[PATCH V14 03/16] xfs: Check for extent overflow when punching a hole
From: Chandan Babu R <hidden>
Date: 2021-01-10 16:10:34
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
The extent mapping the file offset at which a hole has to be inserted will be split into two extents causing extent count to increase by 1. Reviewed-by: Darrick J. Wong <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <redacted> Signed-off-by: Chandan Babu R <redacted> --- fs/xfs/libxfs/xfs_inode_fork.h | 7 +++++++ fs/xfs/xfs_bmap_item.c | 15 +++++++++------ fs/xfs/xfs_bmap_util.c | 10 ++++++++++ 3 files changed, 26 insertions(+), 6 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index 7fc2b129a2e7..bcac769a7df6 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h@@ -40,6 +40,13 @@ struct xfs_ifork { */ #define XFS_IEXT_ADD_NOSPLIT_CNT (1) +/* + * Punching out an extent from the middle of an existing extent can cause the + * extent count to increase by 1. + * i.e. | Old extent | Hole | Old extent | + */ +#define XFS_IEXT_PUNCH_HOLE_CNT (1) + /* * Fork handling. */
diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index 0534304ed0a7..2344757ede63 100644
--- a/fs/xfs/xfs_bmap_item.c
+++ b/fs/xfs/xfs_bmap_item.c@@ -471,6 +471,7 @@ xfs_bui_item_recover( xfs_exntst_t state; unsigned int bui_type; int whichfork; + int iext_delta; int error = 0; if (!xfs_bui_validate(mp, buip)) {
@@ -508,12 +509,14 @@ xfs_bui_item_recover( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); - if (bui_type == XFS_BMAP_MAP) { - error = xfs_iext_count_may_overflow(ip, whichfork, - XFS_IEXT_ADD_NOSPLIT_CNT); - if (error) - goto err_cancel; - } + if (bui_type == XFS_BMAP_MAP) + iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT; + else + iext_delta = XFS_IEXT_PUNCH_HOLE_CNT; + + error = xfs_iext_count_may_overflow(ip, whichfork, iext_delta); + if (error) + goto err_cancel; count = bmap->me_len; error = xfs_trans_log_finish_bmap_update(tp, budp, bui_type, ip,
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index db44bfaabe88..6ac7a6ac2658 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c@@ -891,6 +891,11 @@ xfs_unmap_extent( xfs_trans_ijoin(tp, ip, 0); + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_PUNCH_HOLE_CNT); + if (error) + goto out_trans_cancel; + error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done); if (error) goto out_trans_cancel;
@@ -1168,6 +1173,11 @@ xfs_insert_file_space( xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); + error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, + XFS_IEXT_PUNCH_HOLE_CNT); + if (error) + goto out_trans_cancel; + /* * The extent shifting code works on extent granularity. So, if stop_fsb * is not the starting block of extent, we need to split the extent at
--
2.29.2