[PATCH openEuler-1.0-LTS v2 0/2] xfs: fix stale imap reuse during page writeback
During page write-back operations, a copy of the imap is stored in wpc->imap. Even if the file's imap mapping changes during this process, the subsequent operations continue to reuse wpc->imap, causing data to be written to incorrect blocks that are not mapped to that file. Brian Foster (2): xfs: update fork seq counter on data fork changes xfs: remove superfluous writeback mapping eof trimming fs/xfs/libxfs/xfs_bmap.c | 11 ----------- fs/xfs/libxfs/xfs_bmap.h | 1 - fs/xfs/libxfs/xfs_iext_tree.c | 13 ++++++------- fs/xfs/libxfs/xfs_inode_fork.h | 2 +- fs/xfs/xfs_aops.c | 15 --------------- 5 files changed, 7 insertions(+), 35 deletions(-) -- 2.39.2
From: Brian Foster <bfoster@redhat.com> mainline inclusion from mainline-v5.0-rc6 commit 9f9bc034b84958523689347ee2bdd9c660008e5e category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IDAVXA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The sequence counter in the xfs_ifork structure is only updated on COW forks. This is because the counter is currently only used to optimize out repetitive COW fork checks at writeback time. Tweak the extent code to update the seq counter regardless of the fork type in preparation for using this counter on data forks as well. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Conflicts: fs/xfs/libxfs/xfs_inode_fork.h [Context conflicts] Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/xfs/libxfs/xfs_iext_tree.c | 13 ++++++------- fs/xfs/libxfs/xfs_inode_fork.h | 2 +- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/fs/xfs/libxfs/xfs_iext_tree.c b/fs/xfs/libxfs/xfs_iext_tree.c index 22beaab8f9b4..bcce713a4bb3 100644 --- a/fs/xfs/libxfs/xfs_iext_tree.c +++ b/fs/xfs/libxfs/xfs_iext_tree.c @@ -614,16 +614,15 @@ xfs_iext_realloc_root( } /* - * Increment the sequence counter if we are on a COW fork. This allows - * the writeback code to skip looking for a COW extent if the COW fork - * hasn't changed. We use WRITE_ONCE here to ensure the update to the - * sequence counter is seen before the modifications to the extent - * tree itself take effect. + * Increment the sequence counter on extent tree changes. If we are on a COW + * fork, this allows the writeback code to skip looking for a COW extent if the + * COW fork hasn't changed. We use WRITE_ONCE here to ensure the update to the + * sequence counter is seen before the modifications to the extent tree itself + * take effect. */ static inline void xfs_iext_inc_seq(struct xfs_ifork *ifp, int state) { - if (state & BMAP_COWFORK) - WRITE_ONCE(ifp->if_seq, READ_ONCE(ifp->if_seq) + 1); + WRITE_ONCE(ifp->if_seq, READ_ONCE(ifp->if_seq) + 1); } void diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h index 09e3548afdde..7b845c052fb4 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.h +++ b/fs/xfs/libxfs/xfs_inode_fork.h @@ -15,7 +15,7 @@ struct xfs_dinode; struct xfs_ifork { int64_t if_bytes; /* bytes in if_u1 */ struct xfs_btree_block *if_broot; /* file's incore btree root */ - unsigned int if_seq; /* cow fork mod counter */ + unsigned int if_seq; /* fork mod counter */ int if_height; /* height of the extent tree */ union { void *if_root; /* extent tree root */ -- 2.39.2
From: Brian Foster <bfoster@redhat.com> mainline inclusion from mainline-v5.0-rc6 commit 3b35089807304f208419b5ad9cc3c5f731225cd9 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IDAVXA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Now that the cached writeback mapping is explicitly invalidated on data fork changes, the EOF trimming band-aid is no longer necessary. Remove xfs_trim_extent_eof() as well since it has no other users. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Long Li <leo.lilong@huawei.com> --- fs/xfs/libxfs/xfs_bmap.c | 11 ----------- fs/xfs/libxfs/xfs_bmap.h | 1 - fs/xfs/xfs_aops.c | 15 --------------- 3 files changed, 27 deletions(-) diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index e8eb439a910a..da1da2b3e011 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -3688,17 +3688,6 @@ xfs_trim_extent( } } -/* trim extent to within eof */ -void -xfs_trim_extent_eof( - struct xfs_bmbt_irec *irec, - struct xfs_inode *ip) - -{ - xfs_trim_extent(irec, 0, XFS_B_TO_FSB(ip->i_mount, - i_size_read(VFS_I(ip)))); -} - /* * Trim the returned map to the required bounds */ diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h index 4c9df0499c42..def945d665fd 100644 --- a/fs/xfs/libxfs/xfs_bmap.h +++ b/fs/xfs/libxfs/xfs_bmap.h @@ -181,7 +181,6 @@ static inline bool xfs_bmap_is_real_extent(struct xfs_bmbt_irec *irec) void xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno, xfs_filblks_t len); -void xfs_trim_extent_eof(struct xfs_bmbt_irec *, struct xfs_inode *); int xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd); int xfs_bmap_set_attrforkoff(struct xfs_inode *ip, int size, int *version); void xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork); diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 554c74726552..aa6fe5efa104 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -357,19 +357,6 @@ xfs_map_blocks( if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; - /* - * We have to make sure the cached mapping is within EOF to protect - * against eofblocks trimming on file release leaving us with a stale - * mapping. Otherwise, a page for a subsequent file extending buffered - * write could get picked up by this writeback cycle and written to the - * wrong blocks. - * - * Note that what we really want here is a generic mapping invalidation - * mechanism to protect us from arbitrary extent modifying contexts, not - * just eofblocks. - */ - xfs_trim_extent_eof(&wpc->imap, ip); - /* * COW fork blocks can overlap data fork blocks even if the blocks * aren't shared. COW I/O always takes precedent, so we must always @@ -482,7 +469,6 @@ xfs_map_blocks( } wpc->imap = imap; - xfs_trim_extent_eof(&wpc->imap, ip); trace_xfs_map_blocks_found(ip, offset, count, wpc->io_type, &imap); return 0; allocate_blocks: @@ -494,7 +480,6 @@ xfs_map_blocks( ASSERT(whichfork == XFS_COW_FORK || cow_fsb == NULLFILEOFF || imap.br_startoff + imap.br_blockcount <= cow_fsb); wpc->imap = imap; - xfs_trim_extent_eof(&wpc->imap, ip); trace_xfs_map_blocks_alloc(ip, offset, count, wpc->io_type, &imap); return 0; } -- 2.39.2
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