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author | Mark Fasheh <mark.fasheh@oracle.com> | 2006-04-21 20:49:02 (GMT) |
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committer | Mark Fasheh <mark.fasheh@oracle.com> | 2006-09-20 22:53:40 (GMT) |
commit | aa9588741db907785e4d92c8b768dd6c9077e6f0 (patch) | |
tree | d34da288a9d296a8a2ba19dfa0f1df8429bd3e33 /fs/ocfs2/dir.c | |
parent | e0b4096d34fbd6b30838c417100c9d0ef73c71f2 (diff) | |
download | linux-aa9588741db907785e4d92c8b768dd6c9077e6f0.tar.xz |
ocfs2: implement directory read-ahead
Uptodate.c now knows about read-ahead buffers. Use some more aggressive
logic in ocfs2_readdir().
The two functions which currently use directory read-ahead are
ocfs2_find_entry() and ocfs2_readdir().
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'fs/ocfs2/dir.c')
-rw-r--r-- | fs/ocfs2/dir.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 3d494d1..04e0191 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -74,14 +74,14 @@ static int ocfs2_extend_dir(struct ocfs2_super *osb, int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir) { int error = 0; - unsigned long offset, blk; - int i, num, stored; + unsigned long offset, blk, last_ra_blk = 0; + int i, stored; struct buffer_head * bh, * tmp; struct ocfs2_dir_entry * de; int err; struct inode *inode = filp->f_dentry->d_inode; struct super_block * sb = inode->i_sb; - int have_disk_lock = 0; + unsigned int ra_sectors = 16; mlog_entry("dirino=%llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); @@ -95,9 +95,8 @@ int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir) mlog_errno(error); /* we haven't got any yet, so propagate the error. */ stored = error; - goto bail; + goto bail_nolock; } - have_disk_lock = 1; offset = filp->f_pos & (sb->s_blocksize - 1); @@ -113,16 +112,21 @@ int ocfs2_readdir(struct file * filp, void * dirent, filldir_t filldir) continue; } - /* - * Do the readahead (8k) - */ - if (!offset) { - for (i = 16 >> (sb->s_blocksize_bits - 9), num = 0; + /* The idea here is to begin with 8k read-ahead and to stay + * 4k ahead of our current position. + * + * TODO: Use the pagecache for this. We just need to + * make sure it's cluster-safe... */ + if (!last_ra_blk + || (((last_ra_blk - blk) << 9) <= (ra_sectors / 2))) { + for (i = ra_sectors >> (sb->s_blocksize_bits - 9); i > 0; i--) { tmp = ocfs2_bread(inode, ++blk, &err, 1); if (tmp) brelse(tmp); } + last_ra_blk = blk; + ra_sectors = 8; } revalidate: @@ -194,9 +198,9 @@ revalidate: stored = 0; bail: - if (have_disk_lock) - ocfs2_meta_unlock(inode, 0); + ocfs2_meta_unlock(inode, 0); +bail_nolock: mlog_exit(stored); return stored; |