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| author | Joel Becker <joel.becker@oracle.com> | 2008-10-09 17:20:34 -0700 |
|---|---|---|
| committer | Mark Fasheh <mfasheh@suse.com> | 2008-10-14 11:58:22 -0700 |
| commit | d4a8c93c8248534bdedb07f83c9aebd6f7d1d579 (patch) | |
| tree | f978a7b36d515c29657f271ca5b70281c911a82f /fs/ocfs2/buffer_head_io.c | |
| parent | 5e0b3dec0107540244ba343f983ef4f972db20de (diff) | |
| download | blackbird-op-linux-d4a8c93c8248534bdedb07f83c9aebd6f7d1d579.tar.gz blackbird-op-linux-d4a8c93c8248534bdedb07f83c9aebd6f7d1d579.zip | |
ocfs2: Make cached block reads the common case.
ocfs2_read_blocks() currently requires the CACHED flag for cached I/O.
However, that's the common case. Let's flip it around and provide an
IGNORE_CACHE flag for the special users. This has the added benefit of
cleaning up the code some (ignore_cache takes on its special meaning
earlier in the loop).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Diffstat (limited to 'fs/ocfs2/buffer_head_io.c')
| -rw-r--r-- | fs/ocfs2/buffer_head_io.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c index 718dbe5607ca..7e947c672469 100644 --- a/fs/ocfs2/buffer_head_io.c +++ b/fs/ocfs2/buffer_head_io.c @@ -181,7 +181,8 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, inode, (unsigned long long)block, nr, flags); BUG_ON(!inode); - BUG_ON((flags & OCFS2_BH_READAHEAD) && !(flags & OCFS2_BH_CACHED)); + BUG_ON((flags & OCFS2_BH_READAHEAD) && + (flags & OCFS2_BH_IGNORE_CACHE)); if (bhs == NULL) { status = -EINVAL; @@ -214,7 +215,7 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, } } bh = bhs[i]; - ignore_cache = 0; + ignore_cache = (flags & OCFS2_BH_IGNORE_CACHE); /* There are three read-ahead cases here which we need to * be concerned with. All three assume a buffer has @@ -240,26 +241,27 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, * before our is-it-in-flight check. */ - if (flags & OCFS2_BH_CACHED && - !ocfs2_buffer_uptodate(inode, bh)) { + if (!ignore_cache && !ocfs2_buffer_uptodate(inode, bh)) { mlog(ML_UPTODATE, "bh (%llu), inode %llu not uptodate\n", (unsigned long long)bh->b_blocknr, (unsigned long long)OCFS2_I(inode)->ip_blkno); + /* We're using ignore_cache here to say + * "go to disk" */ ignore_cache = 1; } /* XXX: Can we ever get this and *not* have the cached * flag set? */ if (buffer_jbd(bh)) { - if (!(flags & OCFS2_BH_CACHED) || ignore_cache) + if (ignore_cache) mlog(ML_BH_IO, "trying to sync read a jbd " "managed bh (blocknr = %llu)\n", (unsigned long long)bh->b_blocknr); continue; } - if (!(flags & OCFS2_BH_CACHED) || ignore_cache) { + if (ignore_cache) { if (buffer_dirty(bh)) { /* This should probably be a BUG, or * at least return an error. */ @@ -294,7 +296,7 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, * previously read-ahead buffer may have * completed I/O while we were waiting for the * buffer lock. */ - if ((flags & OCFS2_BH_CACHED) + if (!(flags & OCFS2_BH_IGNORE_CACHE) && !(flags & OCFS2_BH_READAHEAD) && ocfs2_buffer_uptodate(inode, bh)) { unlock_buffer(bh); @@ -344,7 +346,8 @@ int ocfs2_read_blocks(struct inode *inode, u64 block, int nr, mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s, flags=0x%x\n", (unsigned long long)block, nr, - (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes", flags); + ((flags & OCFS2_BH_IGNORE_CACHE) || ignore_cache) ? "no" : "yes", + flags); bail: |
