kernel/git/next/linux-next.git/fs/buffer.c, branch master

Merge branch 'headers' of git://git.infradead.org/users/willy/pagecache.git

2026-09-07T13:49:19+00:00

# Conflicts: # net/ceph/osd_client.c

buffer: clear BH_Write_EIO when a write succeeds, not when one starts

2026-08-31T08:19:23+00:00

BH_Write_EIO is cleared in __bh_submit(), when a buffer that has been written before is submitted for write again. That is early: it says the error is gone at the moment we start trying to fix it, rather than when we have. It also loses errors. A task whose write fails sets the flag and then goes to look at it; if another task redirties the buffer and resubmits it in between, the submission clears the flag and the first task sees no error at all. Neither of them is doing anything wrong. Clear it on successful write completion instead, in the end io handlers - the same three the rest of this series has been converting, plus gfs2's, which already marked errors this way. Then the flag means what it says: the last write of this buffer that finished, failed. A resubmission no longer hides an error that has not been fixed yet, and one that has been fixed clears the flag when the data reaches the disk. __bh_submit() keeps setting BH_Req, which is what the rest of the tree reads it for. Suggested-by: Jan Kara Acked-by: Weidong Zhu Signed-off-by: Chao Shi Link: https://patch.msgid.link/1c976fd191aa6e99dbe65d6a1ec63f8706cc0dfa.1785951556.git.coshi036@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner (Amutable)

buffer: stop touching BH_Uptodate on write completion

2026-08-31T08:19:23+00:00

A buffer whose write failed still holds exactly the data the filesystem asked to be written. It is the disk that is out of date, not the buffer. Clearing BH_Uptodate says the opposite, and callers act on it: - mark_buffer_dirty() has a WARN_ON_ONCE(!buffer_uptodate(bh)). A filesystem that dirties the buffer again after a failed write - which is the normal way to retry - trips it. That is the warning this series started from. - a buffer that is not up to date gets re-read from disk, which replaces the data the filesystem was trying to write with the stale on-disk copy, silently. - the window between the write completing and the buffer being marked not up to date is visible to anyone holding the folio lock, so the state is not even self consistent while it lasts. BH_Write_EIO already records the failure, and by now every place in the tree that needs to know about it tests that flag instead: the two core helpers in this file, adfs, exfat, ext2, ext4, fat, gfs2, jbd2, ocfs2 and omfs, converted one filesystem at a time in the preceding patches. The private completion handler in jbd2 was converted along with its waiters, and ext4 fast commit needed only its waiter, because commit 7f0485dd3017 ("ext4: remove ext4_end_buffer_io_sync()") had already dropped its handler in favour of bh_end_write(). Nothing is left that reads BH_Uptodate to find out whether a write failed. Setting BH_Uptodate on success goes too. A buffer has to be up to date before it can be written - you cannot write out data you do not have - so the only thing that assignment could do is paper over a caller that got that wrong. Write completion now leaves BH_Uptodate alone in both directions. What this changes for readers. A buffer whose write failed stays up to date, so the read paths stop replacing it with the on-disk copy: __bread_gfp() no longer sends it to __bread_slow(), and bh_uptodate_or_lock() reports it as usable. That is the intent. ocfs2 changes the most, because ocfs2_read_blocks() decides whether to go to disk on its own cluster uptodate cache and only tests BH_Uptodate after the wait, so a block whose write failed makes that read return -EIO today and from here it succeeds and hands back the in-memory data. A caller that needs to know the write failed asks BH_Write_EIO. Found by FuzzNvme. Acked-by: Weidong Zhu Signed-off-by: Chao Shi Link: https://patch.msgid.link/61d7d5737f5773f53ee543f375fcde81aa8d28c2.1785951556.git.coshi036@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner (Amutable)

buffer: detect metadata write errors with buffer_write_io_error()

2026-08-31T08:19:22+00:00

Both places in this file that report a metadata write error to a caller do it by testing !buffer_uptodate() after waiting for the write. That works only because the write completion handlers clear BH_Uptodate when the write fails, which is what this series is removing: a buffer whose write failed still holds the correct data, and saying otherwise makes callers rewrite, re-read or WARN over a buffer that was never wrong. BH_Write_EIO is the flag that actually means "the last write of this buffer failed", and both handlers already set it via mark_buffer_write_io_error(). Test that instead. No behaviour change: today a failed write through bh_end_write() or bh_end_async_write() sets BH_Write_EIO and clears BH_Uptodate together, so the two tests agree. They stop agreeing at the end of the series, and this one stays right. Acked-by: Weidong Zhu Signed-off-by: Chao Shi Reviewed-by: Jan Kara Link: https://patch.msgid.link/2b309196b883cc8979800911a47668e225401b2c.1785951556.git.coshi036@gmail.com Signed-off-by: Christian Brauner (Amutable)

buffer: discard BH_Write_EIO along with the rest of the buffer state

2026-08-31T08:19:21+00:00

discard_buffer() strips the state that describes where a buffer lives and what has happened to it, because after an invalidate none of it applies any more. BH_Write_EIO belongs in that set for the same reason: it describes a write of the data that is being thrown away. Leaving it set means a buffer_head reused for a different block starts life carrying somebody else's write error. Like the bforget() change, this is mostly theoretical today and becomes load bearing once the rest of the series makes BH_Write_EIO the report of a failed metadata write. Suggested-by: Jan Kara Acked-by: Weidong Zhu Signed-off-by: Chao Shi Reviewed-by: Jan Kara Link: https://patch.msgid.link/c6e9db48d8d0feb83d4ca29306f4bc1e58f1ee0f.1785951556.git.coshi036@gmail.com Signed-off-by: Christian Brauner (Amutable)

buffer: clear BH_Write_EIO when a buffer is forgotten

2026-08-31T08:19:21+00:00

BH_Write_EIO records that the last write of this buffer failed. It is cleared when the buffer is written again, but a filesystem freeing a metadata block never writes it again. It calls bforget() and hands the block back to the allocator, so the flag outlives the block it refers to. That does not matter much today, because the write error is also recorded by clearing BH_Uptodate and the buffer is discarded soon after. It starts to matter in the rest of this series, which stops clearing BH_Uptodate on write error and makes BH_Write_EIO the way a failed metadata write is reported. bforget() is where a filesystem says it no longer cares about this buffer's contents, so clear the error there alongside the dirty flag. Suggested-by: Jan Kara Acked-by: Weidong Zhu Signed-off-by: Chao Shi Reviewed-by: Jan Kara Link: https://patch.msgid.link/ebe0b4f179ccdac7a9400fe2611623ce218c8d87.1785951556.git.coshi036@gmail.com Signed-off-by: Christian Brauner (Amutable)

buffer: read the folio's mapping directly in buffer_set_crypto_ctx()

2026-08-31T08:19:21+00:00

folio_mapping() was doing two jobs here. One was to turn a slab folio into NULL, which is what made this safe for jbd2's shadow buffers; the previous patch removed the need for that by giving those buffers no folio at all. The other is a hazard. folio_mapping() maps a folio in the swap cache to its swap_address_space, so if a buffer_head were ever attached to such a folio this would hand fscrypt a swap mapping and dereference ->host on it. There is no reason to want that here: this path wants the file's mapping or nothing. Read ->mapping directly. Buffers with no folio are already handled above. Suggested-by: Matthew Wilcox (Oracle) Acked-by: Weidong Zhu Signed-off-by: Chao Shi Link: https://patch.msgid.link/3fe72ec37bf8491a69031db5f3ba1319da935b97.1785951556.git.coshi036@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner (Amutable)

buffer: allow a buffer_head to point at memory outside the page cache

2026-08-31T08:19:21+00:00

jbd2 builds a temporary buffer_head to write out the frozen copy of a metadata block, and that copy lives in slab memory. Today jbd2 points the temporary buffer at the slab folio backing it. A slab folio's ->mapping is not an address_space, so anything that follows bh->b_folio->mapping there gets garbage rather than NULL; mark_buffer_write_io_error() does exactly that, and we are about to start calling it on this buffer. Rather than teach every such helper about slab folios, allow bh->b_folio to be NULL and let b_data point straight at the memory. Code that needs the folio has to check. There are two places in this file: - __bh_submit() adds the data by virtual address using bio_add_virt_nofail(), and skips the cgroup accounting: a buffer that is not in the page cache has no owning folio to attribute writeback to. - buffer_set_crypto_ctx() returns early. fscrypt has no interest in a buffer that is not part of a file mapping, which is why it already returns when the folio has no mapping. Nothing sets b_folio to NULL yet, so this patch is a no-op on its own. A buffer_head without a folio is a narrow thing, not a new general capability. Most of the buffer_head API assumes a folio and will fault or corrupt state without one - touch_buffer(), bh_offset(), the async read completion path, and plenty more - so it is up to whoever builds such a buffer to keep it away from all of that. What NULL buys us is that getting it wrong fails loudly instead of quietly following a slab folio's overloaded ->mapping. It is also only valid over memory that is always mapped: buffers over highmem have no permanent kernel virtual address, which is why folio_set_bh() records a folio and an offset instead. Suggested-by: Matthew Wilcox (Oracle) Acked-by: Weidong Zhu Signed-off-by: Chao Shi Reviewed-by: Jan Kara Link: https://patch.msgid.link/bb6fab2111a48d7ba61887fc1372362576fce6e6.1785951556.git.coshi036@gmail.com Signed-off-by: Christian Brauner (Amutable)

headers: Remove swap.h from suspend.h

2026-08-25T19:12:26+00:00

Nothing in suspend.h needs swap.h. However, many files indirectly depend on some of swap.h's dependencies, so this is a large cross-subsystem patch. Stats: 42 are missing includes of interrupt.h (the question of why swap.h brings in interrupt.h remains unanswered). 10 missing includes of seq_file.h 5 missing includes of swap.h (obviously all files could have just added swap.h, but I preferred to bring in a more minimal inclusion set) 3 missing includes of highmem.h 2 missing includes of device.h 2 missing includes of string_choices.h 1 missing include of cacheflush.h 1 missing include of dma-direction.h 1 missing include of kthread.h 1 missing include of pagemap.h 1 missing include of string_helpers.h 1 missing include of writeback.h I tried to follow whatever conventions appeared to be in use for the various subsystems I touched; for example I added string_choices.h to drm_print.h instead of individually to each driver which used the functions declared there. Signed-off-by: Matthew Wilcox (Oracle)

Merge tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

2026-08-20T20:55:16+00:00

Pull block updates from Jens Axboe: - NVMe updates via Keith: - Enable Clang context analysis for the nvme host driver, adding context annotations across core, fabrics, rdma, tcp and pci - nvmet reservation state exposed through a new namespace-level debugfs directory, plus ABI documentation for the host sysfs and target configfs interfaces - nvme-tcp host memory disclosure fixes on the read path: reject a read that transferred too few bytes, don't accept C2HData based on blk_rq_payload_bytes() alone, and fix the R2T case for a read command - Parallelize nvme-rdma I/O queue allocation and startup (Surabhi) - Apple nvme fixes and quirks: page aligned admin queue buffers, destroy the admin queue on removal, and various DMA/NVMMU correctness fixes - A large pile of nvmet and host fixes for out-of-bounds reads, refcount/resource leaks, and NULL derefs across auth, zns, passthru, pci-epf, rdma and configfs - Various other fixes and cleanups - MD updates via Yu Kuai: - llbitmap reshape support, the large series wiring exact bitmap mapping and reshape lifecycle through raid5 and raid10, growing the page cache in place, and remapping checkpointed bits as reshape progresses - raid5 fixes for lockless max_nr_stripes and recovery_offset accesses, a reshape deadlock with more failed devices than max degraded, and bitmap batch counter consistency - Atomic write handling for raid1/raid10, and removal of the REQ_NOWAIT support from raid1/10/456 - raid5-ppl use-after-free fix in ppl_do_flush() - A batch of smaller fixes across md core and the bitmap code - s390/dasd ESE full-track write support and the surrounding infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block - RWF_DONTCACHE support for block devices, built on new task-context bio completion infrastructure, and wiring it up for the iomap and buffer dropbehind writeback paths - Async io_uring zone reset all, plus zone management command cleanups allowing REQ_NOWAIT and tightening conventional zone rejection - Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared header, handle nogenerate/noverify properly in fs-integrity, and drop the blk-integrity.h include from bdev.c - Split out a new blk_plug.h header - ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS, and a series of hardening fixes around map/unmap and auto buf reg - null_blk cleanups and configfs serialization fixes - nbd queue freeze removal on the setup paths, and a new pre_defined_connections module parameter for pre-created devices - blk-cgroup fixes for the race between policy activation and blkg destruction, and accounting per-cpu stats over possible CPUs across blk-stat, iolatency, iocost and kyber - Various dio fixes: leak on metadata mapping error, validate user space vectors during extraction, and set dma_alignment from the backing file for loop and zloop direct I/O - bio cleanups - Various other fixes and cleanups all over * tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits) nbd: add pre_defined_connections module parameter for pre-created devices nbd: remove queue freeze for newly created nbd from netlink path nbd: factor out a nbd_genl_foreach_sock nbd: skip queue freeze when setting size at device startup nbd: remove queue freeze in nbd_add_socket nbd: clear queue limits on disconnect nbd: disallow NBD_SET_SOCK on an active device nbd: simplify find_fallback() by removing redundant logic blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set() block: mtip32xx: synchronize ioctls with device removal ublk: avoid teardown retry loop on xarray allocation failure null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows block: don't include blk-integrity.h in bdev.c xfs: avoid double deferrals for RWF_DONTCACHE writes loop: Fix recently introduced lock inversion block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead() swim3: Add missing MODULE_DESCRIPTION selftests: ublk: add SET_PARAMS validation test selftests: ublk: add helper for SET_PARAMS ublk: reject non-power-of-2 zone sizes in SET_PARAMS ...