vfs: pagecache usage optimization for pagesize!=blocksize
[safe/jmp/linux-2.6] / fs / ext3 / inode.c
index 84be02e..507d868 100644 (file)
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  Goal-directed block allocation by Stephen Tweedie
- *     (sct@redhat.com), 1993, 1998
+ *     (sct@redhat.com), 1993, 1998
  *  Big-endian to little-endian byte-swapping/bitmaps by
  *        David S. Miller (davem@caip.rutgers.edu), 1995
  *  64-bit file support on 64-bit platforms by Jakub Jelinek
- *     (jj@sunsite.ms.mff.cuni.cz)
+ *     (jj@sunsite.ms.mff.cuni.cz)
  *
  *  Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
  */
@@ -27,7 +27,6 @@
 #include <linux/time.h>
 #include <linux/ext3_jbd.h>
 #include <linux/jbd.h>
-#include <linux/smp_lock.h>
 #include <linux/highuid.h>
 #include <linux/pagemap.h>
 #include <linux/quotaops.h>
@@ -36,6 +35,7 @@
 #include <linux/writeback.h>
 #include <linux/mpage.h>
 #include <linux/uio.h>
+#include <linux/bio.h>
 #include "xattr.h"
 #include "acl.h"
 
@@ -55,7 +55,7 @@ static int ext3_inode_is_fast_symlink(struct inode *inode)
 /*
  * The ext3 forget function must perform a revoke if we are freeing data
  * which has been journaled.  Metadata (eg. indirect blocks) must be
- * revoked in all cases. 
+ * revoked in all cases.
  *
  * "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
@@ -95,7 +95,7 @@ int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
        BUFFER_TRACE(bh, "call ext3_journal_revoke");
        err = ext3_journal_revoke(handle, blocknr, bh);
        if (err)
-               ext3_abort(inode->i_sb, __FUNCTION__,
+               ext3_abort(inode->i_sb, __func__,
                           "error %d when attempting revoke", err);
        BUFFER_TRACE(bh, "exit");
        return err;
@@ -105,7 +105,7 @@ int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
  * Work out how many blocks we need to proceed with the next chunk of a
  * truncate transaction.
  */
-static unsigned long blocks_for_truncate(struct inode *inode) 
+static unsigned long blocks_for_truncate(struct inode *inode)
 {
        unsigned long needed;
 
@@ -122,13 +122,13 @@ static unsigned long blocks_for_truncate(struct inode *inode)
 
        /* But we need to bound the transaction so we don't overflow the
         * journal. */
-       if (needed > EXT3_MAX_TRANS_DATA) 
+       if (needed > EXT3_MAX_TRANS_DATA)
                needed = EXT3_MAX_TRANS_DATA;
 
        return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
 }
 
-/* 
+/*
  * Truncate transactions can be complex and absolutely huge.  So we need to
  * be able to restart the transaction at a conventient checkpoint to make
  * sure we don't overflow the journal.
@@ -136,9 +136,9 @@ static unsigned long blocks_for_truncate(struct inode *inode)
  * start_transaction gets us a new handle for a truncate transaction,
  * and extend_transaction tries to extend the existing one a bit.  If
  * extend fails, we need to propagate the failure up and restart the
- * transaction in the top-level truncate loop. --sct 
+ * transaction in the top-level truncate loop. --sct
  */
-static handle_t *start_transaction(struct inode *inode) 
+static handle_t *start_transaction(struct inode *inode)
 {
        handle_t *result;
 
@@ -215,12 +215,12 @@ void ext3_delete_inode (struct inode * inode)
        ext3_orphan_del(handle, inode);
        EXT3_I(inode)->i_dtime  = get_seconds();
 
-       /* 
+       /*
         * One subtle ordering requirement: if anything has gone wrong
         * (transaction abort, IO errors, whatever), then we can still
         * do these next steps (the fs will already have been marked as
         * having errors), but we can't free the inode if the mark_dirty
-        * fails.  
+        * fails.
         */
        if (ext3_mark_inode_dirty(handle, inode))
                /* If that failed, just do the required in-core inode clear. */
@@ -392,13 +392,13 @@ no_block:
  *     @inode: owner
  *     @ind: descriptor of indirect block.
  *
- *     This function returns the prefered place for block allocation.
+ *     This function returns the preferred place for block allocation.
  *     It is used when heuristic for sequential allocation fails.
  *     Rules are:
  *       + if there is a block to the left of our position - allocate near it.
  *       + if pointer will live in indirect block - allocate near that block.
  *       + if pointer will live in inode - allocate in the same
- *         cylinder group. 
+ *         cylinder group.
  *
  * In the latter case we colour the starting block by the callers PID to
  * prevent it from clashing with concurrent allocations for a different inode
@@ -436,19 +436,17 @@ static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
 }
 
 /**
- *     ext3_find_goal - find a prefered place for allocation.
+ *     ext3_find_goal - find a preferred place for allocation.
  *     @inode: owner
  *     @block:  block we want
- *     @chain:  chain of indirect blocks
  *     @partial: pointer to the last triple within a chain
- *     @goal:  place to store the result.
  *
- *     Normally this function find the prefered place for block allocation,
- *     stores it in *@goal and returns zero.
+ *     Normally this function find the preferred place for block allocation,
+ *     returns it.
  */
 
 static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
-               Indirect chain[4], Indirect *partial)
+                                  Indirect *partial)
 {
        struct ext3_block_alloc_info *block_i;
 
@@ -470,7 +468,7 @@ static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
  *     ext3_blks_to_allocate: Look up the block map and count the number
  *     of direct blocks need to be allocated for the given branch.
  *
- *     @branch: chain of indirect blocks
+ *     @branch: chain of indirect blocks
  *     @k: number of blocks need for indirect blocks
  *     @blks: number of data blocks to be mapped.
  *     @blocks_to_boundary:  the offset in the indirect block
@@ -744,7 +742,7 @@ static int ext3_splice_branch(handle_t *handle, struct inode *inode,
                jbd_debug(5, "splicing indirect only\n");
                BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
                err = ext3_journal_dirty_metadata(handle, where->bh);
-               if (err) 
+               if (err)
                        goto err_out;
        } else {
                /*
@@ -884,7 +882,7 @@ int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
        if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
                ext3_init_block_alloc_info(inode);
 
-       goal = ext3_find_goal(inode, iblock, chain, partial);
+       goal = ext3_find_goal(inode, iblock, partial);
 
        /* the number of blocks need to allocate for [d,t]indirect blocks */
        indirect_blks = (chain + depth) - partial - 1;
@@ -941,55 +939,45 @@ out:
        return err;
 }
 
-#define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+/*
+ * 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.
+ */
+#define DIO_CREDITS 25
 
 static int ext3_get_block(struct inode *inode, sector_t iblock,
                        struct buffer_head *bh_result, int create)
 {
-       handle_t *handle = journal_current_handle();
-       int ret = 0;
+       handle_t *handle = ext3_journal_current_handle();
+       int ret = 0, started = 0;
        unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
 
-       if (!create)
-               goto get_block;         /* A read */
-
-       if (max_blocks == 1)
-               goto get_block;         /* A single block get */
-
-       if (handle->h_transaction->t_state == T_LOCKED) {
-               /*
-                * Huge direct-io writes can hold off commits for long
-                * periods of time.  Let this commit run.
-                */
-               ext3_journal_stop(handle);
-               handle = ext3_journal_start(inode, DIO_CREDITS);
-               if (IS_ERR(handle))
+       if (create && !handle) {        /* Direct IO write... */
+               if (max_blocks > DIO_MAX_BLOCKS)
+                       max_blocks = DIO_MAX_BLOCKS;
+               handle = ext3_journal_start(inode, DIO_CREDITS +
+                               2 * EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb));
+               if (IS_ERR(handle)) {
                        ret = PTR_ERR(handle);
-               goto get_block;
-       }
-
-       if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
-               /*
-                * Getting low on buffer credits...
-                */
-               ret = ext3_journal_extend(handle, DIO_CREDITS);
-               if (ret > 0) {
-                       /*
-                        * Couldn't extend the transaction.  Start a new one.
-                        */
-                       ret = ext3_journal_restart(handle, DIO_CREDITS);
+                       goto out;
                }
+               started = 1;
        }
 
-get_block:
-       if (ret == 0) {
-               ret = ext3_get_blocks_handle(handle, inode, iblock,
+       ret = ext3_get_blocks_handle(handle, inode, iblock,
                                        max_blocks, bh_result, create, 0);
-               if (ret > 0) {
-                       bh_result->b_size = (ret << inode->i_blkbits);
-                       ret = 0;
-               }
+       if (ret > 0) {
+               bh_result->b_size = (ret << inode->i_blkbits);
+               ret = 0;
        }
+       if (started)
+               ext3_journal_stop(handle);
+out:
        return ret;
 }
 
@@ -1028,7 +1016,7 @@ struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
                }
                if (buffer_new(&dummy)) {
                        J_ASSERT(create != 0);
-                       J_ASSERT(handle != 0);
+                       J_ASSERT(handle != NULL);
 
                        /*
                         * Now that we do not always journal data, we should
@@ -1073,7 +1061,7 @@ struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
                return bh;
        if (buffer_uptodate(bh))
                return bh;
-       ll_rw_block(READ, 1, &bh);
+       ll_rw_block(READ_META, 1, &bh);
        wait_on_buffer(bh);
        if (buffer_uptodate(bh))
                return bh;
@@ -1098,7 +1086,7 @@ static int walk_page_buffers(     handle_t *handle,
 
        for (   bh = head, block_start = 0;
                ret == 0 && (bh != head || !block_start);
-               block_start = block_end, bh = next)
+               block_start = block_end, bh = next)
        {
                next = bh->b_this_page;
                block_end = block_start + blocksize;
@@ -1137,7 +1125,7 @@ static int walk_page_buffers(     handle_t *handle,
  * So what we do is to rely on the fact that journal_stop/journal_start
  * will _not_ run commit under these circumstances because handle->h_ref
  * is elevated.  We'll still have enough credits for the tiny quotafile
- * write.  
+ * write.
  */
 static int do_journal_get_write_access(handle_t *handle,
                                        struct buffer_head *bh)
@@ -1147,51 +1135,68 @@ static int do_journal_get_write_access(handle_t *handle,
        return ext3_journal_get_write_access(handle, bh);
 }
 
-static int ext3_prepare_write(struct file *file, struct page *page,
-                             unsigned from, unsigned to)
+static int ext3_write_begin(struct file *file, struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned flags,
+                               struct page **pagep, void **fsdata)
 {
-       struct inode *inode = page->mapping->host;
+       struct inode *inode = mapping->host;
        int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
        handle_t *handle;
        int retries = 0;
+       struct page *page;
+       pgoff_t index;
+       unsigned from, to;
+
+       index = pos >> PAGE_CACHE_SHIFT;
+       from = pos & (PAGE_CACHE_SIZE - 1);
+       to = from + len;
 
 retry:
+       page = __grab_cache_page(mapping, index);
+       if (!page)
+               return -ENOMEM;
+       *pagep = page;
+
        handle = ext3_journal_start(inode, needed_blocks);
        if (IS_ERR(handle)) {
+               unlock_page(page);
+               page_cache_release(page);
                ret = PTR_ERR(handle);
                goto out;
        }
-       if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
-               ret = nobh_prepare_write(page, from, to, ext3_get_block);
-       else
-               ret = block_prepare_write(page, from, to, ext3_get_block);
+       ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+                                                       ext3_get_block);
        if (ret)
-               goto prepare_write_failed;
+               goto write_begin_failed;
 
        if (ext3_should_journal_data(inode)) {
                ret = walk_page_buffers(handle, page_buffers(page),
                                from, to, NULL, do_journal_get_write_access);
        }
-prepare_write_failed:
-       if (ret)
+write_begin_failed:
+       if (ret) {
                ext3_journal_stop(handle);
+               unlock_page(page);
+               page_cache_release(page);
+       }
        if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
                goto retry;
 out:
        return ret;
 }
 
+
 int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
 {
        int err = journal_dirty_data(handle, bh);
        if (err)
-               ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
-                                               bh, handle,err);
+               ext3_journal_abort_handle(__func__, __func__,
+                                               bh, handle, err);
        return err;
 }
 
-/* For commit_write() in data=journal mode */
-static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
+/* For write_end() in data=journal mode */
+static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 {
        if (!buffer_mapped(bh) || buffer_freed(bh))
                return 0;
@@ -1200,98 +1205,150 @@ static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
 }
 
 /*
+ * Generic write_end handler for ordered and writeback ext3 journal modes.
+ * We can't use generic_write_end, because that unlocks the page and we need to
+ * unlock the page after ext3_journal_stop, but ext3_journal_stop must run
+ * after block_write_end.
+ */
+static int ext3_generic_write_end(struct file *file,
+                               struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned copied,
+                               struct page *page, void *fsdata)
+{
+       struct inode *inode = file->f_mapping->host;
+
+       copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+       if (pos+copied > inode->i_size) {
+               i_size_write(inode, pos+copied);
+               mark_inode_dirty(inode);
+       }
+
+       return copied;
+}
+
+/*
  * We need to pick up the new inode size which generic_commit_write gave us
  * `file' can be NULL - eg, when called from page_symlink().
  *
  * ext3 never places buffers on inode->i_mapping->private_list.  metadata
  * buffers are managed internally.
  */
-static int ext3_ordered_commit_write(struct file *file, struct page *page,
-                            unsigned from, unsigned to)
+static int ext3_ordered_write_end(struct file *file,
+                               struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned copied,
+                               struct page *page, void *fsdata)
 {
        handle_t *handle = ext3_journal_current_handle();
-       struct inode *inode = page->mapping->host;
+       struct inode *inode = file->f_mapping->host;
+       unsigned from, to;
        int ret = 0, ret2;
 
+       from = pos & (PAGE_CACHE_SIZE - 1);
+       to = from + len;
+
        ret = walk_page_buffers(handle, page_buffers(page),
                from, to, NULL, ext3_journal_dirty_data);
 
        if (ret == 0) {
                /*
-                * generic_commit_write() will run mark_inode_dirty() if i_size
+                * 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 = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+               new_i_size = pos + copied;
                if (new_i_size > EXT3_I(inode)->i_disksize)
                        EXT3_I(inode)->i_disksize = new_i_size;
-               ret = generic_commit_write(file, page, from, to);
+               ret2 = ext3_generic_write_end(file, mapping, pos, len, copied,
+                                                       page, fsdata);
+               copied = ret2;
+               if (ret2 < 0)
+                       ret = ret2;
        }
        ret2 = ext3_journal_stop(handle);
        if (!ret)
                ret = ret2;
-       return ret;
+       unlock_page(page);
+       page_cache_release(page);
+
+       return ret ? ret : copied;
 }
 
-static int ext3_writeback_commit_write(struct file *file, struct page *page,
-                            unsigned from, unsigned to)
+static int ext3_writeback_write_end(struct file *file,
+                               struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned copied,
+                               struct page *page, void *fsdata)
 {
        handle_t *handle = ext3_journal_current_handle();
-       struct inode *inode = page->mapping->host;
+       struct inode *inode = file->f_mapping->host;
        int ret = 0, ret2;
        loff_t new_i_size;
 
-       new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+       new_i_size = pos + copied;
        if (new_i_size > EXT3_I(inode)->i_disksize)
                EXT3_I(inode)->i_disksize = new_i_size;
 
-       if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
-               ret = nobh_commit_write(file, page, from, to);
-       else
-               ret = generic_commit_write(file, page, from, to);
+       ret2 = ext3_generic_write_end(file, mapping, pos, len, copied,
+                                                       page, fsdata);
+       copied = ret2;
+       if (ret2 < 0)
+               ret = ret2;
 
        ret2 = ext3_journal_stop(handle);
        if (!ret)
                ret = ret2;
-       return ret;
+       unlock_page(page);
+       page_cache_release(page);
+
+       return ret ? ret : copied;
 }
 
-static int ext3_journalled_commit_write(struct file *file,
-                       struct page *page, unsigned from, unsigned to)
+static int ext3_journalled_write_end(struct file *file,
+                               struct address_space *mapping,
+                               loff_t pos, unsigned len, unsigned copied,
+                               struct page *page, void *fsdata)
 {
        handle_t *handle = ext3_journal_current_handle();
-       struct inode *inode = page->mapping->host;
+       struct inode *inode = mapping->host;
        int ret = 0, ret2;
        int partial = 0;
-       loff_t pos;
+       unsigned from, to;
 
-       /*
-        * Here we duplicate the generic_commit_write() functionality
-        */
-       pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+       from = pos & (PAGE_CACHE_SIZE - 1);
+       to = from + len;
+
+       if (copied < len) {
+               if (!PageUptodate(page))
+                       copied = 0;
+               page_zero_new_buffers(page, from+copied, to);
+       }
 
        ret = walk_page_buffers(handle, page_buffers(page), from,
-                               to, &partial, commit_write_fn);
+                               to, &partial, write_end_fn);
        if (!partial)
                SetPageUptodate(page);
-       if (pos > inode->i_size)
-               i_size_write(inode, pos);
+       if (pos+copied > inode->i_size)
+               i_size_write(inode, pos+copied);
        EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
        if (inode->i_size > EXT3_I(inode)->i_disksize) {
                EXT3_I(inode)->i_disksize = inode->i_size;
                ret2 = ext3_mark_inode_dirty(handle, inode);
-               if (!ret) 
+               if (!ret)
                        ret = ret2;
        }
+
        ret2 = ext3_journal_stop(handle);
        if (!ret)
                ret = ret2;
-       return ret;
+       unlock_page(page);
+       page_cache_release(page);
+
+       return ret ? ret : copied;
 }
 
-/* 
+/*
  * bmap() is special.  It gets used by applications such as lilo and by
  * the swapper to find the on-disk block of a specific piece of data.
  *
@@ -1300,10 +1357,10 @@ static int ext3_journalled_commit_write(struct file *file,
  * filesystem and enables swap, then they may get a nasty shock when the
  * data getting swapped to that swapfile suddenly gets overwritten by
  * the original zero's written out previously to the journal and
- * awaiting writeback in the kernel's buffer cache. 
+ * awaiting writeback in the kernel's buffer cache.
  *
  * So, if we see any bmap calls here on a modified, data-journaled file,
- * take extra steps to flush any blocks which might be in the cache. 
+ * take extra steps to flush any blocks which might be in the cache.
  */
 static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
 {
@@ -1312,16 +1369,16 @@ static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
        int err;
 
        if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
-               /* 
+               /*
                 * This is a REALLY heavyweight approach, but the use of
                 * bmap on dirty files is expected to be extremely rare:
                 * only if we run lilo or swapon on a freshly made file
-                * do we expect this to happen. 
+                * do we expect this to happen.
                 *
                 * (bmap requires CAP_SYS_RAWIO so this does not
                 * represent an unprivileged user DOS attack --- we'd be
                 * in trouble if mortal users could trigger this path at
-                * will.) 
+                * will.)
                 *
                 * NB. EXT3_STATE_JDATA is not set on files other than
                 * regular files.  If somebody wants to bmap a directory
@@ -1457,7 +1514,7 @@ static int ext3_ordered_writepage(struct page *page,
         */
 
        /*
-        * And attach them to the current transaction.  But only if 
+        * And attach them to the current transaction.  But only if
         * block_write_full_page() succeeded.  Otherwise they are unmapped,
         * and generally junk.
         */
@@ -1546,7 +1603,7 @@ static int ext3_journalled_writepage(struct page *page,
                        PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
 
                err = walk_page_buffers(handle, page_buffers(page), 0,
-                               PAGE_CACHE_SIZE, NULL, commit_write_fn);
+                               PAGE_CACHE_SIZE, NULL, write_end_fn);
                if (ret == 0)
                        ret = err;
                EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
@@ -1613,7 +1670,8 @@ static int ext3_releasepage(struct page *page, gfp_t wait)
  * if the machine crashes during the write.
  *
  * If the O_DIRECT write is intantiating holes inside i_size and the machine
- * crashes then stale disk data _may_ be exposed inside the file.
+ * crashes then stale disk data _may_ be exposed inside the file. But current
+ * VFS code falls back into buffered path in that case so we are safe.
  */
 static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
                        const struct iovec *iov, loff_t offset,
@@ -1622,7 +1680,7 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
        struct file *file = iocb->ki_filp;
        struct inode *inode = file->f_mapping->host;
        struct ext3_inode_info *ei = EXT3_I(inode);
-       handle_t *handle = NULL;
+       handle_t *handle;
        ssize_t ret;
        int orphan = 0;
        size_t count = iov_length(iov, nr_segs);
@@ -1630,36 +1688,43 @@ static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
        if (rw == WRITE) {
                loff_t final_size = offset + count;
 
-               handle = ext3_journal_start(inode, DIO_CREDITS);
-               if (IS_ERR(handle)) {
-                       ret = PTR_ERR(handle);
-                       goto out;
-               }
                if (final_size > inode->i_size) {
+                       /* Credits for sb + inode write */
+                       handle = ext3_journal_start(inode, 2);
+                       if (IS_ERR(handle)) {
+                               ret = PTR_ERR(handle);
+                               goto out;
+                       }
                        ret = ext3_orphan_add(handle, inode);
-                       if (ret)
-                               goto out_stop;
+                       if (ret) {
+                               ext3_journal_stop(handle);
+                               goto out;
+                       }
                        orphan = 1;
                        ei->i_disksize = inode->i_size;
+                       ext3_journal_stop(handle);
                }
        }
 
-       ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 
+       ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
                                 offset, nr_segs,
                                 ext3_get_block, NULL);
 
-       /*
-        * Reacquire the handle: ext3_get_block() can restart the transaction
-        */
-       handle = journal_current_handle();
-
-out_stop:
-       if (handle) {
+       if (orphan) {
                int err;
 
-               if (orphan && inode->i_nlink)
+               /* Credits for sb + inode write */
+               handle = ext3_journal_start(inode, 2);
+               if (IS_ERR(handle)) {
+                       /* This is really bad luck. We've written the data
+                        * but cannot extend i_size. Bail out and pretend
+                        * the write failed... */
+                       ret = PTR_ERR(handle);
+                       goto out;
+               }
+               if (inode->i_nlink)
                        ext3_orphan_del(handle, inode);
-               if (orphan && ret > 0) {
+               if (ret > 0) {
                        loff_t end = offset + ret;
                        if (end > inode->i_size) {
                                ei->i_disksize = end;
@@ -1702,44 +1767,47 @@ static int ext3_journalled_set_page_dirty(struct page *page)
 }
 
 static const struct address_space_operations ext3_ordered_aops = {
-       .readpage       = ext3_readpage,
-       .readpages      = ext3_readpages,
-       .writepage      = ext3_ordered_writepage,
-       .sync_page      = block_sync_page,
-       .prepare_write  = ext3_prepare_write,
-       .commit_write   = ext3_ordered_commit_write,
-       .bmap           = ext3_bmap,
-       .invalidatepage = ext3_invalidatepage,
-       .releasepage    = ext3_releasepage,
-       .direct_IO      = ext3_direct_IO,
-       .migratepage    = buffer_migrate_page,
+       .readpage               = ext3_readpage,
+       .readpages              = ext3_readpages,
+       .writepage              = ext3_ordered_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext3_write_begin,
+       .write_end              = ext3_ordered_write_end,
+       .bmap                   = ext3_bmap,
+       .invalidatepage         = ext3_invalidatepage,
+       .releasepage            = ext3_releasepage,
+       .direct_IO              = ext3_direct_IO,
+       .migratepage            = buffer_migrate_page,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext3_writeback_aops = {
-       .readpage       = ext3_readpage,
-       .readpages      = ext3_readpages,
-       .writepage      = ext3_writeback_writepage,
-       .sync_page      = block_sync_page,
-       .prepare_write  = ext3_prepare_write,
-       .commit_write   = ext3_writeback_commit_write,
-       .bmap           = ext3_bmap,
-       .invalidatepage = ext3_invalidatepage,
-       .releasepage    = ext3_releasepage,
-       .direct_IO      = ext3_direct_IO,
-       .migratepage    = buffer_migrate_page,
+       .readpage               = ext3_readpage,
+       .readpages              = ext3_readpages,
+       .writepage              = ext3_writeback_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext3_write_begin,
+       .write_end              = ext3_writeback_write_end,
+       .bmap                   = ext3_bmap,
+       .invalidatepage         = ext3_invalidatepage,
+       .releasepage            = ext3_releasepage,
+       .direct_IO              = ext3_direct_IO,
+       .migratepage            = buffer_migrate_page,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 static const struct address_space_operations ext3_journalled_aops = {
-       .readpage       = ext3_readpage,
-       .readpages      = ext3_readpages,
-       .writepage      = ext3_journalled_writepage,
-       .sync_page      = block_sync_page,
-       .prepare_write  = ext3_prepare_write,
-       .commit_write   = ext3_journalled_commit_write,
-       .set_page_dirty = ext3_journalled_set_page_dirty,
-       .bmap           = ext3_bmap,
-       .invalidatepage = ext3_invalidatepage,
-       .releasepage    = ext3_releasepage,
+       .readpage               = ext3_readpage,
+       .readpages              = ext3_readpages,
+       .writepage              = ext3_journalled_writepage,
+       .sync_page              = block_sync_page,
+       .write_begin            = ext3_write_begin,
+       .write_end              = ext3_journalled_write_end,
+       .set_page_dirty         = ext3_journalled_set_page_dirty,
+       .bmap                   = ext3_bmap,
+       .invalidatepage         = ext3_invalidatepage,
+       .releasepage            = ext3_releasepage,
+       .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
 void ext3_set_aops(struct inode *inode)
@@ -1767,7 +1835,6 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
        struct inode *inode = mapping->host;
        struct buffer_head *bh;
        int err = 0;
-       void *kaddr;
 
        blocksize = inode->i_sb->s_blocksize;
        length = blocksize - (offset & (blocksize - 1));
@@ -1779,10 +1846,7 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
         */
        if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
             ext3_should_writeback_data(inode) && PageUptodate(page)) {
-               kaddr = kmap_atomic(page, KM_USER0);
-               memset(kaddr + offset, 0, length);
-               flush_dcache_page(page);
-               kunmap_atomic(kaddr, KM_USER0);
+               zero_user(page, offset, length);
                set_page_dirty(page);
                goto unlock;
        }
@@ -1835,11 +1899,7 @@ static int ext3_block_truncate_page(handle_t *handle, struct page *page,
                        goto unlock;
        }
 
-       kaddr = kmap_atomic(page, KM_USER0);
-       memset(kaddr + offset, 0, length);
-       flush_dcache_page(page);
-       kunmap_atomic(kaddr, KM_USER0);
-
+       zero_user(page, offset, length);
        BUFFER_TRACE(bh, "zeroed end of block");
 
        err = 0;
@@ -2025,7 +2085,7 @@ static void ext3_free_data(handle_t *handle, struct inode *inode,
                           __le32 *first, __le32 *last)
 {
        ext3_fsblk_t block_to_free = 0;    /* Starting block # of a run */
-       unsigned long count = 0;            /* Number of blocks in the run */ 
+       unsigned long count = 0;            /* Number of blocks in the run */
        __le32 *block_to_free_p = NULL;     /* Pointer into inode/ind
                                               corresponding to
                                               block_to_free */
@@ -2054,7 +2114,7 @@ static void ext3_free_data(handle_t *handle, struct inode *inode,
                        } else if (nr == block_to_free + count) {
                                count++;
                        } else {
-                               ext3_clear_blocks(handle, inode, this_bh, 
+                               ext3_clear_blocks(handle, inode, this_bh,
                                                  block_to_free,
                                                  count, block_to_free_p, p);
                                block_to_free = nr;
@@ -2070,7 +2130,21 @@ static void ext3_free_data(handle_t *handle, struct inode *inode,
 
        if (this_bh) {
                BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
-               ext3_journal_dirty_metadata(handle, this_bh);
+
+               /*
+                * The buffer head should have an attached journal head at this
+                * point. However, if the data is corrupted and an indirect
+                * block pointed to itself, it would have been detached when
+                * the block was cleared. Check for this instead of OOPSing.
+                */
+               if (bh2jh(this_bh))
+                       ext3_journal_dirty_metadata(handle, this_bh);
+               else
+                       ext3_error(inode->i_sb, "ext3_free_data",
+                                  "circular indirect block detected, "
+                                  "inode=%lu, block=%llu",
+                                  inode->i_ino,
+                                  (unsigned long long)this_bh->b_blocknr);
        }
 }
 
@@ -2115,7 +2189,7 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
                         */
                        if (!bh) {
                                ext3_error(inode->i_sb, "ext3_free_branches",
-                                          "Read failure, inode=%ld, block="E3FSBLK,
+                                          "Read failure, inode=%lu, block="E3FSBLK,
                                           inode->i_ino, nr);
                                continue;
                        }
@@ -2184,7 +2258,7 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
                                        *p = 0;
                                        BUFFER_TRACE(parent_bh,
                                        "call ext3_journal_dirty_metadata");
-                                       ext3_journal_dirty_metadata(handle, 
+                                       ext3_journal_dirty_metadata(handle,
                                                                    parent_bh);
                                }
                        }
@@ -2196,6 +2270,19 @@ static void ext3_free_branches(handle_t *handle, struct inode *inode,
        }
 }
 
+int ext3_can_truncate(struct inode *inode)
+{
+       if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+               return 0;
+       if (S_ISREG(inode->i_mode))
+               return 1;
+       if (S_ISDIR(inode->i_mode))
+               return 1;
+       if (S_ISLNK(inode->i_mode))
+               return !ext3_inode_is_fast_symlink(inode);
+       return 0;
+}
+
 /*
  * ext3_truncate()
  *
@@ -2240,12 +2327,7 @@ void ext3_truncate(struct inode *inode)
        unsigned blocksize = inode->i_sb->s_blocksize;
        struct page *page;
 
-       if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
-           S_ISLNK(inode->i_mode)))
-               return;
-       if (ext3_inode_is_fast_symlink(inode))
-               return;
-       if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+       if (!ext3_can_truncate(inode))
                return;
 
        /*
@@ -2399,11 +2481,10 @@ out_stop:
 static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
                unsigned long ino, struct ext3_iloc *iloc)
 {
-       unsigned long desc, group_desc, block_group;
+       unsigned long block_group;
        unsigned long offset;
        ext3_fsblk_t block;
-       struct buffer_head *bh;
-       struct ext3_group_desc * gdp;
+       struct ext3_group_desc *gdp;
 
        if (!ext3_valid_inum(sb, ino)) {
                /*
@@ -2415,27 +2496,15 @@ static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
        }
 
        block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
-       if (block_group >= EXT3_SB(sb)->s_groups_count) {
-               ext3_error(sb,"ext3_get_inode_block","group >= groups count");
-               return 0;
-       }
-       smp_rmb();
-       group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
-       desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
-       bh = EXT3_SB(sb)->s_group_desc[group_desc];
-       if (!bh) {
-               ext3_error (sb, "ext3_get_inode_block",
-                           "Descriptor not loaded");
+       gdp = ext3_get_group_desc(sb, block_group, NULL);
+       if (!gdp)
                return 0;
-       }
-
-       gdp = (struct ext3_group_desc *)bh->b_data;
        /*
         * Figure out the offset within the block group inode table
         */
        offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
                EXT3_INODE_SIZE(sb);
-       block = le32_to_cpu(gdp[desc].bg_inode_table) +
+       block = le32_to_cpu(gdp->bg_inode_table) +
                (offset >> EXT3_BLOCK_SIZE_BITS(sb));
 
        iloc->block_group = block_group;
@@ -2469,6 +2538,16 @@ static int __ext3_get_inode_loc(struct inode *inode,
        }
        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);
@@ -2540,7 +2619,7 @@ make_io:
                 */
                get_bh(bh);
                bh->b_end_io = end_buffer_read_sync;
-               submit_bh(READ, bh);
+               submit_bh(READ_META, bh);
                wait_on_buffer(bh);
                if (!buffer_uptodate(bh)) {
                        ext3_error(inode->i_sb, "ext3_get_inode_loc",
@@ -2580,21 +2659,50 @@ void ext3_set_inode_flags(struct inode *inode)
                inode->i_flags |= S_DIRSYNC;
 }
 
-void ext3_read_inode(struct inode * inode)
+/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
+void ext3_get_inode_flags(struct ext3_inode_info *ei)
+{
+       unsigned int flags = ei->vfs_inode.i_flags;
+
+       ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
+                       EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
+       if (flags & S_SYNC)
+               ei->i_flags |= EXT3_SYNC_FL;
+       if (flags & S_APPEND)
+               ei->i_flags |= EXT3_APPEND_FL;
+       if (flags & S_IMMUTABLE)
+               ei->i_flags |= EXT3_IMMUTABLE_FL;
+       if (flags & S_NOATIME)
+               ei->i_flags |= EXT3_NOATIME_FL;
+       if (flags & S_DIRSYNC)
+               ei->i_flags |= EXT3_DIRSYNC_FL;
+}
+
+struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
 {
        struct ext3_iloc iloc;
        struct ext3_inode *raw_inode;
-       struct ext3_inode_info *ei = EXT3_I(inode);
+       struct ext3_inode_info *ei;
        struct buffer_head *bh;
+       struct inode *inode;
+       long ret;
        int block;
 
+       inode = iget_locked(sb, ino);
+       if (!inode)
+               return ERR_PTR(-ENOMEM);
+       if (!(inode->i_state & I_NEW))
+               return inode;
+
+       ei = EXT3_I(inode);
 #ifdef CONFIG_EXT3_FS_POSIX_ACL
        ei->i_acl = EXT3_ACL_NOT_CACHED;
        ei->i_default_acl = EXT3_ACL_NOT_CACHED;
 #endif
        ei->i_block_alloc_info = NULL;
 
-       if (__ext3_get_inode_loc(inode, &iloc, 0))
+       ret = __ext3_get_inode_loc(inode, &iloc, 0);
+       if (ret < 0)
                goto bad_inode;
        bh = iloc.bh;
        raw_inode = ext3_raw_inode(&iloc);
@@ -2607,9 +2715,9 @@ void ext3_read_inode(struct inode * inode)
        }
        inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
        inode->i_size = le32_to_cpu(raw_inode->i_size);
-       inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
-       inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
-       inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
+       inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
+       inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
+       inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
        inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
 
        ei->i_state = 0;
@@ -2625,6 +2733,7 @@ void ext3_read_inode(struct inode * inode)
                    !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
                        /* this inode is deleted */
                        brelse (bh);
+                       ret = -ESTALE;
                        goto bad_inode;
                }
                /* The only unlinked inodes we let through here have
@@ -2632,9 +2741,6 @@ void ext3_read_inode(struct inode * inode)
                 * recovery code: that's fine, we're about to complete
                 * the process of deleting those. */
        }
-       inode->i_blksize = PAGE_SIZE;   /* This is the optimal IO size
-                                        * (for stat), not the fs block
-                                        * size */  
        inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
        ei->i_flags = le32_to_cpu(raw_inode->i_flags);
 #ifdef EXT3_FRAGMENTS
@@ -2669,8 +2775,11 @@ void ext3_read_inode(struct inode * inode)
                 */
                ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
                if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
-                   EXT3_INODE_SIZE(inode->i_sb))
+                   EXT3_INODE_SIZE(inode->i_sb)) {
+                       brelse (bh);
+                       ret = -EIO;
                        goto bad_inode;
+               }
                if (ei->i_extra_isize == 0) {
                        /* The extra space is currently unused. Use it. */
                        ei->i_extra_isize = sizeof(struct ext3_inode) -
@@ -2704,17 +2813,18 @@ void ext3_read_inode(struct inode * inode)
                if (raw_inode->i_block[0])
                        init_special_inode(inode, inode->i_mode,
                           old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
-               else 
+               else
                        init_special_inode(inode, inode->i_mode,
                           new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
        }
        brelse (iloc.bh);
        ext3_set_inode_flags(inode);
-       return;
+       unlock_new_inode(inode);
+       return inode;
 
 bad_inode:
-       make_bad_inode(inode);
-       return;
+       iget_failed(inode);
+       return ERR_PTR(ret);
 }
 
 /*
@@ -2724,8 +2834,8 @@ bad_inode:
  *
  * The caller must have write access to iloc->bh.
  */
-static int ext3_do_update_inode(handle_t *handle, 
-                               struct inode *inode, 
+static int ext3_do_update_inode(handle_t *handle,
+                               struct inode *inode,
                                struct ext3_iloc *iloc)
 {
        struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
@@ -2738,6 +2848,7 @@ static int ext3_do_update_inode(handle_t *handle,
        if (ei->i_state & EXT3_STATE_NEW)
                memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
 
+       ext3_get_inode_flags(ei);
        raw_inode->i_mode = cpu_to_le16(inode->i_mode);
        if(!(test_opt(inode->i_sb, NO_UID32))) {
                raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
@@ -2876,7 +2987,7 @@ int ext3_write_inode(struct inode *inode, int wait)
                return 0;
 
        if (ext3_journal_current_handle()) {
-               jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
+               jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
                dump_stack();
                return -EIO;
        }
@@ -2900,7 +3011,7 @@ int ext3_write_inode(struct inode *inode, int wait)
  * commit will leave the blocks being flushed in an unused state on
  * disk.  (On recovery, the inode will get truncated and the blocks will
  * be freed, so we have a strong guarantee that no future commit will
- * leave these blocks visible to the user.)  
+ * leave these blocks visible to the user.)
  *
  * Called with inode->sem down.
  */
@@ -3043,13 +3154,13 @@ int ext3_mark_iloc_dirty(handle_t *handle,
        return err;
 }
 
-/* 
+/*
  * On success, We end up with an outstanding reference count against
- * iloc->bh.  This _must_ be cleaned up later. 
+ * iloc->bh.  This _must_ be cleaned up later.
  */
 
 int
-ext3_reserve_inode_write(handle_t *handle, struct inode *inode, 
+ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
                         struct ext3_iloc *iloc)
 {
        int err = 0;
@@ -3127,7 +3238,7 @@ void ext3_dirty_inode(struct inode *inode)
                current_handle->h_transaction != handle->h_transaction) {
                /* This task has a transaction open against a different fs */
                printk(KERN_EMERG "%s: transactions do not match!\n",
-                      __FUNCTION__);
+                      __func__);
        } else {
                jbd_debug(5, "marking dirty.  outer handle=%p\n",
                                current_handle);
@@ -3139,7 +3250,7 @@ out:
 }
 
 #if 0
-/* 
+/*
  * Bind an inode's backing buffer_head into this transaction, to prevent
  * it from being flushed to disk early.  Unlike
  * ext3_reserve_inode_write, this leaves behind no bh reference and
@@ -3157,7 +3268,7 @@ static int ext3_pin_inode(handle_t *handle, struct inode *inode)
                        BUFFER_TRACE(iloc.bh, "get_write_access");
                        err = journal_get_write_access(handle, iloc.bh);
                        if (!err)
-                               err = ext3_journal_dirty_metadata(handle, 
+                               err = ext3_journal_dirty_metadata(handle,
                                                                  iloc.bh);
                        brelse(iloc.bh);
                }
@@ -3184,7 +3295,7 @@ int ext3_change_inode_journal_flag(struct inode *inode, int val)
         */
 
        journal = EXT3_JOURNAL(inode);
-       if (is_journal_aborted(journal) || IS_RDONLY(inode))
+       if (is_journal_aborted(journal))
                return -EROFS;
 
        journal_lock_updates(journal);