->b_state = 0;
-               set_buffer_dirty(bh);
-               set_buffer_uptodate(bh);
-               mpage_add_bh_to_extent(mpd, logical, bh);
+               mpage_add_bh_to_extent(mpd, logical, PAGE_CACHE_SIZE,
+                                      (1 << BH_Dirty) | (1 << BH_Uptodate));
+               if (mpd->io_done)
+                       return MPAGE_DA_EXTENT_TAIL;
        } else {
                /*
                 * Page with regular buffer heads, just add all dirty ones
@@ -1887,8 +2317,30 @@ static int __mpage_da_writepage(struct page *page,
                bh = head;
                do {
                        BUG_ON(buffer_locked(bh));
-                       if (buffer_dirty(bh))
-                               mpage_add_bh_to_extent(mpd, logical, bh);
+                       /*
+                        * We need to try to allocate
+                        * unmapped blocks in the same page.
+                        * Otherwise we won't make progress
+                        * with the page in ext4_da_writepage
+                        */
+                       if (ext4_bh_unmapped_or_delay(NULL, bh)) {
+                               mpage_add_bh_to_extent(mpd, logical,
+                                                      bh->b_size,
+                                                      bh->b_state);
+                               if (mpd->io_done)
+                                       return MPAGE_DA_EXTENT_TAIL;
+                       } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
+                               /*
+                                * mapped dirty buffer. We need to update
+                                * the b_state because we look at
+                                * b_state in mpage_da_map_blocks. We don't
+                                * update b_size because if we find an
+                                * unmapped buffer_head later we need to
+                                * use the b_state flag of that buffer_head.
+                                */
+                               if (mpd->b_size == 0)
+                                       mpd->b_state = bh->b_state & BH_FLAGS;
+                       }
                        logical++;
                } while ((bh = bh->b_this_page) != head);
        }
@@ -1897,67 +2349,25 @@ static int __mpage_da_writepage(struct page *page,
 }
 
 /*
- * mpage_da_writepages - walk the list of dirty pages of the given
- * address space, allocates non-allocated blocks, maps newly-allocated
- * blocks to existing bhs and issue IO them
- *
- * @mapping: address space structure to write
- * @wbc: subtract the number of written pages from *@wbc->nr_to_write
- * @get_block: the filesystem's block mapper function.
- *
- * This is a library function, which implements the writepages()
- * address_space_operation.
- *
- * In order to avoid duplication of logic that deals with partial pages,
- * multiple bio per page, etc, we find non-allocated blocks, allocate
- * them with minimal calls to ->get_block() and re-use __mpage_writepage()
+ * This is a special get_blocks_t callback which is used by
+ * ext4_da_write_begin().  It will either return mapped block or
+ * reserve space for a single block.
  *
- * It's important that we call __mpage_writepage() only once for each
- * involved page, otherwise we'd have to implement more complicated logic
- * to deal with pages w/o PG_lock or w/ PG_writeback and so on.
+ * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
+ * We also have b_blocknr = -1 and b_bdev initialized properly
  *
- * See comments to mpage_writepages()
- */
-static int mpage_da_writepages(struct address_space *mapping,
-                              struct writeback_control *wbc,
-                              get_block_t get_block)
-{
-       struct mpage_da_data mpd;
-       int ret;
-
-       if (!get_block)
-               return generic_writepages(mapping, wbc);
-
-       mpd.wbc = wbc;
-       mpd.inode = mapping->host;
-       mpd.lbh.b_size = 0;
-       mpd.lbh.b_state = 0;
-       mpd.lbh.b_blocknr = 0;
-       mpd.first_page = 0;
-       mpd.next_page = 0;
-       mpd.get_block = get_block;
-
-       ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, &mpd);
-
-       /*
-        * Handle last extent of pages
-        */
-       if (mpd.next_page != mpd.first_page) {
-               mpage_da_map_blocks(&mpd);
-               mpage_da_submit_io(&mpd);
-       }
-
-       return ret;
-}
-
-/*
- * this is a special callback for ->write_begin() only
- * it's intention is to return mapped block or reserve space
+ * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
+ * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
+ * initialized properly.
  */
 static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
                                  struct buffer_head *bh_result, int create)
 {
        int ret = 0;
+       sector_t invalid_block = ~((sector_t) 0xffff);
+
+       if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
+               invalid_block = ~0;
 
        BUG_ON(create == 0);
        BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
@@ -1967,7 +2377,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
         * preallocated blocks are unmapped but should treated
         * the same as allocated blocks.
         */
-       ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1,  bh_result, 0, 0, 0);
+       ret = ext4_get_blocks(NULL, inode, iblock, 1,  bh_result, 0);
        if ((ret == 0) && !buffer_delay(bh_result)) {
                /* the block isn't (pre)allocated yet, let's reserve space */
                /*
@@ -1979,115 +2389,408 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
                        /* not enough space to reserve */
                        return ret;
 
-               map_bh(bh_result, inode->i_sb, 0);
+               map_bh(bh_result, inode->i_sb, invalid_block);
                set_buffer_new(bh_result);
                set_buffer_delay(bh_result);
        } else if (ret > 0) {
                bh_result->b_size = (ret << inode->i_blkbits);
+               if (buffer_unwritten(bh_result)) {
+                       /* A delayed write to unwritten bh should
+                        * be marked new and mapped.  Mapped ensures
+                        * that we don't do get_block multiple times
+                        * when we write to the same offset and new
+                        * ensures that we do proper zero out for
+                        * partial write.
+                        */
+                       set_buffer_new(bh_result);
+                       set_buffer_mapped(bh_result);
+               }
                ret = 0;
        }
 
        return ret;
 }
-#define                EXT4_DELALLOC_RSVED     1
-static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
+
+/*
+ * This function is used as a standard get_block_t calback function
+ * when there is no desire to allocate any blocks.  It is used as a
+ * callback function for block_prepare_write(), nobh_writepage(), and
+ * block_write_full_page().  These functions should only try to map a
+ * single block at a time.
+ *
+ * Since this function doesn't do block allocations even if the caller
+ * requests it by passing in create=1, it is critically important that
+ * any caller checks to make sure that any buffer heads are returned
+ * by this function are either all already mapped or marked for
+ * delayed allocation before calling nobh_writepage() or
+ * block_write_full_page().  Otherwise, b_blocknr could be left
+ * unitialized, and the page write functions will be taken by
+ * surprise.
+ */
+static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
                                   struct buffer_head *bh_result, int create)
 {
-       int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
+       int ret = 0;
        unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
-       loff_t disksize = EXT4_I(inode)->i_disksize;
-       handle_t *handle = NULL;
 
-       if (create) {
-               handle = ext4_journal_start(inode, needed_blocks);
-               if (IS_ERR(handle)) {
-                       ret = PTR_ERR(handle);
-                       goto out;
-               }
-       }
+       BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
 
-       ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks,
-                                  bh_result, create, 0, EXT4_DELALLOC_RSVED);
+       /*
+        * we don't want to do block allocation in writepage
+        * so call get_block_wrap with create = 0
+        */
+       ret = ext4_get_blocks(NULL, inode, iblock, max_blocks, bh_result, 0);
+       BUG_ON(create && ret == 0);
        if (ret > 0) {
                bh_result->b_size = (ret << inode->i_blkbits);
+               ret = 0;
+       }
+       return ret;
+}
+
+/*
+ * This function can get called via...
+ *   - ext4_da_writepages after taking page lock (have journal handle)
+ *   - journal_submit_inode_data_buffers (no journal handle)
+ *   - shrink_page_list via pdflush (no journal handle)
+ *   - grab_page_cache when doing write_begin (have journal handle)
+ */
+static int ext4_da_writepage(struct page *page,
+                               struct writeback_control *wbc)
+{
+       int ret = 0;
+       loff_t size;
+       unsigned int len;
+       struct buffer_head *page_bufs;
+       struct inode *inode = page->mapping->host;
+
+       trace_mark(ext4_da_writepage,
+                  "dev %s ino %lu page_index %lu",
+                  inode->i_sb->s_id, inode->i_ino, page->index);
+       size = i_size_read(inode);
+       if (page->index == size >> PAGE_CACHE_SHIFT)
+               len = size & ~PAGE_CACHE_MASK;
+       else
+               len = PAGE_CACHE_SIZE;
 
+       if (page_has_buffers(page)) {
+               page_bufs = page_buffers(page);
+               if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
+                                       ext4_bh_unmapped_or_delay)) {
+                       /*
+                        * We don't want to do  block allocation
+                        * So redirty the page and return
+                        * We may reach here when we do a journal commit
+                        * via journal_submit_inode_data_buffers.
+                        * If we don't have mapping block we just ignore
+                        * them. We can also reach here via shrink_page_list
+                        */
+                       redirty_page_for_writepage(wbc, page);
+                       unlock_page(page);
+                       return 0;
+               }
+       } else {
                /*
-                * Update on-disk size along with block allocation
-                * we don't use 'extend_disksize' as size may change
-                * within already allocated block -bzzz
+                * The test for page_has_buffers() is subtle:
+                * We know the page is dirty but it lost buffers. That means
+                * that at some moment in time after write_begin()/write_end()
+                * has been called all buffers have been clean and thus they
+                * must have been written at least once. So they are all
+                * mapped and we can happily proceed with mapping them
+                * and writing the page.
+                *
+                * Try to initialize the buffer_heads and check whether
+                * all are mapped and non delay. We don't want to
+                * do block allocation here.
                 */
-               disksize = ((loff_t) iblock + ret) << inode->i_blkbits;
-               if (disksize > i_size_read(inode))
-                       disksize = i_size_read(inode);
-               if (disksize > EXT4_I(inode)->i_disksize) {
+               ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+                                         noalloc_get_block_write);
+               if (!ret) {
+                       page_bufs = page_buffers(page);
+                       /* check whether all are mapped and non delay */
+                       if (walk_page_buffers(NULL, page_bufs, 0, len, NULL,
+                                               ext4_bh_unmapped_or_delay)) {
+                               redirty_page_for_writepage(wbc, page);
+                               unlock_page(page);
+                               return 0;
+                       }
+               } else {
                        /*
-                        * XXX: replace with spinlock if seen contended -bzzz
+                        * We can't do block allocation here
+                        * so just redity the page and unlock
+                        * and return
                         */
-                       down_write(&EXT4_I(inode)->i_data_sem);
-                       if (disksize > EXT4_I(inode)->i_disksize)
-                               EXT4_I(inode)->i_disksize = disksize;
-                       up_write(&EXT4_I(inode)->i_data_sem);
-
-                       if (EXT4_I(inode)->i_disksize == disksize) {
-                               if (handle == NULL)
-                                       handle = ext4_journal_start(inode, 1);
-                               if (!IS_ERR(handle))
-                                       ext4_mark_inode_dirty(handle, inode);
-                       }
+                       redirty_page_for_writepage(wbc, page);
+                       unlock_page(page);
+                       return 0;
                }
-
-               ret = 0;
+               /* now mark the buffer_heads as dirty and uptodate */
+               block_commit_write(page, 0, PAGE_CACHE_SIZE);
        }
 
-out:
-       if (handle && !IS_ERR(handle))
-               ext4_journal_stop(handle);
+       if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
+               ret = nobh_writepage(page, noalloc_get_block_write, wbc);
+       else
+               ret = block_write_full_page(page, noalloc_get_block_write,
+                                           wbc);
 
        return ret;
 }
-/* FIXME!! only support data=writeback mode */
-static int ext4_da_writepage(struct page *page,
-                               struct writeback_control *wbc)
+
+/*
+ * This is called via ext4_da_writepages() to
+ * calulate the total number of credits to reserve to fit
+ * a single extent allocation into a single transaction,
+ * ext4_da_writpeages() will loop calling this before
+ * the block allocation.
+ */
+
+static int ext4_da_writepages_trans_blocks(struct inode *inode)
 {
-       struct inode *inode = page->mapping->host;
+       int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
+
+       /*
+        * With non-extent format the journal credit needed to
+        * insert nrblocks contiguous block is dependent on
+        * number of contiguous block. So we will limit
+        * number of contiguous block to a sane value
+        */
+       if (!(inode->i_flags & EXT4_EXTENTS_FL) &&
+           (max_blocks > EXT4_MAX_TRANS_DATA))
+               max_blocks = EXT4_MAX_TRANS_DATA;
+
+       return ext4_chunk_trans_blocks(inode, max_blocks);
+}
+
+static int ext4_da_writepages(struct address_space *mapping,
+                             struct writeback_control *wbc)
+{
+       pgoff_t index;
+       int range_whole = 0;
        handle_t *handle = NULL;
-       int ret = 0;
-       int err;
+       struct mpage_da_data mpd;
+       struct inode *inode = mapping->host;
+       int no_nrwrite_index_update;
+       int pages_written = 0;
+       long pages_skipped;
+       int range_cyclic, cycled = 1, io_done = 0;
+       int needed_blocks, ret = 0, nr_to_writebump = 0;
+       struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
+
+       trace_mark(ext4_da_writepages,
+                  "dev %s ino %lu nr_t_write %ld "
+                  "pages_skipped %ld range_start %llu "
+                  "range_end %llu nonblocking %d "
+                  "for_kupdate %d for_reclaim %d "
+                  "for_writepages %d range_cyclic %d",
+                  inode->i_sb->s_id, inode->i_ino,
+                  wbc->nr_to_write, wbc->pages_skipped,
+                  (unsigned long long) wbc->range_start,
+                  (unsigned long long) wbc->range_end,
+                  wbc->nonblocking, wbc->for_kupdate,
+                  wbc->for_reclaim, wbc->for_writepages,
+                  wbc->range_cyclic);
 
-       if (ext4_journal_current_handle())
-               goto out_fail;
+       /*
+        * No pages to write? This is mainly a kludge to avoid starting
+        * a transaction for special inodes like journal inode on last iput()
+        * because that could violate lock ordering on umount
+        */
+       if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+               return 0;
 
-       handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
-       if (IS_ERR(handle)) {
-               ret = PTR_ERR(handle);
-               goto out_fail;
+       /*
+        * If the filesystem has aborted, it is read-only, so return
+        * right away instead of dumping stack traces later on that
+        * will obscure the real source of the problem.  We test
+        * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because
+        * the latter could be true if the filesystem is mounted
+        * read-only, and in that case, ext4_da_writepages should
+        * *never* be called, so if that ever happens, we would want
+        * the stack trace.
+        */
+       if (unlikely(sbi->s_mount_opt & EXT4_MOUNT_ABORT))
+               return -EROFS;
+
+       /*
+        * Make sure nr_to_write is >= sbi->s_mb_stream_request
+        * This make sure small files blocks are allocated in
+        * single attempt. This ensure that small files
+        * get less fragmented.
+        */
+       if (wbc->nr_to_write < sbi->s_mb_stream_request) {
+               nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write;
+               wbc->nr_to_write = sbi->s_mb_stream_request;
        }
+       if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
+               range_whole = 1;
+
+       range_cyclic = wbc->range_cyclic;
+       if (wbc->range_cyclic) {
+               index = mapping->writeback_index;
+               if (index)
+                       cycled = 0;
+               wbc->range_start = index << PAGE_CACHE_SHIFT;
+               wbc->range_end  = LLONG_MAX;
+               wbc->range_cyclic = 0;
+       } else
+               index = wbc->range_start >> PAGE_CACHE_SHIFT;
+
+       mpd.wbc = wbc;
+       mpd.inode = mapping->host;
+
+       /*
+        * we don't want write_cache_pages to update
+        * nr_to_write and writeback_index
+        */
+       no_nrwrite_index_update = wbc->no_nrwrite_index_update;
+       wbc->no_nrwrite_index_update = 1;
+       pages_skipped = wbc->pages_skipped;
+
+retry:
+       while (!ret && wbc->nr_to_write > 0) {
+
+               /*
+                * we  insert one extent at a time. So we need
+                * credit needed for single extent allocation.
+                * journalled mode is currently not supported
+                * by delalloc
+                */
+               BUG_ON(ext4_should_journal_data(inode));
+               needed_blocks = ext4_da_writepages_trans_blocks(inode);
 
-       if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
-               ret = nobh_writepage(page, ext4_get_block, wbc);
-       else
-               ret = block_write_full_page(page, ext4_get_block, wbc);
+               /* start a new transaction*/
+               handle = ext4_journal_start(inode, needed_blocks);
+               if (IS_ERR(handle)) {
+                       ret = PTR_ERR(handle);
+                       printk(KERN_CRIT "%s: jbd2_start: "
+                              "%ld pages, ino %lu; err %d\n", __func__,
+                               wbc->nr_to_write, inode->i_ino, ret);
+                       dump_stack();
+                       goto out_writepages;
+               }
 
-       if (!ret && inode->i_size > EXT4_I(inode)->i_disksize) {
-               EXT4_I(inode)->i_disksize = inode->i_size;
-               ext4_mark_inode_dirty(handle, inode);
-       }
+               /*
+                * Now call __mpage_da_writepage to find the next
+                * contiguous region of logical blocks that need
+                * blocks to be allocated by ext4.  We don't actually
+                * submit the blocks for I/O here, even though
+                * write_cache_pages thinks it will, and will set the
+                * pages as clean for write before calling
+                * __mpage_da_writepage().
+                */
+               mpd.b_size = 0;
+               mpd.b_state = 0;
+               mpd.b_blocknr = 0;
+               mpd.first_page = 0;
+               mpd.next_page = 0;
+               mpd.io_done = 0;
+               mpd.pages_written = 0;
+               mpd.retval = 0;
+               ret = write_cache_pages(mapping, wbc, __mpage_da_writepage,
+                                       &mpd);
+               /*
+                * If we have a contigous extent of pages and we
+                * haven't done the I/O yet, map the blocks and submit
+                * them for I/O.
+                */
+               if (!mpd.io_done && mpd.next_page != mpd.first_page) {
+                       if (mpage_da_map_blocks(&mpd) == 0)
+                               mpage_da_submit_io(&mpd);
+                       mpd.io_done = 1;
+                       ret = MPAGE_DA_EXTENT_TAIL;
+               }
+               wbc->nr_to_write -= mpd.pages_written;
 
-       err = ext4_journal_stop(handle);
-       if (!ret)
-               ret = err;
-       return ret;
+               ext4_journal_stop(handle);
 
-out_fail:
-       redirty_page_for_writepage(wbc, page);
-       unlock_page(page);
+               if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
+                       /* commit the transaction which would
+                        * free blocks released in the transaction
+                        * and try again
+                        */
+                       jbd2_journal_force_commit_nested(sbi->s_journal);
+                       wbc->pages_skipped = pages_skipped;
+                       ret = 0;
+               } else if (ret == MPAGE_DA_EXTENT_TAIL) {
+                       /*
+                        * got one extent now try with
+                        * rest of the pages
+                        */
+                       pages_written += mpd.pages_written;
+                       wbc->pages_skipped = pages_skipped;
+                       ret = 0;
+                       io_done = 1;
+               } else if (wbc->nr_to_write)
+                       /*
+                        * There is no more writeout needed
+                        * or we requested for a noblocking writeout
+                        * and we found the device congested
+                        */
+                       break;
+       }
+       if (!io_done && !cycled) {
+               cycled = 1;
+               index = 0;
+               wbc->range_start = index << PAGE_CACHE_SHIFT;
+               wbc->range_end  = mapping->writeback_index - 1;
+               goto retry;
+       }
+       if (pages_skipped != wbc->pages_skipped)
+               printk(KERN_EMERG "This should not happen leaving %s "
+                               "with nr_to_write = %ld ret = %d\n",
+                               __func__, wbc->nr_to_write, ret);
+
+       /* Update index */
+       index += pages_written;
+       wbc->range_cyclic = range_cyclic;
+       if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
+               /*
+                * set the writeback_index so that range_cyclic
+                * mode will write it back later
+                */
+               mapping->writeback_index = index;
+
+out_writepages:
+       if (!no_nrwrite_index_update)
+               wbc->no_nrwrite_index_update = 0;
+       wbc->nr_to_write -= nr_to_writebump;
+       trace_mark(ext4_da_writepage_result,
+                  "dev %s ino %lu ret %d pages_written %d "
+                  "pages_skipped %ld congestion %d "
+                  "more_io %d no_nrwrite_index_update %d",
+                  inode->i_sb->s_id, inode->i_ino, ret,
+                  pages_written, wbc->pages_skipped,
+                  wbc->encountered_congestion, wbc->more_io,
+                  wbc->no_nrwrite_index_update);
        return ret;
 }
 
-static int ext4_da_writepages(struct address_space *mapping,
-                               struct writeback_control *wbc)
+#define FALL_BACK_TO_NONDELALLOC 1
+static int ext4_nonda_switch(struct super_block *sb)
 {
-       return mpage_da_writepages(mapping, wbc, ext4_da_get_block_write);
+       s64 free_blocks, dirty_blocks;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+       /*
+        * switch to non delalloc mode if we are running low
+        * on free block. The free block accounting via percpu
+        * counters can get slightly wrong with percpu_counter_batch getting
+        * accumulated on each CPU without updating global counters
+        * Delalloc need an accurate free block accounting. So switch
+        * to non delalloc when we are near to error range.
+        */
+       free_blocks  = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
+       dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter);
+       if (2 * free_blocks < 3 * dirty_blocks ||
+               free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) {
+               /*
+                * free block count is less that 150% of dirty blocks
+                * or free blocks is less that watermark
+                */
+               return 1;
+       }
+       return 0;
 }
 
 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
@@ -2105,6 +2808,17 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
        from = pos & (PAGE_CACHE_SIZE - 1);
        to = from + len;
 
+       if (ext4_nonda_switch(inode->i_sb)) {
+               *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
+               return ext4_write_begin(file, mapping, pos,
+                                       len, flags, pagep, fsdata);
+       }
+       *fsdata = (void *)0;
+
+       trace_mark(ext4_da_write_begin,
+                  "dev %s ino %lu pos %llu len %u flags %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, flags);
 retry:
        /*
         * With delayed allocation, we don't log the i_disksize update
@@ -2117,18 +2831,31 @@ retry:
                ret = PTR_ERR(handle);
                goto out;
        }
+       /* We cannot recurse into the filesystem as the transaction is already
+        * started */
+       flags |= AOP_FLAG_NOFS;
 
-       page = __grab_cache_page(mapping, index);
-       if (!page)
-               return -ENOMEM;
+       page = grab_cache_page_write_begin(mapping, index, flags);
+       if (!page) {
+               ext4_journal_stop(handle);
+               ret = -ENOMEM;
+               goto out;
+       }
        *pagep = page;
 
        ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-                                                       ext4_da_get_block_prep);
+                               ext4_da_get_block_prep);
        if (ret < 0) {
                unlock_page(page);
                ext4_journal_stop(handle);
                page_cache_release(page);
+               /*
+                * block_write_begin may have instantiated a few blocks
+                * outside i_size.  Trim these off again. Don't need
+                * i_size_read because we hold i_mutex.
+                */
+               if (pos + len > inode->i_size)
+                       vmtruncate(inode, inode->i_size);
        }
 
        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -2137,9 +2864,27 @@ out:
        return ret;
 }
 
-static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+/*
+ * Check if we should update i_disksize
+ * when write to the end of file but not require block allocation
+ */
+static int ext4_da_should_update_i_disksize(struct page *page,
+                                        unsigned long offset)
 {
-       return !buffer_mapped(bh) || buffer_delay(bh);
+       struct buffer_head *bh;
+       struct inode *inode = page->mapping->host;
+       unsigned int idx;
+       int i;
+
+       bh = page_buffers(page);
+       idx = offset >> inode->i_blkbits;
+
+       for (i = 0; i < idx; i++)
+               bh = bh->b_this_page;
+
+       if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
+               return 0;
+       return 1;
 }
 
 static int ext4_da_write_end(struct file *file,
@@ -2151,6 +2896,27 @@ static int ext4_da_write_end(struct file *file,
        int ret = 0, ret2;
        handle_t *handle = ext4_journal_current_handle();
        loff_t new_i_size;
+       unsigned long start, end;
+       int write_mode = (int)(unsigned long)fsdata;
+
+       if (write_mode == FALL_BACK_TO_NONDELALLOC) {
+               if (ext4_should_order_data(inode)) {
+                       return ext4_ordered_write_end(file, mapping, pos,
+                                       len, copied, page, fsdata);
+               } else if (ext4_should_writeback_data(inode)) {
+                       return ext4_writeback_write_end(file, mapping, pos,
+                                       len, copied, page, fsdata);
+               } else {
+                       BUG();
+               }
+       }
+
+       trace_mark(ext4_da_write_end,
+                  "dev %s ino %lu pos %llu len %u copied %u",
+                  inode->i_sb->s_id, inode->i_ino,
+                  (unsigned long long) pos, len, copied);
+       start = pos & (PAGE_CACHE_SIZE - 1);
+       end = start + copied - 1;
 
        /*
         * generic_write_end() will run mark_inode_dirty() if i_size
@@ -2159,18 +2925,28 @@ static int ext4_da_write_end(struct file *file,
         */
 
        new_i_size = pos + copied;
-       if (new_i_size > EXT4_I(inode)->i_disksize)
-               if (!walk_page_buffers(NULL, page_buffers(page),
-                                      0, len, NULL, ext4_bh_unmapped_or_delay)){
-                       /*
-                        * Updating i_disksize when extending file without
-                        * needing block allocation
-                        */
-                       if (ext4_should_order_data(inode))
-                               ret = ext4_jbd2_file_inode(handle, inode);
+       if (new_i_size > EXT4_I(inode)->i_disksize) {
+               if (ext4_da_should_update_i_disksize(page, end)) {
+                       down_write(&EXT4_I(inode)->i_data_sem);
+                       if (new_i_size > EXT4_I(inode)->i_disksize) {
+                               /*
+                                * Updating i_disksize when extending file
+                                * without needing block allocation
+                                */
+                               if (ext4_should_order_data(inode))
+                                       ret = ext4_jbd2_file_inode(handle,
+                                                                  inode);
 
-                       EXT4_I(inode)->i_disksize = new_i_size;
+                               EXT4_I(inode)->i_disksize = new_i_size;
+                       }
+                       up_write(&EXT4_I(inode)->i_data_sem);
+                       /* We need to mark inode dirty even if
+                        * new_i_size is less that inode->i_size
+                        * bu greater than i_disksize.(hint delalloc)
+                        */
+                       ext4_mark_inode_dirty(handle, inode);
                }
+       }
        ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                        page, fsdata);
        copied = ret2;
@@ -2200,6 +2976,48 @@ out:
        return;
 }
 
+/*
+ * Force all delayed allocation blocks to be allocated for a given inode.
+ */
+int ext4_alloc_da_blocks(struct inode *inode)
+{
+       if (!EXT4_I(inode)->i_reserved_data_blocks &&
+           !EXT4_I(inode)->i_reserved_meta_blocks)
+               return 0;
+
+       /*
+        * We do something simple for now.  The filemap_flush() will
+        * also start triggering a write of the data blocks, which is
+        * not strictly speaking necessary (and for users of
+        * laptop_mode, not even desirable).  However, to do otherwise
+        * would require replicating code paths in:
+        * 
+        * ext4_da_writepages() ->
+        *    write_cache_pages() ---> (via passed in callback function)
+        *        __mpage_da_writepage() -->
+        *           mpage_add_bh_to_extent()
+        *           mpage_da_map_blocks()
+        *
+        * The problem is that write_cache_pages(), located in
+        * mm/page-writeback.c, marks pages clean in preparation for
+        * doing I/O, which is not desirable if we're not planning on
+        * doing I/O at all.
+        *
+        * We could call write_cache_pages(), and then redirty all of
+        * the pages by calling redirty_page_for_writeback() but that
+        * would be ugly in the extreme.  So instead we would need to
+        * replicate parts of the code in the above functions,
+        * simplifying them becuase we wouldn't actually intend to
+        * write out the pages, but rather only collect contiguous
+        * logical block extents, call the multi-block allocator, and
+        * then update the buffer heads with the block allocations.
+        * 
+        * For now, though, we'll cheat by calling filemap_flush(),
+        * which will map the blocks, and start the I/O, but not
+        * actually wait for the I/O to complete.
+        */
+       return filemap_flush(inode->i_mapping);
+}
 
 /*
  * bmap() is special.  It gets used by applications such as lilo and by
@@ -2231,7 +3049,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
                filemap_write_and_wait(mapping);
        }
 
-       if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
+       if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
                /*
                 * This is a REALLY heavyweight approach, but the use of
                 * bmap on dirty files is expected to be extremely rare:
@@ -2260,7 +3078,7 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
                        return 0;
        }
 
-       return generic_block_bmap(mapping,block,ext4_get_block);
+       return generic_block_bmap(mapping, block, ext4_get_block);
 }
 
 static int bget_one(handle_t *handle, struct buffer_head *bh)
@@ -2334,12 +3152,12 @@ static int __ext4_normal_writepage(struct page *page,
        struct inode *inode = page->mapping->host;
 
        if (test_opt(inode->i_sb, NOBH))
-               return nobh_writepage(page, ext4_get_block, wbc);
+               return nobh_writepage(page, noalloc_get_block_write, wbc);
        else
-               return block_write_full_page(page, ext4_get_block, wbc);
+               return block_write_full_page(page, noalloc_get_block_write,
+                                            wbc);
 }
 
-
 static int ext4_normal_writepage(struct page *page,
                                struct writeback_control *wbc)
 {
@@ -2347,14 +3165,28 @@ static int ext4_normal_writepage(struct page *page,
        loff_t size = i_size_read(inode);
        loff_t len;
 
+       trace_mark(ext4_normal_writepage,
+                  "dev %s ino %lu page_index %lu",
+                  inode->i_sb->s_id, inode->i_ino, page->index);
        J_ASSERT(PageLocked(page));
-       J_ASSERT(page_has_buffers(page));
        if (page->index == size >> PAGE_CACHE_SHIFT)
                len = size & ~PAGE_CACHE_MASK;
        else
                len = PAGE_CACHE_SIZE;
-       BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
-                                ext4_bh_unmapped_or_delay));
+
+       if (page_has_buffers(page)) {
+               /* if page has buffers it should all be mapped
+                * and allocated. If there are not buffers attached
+                * to the page we know the page is dirty but it lost
+                * buffers. That means that at some moment in time
+                * after write_begin() / write_end() has been called
+                * all buffers have been clean and thus they must have been
+                * written at least once. So they are all mapped and we can
+                * happily proceed with mapping them and writing the page.
+                */
+               BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+                                       ext4_bh_unmapped_or_delay));
+       }
 
        if (!ext4_journal_current_handle())
                return __ext4_normal_writepage(page, wbc);
@@ -2374,7 +3206,8 @@ static int __ext4_journalled_writepage(struct page *page,
        int ret = 0;
        int err;
 
-       ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, ext4_get_block);
+       ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+                                 noalloc_get_block_write);
        if (ret != 0)
                goto out_unlock;
 
@@ -2420,14 +3253,28 @@ static int ext4_journalled_writepage(struct page *page,
        loff_t size = i_size_read(inode);
        loff_t len;
 
+       trace_mark(ext4_journalled_writepage,
+                  "dev %s ino %lu page_index %lu",
+                  inode->i_sb->s_id, inode->i_ino, page->index);
        J_ASSERT(PageLocked(page));
-       J_ASSERT(page_has_buffers(page));
        if (page->index == size >> PAGE_CACHE_SHIFT)
                len = size & ~PAGE_CACHE_MASK;
        else
                len = PAGE_CACHE_SIZE;
-       BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
-                                ext4_bh_unmapped_or_delay));
+
+       if (page_has_buffers(page)) {
+               /* if page has buffers it should all be mapped
+                * and allocated. If there are not buffers attached
+                * to the page we know the page is dirty but it lost
+                * buffers. That means that at some moment in time
+                * after write_begin() / write_end() has been called
+                * all buffers have been clean and thus they must have been
+                * written at least once. So they are all mapped and we can
+                * happily proceed with mapping them and writing the page.
+                */
+               BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+                                       ext4_bh_unmapped_or_delay));
+       }
 
        if (ext4_journal_current_handle())
                goto no_write;
@@ -2445,7 +3292,8 @@ static int ext4_journalled_writepage(struct page *page,
                 * really know unless we go poke around in the buffer_heads.
                 * But block_write_full_page will do the right thing.
                 */
-               return block_write_full_page(page, ext4_get_block, wbc);
+               return block_write_full_page(page, noalloc_get_block_write,
+                                            wbc);
        }
 no_write:
        redirty_page_for_writepage(wbc, page);
@@ -2475,7 +3323,10 @@ static void ext4_invalidatepage(struct page *page, unsigned long offset)
        if (offset == 0)
                ClearPageChecked(page);
 
-       jbd2_journal_invalidatepage(journal, page, offset);
+       if (journal)
+               jbd2_journal_invalidatepage(journal, page, offset);
+       else
+               block_invalidatepage(page, offset);
 }
 
 static int ext4_releasepage(struct page *page, gfp_t wait)
@@ -2485,7 +3336,10 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
        WARN_ON(PageChecked(page));
        if (!page_has_buffers(page))
                return 0;
-       return jbd2_journal_try_to_free_buffers(journal, page, wait);
+       if (journal)
+               return jbd2_journal_try_to_free_buffers(journal, page, wait);
+       else
+               return try_to_free_buffers(page);
 }
 
 /*
@@ -2591,64 +3445,71 @@ static int ext4_journalled_set_page_dirty(struct page *page)
 }
 
 static const struct address_space_operations ext4_ordered_aops = {
-       .readpage       = ext4_readpage,
-       .readpages      = ext4_readpages,
-       .writepage      = ext4_normal_writepage,
-       .sync_page      = block_sync_page,
-       .write_begin    = ext4_write_begin,
-       .write_end      = ext4_ordered_write_end,
-       .bmap           = ext4_bmap,
-       .invalidatepage = ext4_invalidatepage,
-       .releasepage    = ext4_releasepage,
-       .direct_IO      = ext4_direct_IO,
-       .migratepage    = buffer_migrate_page,
+       .readpage               = ext4_readpage,
+       .readpages              = ext4_readpages,
+       .writepage              = ext4_normal_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext4_write_begin,
+       .write_end              = ext4_ordered_write_end,
+       .bmap                   = ext4_bmap,
+       .invalidatepage         = ext4_invalidatepage,
+       .releasepage            = ext4_releasepage,
+       .direct_IO              = ext4_direct_IO,
+       .migratepage            = buffer_migrate_page,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_writeback_aops = {
-       .readpage       = ext4_readpage,
-       .readpages      = ext4_readpages,
-       .writepage      = ext4_normal_writepage,
-       .sync_page      = block_sync_page,
-       .write_begin    = ext4_write_begin,
-       .write_end      = ext4_writeback_write_end,
-       .bmap           = ext4_bmap,
-       .invalidatepage = ext4_invalidatepage,
-       .releasepage    = ext4_releasepage,
-       .direct_IO      = ext4_direct_IO,
-       .migratepage    = buffer_migrate_page,
+       .readpage               = ext4_readpage,
+       .readpages              = ext4_readpages,
+       .writepage              = ext4_normal_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext4_write_begin,
+       .write_end              = ext4_writeback_write_end,
+       .bmap                   = ext4_bmap,
+       .invalidatepage         = ext4_invalidatepage,
+       .releasepage            = ext4_releasepage,
+       .direct_IO              = ext4_direct_IO,
+       .migratepage            = buffer_migrate_page,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_journalled_aops = {
-       .readpage       = ext4_readpage,
-       .readpages      = ext4_readpages,
-       .writepage      = ext4_journalled_writepage,
-       .sync_page      = block_sync_page,
-       .write_begin    = ext4_write_begin,
-       .write_end      = ext4_journalled_write_end,
-       .set_page_dirty = ext4_journalled_set_page_dirty,
-       .bmap           = ext4_bmap,
-       .invalidatepage = ext4_invalidatepage,
-       .releasepage    = ext4_releasepage,
+       .readpage               = ext4_readpage,
+       .readpages              = ext4_readpages,
+       .writepage              = ext4_journalled_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext4_write_begin,
+       .write_end              = ext4_journalled_write_end,
+       .set_page_dirty         = ext4_journalled_set_page_dirty,
+       .bmap                   = ext4_bmap,
+       .invalidatepage         = ext4_invalidatepage,
+       .releasepage            = ext4_releasepage,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext4_da_aops = {
-       .readpage       = ext4_readpage,
-       .readpages      = ext4_readpages,
-       .writepage      = ext4_da_writepage,
-       .writepages     = ext4_da_writepages,
-       .sync_page      = block_sync_page,
-       .write_begin    = ext4_da_write_begin,
-       .write_end      = ext4_da_write_end,
-       .bmap           = ext4_bmap,
-       .invalidatepage = ext4_da_invalidatepage,
-       .releasepage    = ext4_releasepage,
-       .direct_IO      = ext4_direct_IO,
-       .migratepage    = buffer_migrate_page,
+       .readpage               = ext4_readpage,
+       .readpages              = ext4_readpages,
+       .writepage              = ext4_da_writepage,
+       .writepages             = ext4_da_writepages,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext4_da_write_begin,
+       .write_end              = ext4_da_write_end,
+       .bmap                   = ext4_bmap,
+       .invalidatepage         = ext4_da_invalidatepage,
+       .releasepage            = ext4_releasepage,
+       .direct_IO              = ext4_direct_IO,
+       .migratepage            = buffer_migrate_page,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 void ext4_set_aops(struct inode *inode)
 {
-       if (ext4_should_order_data(inode))
+       if (ext4_should_order_data(inode) &&
+               test_opt(inode->i_sb, DELALLOC))
+               inode->i_mapping->a_ops = &ext4_da_aops;
+       else if (ext4_should_order_data(inode))
                inode->i_mapping->a_ops = &ext4_ordered_aops;
        else if (ext4_should_writeback_data(inode) &&
                 test_opt(inode->i_sb, DELALLOC))
@@ -2750,7 +3611,7 @@ int ext4_block_truncate_page(handle_t *handle,
 
        err = 0;
        if (ext4_should_journal_data(inode)) {
-               err = ext4_journal_dirty_metadata(handle, bh);
+               err = ext4_handle_dirty_metadata(handle, inode, bh);
        } else {
                if (ext4_should_order_data(inode))
                        err = ext4_jbd2_file_inode(handle, inode);
@@ -2832,7 +3693,7 @@ static Indirect *ext4_find_shared(struct inode *inode, int depth,
        if (!partial->key && *partial->p)
                /* Writer: end */
                goto no_top;
-       for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
+       for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--)
                ;
        /*
         * OK, we've found the last block that must survive. The rest of our
@@ -2851,7 +3712,7 @@ static Indirect *ext4_find_shared(struct inode *inode, int depth,
        }
        /* Writer: end */
 
-       while(partial > p) {
+       while (partial > p) {
                brelse(partial->bh);
                partial--;
        }
@@ -2874,8 +3735,8 @@ static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
        __le32 *p;
        if (try_to_extend_transaction(handle, inode)) {
                if (bh) {
-                       BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-                       ext4_journal_dirty_metadata(handle, bh);
+                       BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+                       ext4_handle_dirty_metadata(handle, inode, bh);
                }
                ext4_mark_inode_dirty(handle, inode);
                ext4_journal_test_restart(handle, inode);
@@ -2975,7 +3836,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
                                  count, block_to_free_p, p);
 
        if (this_bh) {
-               BUFFER_TRACE(this_bh, "call ext4_journal_dirty_metadata");
+               BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
 
                /*
                 * The buffer head should have an attached journal head at this
@@ -2983,8 +3844,8 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
                 * block pointed to itself, it would have been detached when
                 * the block was cleared. Check for this instead of OOPSing.
                 */
-               if (bh2jh(this_bh))
-                       ext4_journal_dirty_metadata(handle, this_bh);
+               if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
+                       ext4_handle_dirty_metadata(handle, inode, this_bh);
                else
                        ext4_error(inode->i_sb, __func__,
                                   "circular indirect block detected, "
@@ -3014,7 +3875,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
        ext4_fsblk_t nr;
        __le32 *p;
 
-       if (is_handle_aborted(handle))
+       if (ext4_handle_is_aborted(handle))
                return;
 
        if (depth--) {
@@ -3043,9 +3904,9 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
                        /* This zaps the entire block.  Bottom up. */
                        BUFFER_TRACE(bh, "free child branches");
                        ext4_free_branches(handle, inode, bh,
-                                          (__le32*)bh->b_data,
-                                          (__le32*)bh->b_data + addr_per_block,
-                                          depth);
+                                       (__le32 *) bh->b_data,
+                                       (__le32 *) bh->b_data + addr_per_block,
+                                       depth);
 
                        /*
                         * We've probably journalled the indirect block several
@@ -3084,7 +3945,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
                         * will merely complain about releasing a free block,
                         * rather than leaking blocks.
                         */
-                       if (is_handle_aborted(handle))
+                       if (ext4_handle_is_aborted(handle))
                                return;
                        if (try_to_extend_transaction(handle, inode)) {
                                ext4_mark_inode_dirty(handle, inode);
@@ -3103,9 +3964,10 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
                                                                   parent_bh)){
                                        *p = 0;
                                        BUFFER_TRACE(parent_bh,
-                                       "call ext4_journal_dirty_metadata");
-                                       ext4_journal_dirty_metadata(handle,
-                                                                   parent_bh);
+                                       "call ext4_handle_dirty_metadata");
+                                       ext4_handle_dirty_metadata(handle,
+                                                                  inode,
+                                                                  parent_bh);
                                }
                        }
                }
@@ -3175,6 +4037,9 @@ void ext4_truncate(struct inode *inode)
        if (!ext4_can_truncate(inode))
                return;
 
+       if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
+               ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
+
        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                ext4_ext_truncate(inode);
                return;
@@ -3208,6 +4073,14 @@ void ext4_truncate(struct inode *inode)
                goto out_stop;
 
        /*
+        * From here we block out all ext4_get_block() callers who want to
+        * modify the block allocation tree.
+        */
+       down_write(&ei->i_data_sem);
+
+       ext4_discard_preallocations(inode);
+
+       /*
         * The orphan list entry will now protect us from any crash which
         * occurs before the truncate completes, so it is now safe to propagate
         * the new, shorter inode size (held for now in i_size) into the
@@ -3216,12 +4089,6 @@ void ext4_truncate(struct inode *inode)
         */
        ei->i_disksize = inode->i_size;
 
-       /*
-        * From here we block out all ext4_get_block() callers who want to
-        * modify the block allocation tree.
-        */
-       down_write(&ei->i_data_sem);
-
        if (n == 1) {           /* direct blocks */
                ext4_free_data(handle, inode, NULL, i_data+offsets[0],
                               i_data + EXT4_NDIR_BLOCKS);
@@ -3282,8 +4149,6 @@ do_indirects:
                ;
        }
 
-       ext4_discard_reservation(inode);
-
        up_write(&ei->i_data_sem);
        inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
        ext4_mark_inode_dirty(handle, inode);
@@ -3293,7 +4158,7 @@ do_indirects:
         * synchronous
         */
        if (IS_SYNC(inode))
-               handle->h_sync = 1;
+               ext4_handle_sync(handle);
 out_stop:
        /*
         * If this was a simple ftruncate(), and the file will remain alive
@@ -3308,41 +4173,6 @@ out_stop:
        ext4_journal_stop(handle);
 }
 
-static ext4_fsblk_t ext4_get_inode_block(struct super_block *sb,
-               unsigned long ino, struct ext4_iloc *iloc)
-{
-       ext4_group_t block_group;
-       unsigned long offset;
-       ext4_fsblk_t block;
-       struct ext4_group_desc *gdp;
-
-       if (!ext4_valid_inum(sb, ino)) {
-               /*
-                * This error is already checked for in namei.c unless we are
-                * looking at an NFS filehandle, in which case no error
-                * report is needed
-                */
-               return 0;
-       }
-
-       block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
-       gdp = ext4_get_group_desc(sb, block_group, NULL);
-       if (!gdp)
-               return 0;
-
-       /*
-        * Figure out the offset within the block group inode table
-        */
-       offset = ((ino - 1) % EXT4_INODES_PER_GROUP(sb)) *
-               EXT4_INODE_SIZE(sb);
-       block = ext4_inode_table(sb, gdp) +
-               (offset >> EXT4_BLOCK_SIZE_BITS(sb));
-
-       iloc->block_group = block_group;
-       iloc->offset = offset & (EXT4_BLOCK_SIZE(sb) - 1);
-       return block;
-}
-
 /*
  * ext4_get_inode_loc returns with an extra refcount against the inode's
  * underlying buffer_head on success. If 'in_mem' is true, we have all
@@ -3352,23 +4182,49 @@ static ext4_fsblk_t ext4_get_inode_block(struct super_block *sb,
 static int __ext4_get_inode_loc(struct inode *inode,
                                struct ext4_iloc *iloc, int in_mem)
 {
-       ext4_fsblk_t block;
-       struct buffer_head *bh;
+       struct ext4_group_desc  *gdp;
+       struct buffer_head      *bh;
+       struct super_block      *sb = inode->i_sb;
+       ext4_fsblk_t            block;
+       int                     inodes_per_block, inode_offset;
+
+       iloc->bh = NULL;
+       if (!ext4_valid_inum(sb, inode->i_ino))
+               return -EIO;
 
-       block = ext4_get_inode_block(inode->i_sb, inode->i_ino, iloc);
-       if (!block)
+       iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
+       gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
+       if (!gdp)
                return -EIO;
 
-       bh = sb_getblk(inode->i_sb, block);
+       /*
+        * Figure out the offset within the block group inode table
+        */
+       inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
+       inode_offset = ((inode->i_ino - 1) %
+                       EXT4_INODES_PER_GROUP(sb));
+       block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
+       iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
+
+       bh = sb_getblk(sb, block);
        if (!bh) {
-               ext4_error (inode->i_sb, "ext4_get_inode_loc",
-                               "unable to read inode block - "
-                               "inode=%lu, block=%llu",
-                                inode->i_ino, block);
+               ext4_error(sb, "ext4_get_inode_loc", "unable to read "
+                          "inode block - inode=%lu, block=%llu",
+                          inode->i_ino, block);
                return -EIO;
        }
        if (!buffer_uptodate(bh)) {
                lock_buffer(bh);
+
+               /*
+                * If the buffer has the write error flag, we have failed
+                * to write out another inode in the same block.  In this
+                * case, we don't have to read the block because we may
+                * read the old inode data successfully.
+                */
+               if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
+                       set_buffer_uptodate(bh);
+
                if (buffer_uptodate(bh)) {
                        /* someone brought it uptodate while we waited */
                        unlock_buffer(bh);
@@ -3382,28 +4238,12 @@ static int __ext4_get_inode_loc(struct inode *inode,
                 */
                if (in_mem) {
                        struct buffer_head *bitmap_bh;
-                       struct ext4_group_desc *desc;
-                       int inodes_per_buffer;
-                       int inode_offset, i;
-                       ext4_group_t block_group;
-                       int start;
-
-                       block_group = (inode->i_ino - 1) /
-                                       EXT4_INODES_PER_GROUP(inode->i_sb);
-                       inodes_per_buffer = bh->b_size /
-                               EXT4_INODE_SIZE(inode->i_sb);
-                       inode_offset = ((inode->i_ino - 1) %
-                                       EXT4_INODES_PER_GROUP(inode->i_sb));
-                       start = inode_offset & ~(inodes_per_buffer - 1);
+                       int i, start;
 
-                       /* Is the inode bitmap in cache? */
-                       desc = ext4_get_group_desc(inode->i_sb,
-                                               block_group, NULL);
-                       if (!desc)
-                               goto make_io;
+                       start = inode_offset & ~(inodes_per_block - 1);
 
-                       bitmap_bh = sb_getblk(inode->i_sb,
-                               ext4_inode_bitmap(inode->i_sb, desc));
+                       /* Is the inode bitmap in cache? */
+                       bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
                        if (!bitmap_bh)
                                goto make_io;
 
@@ -3416,14 +4256,14 @@ static int __ext4_get_inode_loc(struct inode *inode,
                                brelse(bitmap_bh);
                                goto make_io;
                        }
-                       for (i = start; i < start + inodes_per_buffer; i++) {
+                       for (i = start; i < start + inodes_per_block; i++) {
                                if (i == inode_offset)
                                        continue;
                                if (ext4_test_bit(i, bitmap_bh->b_data))
                                        break;
                        }
                        brelse(bitmap_bh);
-                       if (i == start + inodes_per_buffer) {
+                       if (i == start + inodes_per_block) {
                                /* all other inodes are free, so skip I/O */
                                memset(bh->b_data, 0, bh->b_size);
                                set_buffer_uptodate(bh);
@@ -3434,6 +4274,31 @@ static int __ext4_get_inode_loc(struct inode *inode,
 
 make_io:
                /*
+                * If we need to do any I/O, try to pre-readahead extra
+                * blocks from the inode table.
+                */
+               if (EXT4_SB(sb)->s_inode_readahead_blks) {
+                       ext4_fsblk_t b, end, table;
+                       unsigned num;
+
+                       table = ext4_inode_table(sb, gdp);
+                       /* s_inode_readahead_blks is always a power of 2 */
+                       b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
+                       if (table > b)
+                               b = table;
+                       end = b + EXT4_SB(sb)->s_inode_readahead_blks;
+                       num = EXT4_INODES_PER_GROUP(sb);
+                       if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                                      EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
+                               num -= ext4_itable_unused_count(sb, gdp);
+                       table += num / inodes_per_block;
+                       if (end > table)
+                               end = table;
+                       while (b <= end)
+                               sb_breadahead(sb, b++);
+               }
+
+               /*
                 * There are other valid inodes in the buffer, this inode
                 * has in-inode xattrs, or we don't have this inode in memory.
                 * Read the block from disk.
@@ -3443,10 +4308,9 @@ make_io:
                submit_bh(READ_META, bh);
                wait_on_buffer(bh);
                if (!buffer_uptodate(bh)) {
-                       ext4_error(inode->i_sb, "ext4_get_inode_loc",
-                                       "unable to read inode block - "
-                                       "inode=%lu, block=%llu",
-                                       inode->i_ino, block);
+                       ext4_error(sb, __func__,
+                                  "unable to read inode block - inode=%lu, "
+                                  "block=%llu", inode->i_ino, block);
                        brelse(bh);
                        return -EIO;
                }
@@ -3538,11 +4402,10 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                return inode;
 
        ei = EXT4_I(inode);
-#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
        ei->i_acl = EXT4_ACL_NOT_CACHED;
        ei->i_default_acl = EXT4_ACL_NOT_CACHED;
 #endif
-       ei->i_block_alloc_info = NULL;
 
        ret = __ext4_get_inode_loc(inode, &iloc, 0);
        if (ret < 0)
@@ -3552,7 +4415,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
        inode->i_mode = le16_to_cpu(raw_inode->i_mode);
        inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
        inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
-       if(!(test_opt (inode->i_sb, NO_UID32))) {
+       if (!(test_opt(inode->i_sb, NO_UID32))) {
                inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
                inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
        }
@@ -3570,7 +4433,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                if (inode->i_mode == 0 ||
                    !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
                        /* this inode is deleted */
-                       brelse (bh);
+                       brelse(bh);
                        ret = -ESTALE;
                        goto bad_inode;
                }
@@ -3582,15 +4445,14 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
        ei->i_flags = le32_to_cpu(raw_inode->i_flags);
        inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
        ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
-       if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
-           cpu_to_le32(EXT4_OS_HURD)) {
+       if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
                ei->i_file_acl |=
                        ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
-       }
        inode->i_size = ext4_isize(raw_inode);
        ei->i_disksize = inode->i_size;
        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
        ei->i_block_group = iloc.block_group;
+       ei->i_last_alloc_group = ~0;
        /*
         * NOTE! The in-memory inode i_data array is in little-endian order
         * even on big-endian machines: we do NOT byteswap the block numbers!
@@ -3603,7 +4465,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
                if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
                    EXT4_INODE_SIZE(inode->i_sb)) {
-                       brelse (bh);
+                       brelse(bh);
                        ret = -EIO;
                        goto bad_inode;
                }
@@ -3633,6 +4495,34 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                        (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
        }
 
+       ret = 0;
+       if (ei->i_file_acl &&
+           ((ei->i_file_acl < 
+             (le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block) +
+              EXT4_SB(sb)->s_gdb_count)) ||
+            (ei->i_file_acl >= ext4_blocks_count(EXT4_SB(sb)->s_es)))) {
+               ext4_error(sb, __func__,
+                          "bad extended attribute block %llu in inode #%lu",
+                          ei->i_file_acl, inode->i_ino);
+               ret = -EIO;
+               goto bad_inode;
+       } else if (ei->i_flags & EXT4_EXTENTS_FL) {
+               if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+                   (S_ISLNK(inode->i_mode) &&
+                    !ext4_inode_is_fast_symlink(inode)))
+                       /* Validate extent which is part of inode */
+                       ret = ext4_ext_check_inode(inode);
+       } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+                  (S_ISLNK(inode->i_mode) &&
+                   !ext4_inode_is_fast_symlink(inode))) {
+               /* Validate block references which are part of inode */
+               ret = ext4_check_inode_blockref(inode);
+       }
+       if (ret) {
+               brelse(bh);
+               goto bad_inode;
+       }
+
        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &ext4_file_inode_operations;
                inode->i_fop = &ext4_file_operations;
@@ -3641,13 +4531,16 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                inode->i_op = &ext4_dir_inode_operations;
                inode->i_fop = &ext4_dir_operations;
        } else if (S_ISLNK(inode->i_mode)) {
-               if (ext4_inode_is_fast_symlink(inode))
+               if (ext4_inode_is_fast_symlink(inode)) {
                        inode->i_op = &ext4_fast_symlink_inode_operations;
-               else {
+                       nd_terminate_link(ei->i_data, inode->i_size,
+                               sizeof(ei->i_data) - 1);
+               } else {
                        inode->i_op = &ext4_symlink_inode_operations;
                        ext4_set_aops(inode);
                }
-       } else {
+       } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+             S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
                inode->i_op = &ext4_special_inode_operations;
                if (raw_inode->i_block[0])
                        init_special_inode(inode, inode->i_mode,
@@ -3655,8 +4548,15 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                else
                        init_special_inode(inode, inode->i_mode,
                           new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
+       } else {
+               brelse(bh);
+               ret = -EIO;
+               ext4_error(inode->i_sb, __func__, 
+                          "bogus i_mode (%o) for inode=%lu",
+                          inode->i_mode, inode->i_ino);
+               goto bad_inode;
        }
-       brelse (iloc.bh);
+       brelse(iloc.bh);
        ext4_set_inode_flags(inode);
        unlock_new_inode(inode);
        return inode;
@@ -3673,7 +4573,6 @@ static int ext4_inode_blocks_set(handle_t *handle,
        struct inode *inode = &(ei->vfs_inode);
        u64 i_blocks = inode->i_blocks;
        struct super_block *sb = inode->i_sb;
-       int err = 0;
 
        if (i_blocks <= ~0U) {
                /*
@@ -3683,36 +4582,27 @@ static int ext4_inode_blocks_set(handle_t *handle,
                raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
                raw_inode->i_blocks_high = 0;
                ei->i_flags &= ~EXT4_HUGE_FILE_FL;
-       } else if (i_blocks <= 0xffffffffffffULL) {
+               return 0;
+       }
+       if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
+               return -EFBIG;
+
+       if (i_blocks <= 0xffffffffffffULL) {
                /*
                 * i_blocks can be represented in a 48 bit variable
                 * as multiple of 512 bytes
                 */
-               err = ext4_update_rocompat_feature(handle, sb,
-                                           EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
-               if (err)
-                       goto  err_out;
-               /* i_block is stored in the split  48 bit fields */
                raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
                raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
                ei->i_flags &= ~EXT4_HUGE_FILE_FL;
        } else {
-               /*
-                * i_blocks should be represented in a 48 bit variable
-                * as multiple of  file system block size
-                */
-               err = ext4_update_rocompat_feature(handle, sb,
-                                           EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
-               if (err)
-                       goto  err_out;
                ei->i_flags |= EXT4_HUGE_FILE_FL;
                /* i_block is stored in file system block size */
                i_blocks = i_blocks >> (inode->i_blkbits - 9);
                raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
                raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
        }
-err_out:
-       return err;
+       return 0;
 }
 
 /*
@@ -3738,14 +4628,14 @@ static int ext4_do_update_inode(handle_t *handle,
 
        ext4_get_inode_flags(ei);
        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
-       if(!(test_opt(inode->i_sb, NO_UID32))) {
+       if (!(test_opt(inode->i_sb, NO_UID32))) {
                raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
                raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
 /*
  * Fix up interoperability with old kernels. Otherwise, old inodes get
  * re-used with the upper 16 bits of the uid/gid intact
  */
-               if(!ei->i_dtime) {
+               if (!ei->i_dtime) {
                        raw_inode->i_uid_high =
                                cpu_to_le16(high_16_bits(inode->i_uid));
                        raw_inode->i_gid_high =
@@ -3797,8 +4687,8 @@ static int ext4_do_update_inode(handle_t *handle,
                        EXT4_SET_RO_COMPAT_FEATURE(sb,
                                        EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
                        sb->s_dirt = 1;
-                       handle->h_sync = 1;
-                       err = ext4_journal_dirty_metadata(handle,
+                       ext4_handle_sync(handle);
+                       err = ext4_handle_dirty_metadata(handle, inode,
                                        EXT4_SB(sb)->s_sbh);
                }
        }
@@ -3825,15 +4715,14 @@ static int ext4_do_update_inode(handle_t *handle,
                raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
        }
 
-
-       BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-       rc = ext4_journal_dirty_metadata(handle, bh);
+       BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+       rc = ext4_handle_dirty_metadata(handle, inode, bh);
        if (!err)
                err = rc;
        ei->i_state &= ~EXT4_STATE_NEW;
 
 out_brelse:
-       brelse (bh);
+       brelse(bh);
        ext4_std_error(inode->i_sb, err);
        return err;
 }
@@ -3890,6 +4779,25 @@ int ext4_write_inode(struct inode *inode, int wait)
        return ext4_force_commit(inode->i_sb);
 }
 
+int __ext4_write_dirty_metadata(struct inode *inode, struct buffer_head *bh)
+{
+       int err = 0;
+
+       mark_buffer_dirty(bh);
+       if (inode && inode_needs_sync(inode)) {
+               sync_dirty_buffer(bh);
+               if (buffer_req(bh) && !buffer_uptodate(bh)) {
+                       ext4_error(inode->i_sb, __func__,
+                                  "IO error syncing inode, "
+                                  "inode=%lu, block=%llu",
+                                  inode->i_ino,
+                                  (unsigned long long)bh->b_blocknr);
+                       err = -EIO;
+               }
+       }
+       return err;
+}
+
 /*
  * ext4_setattr()
  *
@@ -3936,7 +4844,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                        error = PTR_ERR(handle);
                        goto err_out;
                }
-               error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
+               error = vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
                if (error) {
                        ext4_journal_stop(handle);
                        return error;
@@ -4014,58 +4922,158 @@ err_out:
        return error;
 }
 
+int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
+                struct kstat *stat)
+{
+       struct inode *inode;
+       unsigned long delalloc_blocks;
+
+       inode = dentry->d_inode;
+       generic_fillattr(inode, stat);
+
+       /*
+        * We can't update i_blocks if the block allocation is delayed
+        * otherwise in the case of system crash before the real block
+        * allocation is done, we will have i_blocks inconsistent with
+        * on-disk file blocks.
+        * We always keep i_blocks updated together with real
+        * allocation. But to not confuse with user, stat
+        * will return the blocks that include the delayed allocation
+        * blocks for this file.
+        */
+       spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+       delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks;
+       spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+       stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
+       return 0;
+}
+
+static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
+                                     int chunk)
+{
+       int indirects;
+
+       /* if nrblocks are contiguous */
+       if (chunk) {
+               /*
+                * With N contiguous data blocks, it need at most
+                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
+                * 2 dindirect blocks
+                * 1 tindirect block
+                */
+               indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
+               return indirects + 3;
+       }
+       /*
+        * if nrblocks are not contiguous, worse case, each block touch
+        * a indirect block, and each indirect block touch a double indirect
+        * block, plus a triple indirect block
+        */
+       indirects = nrblocks * 2 + 1;
+       return indirects;
+}
+
+static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+               return ext4_indirect_trans_blocks(inode, nrblocks, chunk);
+       return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
+}
 
 /*
- * How many blocks doth make a writepage()?
- *
- * With N blocks per page, it may be:
- * N data blocks
- * 2 indirect block
- * 2 dindirect
- * 1 tindirect
- * N+5 bitmap blocks (from the above)
- * N+5 group descriptor summary blocks
- * 1 inode block
- * 1 superblock.
- * 2 * EXT4_SINGLEDATA_TRANS_BLOCKS for the quote files
+ * Account for index blocks, block groups bitmaps and block group
+ * descriptor blocks if modify datablocks and index blocks
+ * worse case, the indexs blocks spread over different block groups
  *
- * 3 * (N + 5) + 2 + 2 * EXT4_SINGLEDATA_TRANS_BLOCKS
+ * If datablocks are discontiguous, they are possible to spread over
+ * different block groups too. If they are contiugous, with flexbg,
+ * they could still across block group boundary.
  *
- * With ordered or writeback data it's the same, less the N data blocks.
+ * Also account for superblock, inode, quota and xattr blocks
+ */
+int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+       ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
+       int gdpblocks;
+       int idxblocks;
+       int ret = 0;
+
+       /*
+        * How many index blocks need to touch to modify nrblocks?
+        * The "Chunk" flag indicating whether the nrblocks is
+        * physically contiguous on disk
+        *
+        * For Direct IO and fallocate, they calls get_block to allocate
+        * one single extent at a time, so they could set the "Chunk" flag
+        */
+       idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
+
+       ret = idxblocks;
+
+       /*
+        * Now let's see how many group bitmaps and group descriptors need
+        * to account
+        */
+       groups = idxblocks;
+       if (chunk)
+               groups += 1;
+       else
+               groups += nrblocks;
+
+       gdpblocks = groups;
+       if (groups > ngroups)
+               groups = ngroups;
+       if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
+               gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
+
+       /* bitmaps and block group descriptor blocks */
+       ret += groups + gdpblocks;
+
+       /* Blocks for super block, inode, quota and xattr blocks */
+       ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
+
+       return ret;
+}
+
+/*
+ * Calulate the total number of credits to reserve to fit
+ * the modification of a single pages into a single transaction,
+ * which may include multiple chunks of block allocations.
  *
- * If the inode's direct blocks can hold an integral number of pages then a
- * page cannot straddle two indirect blocks, and we can only touch one indirect
- * and dindirect block, and the "5" above becomes "3".
+ * This could be called via ext4_write_begin()
  *
- * This still overestimates under most circumstances.  If we were to pass the
- * start and end offsets in here as well we could do block_to_path() on each
- * block and work out the exact number of indirects which are touched.  Pah.
+ * We need to consider the worse case, when
+ * one new block per extent.
  */
-
 int ext4_writepage_trans_blocks(struct inode *inode)
 {
        int bpp = ext4_journal_blocks_per_page(inode);
-       int indirects = (EXT4_NDIR_BLOCKS % bpp) ? 5 : 3;
        int ret;
 
-       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-               return ext4_ext_writepage_trans_blocks(inode, bpp);
+       ret = ext4_meta_trans_blocks(inode, bpp, 0);
 
+       /* Account for data blocks for journalled mode */
        if (ext4_should_journal_data(inode))
-               ret = 3 * (bpp + indirects) + 2;
-       else
-               ret = 2 * (bpp + indirects) + 2;
-
-#ifdef CONFIG_QUOTA
-       /* We know that structure was already allocated during DQUOT_INIT so
-        * we will be updating only the data blocks + inodes */
-       ret += 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
+               ret += bpp;
        return ret;
 }
 
 /*
+ * Calculate the journal credits for a chunk of data modification.
+ *
+ * This is called from DIO, fallocate or whoever calling
+ * ext4_get_blocks() to map/allocate a chunk of contigous disk blocks.
+ *
+ * journal buffers for data blocks are not included here, as DIO
+ * and fallocate do no need to journal data buffers.
+ */
+int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
+{
+       return ext4_meta_trans_blocks(inode, nrblocks, 1);
+}
+
+/*
  * The caller must have previously called ext4_reserve_inode_write().
  * Give this, we know that the caller already has write access to iloc->bh.
  */
@@ -4095,16 +5103,15 @@ int
 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
                         struct ext4_iloc *iloc)
 {
-       int err = 0;
-       if (handle) {
-               err = ext4_get_inode_loc(inode, iloc);
-               if (!err) {
-                       BUFFER_TRACE(iloc->bh, "get_write_access");
-                       err = ext4_journal_get_write_access(handle, iloc->bh);
-                       if (err) {
-                               brelse(iloc->bh);
-                               iloc->bh = NULL;
-                       }
+       int err;
+
+       err = ext4_get_inode_loc(inode, iloc);
+       if (!err) {
+               BUFFER_TRACE(iloc->bh, "get_write_access");
+               err = ext4_journal_get_write_access(handle, iloc->bh);
+               if (err) {
+                       brelse(iloc->bh);
+                       iloc->bh = NULL;
                }
        }
        ext4_std_error(inode->i_sb, err);
@@ -4176,7 +5183,8 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 
        might_sleep();
        err = ext4_reserve_inode_write(handle, inode, &iloc);
-       if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
+       if (ext4_handle_valid(handle) &&
+           EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
            !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
                /*
                 * We need extra buffer credits since we may write into EA block
@@ -4216,7 +5224,7 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
  * i_size has been changed by generic_commit_write() and we thus need
  * to include the updated inode in the current transaction.
  *
- * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
+ * Also, vfs_dq_alloc_block() will always dirty the inode when blocks
  * are allocated to the file.
  *
  * If the inode is marked synchronous, we don't honour that here - doing
@@ -4228,6 +5236,11 @@ void ext4_dirty_inode(struct inode *inode)
        handle_t *current_handle = ext4_journal_current_handle();
        handle_t *handle;
 
+       if (!ext4_handle_valid(current_handle)) {
+               ext4_mark_inode_dirty(current_handle, inode);
+               return;
+       }
+
        handle = ext4_journal_start(inode, 2);
        if (IS_ERR(handle))
                goto out;
@@ -4265,8 +5278,9 @@ static int ext4_pin_inode(handle_t *handle, struct inode *inode)
                        BUFFER_TRACE(iloc.bh, "get_write_access");
                        err = jbd2_journal_get_write_access(handle, iloc.bh);
                        if (!err)
-                               err = ext4_journal_dirty_metadata(handle,
-                                                                 iloc.bh);
+                               err = ext4_handle_dirty_metadata(handle,
+                                                                inode,
+                                                                iloc.bh);
                        brelse(iloc.bh);
                }
        }
@@ -4292,6 +5306,8 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
         */
 
        journal = EXT4_JOURNAL(inode);
+       if (!journal)
+               return 0;
        if (is_journal_aborted(journal))
                return -EROFS;
 
@@ -4321,7 +5337,7 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
                return PTR_ERR(handle);
 
        err = ext4_mark_inode_dirty(handle, inode);
-       handle->h_sync = 1;
+       ext4_handle_sync(handle);
        ext4_journal_stop(handle);
        ext4_std_error(inode->i_sb, err);
 
@@ -4333,11 +5349,13 @@ static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
        return !buffer_mapped(bh);
 }
 
-int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
+       struct page *page = vmf->page;
        loff_t size;
        unsigned long len;
        int ret = -EINVAL;
+       void *fsdata;
        struct file *file = vma->vm_file;
        struct inode *inode = file->f_path.dentry->d_inode;
        struct address_space *mapping = inode->i_mapping;
@@ -4376,15 +5394,17 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
         * on the same page though
         */
        ret = mapping->a_ops->write_begin(file, mapping, page_offset(page),
-                       len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+                       len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
        if (ret < 0)
                goto out_unlock;
        ret = mapping->a_ops->write_end(file, mapping, page_offset(page),
-                       len, len, page, NULL);
+                       len, len, page, fsdata);
        if (ret < 0)
                goto out_unlock;
        ret = 0;
 out_unlock:
+       if (ret)
+               ret = VM_FAULT_SIGBUS;
        up_read(&inode->i_alloc_sem);
        return ret;
 }