From 4d3c07591534517c633945c8d8e6526f10e3fabc Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 10 Sep 2026 21:42:28 -0700 Subject: [PATCH] xfs: fix under-reservation of blocks when repairing sf directories Whilst running QA on XFS for-next as of 7.3-rc2 with MKFS_OPTIONS="-n size=8192", I observed the following (trimmed) dmesg splat: XFS: Assertion failed: args->total >= dp->i_nblocks - nblks, file: fs/xfs/libxfs/xfs_da_btree.c, line: 2387 WARNING: fs/xfs/xfs_message.c:104 at assfail+0x46/0x4a [xfs], CPU#0: xfs_scrub/1426511 CPU: 0 UID: 0 PID: 1426511 Comm: xfs_scrub Tainted: G W 7.3.0-rc2-djwx #rc2 PREEMPT(lazy) 6e418570b606a39783b0e7e7b30dc407b965f9e8 Tainted: [W]=WARN RIP: 0010:assfail+0x46/0x4a [xfs] RSP: 0018:ffffc900010d7890 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000ffffffd1 RDX: 0000000000000000 RSI: 0000000000000021 RDI: ffffffffa059fd38 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000a R11: 000000007fffffff R12: ffffc900010d7940 R13: ffff888368d8f980 R14: ffffc900010d7a48 R15: ffffc900010d78d0 FS: 00007f445c5ce680(0000) GS:ffff8884a97ea000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f443803b9a8 CR3: 0000000107a4b000 CR4: 00000000003506f0 Call Trace: xfs_da_grow_inode_int+0x2e0/0x300 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xfs_dir2_grow_inode+0x6e/0x150 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xfs_dir2_sf_to_block+0x149/0x870 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xrep_dir_swap_prep+0xe2/0x110 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xrep_dir_swap+0xfb/0x2f0 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xrep_dir_rebuild_tree+0x99/0x100 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xrep_directory+0x83/0x1c0 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xrep_attempt+0x4f/0x1e0 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xfs_scrub_metadata+0x393/0x5b0 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xfs_ioc_scrubv_metadata+0x306/0x570 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] xfs_file_ioctl+0xa4f/0x1150 [xfs 5de2257e14108c136f11317e6bbb8ac77efd392c] __x64_sys_ioctl+0x76/0xc0 do_syscall_64+0x7a/0x3b0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 This is a consequence of commit 0fe77e57588b98, which added the following assertion to xfs_da_grow_inode_int: ASSERT(args->total >= dp->i_nblocks - nblks); Tracing this back to xrep_dir_swap_prep, I noticed that the xfs_da_args object that's passed to xfs_dir2_sf_to_block sets args->total to 1. This is incorrect because mkfs set the directory block size to 8k and the filesystem block size to 4k. In other words, args->total should be 2 here, not 1. Dave Chinner tripped over the same problem with the same branch through a different channel -- his test setup set the fs block size to 1k, in which case the directory block size is still set to 4k. Here, args->total should be 4. Changing the assignment of args->total to sc->mp->m_dir_geo->fsbcount makes the assertion go away, but that isn't a complete fix. In xrep_tempexch_estimate, we also incorrectly assume that a shortform conversion requires 1 fsblock when it should be m_dir_geo->fsbcount. Without that, we can under-reserve space in the transaction and cause a filesystem shutdown. Note that the xfs_dabuf_nfsb helper will compute the correct value for directories and xattr, so we use that instead of open-coding the logic. Also fix xrep_xattr_swap_prep to assign args->total via xfs_dabuf_nfsb to avoid one logic bomb if we ever support multi-fsblock attrs. Cc: stable@vger.kernel.org # v6.10 Cc: floss@jetm.me Reported-by: dgc@kernel.org Fixes: 629fdaf5f5b1b7 ("xfs: use atomic extent swapping to fix user file fork data") Tripped-by: 0fe77e57588b98 ("xfs: assert the reservation covers each da fork growth") Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Carlos Maiolino --- fs/xfs/libxfs/xfs_da_btree.c | 2 +- fs/xfs/libxfs/xfs_da_btree.h | 2 ++ fs/xfs/scrub/attr_repair.c | 2 +- fs/xfs/scrub/dir_repair.c | 2 +- fs/xfs/scrub/tempfile.c | 29 ++++++++++++++++++++++------- 5 files changed, 27 insertions(+), 10 deletions(-) diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c index 8cbdd6574755..3d02a0d7ba44 100644 --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -130,7 +130,7 @@ xfs_da_state_reset( state->mp = state->args->dp->i_mount; } -static inline int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork) +inline int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork) { if (whichfork == XFS_DATA_FORK) return mp->m_dir_geo->fsbcount; diff --git a/fs/xfs/libxfs/xfs_da_btree.h b/fs/xfs/libxfs/xfs_da_btree.h index afcf2d3c7a21..a718b1ceb0aa 100644 --- a/fs/xfs/libxfs/xfs_da_btree.h +++ b/fs/xfs/libxfs/xfs_da_btree.h @@ -244,4 +244,6 @@ xfs_failaddr_t xfs_da3_node_header_check(struct xfs_buf *bp, xfs_ino_t owner); extern struct kmem_cache *xfs_da_state_cache; +int xfs_dabuf_nfsb(struct xfs_mount *mp, int whichfork); + #endif /* __XFS_DA_BTREE_H__ */ diff --git a/fs/xfs/scrub/attr_repair.c b/fs/xfs/scrub/attr_repair.c index 6e6af142f1fb..28f92e9ba72b 100644 --- a/fs/xfs/scrub/attr_repair.c +++ b/fs/xfs/scrub/attr_repair.c @@ -1294,7 +1294,7 @@ xrep_xattr_swap_prep( .geo = sc->mp->m_attr_geo, .whichfork = XFS_ATTR_FORK, .trans = sc->tp, - .total = 1, + .total = xfs_dabuf_nfsb(sc->mp, XFS_ATTR_FORK), .owner = I_INO(sc->ip), }; diff --git a/fs/xfs/scrub/dir_repair.c b/fs/xfs/scrub/dir_repair.c index 31a23c5f386a..d9d6b7e2abda 100644 --- a/fs/xfs/scrub/dir_repair.c +++ b/fs/xfs/scrub/dir_repair.c @@ -1488,7 +1488,7 @@ xrep_dir_swap_prep( .geo = sc->mp->m_dir_geo, .whichfork = XFS_DATA_FORK, .trans = sc->tp, - .total = 1, + .total = xfs_dabuf_nfsb(sc->mp, XFS_DATA_FORK), .owner = I_INO(sc->ip), }; diff --git a/fs/xfs/scrub/tempfile.c b/fs/xfs/scrub/tempfile.c index 98820003b929..59a9213a3c7d 100644 --- a/fs/xfs/scrub/tempfile.c +++ b/fs/xfs/scrub/tempfile.c @@ -649,6 +649,19 @@ xrep_tempexch_prep_request( return 0; } +static inline unsigned int +xrep_tempexch_estimate_sf_resblks( + struct xfs_scrub *sc, + int whichfork) +{ + /* repairing a symlink target */ + if (S_ISLNK(VFS_I(sc->ip)->i_mode) && whichfork == XFS_DATA_FORK) + return 1; + + /* everything else is a directory or an xattr structure */ + return xfs_dabuf_nfsb(sc->mp, whichfork); +} + /* * Fill out the mapping exchange resource estimation structures in preparation * for exchanging the contents of a metadata file that we've rebuilt in the @@ -663,6 +676,8 @@ xrep_tempexch_estimate( struct xfs_ifork *ifp; struct xfs_ifork *tifp; int whichfork = xfs_exchmaps_reqfork(req); + unsigned int sf_resblks = + xrep_tempexch_estimate_sf_resblks(sc, whichfork); int state = 0; /* @@ -693,9 +708,9 @@ xrep_tempexch_estimate( * plus the block we converted. */ req->ip1_bcount = sc->tempip->i_nblocks; - req->ip2_bcount = 1; + req->ip2_bcount = sf_resblks; req->nr_exchanges = 1 + tifp->if_nextents; - req->resblks = 1; + req->resblks = sf_resblks; break; case 2: /* @@ -707,10 +722,10 @@ xrep_tempexch_estimate( * is (worst case) the extent count of the file being repaired * plus the block we converted. */ - req->ip1_bcount = 1; + req->ip1_bcount = sf_resblks; req->ip2_bcount = sc->ip->i_nblocks; req->nr_exchanges = 1 + ifp->if_nextents; - req->resblks = 1; + req->resblks = sf_resblks; break; case 3: /* @@ -722,10 +737,10 @@ xrep_tempexch_estimate( * fileoff 0. Presumably, the caller could not exchange the * two inode fork areas directly. */ - req->ip1_bcount = 1; - req->ip2_bcount = 1; + req->ip1_bcount = sf_resblks; + req->ip2_bcount = sf_resblks; req->nr_exchanges = 1; - req->resblks = 2; + req->resblks = 2 * sf_resblks; break; }