[PATCH 11/45] xfs: xfs_buf_item_size_segment() needs to pass segment offset
From: Dave Chinner <david@fromorbit.com>
Date: 2021-03-05 05:12:00
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Dave Chinner <redacted> Otherwise it doesn't correctly calculate the number of vectors in a logged buffer that has a contiguous map that gets split into multiple regions because the range spans discontigous memory. Probably never been hit in practice - we don't log contiguous ranges on unmapped buffers (inode clusters). Signed-off-by: Dave Chinner <redacted> Reviewed-by: Darrick J. Wong <djwong@kernel.org> --- fs/xfs/xfs_buf_item.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-)
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 0628a65d9c55..91dc7d8c9739 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c@@ -55,6 +55,18 @@ xfs_buf_log_format_size( (blfp->blf_map_size * sizeof(blfp->blf_data_map[0])); } +static inline bool +xfs_buf_item_straddle( + struct xfs_buf *bp, + uint offset, + int next_bit, + int last_bit) +{ + return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != + (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + + XFS_BLF_CHUNK); +} + /* * Return the number of log iovecs and space needed to log the given buf log * item segment.
@@ -67,6 +79,7 @@ STATIC void xfs_buf_item_size_segment( struct xfs_buf_log_item *bip, struct xfs_buf_log_format *blfp, + uint offset, int *nvecs, int *nbytes) {
@@ -101,12 +114,8 @@ xfs_buf_item_size_segment( */ if (next_bit == -1) { break; - } else if (next_bit != last_bit + 1) { - last_bit = next_bit; - (*nvecs)++; - } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) != - (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + - XFS_BLF_CHUNK)) { + } else if (next_bit != last_bit + 1 || + xfs_buf_item_straddle(bp, offset, next_bit, last_bit)) { last_bit = next_bit; (*nvecs)++; } else {
@@ -141,8 +150,10 @@ xfs_buf_item_size( int *nbytes) { struct xfs_buf_log_item *bip = BUF_ITEM(lip); + struct xfs_buf *bp = bip->bli_buf; int i; int bytes; + uint offset = 0; ASSERT(atomic_read(&bip->bli_refcount) > 0); if (bip->bli_flags & XFS_BLI_STALE) {
@@ -184,8 +195,9 @@ xfs_buf_item_size( */ bytes = 0; for (i = 0; i < bip->bli_format_count; i++) { - xfs_buf_item_size_segment(bip, &bip->bli_formats[i], + xfs_buf_item_size_segment(bip, &bip->bli_formats[i], offset, nvecs, &bytes); + offset += BBTOB(bp->b_maps[i].bm_len); } /*
@@ -212,18 +224,6 @@ xfs_buf_item_copy_iovec( nbits * XFS_BLF_CHUNK); } -static inline bool -xfs_buf_item_straddle( - struct xfs_buf *bp, - uint offset, - int next_bit, - int last_bit) -{ - return xfs_buf_offset(bp, offset + (next_bit << XFS_BLF_SHIFT)) != - (xfs_buf_offset(bp, offset + (last_bit << XFS_BLF_SHIFT)) + - XFS_BLF_CHUNK); -} - static void xfs_buf_item_format_segment( struct xfs_buf_log_item *bip,
--
2.28.0