Commit graph

12 commits

Author SHA1 Message Date
Christoph Hellwig
c1fb97d317
iomap: submit read bio after each extent
Currently the iomap buffered read path tries to build up read context
(i.e. bios for the typical block based case) over multiple iomaps as
long as the sector matches.  This does not take into account files
that can map to multiple different devices.  While this could be fixed
by a bdev check in iomap_bio_read_folio_range, the building up of I/O
over iomaps actually was a problem for the not yet merged ext2 iomap
port, as that does want to send out I/O at the end of an indirect
block mapped range.

So instead of adding more checks move over to a model where a bio only
spans a single iomap.  Change ->submit_read to be called after each
iteration so that the bio based users submit the bio after each iomap.
Fuse is unchanged because the previous commit stopped using ->submit_read
for it.

Fixes: dfeab2e95a ("erofs: add multiple device support")
Reported-by: Kelu Ye <yekelu1@huawei.com>
Reported-by: Yifan Zhao <zhaoyifan28@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260629121750.3392300-4-hch@lst.de
Tested-by: Yifan Zhao <zhaoyifan28@huawei.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01 15:26:47 +02:00
Christoph Hellwig
044472d5ee
iomap: consolidate bio submission
Add a iomap_bio_submit_read_endio helper factored out of
iomap_bio_submit_read to that all ->submit_read implementations for
iomap_read_ops that use iomap_bio_read_folio_range can shared the
logic.

Right now that logic is mostly trivial, but already has a bug for XFS
because the XFS version is too trivial:  file system integrity validation
needs a workqueue context and thus can't happen from the default iomap
bi_end_io I/O handler.  Unfortunately the iomap refactoring just before
fs integrity landed moved code around here and the call go misplaced,
meaning it never got called.  The PI information still is verified by
the block layer, but the offloading is less efficient (and the future
userspace interface can't get at it).

Fixes: 0b10a37052 ("iomap: support T10 protection information")
Cc: stable@vger.kernel.org # v7.1
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260629121750.3392300-2-hch@lst.de
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-07-01 15:26:47 +02:00
Linus Torvalds
0f00132132 vfs-7.1-rc1.integrity
Please consider pulling these changes from the signed vfs-7.1-rc1.integrity tag.
 
 Thanks!
 Christian
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCadjZCgAKCRCRxhvAZXjc
 ogmqAQCMD0V+pHwBAGwPQYBPc6Tf4LCxqNAmt/kypYsdVWkweQEAxbbeBPUigid5
 QeO0zCunikgIjMyJDXINpUPgsLYvyAo=
 =q2L6
 -----END PGP SIGNATURE-----

Merge tag 'vfs-7.1-rc1.integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs integrity updates from Christian Brauner:
 "This adds support to generate and verify integrity information (aka
  T10 PI) in the file system, instead of the automatic below the covers
  support that is currently used.

  The implementation is based on refactoring the existing block layer PI
  code to be reusable for this use case, and then adding relatively
  small wrappers for the file system use case. These are then used in
  iomap to implement the semantics, and wired up in XFS with a small
  amount of glue code.

  Compared to the baseline this does not change performance for writes,
  but increases read performance up to 15% for 4k I/O, with the benefit
  decreasing with larger I/O sizes as even the baseline maxes out the
  device quickly on my older enterprise SSD"

* tag 'vfs-7.1-rc1.integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  xfs: support T10 protection information
  iomap: support T10 protection information
  iomap: support ioends for buffered reads
  iomap: add a bioset pointer to iomap_read_folio_ops
  ntfs3: remove copy and pasted iomap code
  iomap: allow file systems to hook into buffered read bio submission
  iomap: only call into ->submit_read when there is a read_ctx
  iomap: pass the iomap_iter to ->submit_read
  iomap: refactor iomap_bio_read_folio_range
  block: pass a maxlen argument to bio_iov_iter_bounce
  block: add fs_bio_integrity helpers
  block: make max_integrity_io_size public
  block: prepare generation / verification helpers for fs usage
  block: add a bdev_has_integrity_csum helper
  block: factor out a bio_integrity_setup_default helper
  block: factor out a bio_integrity_action helper
2026-04-13 10:40:26 -07:00
Darrick J. Wong
f621324dfb
iomap: fix lockdep complaint when reads fail
Zorro Lang reported the following lockdep splat:

"While running fstests xfs/556 on kernel 7.0.0-rc4+ (HEAD=04a9f1766954),
a lockdep warning was triggered indicating an inconsistent lock state
for sb->s_type->i_lock_key.

"The deadlock might occur because iomap_read_end_io (called from a
hardware interrupt completion path) invokes fserror_report, which then
calls igrab.  igrab attempts to acquire the i_lock spinlock. However,
the i_lock is frequently acquired in process context with interrupts
enabled. If an interrupt occurs while a process holds the i_lock, and
that interrupt handler calls fserror_report, the system deadlocks.

"I hit this warning several times by running xfs/556 (mostly) or
generic/648 on xfs. More details refer to below console log."

along with this dmesg, for which I've cleaned up the stacktraces:

 run fstests xfs/556 at 2026-03-18 20:05:30
 XFS (sda3): Mounting V5 Filesystem 396e9164-c45a-4e05-be9d-b38c2c5c6477
 XFS (sda3): Ending clean mount
 XFS (sda3): Unmounting Filesystem 396e9164-c45a-4e05-be9d-b38c2c5c6477
 XFS (sda3): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
 XFS (sda3): Ending clean mount
 XFS (sda3): Unmounting Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
 XFS (dm-0): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
 XFS (dm-0): Ending clean mount
 device-mapper: table: 253:0: adding target device (start sect 209 len 1) caused an alignment inconsistency
 device-mapper: table: 253:0: adding target device (start sect 210 len 62914350) caused an alignment inconsistency
 buffer_io_error: 6 callbacks suppressed
 Buffer I/O error on dev dm-0, logical block 209, async page read
 Buffer I/O error on dev dm-0, logical block 209, async page read
 XFS (dm-0): Unmounting Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
 XFS (dm-0): Mounting V5 Filesystem bf3f89c3-3c45-4650-a9c7-744f39c0191e
 XFS (dm-0): Ending clean mount

 ================================
 WARNING: inconsistent lock state
 7.0.0-rc4+ #1 Tainted: G S      W
 --------------------------------
 inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
 od/2368602 [HC1[1]:SC0[0]:HE0:SE1] takes:
 ff1100069f2b4a98 (&sb->s_type->i_lock_key#31){?.+.}-{3:3}, at: igrab+0x28/0x1a0
 {HARDIRQ-ON-W} state was registered at:
   __lock_acquire+0x40d/0xbd0
   lock_acquire.part.0+0xbd/0x260
   _raw_spin_lock+0x37/0x80
   unlock_new_inode+0x66/0x2a0
   xfs_iget+0x67b/0x7b0 [xfs]
   xfs_mountfs+0xde4/0x1c80 [xfs]
   xfs_fs_fill_super+0xe86/0x17a0 [xfs]
   get_tree_bdev_flags+0x312/0x590
   vfs_get_tree+0x8d/0x2f0
   vfs_cmd_create+0xb2/0x240
   __do_sys_fsconfig+0x3d8/0x9a0
   do_syscall_64+0x13a/0x1520
   entry_SYSCALL_64_after_hwframe+0x76/0x7e
 irq event stamp: 3118
 hardirqs last  enabled at (3117): [<ffffffffb54e4ad8>] _raw_spin_unlock_irq+0x28/0x50
 hardirqs last disabled at (3118): [<ffffffffb54b84c9>] common_interrupt+0x19/0xe0
 softirqs last  enabled at (3040): [<ffffffffb290ca28>] handle_softirqs+0x6b8/0x950
 softirqs last disabled at (3023): [<ffffffffb290ce4d>] __irq_exit_rcu+0xfd/0x250

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&sb->s_type->i_lock_key#31);
   <Interrupt>
     lock(&sb->s_type->i_lock_key#31);

  *** DEADLOCK ***

 1 lock held by od/2368602:
  #0: ff1100069f2b4b58 (&sb->s_type->i_mutex_key#19){++++}-{4:4}, at: xfs_ilock+0x324/0x4b0 [xfs]

 stack backtrace:
 CPU: 15 UID: 0 PID: 2368602 Comm: od Kdump: loaded Tainted: G S      W           7.0.0-rc4+ #1 PREEMPT(full)
 Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN
 Hardware name: Dell Inc. PowerEdge R660/0R5JJC, BIOS 2.1.5 03/14/2024
 Call Trace:
  <IRQ>
  dump_stack_lvl+0x6f/0xb0
  print_usage_bug.part.0+0x230/0x2c0
  mark_lock_irq+0x3ce/0x5b0
  mark_lock+0x1cb/0x3d0
  mark_usage+0x109/0x120
  __lock_acquire+0x40d/0xbd0
  lock_acquire.part.0+0xbd/0x260
  _raw_spin_lock+0x37/0x80
  igrab+0x28/0x1a0
  fserror_report+0x127/0x2d0
  iomap_finish_folio_read+0x13c/0x280
  iomap_read_end_io+0x10e/0x2c0
  clone_endio+0x37e/0x780 [dm_mod]
  blk_update_request+0x448/0xf00
  scsi_end_request+0x74/0x750
  scsi_io_completion+0xe9/0x7c0
  _scsih_io_done+0x6ba/0x1ca0 [mpt3sas]
  _base_process_reply_queue+0x249/0x15b0 [mpt3sas]
  _base_interrupt+0x95/0xe0 [mpt3sas]
  __handle_irq_event_percpu+0x1f0/0x780
  handle_irq_event+0xa9/0x1c0
  handle_edge_irq+0x2ef/0x8a0
  __common_interrupt+0xa0/0x170
  common_interrupt+0xb7/0xe0
  </IRQ>
  <TASK>
  asm_common_interrupt+0x26/0x40
 RIP: 0010:_raw_spin_unlock_irq+0x2e/0x50
 Code: 0f 1f 44 00 00 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 b5 73 5e fd 48 89 df e8 ed e2 5e fd e8 08 78 8f fd fb bf 01 00 00 00 <e8> 8d 56 4d fd 65 8b 05 46 d5 1d 03 85 c0 74 06 5b c3 cc cc cc cc
 RSP: 0018:ffa0000027d07538 EFLAGS: 00000206
 RAX: 0000000000000c2d RBX: ffffffffb6614bc8 RCX: 0000000000000080
 RDX: 0000000000000000 RSI: ffffffffb6306a01 RDI: 0000000000000001
 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
 R10: ffffffffb75efc67 R11: 0000000000000001 R12: ff1100015ada0000
 R13: 0000000000000083 R14: 0000000000000002 R15: ffffffffb6614c10
  folio_wait_bit_common+0x407/0x780
  filemap_update_page+0x8e7/0xbd0
  filemap_get_pages+0x904/0xc50
  filemap_read+0x320/0xc20
  xfs_file_buffered_read+0x2aa/0x380 [xfs]
  xfs_file_read_iter+0x263/0x4a0 [xfs]
  vfs_read+0x6cb/0xb70
  ksys_read+0xf9/0x1d0
  do_syscall_64+0x13a/0x1520

Zorro's diagnosis makes sense, so the solution is to kick the failed
read handling to a workqueue much like we added for writeback ioends in
commit 294f54f849 ("fserror: fix lockdep complaint when igrabbing
inode").

Cc: Zorro Lang <zlang@redhat.com>
Link: https://lore.kernel.org/linux-xfs/20260319194303.efw4wcu7c4idhthz@doltdoltdolt/
Fixes: a9d573ee88 ("iomap: report file I/O errors to the VFS")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Link: https://patch.msgid.link/20260323210017.GL6223@frogsfrogsfrogs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-24 09:14:46 +01:00
Christoph Hellwig
0b10a37052
iomap: support T10 protection information
Add support for generating / verifying protection information in iomap.
This is done by hooking into the bio submission and then using the
generic PI helpers.  Compared to just using the block layer auto PI
this extends the protection envelope and also prepares for eventually
passing through PI from userspace at least for direct I/O.

To generate or verify PI, the file system needs to set the
IOMAP_F_INTEGRITY flag on the iomap for the request, and ensure the
ioends are used for all integrity I/O.  Additionally the file system
must defer read I/O completions to user context so that the guard
tag validation isn't run from interrupt context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-16-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:17 +01:00
Christoph Hellwig
e8f9cf03c9
iomap: support ioends for buffered reads
Support using the ioend structure to defer I/O completion for
buffered reads by calling into the buffered read I/O completion
handler from iomap_finish_ioend.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-15-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:15 +01:00
Christoph Hellwig
57287771fa
iomap: add a bioset pointer to iomap_read_folio_ops
Optionally allocate the bio from the bioset provided in
iomap_read_folio_ops.  If no bioset is provided, fs_bio_set is still
used, which is the standard bioset for file systems.

Based on a patch from Goldwyn Rodrigues <rgoldwyn@suse.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-14-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:03 +01:00
Christoph Hellwig
5f4fe046cb
iomap: allow file systems to hook into buffered read bio submission
File systems such as btrfs have additional operations with bios such as
verifying data checksums.  Allow file systems to hook into submission
of the bio to allow for this processing by replacing the direct
submit_bio call in iomap_read_alloc_bio with a call into ->submit_read
and exporting iomap_read_alloc_bio.  Also add a new field to
struct iomap_read_folio_ctx to track the file logic offset of the current
read context.

Based on a patch from Goldwyn Rodrigues <rgoldwyn@suse.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-12-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:03 +01:00
Christoph Hellwig
19fb5f9780
iomap: only call into ->submit_read when there is a read_ctx
Move the NULL check into the callers to simplify the callees.

Fuse was missing this before, but has a constant read_ctx that is
never NULL or changed, so no change here either.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-11-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:03 +01:00
Christoph Hellwig
4d25c7d688
iomap: pass the iomap_iter to ->submit_read
This provides additional context for file systems.

Rename the fuse instance to match the method name while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-10-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:03 +01:00
Christoph Hellwig
2580a0095f
iomap: refactor iomap_bio_read_folio_range
Split out the logic to allocate a new bio and only keep the fast path
that adds more data to an existing bio in iomap_bio_read_folio_range.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260223132021.292832-9-hch@lst.de
Tested-by: Anuj Gupta <anuj20.g@samsung.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-10 10:29:03 +01:00
Christoph Hellwig [1]
c2b1adc462
iomap: move buffered io bio logic into new file
Move bio logic in the buffered io code into its own file and remove
CONFIG_BLOCK gating for iomap read/readahead.

[1] https://lore.kernel.org/linux-fsdevel/aMK2GuumUf93ep99@infradead.org/

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-05 12:57:23 +01:00