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| author | Fengguang Wu <wfg@mail.ustc.edu.cn> | 2007-07-19 01:48:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-19 10:04:44 -0700 |
| commit | dc7868fcb9a73990e6f30371c1be465c436a7a7f (patch) | |
| tree | 21dfd3e625bb4a9f78a7795f0a5b110c3dd8843e /fs/ext4/dir.c | |
| parent | a08a166fe77d9f9ad88ed6d06b97e73453661f89 (diff) | |
| download | blackbird-op-linux-dc7868fcb9a73990e6f30371c1be465c436a7a7f.tar.gz blackbird-op-linux-dc7868fcb9a73990e6f30371c1be465c436a7a7f.zip | |
readahead: convert ext3/ext4 invocations
Convert ext3/ext4 dir reads to use on-demand readahead.
Readahead for dirs operates _not_ on file level, but on blockdev level. This
makes a difference when the data blocks are not continuous. And the read
routine is somehow opaque: there's no handy info about the status of current
page. So a simplified call scheme is employed: to call into readahead
whenever the current page falls out of readahead windows.
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ext4/dir.c')
| -rw-r--r-- | fs/ext4/dir.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index e8ad06e28318..0a872a09fed8 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -135,12 +135,14 @@ static int ext4_readdir(struct file * filp, map_bh.b_state = 0; err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0); if (err > 0) { - page_cache_readahead(sb->s_bdev->bd_inode->i_mapping, - &filp->f_ra, - filp, - map_bh.b_blocknr >> - (PAGE_CACHE_SHIFT - inode->i_blkbits), - 1); + pgoff_t index = map_bh.b_blocknr >> + (PAGE_CACHE_SHIFT - inode->i_blkbits); + if (!ra_has_index(&filp->f_ra, index)) + page_cache_readahead_ondemand( + sb->s_bdev->bd_inode->i_mapping, + &filp->f_ra, filp, + NULL, index, 1); + filp->f_ra.prev_index = index; bh = ext4_bread(NULL, inode, blk, 0, &err); } |
