fs: symlink write_begin allocation context fix
[safe/jmp/linux-2.6] / fs / ext4 / extents.c
index 47929c4..ea2ce3c 100644 (file)
@@ -40,6 +40,7 @@
 #include <linux/slab.h>
 #include <linux/falloc.h>
 #include <asm/uaccess.h>
+#include <linux/fiemap.h>
 #include "ext4_jbd2.h"
 #include "ext4_extents.h"
 
@@ -92,17 +93,16 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
        ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
 }
 
-static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
+static int ext4_ext_journal_restart(handle_t *handle, int needed)
 {
        int err;
 
        if (handle->h_buffer_credits > needed)
-               return handle;
-       if (!ext4_journal_extend(handle, needed))
-               return handle;
-       err = ext4_journal_restart(handle, needed);
-
-       return handle;
+               return 0;
+       err = ext4_journal_extend(handle, needed);
+       if (err <= 0)
+               return err;
+       return ext4_journal_restart(handle, needed);
 }
 
 /*
@@ -180,15 +180,18 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
        return bg_start + colour + block;
 }
 
+/*
+ * Allocation for a meta data block
+ */
 static ext4_fsblk_t
-ext4_ext_new_block(handle_t *handle, struct inode *inode,
+ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
                        struct ext4_ext_path *path,
                        struct ext4_extent *ex, int *err)
 {
        ext4_fsblk_t goal, newblock;
 
        goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
-       newblock = ext4_new_block(handle, inode, goal, err);
+       newblock = ext4_new_meta_block(handle, inode, goal, err);
        return newblock;
 }
 
@@ -246,6 +249,36 @@ static int ext4_ext_space_root_idx(struct inode *inode)
        return size;
 }
 
+/*
+ * Calculate the number of metadata blocks needed
+ * to allocate @blocks
+ * Worse case is one block per extent
+ */
+int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
+{
+       int lcap, icap, rcap, leafs, idxs, num;
+       int newextents = blocks;
+
+       rcap = ext4_ext_space_root_idx(inode);
+       lcap = ext4_ext_space_block(inode);
+       icap = ext4_ext_space_block_idx(inode);
+
+       /* number of new leaf blocks needed */
+       num = leafs = (newextents + lcap - 1) / lcap;
+
+       /*
+        * Worse case, we need separate index block(s)
+        * to link all new leaf blocks
+        */
+       idxs = (leafs + icap - 1) / icap;
+       do {
+               num += idxs;
+               idxs = (idxs + icap - 1) / icap;
+       } while (idxs > rcap);
+
+       return num;
+}
+
 static int
 ext4_ext_max_entries(struct inode *inode, int depth)
 {
@@ -351,8 +384,8 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
        ext_debug("\n");
 }
 #else
-#define ext4_ext_show_path(inode,path)
-#define ext4_ext_show_leaf(inode,path)
+#define ext4_ext_show_path(inode, path)
+#define ext4_ext_show_leaf(inode, path)
 #endif
 
 void ext4_ext_drop_refs(struct ext4_ext_path *path)
@@ -408,9 +441,10 @@ ext4_ext_binsearch_idx(struct inode *inode,
                for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
                  if (k != 0 &&
                      le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
-                               printk("k=%d, ix=0x%p, first=0x%p\n", k,
-                                       ix, EXT_FIRST_INDEX(eh));
-                               printk("%u <= %u\n",
+                               printk(KERN_DEBUG "k=%d, ix=0x%p, "
+                                      "first=0x%p\n", k,
+                                      ix, EXT_FIRST_INDEX(eh));
+                               printk(KERN_DEBUG "%u <= %u\n",
                                       le32_to_cpu(ix->ei_block),
                                       le32_to_cpu(ix[-1].ei_block));
                        }
@@ -524,6 +558,7 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
                alloc = 1;
        }
        path[0].p_hdr = eh;
+       path[0].p_bh = NULL;
 
        i = depth;
        /* walk through the tree */
@@ -552,12 +587,14 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
        }
 
        path[ppos].p_depth = i;
-       path[ppos].p_hdr = eh;
        path[ppos].p_ext = NULL;
        path[ppos].p_idx = NULL;
 
        /* find extent */
        ext4_ext_binsearch(inode, path + ppos, block);
+       /* if not an empty leaf */
+       if (path[ppos].p_ext)
+               path[ppos].p_block = ext_pblock(path[ppos].p_ext);
 
        ext4_ext_show_path(inode, path);
 
@@ -688,7 +725,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        /* allocate all needed blocks */
        ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
        for (a = 0; a < depth - at; a++) {
-               newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+               newblock = ext4_ext_new_meta_block(handle, inode, path,
+                                                  newext, &err);
                if (newblock == 0)
                        goto cleanup;
                ablocks[a] = newblock;
@@ -884,7 +922,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
        ext4_fsblk_t newblock;
        int err = 0;
 
-       newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
+       newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
        if (newblock == 0)
                return err;
 
@@ -981,6 +1019,8 @@ repeat:
                /* if we found index with free entry, then use that
                 * entry: create all needed subtree and add new leaf */
                err = ext4_ext_split(handle, inode, path, newext, i);
+               if (err)
+                       goto out;
 
                /* refill path */
                ext4_ext_drop_refs(path);
@@ -1403,7 +1443,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
 
        /*
         * get the next allocated block if the extent in the path
-        * is before the requested block(s) 
+        * is before the requested block(s)
         */
        if (b2 < b1) {
                b2 = ext4_ext_next_allocated_block(path);
@@ -1437,7 +1477,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
                                struct ext4_ext_path *path,
                                struct ext4_extent *newext)
 {
-       struct ext4_extent_header * eh;
+       struct ext4_extent_header *eh;
        struct ext4_extent *ex, *fex;
        struct ext4_extent *nearex; /* nearest extent */
        struct ext4_ext_path *npath = NULL;
@@ -1587,6 +1627,113 @@ cleanup:
        return err;
 }
 
+int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
+                       ext4_lblk_t num, ext_prepare_callback func,
+                       void *cbdata)
+{
+       struct ext4_ext_path *path = NULL;
+       struct ext4_ext_cache cbex;
+       struct ext4_extent *ex;
+       ext4_lblk_t next, start = 0, end = 0;
+       ext4_lblk_t last = block + num;
+       int depth, exists, err = 0;
+
+       BUG_ON(func == NULL);
+       BUG_ON(inode == NULL);
+
+       while (block < last && block != EXT_MAX_BLOCK) {
+               num = last - block;
+               /* find extent for this block */
+               path = ext4_ext_find_extent(inode, block, path);
+               if (IS_ERR(path)) {
+                       err = PTR_ERR(path);
+                       path = NULL;
+                       break;
+               }
+
+               depth = ext_depth(inode);
+               BUG_ON(path[depth].p_hdr == NULL);
+               ex = path[depth].p_ext;
+               next = ext4_ext_next_allocated_block(path);
+
+               exists = 0;
+               if (!ex) {
+                       /* there is no extent yet, so try to allocate
+                        * all requested space */
+                       start = block;
+                       end = block + num;
+               } else if (le32_to_cpu(ex->ee_block) > block) {
+                       /* need to allocate space before found extent */
+                       start = block;
+                       end = le32_to_cpu(ex->ee_block);
+                       if (block + num < end)
+                               end = block + num;
+               } else if (block >= le32_to_cpu(ex->ee_block)
+                                       + ext4_ext_get_actual_len(ex)) {
+                       /* need to allocate space after found extent */
+                       start = block;
+                       end = block + num;
+                       if (end >= next)
+                               end = next;
+               } else if (block >= le32_to_cpu(ex->ee_block)) {
+                       /*
+                        * some part of requested space is covered
+                        * by found extent
+                        */
+                       start = block;
+                       end = le32_to_cpu(ex->ee_block)
+                               + ext4_ext_get_actual_len(ex);
+                       if (block + num < end)
+                               end = block + num;
+                       exists = 1;
+               } else {
+                       BUG();
+               }
+               BUG_ON(end <= start);
+
+               if (!exists) {
+                       cbex.ec_block = start;
+                       cbex.ec_len = end - start;
+                       cbex.ec_start = 0;
+                       cbex.ec_type = EXT4_EXT_CACHE_GAP;
+               } else {
+                       cbex.ec_block = le32_to_cpu(ex->ee_block);
+                       cbex.ec_len = ext4_ext_get_actual_len(ex);
+                       cbex.ec_start = ext_pblock(ex);
+                       cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
+               }
+
+               BUG_ON(cbex.ec_len == 0);
+               err = func(inode, path, &cbex, ex, cbdata);
+               ext4_ext_drop_refs(path);
+
+               if (err < 0)
+                       break;
+
+               if (err == EXT_REPEAT)
+                       continue;
+               else if (err == EXT_BREAK) {
+                       err = 0;
+                       break;
+               }
+
+               if (ext_depth(inode) != depth) {
+                       /* depth was changed. we have to realloc path */
+                       kfree(path);
+                       path = NULL;
+               }
+
+               block = cbex.ec_block + cbex.ec_len;
+       }
+
+       if (path) {
+               ext4_ext_drop_refs(path);
+               kfree(path);
+       }
+
+       return err;
+}
+
 static void
 ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
                        __u32 len, ext4_fsblk_t start, int type)
@@ -1709,54 +1856,61 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
 }
 
 /*
- * ext4_ext_calc_credits_for_insert:
- * This routine returns max. credits that the extent tree can consume.
- * It should be OK for low-performance paths like ->writepage()
- * To allow many writing processes to fit into a single transaction,
- * the caller should calculate credits under i_data_sem and
- * pass the actual path.
+ * ext4_ext_calc_credits_for_single_extent:
+ * This routine returns max. credits that needed to insert an extent
+ * to the extent tree.
+ * When pass the actual path, the caller should calculate credits
+ * under i_data_sem.
  */
-int ext4_ext_calc_credits_for_insert(struct inode *inode,
+int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
                                                struct ext4_ext_path *path)
 {
-       int depth, needed;
-
        if (path) {
+               int depth = ext_depth(inode);
+               int ret = 0;
+
                /* probably there is space in leaf? */
-               depth = ext_depth(inode);
                if (le16_to_cpu(path[depth].p_hdr->eh_entries)
-                               < le16_to_cpu(path[depth].p_hdr->eh_max))
-                       return 1;
-       }
-
-       /*
-        * given 32-bit logical block (4294967296 blocks), max. tree
-        * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
-        * Let's also add one more level for imbalance.
-        */
-       depth = 5;
+                               < le16_to_cpu(path[depth].p_hdr->eh_max)) {
 
-       /* allocation of new data block(s) */
-       needed = 2;
+                       /*
+                        *  There are some space in the leaf tree, no
+                        *  need to account for leaf block credit
+                        *
+                        *  bitmaps and block group descriptor blocks
+                        *  and other metadat blocks still need to be
+                        *  accounted.
+                        */
+                       /* 1 bitmap, 1 block group descriptor */
+                       ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
+               }
+       }
 
-       /*
-        * tree can be full, so it would need to grow in depth:
-        * we need one credit to modify old root, credits for
-        * new root will be added in split accounting
-        */
-       needed += 1;
+       return ext4_chunk_trans_blocks(inode, nrblocks);
+}
 
-       /*
-        * Index split can happen, we would need:
-        *    allocate intermediate indexes (bitmap + group)
-        *  + change two blocks at each level, but root (already included)
-        */
-       needed += (depth * 2) + (depth * 2);
+/*
+ * How many index/leaf blocks need to change/allocate to modify nrblocks?
+ *
+ * if nrblocks are fit in a single extent (chunk flag is 1), then
+ * in the worse case, each tree level index/leaf need to be changed
+ * if the tree split due to insert a new extent, then the old tree
+ * index/leaf need to be updated too
+ *
+ * If the nrblocks are discontiguous, they could cause
+ * the whole tree split more than once, but this is really rare.
+ */
+int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
+{
+       int index;
+       int depth = ext_depth(inode);
 
-       /* any allocation modifies superblock */
-       needed += 1;
+       if (chunk)
+               index = depth * 2;
+       else
+               index = depth * 3;
 
-       return needed;
+       return index;
 }
 
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
@@ -1872,22 +2026,22 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
                        BUG_ON(b != ex_ee_block + ex_ee_len - 1);
                }
 
-               /* at present, extent can't cross block group: */
-               /* leaf + bitmap + group desc + sb + inode */
-               credits = 5;
+               /*
+                * 3 for leaf, sb, and inode plus 2 (bmap and group
+                * descriptor) for each block group; assume two block
+                * groups plus ex_ee_len/blocks_per_block_group for
+                * the worst case
+                */
+               credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
                if (ex == EXT_FIRST_EXTENT(eh)) {
                        correct_index = 1;
                        credits += (ext_depth(inode)) + 1;
                }
-#ifdef CONFIG_QUOTA
                credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
 
-               handle = ext4_ext_journal_restart(handle, credits);
-               if (IS_ERR(handle)) {
-                       err = PTR_ERR(handle);
+               err = ext4_ext_journal_restart(handle, credits);
+               if (err)
                        goto out;
-               }
 
                err = ext4_ext_get_access(handle, inode, path + depth);
                if (err)
@@ -2097,7 +2251,7 @@ void ext4_ext_init(struct super_block *sb)
         */
 
        if (test_opt(sb, EXTENTS)) {
-               printk("EXT4-fs: file extents enabled");
+               printk(KERN_INFO "EXT4-fs: file extents enabled");
 #ifdef AGGRESSIVE_TEST
                printk(", aggressive tests");
 #endif
@@ -2287,7 +2441,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                unsigned int newdepth;
                /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
                if (allocated <= EXT4_EXT_ZERO_LEN) {
-                       /* Mark first half uninitialized.
+                       /*
+                        * iblock == ee_block is handled by the zerouout
+                        * at the beginning.
+                        * Mark first half uninitialized.
                         * Mark second half initialized and zero out the
                         * initialized extent
                         */
@@ -2310,7 +2467,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                                ex->ee_len   = orig_ex.ee_len;
                                ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
                                ext4_ext_dirty(handle, inode, path + depth);
-                               /* zeroed the full extent */
+                               /* blocks available from iblock */
                                return allocated;
 
                        } else if (err)
@@ -2338,6 +2495,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                                        err = PTR_ERR(path);
                                        return err;
                                }
+                               /* get the second half extent details */
                                ex = path[depth].p_ext;
                                err = ext4_ext_get_access(handle, inode,
                                                                path + depth);
@@ -2367,6 +2525,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                        ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
                        ext4_ext_dirty(handle, inode, path + depth);
                        /* zeroed the full extent */
+                       /* blocks available from iblock */
                        return allocated;
 
                } else if (err)
@@ -2382,23 +2541,22 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                 */
                orig_ex.ee_len = cpu_to_le16(ee_len -
                                                ext4_ext_get_actual_len(ex3));
-               if (newdepth != depth) {
-                       depth = newdepth;
-                       ext4_ext_drop_refs(path);
-                       path = ext4_ext_find_extent(inode, iblock, path);
-                       if (IS_ERR(path)) {
-                               err = PTR_ERR(path);
-                               goto out;
-                       }
-                       eh = path[depth].p_hdr;
-                       ex = path[depth].p_ext;
-                       if (ex2 != &newex)
-                               ex2 = ex;
-
-                       err = ext4_ext_get_access(handle, inode, path + depth);
-                       if (err)
-                               goto out;
+               depth = newdepth;
+               ext4_ext_drop_refs(path);
+               path = ext4_ext_find_extent(inode, iblock, path);
+               if (IS_ERR(path)) {
+                       err = PTR_ERR(path);
+                       goto out;
                }
+               eh = path[depth].p_hdr;
+               ex = path[depth].p_ext;
+               if (ex2 != &newex)
+                       ex2 = ex;
+
+               err = ext4_ext_get_access(handle, inode, path + depth);
+               if (err)
+                       goto out;
+
                allocated = max_blocks;
 
                /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
@@ -2416,6 +2574,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                        ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
                        ext4_ext_dirty(handle, inode, path + depth);
                        /* zero out the first half */
+                       /* blocks available from iblock */
                        return allocated;
                }
        }
@@ -2529,6 +2688,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
        int err = 0, depth, ret;
        unsigned long allocated = 0;
        struct ext4_allocation_request ar;
+       loff_t disksize;
 
        __clear_bit(BH_New, &bh_result->b_state);
        ext_debug("blocks %u/%lu requested for inode %u\n",
@@ -2616,8 +2776,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                                 */
                                if (allocated > max_blocks)
                                        allocated = max_blocks;
-                               /* mark the buffer unwritten */
-                               __set_bit(BH_Unwritten, &bh_result->b_state);
+                               set_buffer_unwritten(bh_result);
                                goto out2;
                        }
 
@@ -2646,11 +2805,8 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                goto out2;
        }
        /*
-        * 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) && (!EXT4_I(inode)->i_block_alloc_info))
-               ext4_init_block_alloc_info(inode);
 
        /* find neighbour allocated blocks */
        ar.lleft = iblock;
@@ -2710,20 +2866,25 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                /* free data blocks we just allocated */
                /* not a good idea to call discard here directly,
                 * but otherwise we'd need to call it every free() */
-               ext4_mb_discard_inode_preallocations(inode);
+               ext4_discard_preallocations(inode);
                ext4_free_blocks(handle, inode, ext_pblock(&newex),
                                        ext4_ext_get_actual_len(&newex), 0);
                goto out2;
        }
 
-       if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize)
-               EXT4_I(inode)->i_disksize = inode->i_size;
-
        /* previous routine could use block we allocated */
        newblock = ext_pblock(&newex);
        allocated = ext4_ext_get_actual_len(&newex);
 outnew:
-       __set_bit(BH_New, &bh_result->b_state);
+       if (extend_disksize) {
+               disksize = ((loff_t) iblock + ar.len) << inode->i_blkbits;
+               if (disksize > i_size_read(inode))
+                       disksize = i_size_read(inode);
+               if (disksize > EXT4_I(inode)->i_disksize)
+                       EXT4_I(inode)->i_disksize = disksize;
+       }
+
+       set_buffer_new(bh_result);
 
        /* Cache only when it is _not_ an uninitialized extent */
        if (create != EXT4_CREATE_UNINITIALIZED_EXT)
@@ -2733,7 +2894,7 @@ out:
        if (allocated > max_blocks)
                allocated = max_blocks;
        ext4_ext_show_leaf(inode, path);
-       __set_bit(BH_Mapped, &bh_result->b_state);
+       set_buffer_mapped(bh_result);
        bh_result->b_bdev = inode->i_sb->s_bdev;
        bh_result->b_blocknr = newblock;
 out2:
@@ -2744,7 +2905,7 @@ out2:
        return err ? err : allocated;
 }
 
-void ext4_ext_truncate(struct inode * inode, struct page *page)
+void ext4_ext_truncate(struct inode *inode)
 {
        struct address_space *mapping = inode->i_mapping;
        struct super_block *sb = inode->i_sb;
@@ -2755,33 +2916,27 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
        /*
         * probably first extent we're gonna free will be last in block
         */
-       err = ext4_writepage_trans_blocks(inode) + 3;
+       err = ext4_writepage_trans_blocks(inode);
        handle = ext4_journal_start(inode, err);
-       if (IS_ERR(handle)) {
-               if (page) {
-                       clear_highpage(page);
-                       flush_dcache_page(page);
-                       unlock_page(page);
-                       page_cache_release(page);
-               }
+       if (IS_ERR(handle))
                return;
-       }
 
-       if (page)
-               ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+       if (inode->i_size & (sb->s_blocksize - 1))
+               ext4_block_truncate_page(handle, mapping, inode->i_size);
+
+       if (ext4_orphan_add(handle, inode))
+               goto out_stop;
 
        down_write(&EXT4_I(inode)->i_data_sem);
        ext4_ext_invalidate_cache(inode);
 
-       ext4_mb_discard_inode_preallocations(inode);
+       ext4_discard_preallocations(inode);
 
        /*
         * TODO: optimization is possible here.
         * Probably we need not scan at all,
         * because page truncation is enough.
         */
-       if (ext4_orphan_add(handle, inode))
-               goto out_stop;
 
        /* we have to know where to truncate from in crash case */
        EXT4_I(inode)->i_disksize = inode->i_size;
@@ -2798,6 +2953,7 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
                handle->h_sync = 1;
 
 out_stop:
+       up_write(&EXT4_I(inode)->i_data_sem);
        /*
         * If this was a simple ftruncate() and the file will remain alive,
         * then we need to clear up the orphan record which we created above.
@@ -2808,33 +2964,11 @@ out_stop:
        if (inode->i_nlink)
                ext4_orphan_del(handle, inode);
 
-       up_write(&EXT4_I(inode)->i_data_sem);
        inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
        ext4_mark_inode_dirty(handle, inode);
        ext4_journal_stop(handle);
 }
 
-/*
- * ext4_ext_writepage_trans_blocks:
- * calculate max number of blocks we could modify
- * in order to allocate new block for an inode
- */
-int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
-{
-       int needed;
-
-       needed = ext4_ext_calc_credits_for_insert(inode, NULL);
-
-       /* caller wants to allocate num blocks, but note it includes sb */
-       needed = needed * num - (num - 1);
-
-#ifdef CONFIG_QUOTA
-       needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
-#endif
-
-       return needed;
-}
-
 static void ext4_falloc_update_inode(struct inode *inode,
                                int mode, loff_t new_size, int update_ctime)
 {
@@ -2849,10 +2983,11 @@ static void ext4_falloc_update_inode(struct inode *inode,
         * Update only when preallocation was requested beyond
         * the file size.
         */
-       if (!(mode & FALLOC_FL_KEEP_SIZE) &&
-                               new_size > i_size_read(inode)) {
-               i_size_write(inode, new_size);
-               EXT4_I(inode)->i_disksize = new_size;
+       if (!(mode & FALLOC_FL_KEEP_SIZE)) {
+               if (new_size > i_size_read(inode))
+                       i_size_write(inode, new_size);
+               if (new_size > EXT4_I(inode)->i_disksize)
+                       ext4_update_i_disksize(inode, new_size);
        }
 
 }
@@ -2895,10 +3030,9 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
        max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
                                                        - block;
        /*
-        * credits to insert 1 extent into extent tree + buffers to be able to
-        * modify 1 super block, 1 block bitmap and 1 group descriptor.
+        * credits to insert 1 extent into extent tree
         */
-       credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+       credits = ext4_chunk_trans_blocks(inode, max_blocks);
        mutex_lock(&inode->i_mutex);
 retry:
        while (ret >= 0 && ret < max_blocks) {
@@ -2911,7 +3045,7 @@ retry:
                }
                ret = ext4_get_blocks_wrap(handle, inode, block,
                                          max_blocks, &map_bh,
-                                         EXT4_CREATE_UNINITIALIZED_EXT, 0);
+                                         EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);
                if (ret <= 0) {
 #ifdef EXT4FS_DEBUG
                        WARN_ON(ret <= 0);
@@ -2945,3 +3079,143 @@ retry:
        mutex_unlock(&inode->i_mutex);
        return ret > 0 ? ret2 : ret;
 }
+
+/*
+ * Callback function called for each extent to gather FIEMAP information.
+ */
+int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,
+                      struct ext4_ext_cache *newex, struct ext4_extent *ex,
+                      void *data)
+{
+       struct fiemap_extent_info *fieinfo = data;
+       unsigned long blksize_bits = inode->i_sb->s_blocksize_bits;
+       __u64   logical;
+       __u64   physical;
+       __u64   length;
+       __u32   flags = 0;
+       int     error;
+
+       logical =  (__u64)newex->ec_block << blksize_bits;
+
+       if (newex->ec_type == EXT4_EXT_CACHE_GAP) {
+               pgoff_t offset;
+               struct page *page;
+               struct buffer_head *bh = NULL;
+
+               offset = logical >> PAGE_SHIFT;
+               page = find_get_page(inode->i_mapping, offset);
+               if (!page || !page_has_buffers(page))
+                       return EXT_CONTINUE;
+
+               bh = page_buffers(page);
+
+               if (!bh)
+                       return EXT_CONTINUE;
+
+               if (buffer_delay(bh)) {
+                       flags |= FIEMAP_EXTENT_DELALLOC;
+                       page_cache_release(page);
+               } else {
+                       page_cache_release(page);
+                       return EXT_CONTINUE;
+               }
+       }
+
+       physical = (__u64)newex->ec_start << blksize_bits;
+       length =   (__u64)newex->ec_len << blksize_bits;
+
+       if (ex && ext4_ext_is_uninitialized(ex))
+               flags |= FIEMAP_EXTENT_UNWRITTEN;
+
+       /*
+        * If this extent reaches EXT_MAX_BLOCK, it must be last.
+        *
+        * Or if ext4_ext_next_allocated_block is EXT_MAX_BLOCK,
+        * this also indicates no more allocated blocks.
+        *
+        * XXX this might miss a single-block extent at EXT_MAX_BLOCK
+        */
+       if (logical + length - 1 == EXT_MAX_BLOCK ||
+           ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
+               flags |= FIEMAP_EXTENT_LAST;
+
+       error = fiemap_fill_next_extent(fieinfo, logical, physical,
+                                       length, flags);
+       if (error < 0)
+               return error;
+       if (error == 1)
+               return EXT_BREAK;
+
+       return EXT_CONTINUE;
+}
+
+/* fiemap flags we can handle specified here */
+#define EXT4_FIEMAP_FLAGS      (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
+
+int ext4_xattr_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
+{
+       __u64 physical = 0;
+       __u64 length;
+       __u32 flags = FIEMAP_EXTENT_LAST;
+       int blockbits = inode->i_sb->s_blocksize_bits;
+       int error = 0;
+
+       /* in-inode? */
+       if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
+               struct ext4_iloc iloc;
+               int offset;     /* offset of xattr in inode */
+
+               error = ext4_get_inode_loc(inode, &iloc);
+               if (error)
+                       return error;
+               physical = iloc.bh->b_blocknr << blockbits;
+               offset = EXT4_GOOD_OLD_INODE_SIZE +
+                               EXT4_I(inode)->i_extra_isize;
+               physical += offset;
+               length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
+               flags |= FIEMAP_EXTENT_DATA_INLINE;
+       } else { /* external block */
+               physical = EXT4_I(inode)->i_file_acl << blockbits;
+               length = inode->i_sb->s_blocksize;
+       }
+
+       if (physical)
+               error = fiemap_fill_next_extent(fieinfo, 0, physical,
+                                               length, flags);
+       return (error < 0 ? error : 0);
+}
+
+int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+               __u64 start, __u64 len)
+{
+       ext4_lblk_t start_blk;
+       ext4_lblk_t len_blks;
+       int error = 0;
+
+       /* fallback to generic here if not in extents fmt */
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+               return generic_block_fiemap(inode, fieinfo, start, len,
+                       ext4_get_block);
+
+       if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
+               return -EBADR;
+
+       if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+               error = ext4_xattr_fiemap(inode, fieinfo);
+       } else {
+               start_blk = start >> inode->i_sb->s_blocksize_bits;
+               len_blks = len >> inode->i_sb->s_blocksize_bits;
+
+               /*
+                * Walk the extent tree gathering extent information.
+                * ext4_ext_fiemap_cb will push extents back to user.
+                */
+               down_write(&EXT4_I(inode)->i_data_sem);
+               error = ext4_ext_walk_space(inode, start_blk, len_blks,
+                                         ext4_ext_fiemap_cb, fieinfo);
+               up_write(&EXT4_I(inode)->i_data_sem);
+       }
+
+       return error;
+}
+