From c3f8fc73ac97b76a12692088ef9cace9af8422c0 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 12 Nov 2012 22:54:01 +1100 Subject: xfs: make buffer read verication an IO completion function Add a verifier function callback capability to the buffer read interfaces. This will be used by the callers to supply a function that verifies the contents of the buffer when it is read from disk. This patch does not provide callback functions, but simply modifies the interfaces to allow them to be called. The reason for adding this to the read interfaces is that it is very difficult to tell fom the outside is a buffer was just read from disk or whether we just pulled it out of cache. Supplying a callbck allows the buffer cache to use it's internal knowledge of the buffer to execute it only when the buffer is read from disk. It is intended that the verifier functions will mark the buffer with an EFSCORRUPTED error when verification fails. This allows the reading context to distinguish a verification error from an IO error, and potentially take further actions on the buffer (e.g. attempt repair) based on the error reported. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Phil White Signed-off-by: Ben Myers --- fs/xfs/xfs_trans_buf.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'fs/xfs/xfs_trans_buf.c') diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c index 6311b99c267f..977628207b45 100644 --- a/fs/xfs/xfs_trans_buf.c +++ b/fs/xfs/xfs_trans_buf.c @@ -257,7 +257,8 @@ xfs_trans_read_buf_map( struct xfs_buf_map *map, int nmaps, xfs_buf_flags_t flags, - struct xfs_buf **bpp) + struct xfs_buf **bpp, + xfs_buf_iodone_t verify) { xfs_buf_t *bp; xfs_buf_log_item_t *bip; @@ -265,7 +266,7 @@ xfs_trans_read_buf_map( *bpp = NULL; if (!tp) { - bp = xfs_buf_read_map(target, map, nmaps, flags); + bp = xfs_buf_read_map(target, map, nmaps, flags, verify); if (!bp) return (flags & XBF_TRYLOCK) ? EAGAIN : XFS_ERROR(ENOMEM); @@ -312,7 +313,9 @@ xfs_trans_read_buf_map( if (!(XFS_BUF_ISDONE(bp))) { trace_xfs_trans_read_buf_io(bp, _RET_IP_); ASSERT(!XFS_BUF_ISASYNC(bp)); + ASSERT(bp->b_iodone == NULL); XFS_BUF_READ(bp); + bp->b_iodone = verify; xfsbdstrat(tp->t_mountp, bp); error = xfs_buf_iowait(bp); if (error) { @@ -349,7 +352,7 @@ xfs_trans_read_buf_map( return 0; } - bp = xfs_buf_read_map(target, map, nmaps, flags); + bp = xfs_buf_read_map(target, map, nmaps, flags, verify); if (bp == NULL) { *bpp = NULL; return (flags & XBF_TRYLOCK) ? -- cgit v1.2.3 From 1813dd64057490e7a0678a885c4fe6d02f78bdc1 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 14 Nov 2012 17:54:40 +1100 Subject: xfs: convert buffer verifiers to an ops structure. To separate the verifiers from iodone functions and associate read and write verifiers at the same time, introduce a buffer verifier operations structure to the xfs_buf. This avoids the need for assigning the write verifier, clearing the iodone function and re-running ioend processing in the read verifier, and gets rid of the nasty "b_pre_io" name for the write verifier function pointer. If we ever need to, it will also be easier to add further content specific callbacks to a buffer with an ops structure in place. We also avoid needing to export verifier functions, instead we can simply export the ops structures for those that are needed outside the function they are defined in. This patch also fixes a directory block readahead verifier issue it exposed. This patch also adds ops callbacks to the inode/alloc btree blocks initialised by growfs. These will need more work before they will work with CRCs. Signed-off-by: Dave Chinner Reviewed-by: Phil White Signed-off-by: Ben Myers --- fs/xfs/xfs_trans_buf.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/xfs/xfs_trans_buf.c') diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c index 977628207b45..4fc17d479d42 100644 --- a/fs/xfs/xfs_trans_buf.c +++ b/fs/xfs/xfs_trans_buf.c @@ -258,7 +258,7 @@ xfs_trans_read_buf_map( int nmaps, xfs_buf_flags_t flags, struct xfs_buf **bpp, - xfs_buf_iodone_t verify) + const struct xfs_buf_ops *ops) { xfs_buf_t *bp; xfs_buf_log_item_t *bip; @@ -266,7 +266,7 @@ xfs_trans_read_buf_map( *bpp = NULL; if (!tp) { - bp = xfs_buf_read_map(target, map, nmaps, flags, verify); + bp = xfs_buf_read_map(target, map, nmaps, flags, ops); if (!bp) return (flags & XBF_TRYLOCK) ? EAGAIN : XFS_ERROR(ENOMEM); @@ -315,7 +315,7 @@ xfs_trans_read_buf_map( ASSERT(!XFS_BUF_ISASYNC(bp)); ASSERT(bp->b_iodone == NULL); XFS_BUF_READ(bp); - bp->b_iodone = verify; + bp->b_ops = ops; xfsbdstrat(tp->t_mountp, bp); error = xfs_buf_iowait(bp); if (error) { @@ -352,7 +352,7 @@ xfs_trans_read_buf_map( return 0; } - bp = xfs_buf_read_map(target, map, nmaps, flags, verify); + bp = xfs_buf_read_map(target, map, nmaps, flags, ops); if (bp == NULL) { *bpp = NULL; return (flags & XBF_TRYLOCK) ? -- cgit v1.2.3