From: Joel Becker Date: Fri, 10 Oct 2008 00:20:34 +0000 (-0700) Subject: ocfs2: Make cached block reads the common case. X-Git-Tag: v2.6.28-rc1~572^2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=d4a8c93c8248534bdedb07f83c9aebd6f7d1d579;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Mark Fasheh --- diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c index 718dbe5607c..7e947c67246 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: diff --git a/fs/ocfs2/buffer_head_io.h b/fs/ocfs2/buffer_head_io.h index a2ef9e5f8bf..75e1dcb1ade 100644 --- a/fs/ocfs2/buffer_head_io.h +++ b/fs/ocfs2/buffer_head_io.h @@ -49,7 +49,7 @@ int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block, int ocfs2_write_super_or_backup(struct ocfs2_super *osb, struct buffer_head *bh); -#define OCFS2_BH_CACHED 1 +#define OCFS2_BH_IGNORE_CACHE 1 #define OCFS2_BH_READAHEAD 8 static inline int ocfs2_read_block(struct inode *inode, u64 off, @@ -63,7 +63,7 @@ static inline int ocfs2_read_block(struct inode *inode, u64 off, goto bail; } - status = ocfs2_read_blocks(inode, off, 1, bh, OCFS2_BH_CACHED); + status = ocfs2_read_blocks(inode, off, 1, bh, 0); bail: return status; diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c index 60be3ba1f5d..026e6eb8518 100644 --- a/fs/ocfs2/dir.c +++ b/fs/ocfs2/dir.c @@ -88,7 +88,7 @@ static struct buffer_head *ocfs2_bread(struct inode *inode, struct buffer_head *bh = NULL; int tmperr; u64 p_blkno; - int readflags = OCFS2_BH_CACHED; + int readflags = 0; if (reada) readflags |= OCFS2_BH_READAHEAD; diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c index 8381c26b21a..4903688f72a 100644 --- a/fs/ocfs2/inode.c +++ b/fs/ocfs2/inode.c @@ -461,7 +461,8 @@ static int ocfs2_read_locked_inode(struct inode *inode, } if (can_lock) - status = ocfs2_read_blocks(inode, args->fi_blkno, 1, &bh, 0); + status = ocfs2_read_blocks(inode, args->fi_blkno, 1, &bh, + OCFS2_BH_IGNORE_CACHE); else status = ocfs2_read_blocks_sync(osb, args->fi_blkno, 1, &bh); if (status < 0) { diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c index d161fe5e3bd..81e40677eec 100644 --- a/fs/ocfs2/journal.c +++ b/fs/ocfs2/journal.c @@ -1134,7 +1134,8 @@ static int ocfs2_read_journal_inode(struct ocfs2_super *osb, } SET_INODE_JOURNAL(inode); - status = ocfs2_read_blocks(inode, OCFS2_I(inode)->ip_blkno, 1, bh, 0); + status = ocfs2_read_blocks(inode, OCFS2_I(inode)->ip_blkno, 1, bh, + OCFS2_BH_IGNORE_CACHE); if (status < 0) { mlog_errno(status); goto bail; diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c index 3ea740d15fe..687b28713c3 100644 --- a/fs/ocfs2/localalloc.c +++ b/fs/ocfs2/localalloc.c @@ -249,7 +249,7 @@ int ocfs2_load_local_alloc(struct ocfs2_super *osb) } status = ocfs2_read_blocks(inode, OCFS2_I(inode)->ip_blkno, 1, - &alloc_bh, 0); + &alloc_bh, OCFS2_BH_IGNORE_CACHE); if (status < 0) { mlog_errno(status); goto bail; @@ -460,7 +460,7 @@ int ocfs2_begin_local_alloc_recovery(struct ocfs2_super *osb, mutex_lock(&inode->i_mutex); status = ocfs2_read_blocks(inode, OCFS2_I(inode)->ip_blkno, 1, - &alloc_bh, 0); + &alloc_bh, OCFS2_BH_IGNORE_CACHE); if (status < 0) { mlog_errno(status); goto bail; diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c index 357d3fe18c3..bdda2d8f850 100644 --- a/fs/ocfs2/slot_map.c +++ b/fs/ocfs2/slot_map.c @@ -150,7 +150,8 @@ int ocfs2_refresh_slot_info(struct ocfs2_super *osb) * be !NULL. Thus, ocfs2_read_blocks() will ignore blocknr. If * this is not true, the read of -1 (UINT64_MAX) will fail. */ - ret = ocfs2_read_blocks(si->si_inode, -1, si->si_blocks, si->si_bh, 0); + ret = ocfs2_read_blocks(si->si_inode, -1, si->si_blocks, si->si_bh, + OCFS2_BH_IGNORE_CACHE); if (ret == 0) { spin_lock(&osb->osb_lock); ocfs2_update_slot_info(si); @@ -403,7 +404,8 @@ static int ocfs2_map_slot_buffers(struct ocfs2_super *osb, (unsigned long long)blkno); bh = NULL; /* Acquire a fresh bh */ - status = ocfs2_read_blocks(si->si_inode, blkno, 1, &bh, 0); + status = ocfs2_read_blocks(si->si_inode, blkno, 1, &bh, + OCFS2_BH_IGNORE_CACHE); if (status < 0) { mlog_errno(status); goto bail;