linux.git/fs/iomap, branch v5.10.258

iomap: reject delalloc mappings during writeback

2026-04-18T08:30:59+00:00

[ Upstream commit d320f160aa5ff36cdf83c645cca52b615e866e32 ]

Filesystems should never provide a delayed allocation mapping to
writeback; they're supposed to allocate the space before replying.
This can lead to weird IO errors and crashes in the block layer if the
filesystem is being malicious, or if it hadn't set iomap->dev because
it's a delalloc mapping.

Fix this by failing writeback on delalloc mappings.  Currently no
filesystems actually misbehave in this manner, but we ought to be
stricter about things like that.

Cc: stable@vger.kernel.org # v5.5
Fixes: 598ecfbaa742ac ("iomap: lift the xfs writeback code to iomap")
Signed-off-by: Darrick J. Wong 
Link: https://patch.msgid.link/20260302173002.GL13829@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig 
Reviewed-by: Carlos Maiolino 
Signed-off-by: Christian Brauner 
[ Different error handling structure ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

iomap: fix submission side handling of completion side errors

2026-03-04T12:19:22+00:00

[ Upstream commit 4ad357e39b2ecd5da7bcc7e840ee24d179593cd5 ]

The "if (dio->error)" in iomap_dio_bio_iter exists to stop submitting
more bios when a completion already return an error.  Commit cfe057f7db1f
("iomap_dio_actor(): fix iov_iter bugs") made it revert the iov by
"copied", which is very wrong given that we've already consumed that
range and submitted a bio for it.

Fixes: cfe057f7db1f ("iomap_dio_actor(): fix iov_iter bugs")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Damien Le Moal 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

iomap: add the new iomap_iter model

2025-10-29T13:01:18+00:00

[ Upstream commit f4b896c213f0752adc828ddc11bd55419ffab248 ]

The iomap_iter struct provides a convenient way to package up and
maintain all the arguments to the various mapping and operation
functions.  It is operated on using the iomap_iter() function that
is called in loop until the whole range has been processed.  Compared
to the existing iomap_apply() function this avoid an indirect call
for each iteration.

For now iomap_iter() calls back into the existing ->iomap_begin and
->iomap_end methods, but in the future this could be further optimized
to avoid indirect calls entirely.

Based on an earlier patch from Matthew Wilcox .

Signed-off-by: Christoph Hellwig 
[djwong: add to apply.c to preserve git history of iomap loop control]
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Stable-dep-of: 154d1e7ad9e5 ("dax: skip read lock assertion for read-only filesystems")
Signed-off-by: Sasha Levin

iomap: update ki_pos a little later in iomap_dio_complete

2024-11-08T15:21:58+00:00

upstream 936e114a245b6e38e0dbf706a67e7611fc993da1 commit.

Move the ki_pos update down a bit to prepare for a better common helper
that invalidates pages based of an iocb.

Link: https://lkml.kernel.org/r/20230601145904.1385409-3-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Darrick J. Wong 
Cc: Al Viro 
Cc: Andreas Gruenbacher 
Cc: Anna Schumaker 
Cc: Chao Yu 
Cc: Christian Brauner 
Cc: Ilya Dryomov 
Cc: Jaegeuk Kim 
Cc: Jens Axboe 
Cc: Johannes Thumshirn 
Cc: Matthew Wilcox 
Cc: Miklos Szeredi 
Cc: Miklos Szeredi 
Cc: Theodore Ts'o 
Cc: Trond Myklebust 
Cc: Xiubo Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Mahmoud Adam 
Signed-off-by: Sasha Levin

xfs: use current->journal_info for detecting transaction recursion

2022-07-07T15:52:19+00:00

commit 756b1c343333a5aefcc26b0409f3fd16f72281bf upstream.

Because the iomap code using PF_MEMALLOC_NOFS to detect transaction
recursion in XFS is just wrong. Remove it from the iomap code and
replace it with XFS specific internal checks using
current->journal_info instead.

[djwong: This change also realigns the lifetime of NOFS flag changes to
match the incore transaction, instead of the inconsistent scheme we have
now.]

Fixes: 9070733b4efa ("xfs: abstract PF_FSTRANS to PF_MEMALLOC_NOFS")
Signed-off-by: Dave Chinner 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Amir Goldstein 
Acked-by: Darrick J. Wong 
Signed-off-by: Greg Kroah-Hartman

iomap: iomap_write_failed fix

2022-06-09T08:21:06+00:00

[ Upstream commit b71450e2cc4b3c79f33c5bd276d152af9bd54f79 ]

The @lend parameter of truncate_pagecache_range() should be the offset
of the last byte of the hole, not the first byte beyond it.

Fixes: ae259a9c8593 ("fs: introduce iomap infrastructure")
Signed-off-by: Andreas Gruenbacher 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Sasha Levin

treewide: Change list_sort to use const pointers

2021-09-30T08:11:04+00:00

[ Upstream commit 4f0f586bf0c898233d8f316f471a21db2abd522d ]

list_sort() internally casts the comparison function passed to it
to a different type with constant struct list_head pointers, and
uses this pointer to call the functions, which trips indirect call
Control-Flow Integrity (CFI) checking.

Instead of removing the consts, this change defines the
list_cmp_func_t type and changes the comparison function types of
all list_sort() callers to use const pointers, thus avoiding type
mismatches.

Suggested-by: Nick Desaulniers 
Signed-off-by: Sami Tolvanen 
Reviewed-by: Nick Desaulniers 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Kees Cook 
Tested-by: Nick Desaulniers 
Tested-by: Nathan Chancellor 
Signed-off-by: Kees Cook 
Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
Signed-off-by: Sasha Levin

iomap: pass writeback errors to the mapping

2021-09-18T11:40:29+00:00

[ Upstream commit b69eea82d37d9ee7cfb3bf05103549dd4ed5ffc3 ]

Modern-day mapping_set_error has the ability to squash the usual
negative error code into something appropriate for long-term storage in
a struct address_space -- ENOSPC becomes AS_ENOSPC, and everything else
becomes EIO.  iomap squashes /everything/ to EIO, just as XFS did before
that, but this doesn't make sense.

Fix this by making it so that we can pass ENOSPC to userspace when
writeback fails due to space problems.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Matthew Wilcox (Oracle) 
Signed-off-by: Sasha Levin

mm/swap: consider max pages in iomap_swapfile_add_extent

2021-09-15T07:50:42+00:00

[ Upstream commit 36ca7943ac18aebf8aad4c50829eb2ea5ec847df ]

When the max pages (last_page in the swap header + 1) is smaller than
the total pages (inode size) of the swapfile, iomap_swapfile_activate
overwrites sis->max with total pages.

However, frontswap_map is a swap page state bitmap allocated using the
initial sis->max page count read from the swap header.  If swapfile
activation increases sis->max, it's possible for the frontswap code to
walk off the end of the bitmap, thereby corrupting kernel memory.

[djwong: modify the description a bit; the original paragraph reads:

"However, frontswap_map is allocated using max pages. When test and clear
the sis offset, which is larger than max pages, of frontswap_map in
__frontswap_invalidate_page(), neighbors of frontswap_map may be
overwritten, i.e., slab is polluted."

Note also that this bug resulted in a behavioral change: activating a
swap file that was formatted and later extended results in all pages
being activated, not the number of pages recorded in the swap header.]

This fixes the issue by considering the limitation of max pages of swap
info in iomap_swapfile_add_extent().

To reproduce the case, compile kernel with slub RED ZONE, then run test:
$ sudo stress-ng -a 1 -x softlockup,resources -t 72h --metrics --times \
 --verify -v -Y /root/tmpdir/stress-ng/stress-statistic-12.yaml \
 --log-file /root/tmpdir/stress-ng/stress-logfile-12.txt \
 --temp-path /root/tmpdir/stress-ng/

We'll get the error log as below:

[ 1151.015141] =============================================================================
[ 1151.016489] BUG kmalloc-16 (Not tainted): Right Redzone overwritten
[ 1151.017486] -----------------------------------------------------------------------------
[ 1151.017486]
[ 1151.018997] Disabling lock debugging due to kernel taint
[ 1151.019873] INFO: 0x0000000084e43932-0x0000000098d17cae @offset=7392. First byte 0x0 instead of 0xcc
[ 1151.021303] INFO: Allocated in __do_sys_swapon+0xcf6/0x1170 age=43417 cpu=9 pid=3816
[ 1151.022538]  __slab_alloc+0xe/0x20
[ 1151.023069]  __kmalloc_node+0xfd/0x4b0
[ 1151.023704]  __do_sys_swapon+0xcf6/0x1170
[ 1151.024346]  do_syscall_64+0x33/0x40
[ 1151.024925]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.025749] INFO: Freed in put_cred_rcu+0xa1/0xc0 age=43424 cpu=3 pid=2041
[ 1151.026889]  kfree+0x276/0x2b0
[ 1151.027405]  put_cred_rcu+0xa1/0xc0
[ 1151.027949]  rcu_do_batch+0x17d/0x410
[ 1151.028566]  rcu_core+0x14e/0x2b0
[ 1151.029084]  __do_softirq+0x101/0x29e
[ 1151.029645]  asm_call_irq_on_stack+0x12/0x20
[ 1151.030381]  do_softirq_own_stack+0x37/0x40
[ 1151.031037]  do_softirq.part.15+0x2b/0x30
[ 1151.031710]  __local_bh_enable_ip+0x4b/0x50
[ 1151.032412]  copy_fpstate_to_sigframe+0x111/0x360
[ 1151.033197]  __setup_rt_frame+0xce/0x480
[ 1151.033809]  arch_do_signal+0x1a3/0x250
[ 1151.034463]  exit_to_user_mode_prepare+0xcf/0x110
[ 1151.035242]  syscall_exit_to_user_mode+0x27/0x190
[ 1151.035970]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.036795] INFO: Slab 0x000000003b9de4dc objects=44 used=9 fp=0x00000000539e349e flags=0xfffffc0010201
[ 1151.038323] INFO: Object 0x000000004855ba01 @offset=7376 fp=0x0000000000000000
[ 1151.038323]
[ 1151.039683] Redzone  000000008d0afd3d: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
[ 1151.041180] Object   000000004855ba01: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[ 1151.042714] Redzone  0000000084e43932: 00 00 00 c0 cc cc cc cc                          ........
[ 1151.044120] Padding  000000000864c042: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[ 1151.045615] CPU: 5 PID: 3816 Comm: stress-ng Tainted: G    B             5.10.50+ #7
[ 1151.046846] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 1151.048633] Call Trace:
[ 1151.049072]  dump_stack+0x57/0x6a
[ 1151.049585]  check_bytes_and_report+0xed/0x110
[ 1151.050320]  check_object+0x1eb/0x290
[ 1151.050924]  ? __x64_sys_swapoff+0x39a/0x540
[ 1151.051646]  free_debug_processing+0x151/0x350
[ 1151.052333]  __slab_free+0x21a/0x3a0
[ 1151.052938]  ? _cond_resched+0x2d/0x40
[ 1151.053529]  ? __vunmap+0x1de/0x220
[ 1151.054139]  ? __x64_sys_swapoff+0x39a/0x540
[ 1151.054796]  ? kfree+0x276/0x2b0
[ 1151.055307]  kfree+0x276/0x2b0
[ 1151.055832]  __x64_sys_swapoff+0x39a/0x540
[ 1151.056466]  do_syscall_64+0x33/0x40
[ 1151.057084]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1151.057866] RIP: 0033:0x150340b0ffb7
[ 1151.058481] Code: Unable to access opcode bytes at RIP 0x150340b0ff8d.
[ 1151.059537] RSP: 002b:00007fff7f4ee238 EFLAGS: 00000246 ORIG_RAX: 00000000000000a8
[ 1151.060768] RAX: ffffffffffffffda RBX: 00007fff7f4ee66c RCX: 0000150340b0ffb7
[ 1151.061904] RDX: 000000000000000a RSI: 0000000000018094 RDI: 00007fff7f4ee860
[ 1151.063033] RBP: 00007fff7f4ef980 R08: 0000000000000000 R09: 0000150340a672bd
[ 1151.064135] R10: 00007fff7f4edca0 R11: 0000000000000246 R12: 0000000000018094
[ 1151.065253] R13: 0000000000000005 R14: 000000000160d930 R15: 00007fff7f4ee66c
[ 1151.066413] FIX kmalloc-16: Restoring 0x0000000084e43932-0x0000000098d17cae=0xcc
[ 1151.066413]
[ 1151.067890] FIX kmalloc-16: Object at 0x000000004855ba01 not freed

Fixes: 67482129cdab ("iomap: add a swapfile activation function")
Fixes: a45c0eccc564 ("iomap: move the swapfile code into a separate file")
Signed-off-by: Gang Deng 
Signed-off-by: Xu Yu 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Sasha Levin

iomap: remove the length variable in iomap_seek_hole

2021-07-31T06:16:12+00:00

[ Upstream commit 49694d14ff68fa4b5f86019dbcfb44a8bd213e58 ]

The length variable is rather pointless given that it can be trivially
deduced from offset and size.  Also the initial calculation can lead
to KASAN warnings.

Signed-off-by: Christoph Hellwig 
Reported-by: Leizhen (ThunderTown) 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Matthew Wilcox (Oracle) 
Signed-off-by: Sasha Levin