linux.git/include/linux/nfs_fs.h, branch v7.3-rc2 Linux kernel source tree Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2026-08-27T16:17:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2026-08-27T16:17:06+00:00 18fbf5151d2c0bfe433c7428eef03cabf5fdb2fa Pull more MM updates from Andrew Morton: - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff" (Lorenzo Stoakes) Index MAP_PRIVATE file-backed folios by their anonymous page offset to resolve confusion around reverse mapping for zeroed and CoW'd file-backed memory. Use this new VMA anonymous page offset tracking to eliminate index conflicts and lay the foundation for scalable CoW performance improvements. - "promote mapped executable folios after first usage for MGLRU" (Baolin Wang) Make MGLRU's protection of mapped executable file folios more reliable. Follow the classical LRU's logic, promoting mapped executable file folios after their first usage to give executable code a better chance to stay in memory and improve workload performance. - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen) Fix per-node proactive reclaim interface's ignoring the swappiness parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness() into a single function that checks proactive_swappiness regardless of kernel configuration. - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost" (Usama Arif) Reduce lru_lock contention in the reclaim path by deriving scan-balance costs from vmstat counters rather than lock-acquired producer updates. Read and decay these cost signals on the reclaim side under a dedicated per-lruvec lock, reducing total LRU lock wait time by over 60% without impacting scan throughput. - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky) Fix two low-risk zram bugs which Sashiko spotted in drive-by review. - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's memcg" (Zi Yan) Fix xas_split_alloc() by enabling target folio memcg charging during splits and adding the missing __GFP_ACCOUNT flag for proper XArray node memory accounting. - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick) Replace hardcoded binary names in selftests/mm/.gitignore with a generic pattern-matching rule to automatically ignore generated test files and avoid manual updates when adding new tests. - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon) Make the incompatibility between FLATMEM and NUMA explicit in mm/Kconfig and remove the unused pgdat_page_ext_init() function. - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang) Clean up zram compression backends by removing redundant error cleanup, adding parameter and dictionary validation, auto-prefixing algorithm error logs, and resetting parameters prior to reinitialization. - "zram: fix stale scan bounds after reinitialization" (Longlong Xia) Prevent out-of-bounds slot accesses during concurrent zram resets by moving table scan bound calculations under dev_lock in writeback_store() and read_block_state(). - "add anon mTHP collapse test cases" (Baolin Wang) Extend selftests helper functions to support arbitrary page orders and add new test cases and options for mTHP collapse in khugepaged. - "selftests/mm: Handle unsupported and transient test conditions" (Muhammad Usama Anjum) Update MM selftests to report a SKIP status instead of a failure when required kernel or filesystem features are unsupported, while adding retry logic for transient page migration errors. - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia) Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled and extend shrink_memcg() to support batch writeback for improved writeback efficiency. - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan) Introduce an IOCTL-based binary interface for memory allocation profiling that enables kernel-side filtering before per-CPU counter aggregation. This eliminates the text-parsing overhead of /proc/allocinfo and provides up to a 20x speedup by transferring only filtered allocation data to userspace. - "better block swap batching and a different take on swap_ops v5" (Christoph Hellwig) Refactor block swap I/O to use swap_iocb for batching instead of single-bio requests and rebase the swap_ops interface, achieving faster swap throughput during kernel builds. - "mm: kmemleak: reduce transient false positives by confirming leaks" (Catalin Marinas) Reduce false-positive kmemleak reports by combining two kmemleak enhancements that add a second confirmation scan and a configurable minimum unreferenced scan count module parameter. - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels" (Breno Leitao) Auto-scanning kernels can generate false-positive memory leak reports on single scans, so this patch defaults min_unref_scans to 2 when CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming scan. - "swap_ops updates" (Christoph Hellwig) Batching I/O for synchronous swap devices causes performance regressions and filesystem-based swap suffers from double-indirection overhead. This series resolves both issues by reintroducing per-folio writes for synchronous swap and allowing filesystems to directly export their own swap_ops. - "mm/khugepaged: several cleanups" (Nico Pache) khugepaged accumulated redundant state-checking patterns and outdated comments following mTHP integration. Introduce dedicated helpers for PTE validation and event counting while refreshing the internal documentation. - "maple_tree: lock checking and clean ups" (Liam Howlett) Syzbot reports incorrectly blame memory management exit paths for locking bugs, maple tree erase operations risk allocation failures without gfp flags and internal documentation lacks clarity. Improve lock error detection, update docs, fix race and allocation edge cases and optimize erase allocations using a fallback to GFP_KERNEL | GFP_NOFAIL. * tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits) selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC memcg: move LRU size accounting on reparenting instead of copying it mm/vmscan: fix comment logic in balance_pgdat maple_tree: add helper mas_make_walkable() maple_tree: avoid extra gap calculation maple_tree: fix argument name in header maple_tree: change two GFP flags in tests maple_tree: document erase and allocations better maple_tree: avoid mas_erase() and mtree_erase() failures maple_tree: document that erase may use GFP_KERNEL for allocations maple_tree: catch race in mas_alloc_cyclic() maple_tree: add bulk parent set helper maple_tree: micro optimisation of mas_wr_store_type() maple_tree: optimise mas_wr_node_store() when not in rcu mode maple_tree: use prefetched value in mas_wr_store_type() maple_tree: clarify comments on mas_nomem() maple_tree: drop MAPLE_ALLOC_SLOTS maple_tree: drop dead code from mas_extend_spanning_null() maple_tree: documentation fix maple_tree: add write lock checking with lockdep sequence numbers ... 
Pull more MM updates from Andrew Morton:

 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes)

   Index MAP_PRIVATE file-backed folios by their anonymous page offset
   to resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.

   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.

 - "promote mapped executable folios after first usage for MGLRU"
   (Baolin Wang)

   Make MGLRU's protection of mapped executable file folios more
   reliable. Follow the classical LRU's logic, promoting mapped
   executable file folios after their first usage to give executable
   code a better chance to stay in memory and improve workload
   performance.

 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
   Chen)

   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating
   sc_swappiness() into a single function that checks
   proactive_swappiness regardless of kernel configuration.

 - "mm/vmscan: reduce lru_lock contention via vmstat-derived
   scan-balance cost" (Usama Arif)

   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.

   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over
   60% without impacting scan throughput.

 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)

   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.

 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan)

   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray
   node memory accounting.

 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)

   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.

 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)

   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.

 - "zram: fix zstd error paths and add parameter validation" (Haoqin
   Huang)

   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.

 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia)

   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in
   writeback_store() and read_block_state().

 - "add anon mTHP collapse test cases" (Baolin Wang)

   Extend selftests helper functions to support arbitrary page orders
   and add new test cases and options for mTHP collapse in khugepaged.

 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum)

   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.

 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)

   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.

 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
   Baghdasaryan)

   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.

   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.

 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig)

   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving
   faster swap throughput during kernel builds.

 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas)

   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.

 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao)

   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
   confirming scan.

 - "swap_ops updates" (Christoph Hellwig)

   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead. This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly
   export their own swap_ops.

 - "mm/khugepaged: several cleanups" (Nico Pache)

   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration. Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.

 - "maple_tree: lock checking and clean ups" (Liam Howlett)

   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.

   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to
   GFP_KERNEL | GFP_NOFAIL.

* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
  selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
  memcg: move LRU size accounting on reparenting instead of copying it
  mm/vmscan: fix comment logic in balance_pgdat
  maple_tree: add helper mas_make_walkable()
  maple_tree: avoid extra gap calculation
  maple_tree: fix argument name in header
  maple_tree: change two GFP flags in tests
  maple_tree: document erase and allocations better
  maple_tree: avoid mas_erase() and mtree_erase() failures
  maple_tree: document that erase may use GFP_KERNEL for allocations
  maple_tree: catch race in mas_alloc_cyclic()
  maple_tree: add bulk parent set helper
  maple_tree: micro optimisation of mas_wr_store_type()
  maple_tree: optimise mas_wr_node_store() when not in rcu mode
  maple_tree: use prefetched value in mas_wr_store_type()
  maple_tree: clarify comments on mas_nomem()
  maple_tree: drop MAPLE_ALLOC_SLOTS
  maple_tree: drop dead code from mas_extend_spanning_null()
  maple_tree: documentation fix
  maple_tree: add write lock checking with lockdep sequence numbers
  ...
mm/swap: move swap_ops into file systems for file system-based swap 2026-08-25T01:43:20+00:00 Christoph Hellwig hch@lst.de 2026-07-23T05:46:06+00:00 22779ae8175aad7c04827db44e934e53bf2bd2d4 Currently swap to and from file systems goes through two indirect calls between the swap ops and the swap_rw method. Reduce this by directly providing the swap_ops from the file system. For this refactor swap_fs_submit into a swap_fs_prepare_rw helper that initializes the iov_iter on the callers stack so that file systems can call it directly, and use that to initialize file system specific ops in the NFS and SMB clients, which then get passed to swap_fs_activate. Link: https://lore.kernel.org/20260723054622.3460249-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Kairui Song <kasong@tencent.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Steve French <sfrench@samba.org> Cc: Usama Arif <usama.arif@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Currently swap to and from file systems goes through two indirect calls
between the swap ops and the swap_rw method.  Reduce this by directly
providing the swap_ops from the file system.

For this refactor swap_fs_submit into a swap_fs_prepare_rw helper that
initializes the iov_iter on the callers stack so that file systems can
call it directly, and use that to initialize file system specific ops in
the NFS and SMB clients, which then get passed to swap_fs_activate.

Link: https://lore.kernel.org/20260723054622.3460249-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Steve French <sfrench@samba.org>
Cc: Usama Arif <usama.arif@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
nfs4.2: open UNCACHEABLE_FILE_DATA files with O_DIRECT 2026-08-17T16:02:07+00:00 Mike Snitzer snitzer@kernel.org 2026-07-27T21:09:40+00:00 b4dd7f81592287c9b4070e6669732d8770269303 Honor the per-file UNCACHEABLE_FILE_DATA attribute by transparently opening such regular files with O_DIRECT, so reads and writes bypass the page cache as the attribute requires, without the application having to request O_DIRECT itself. This follows the model the specification describes: the attribute is "similar in intent to O_DIRECT" and clients "retain flexibility in how they satisfy the requirements" (draft-ietf-nfsv4-uncacheable-files Section 4.4, "Relationship to Direct I/O"), and its Implementation Status (Section 6) describes a prototype Linux client that "treats the attribute as an indication to use O_DIRECT-like behavior for file access". Introduce an NFS_CONTEXT_O_DIRECT open-context flag: nfs4_atomic_open() sets it when the resolved inode has uncacheable_file_data set (and the open is not O_APPEND), and the open paths nfs_atomic_open() and nfs4_file_open() apply O_DIRECT to the file when the flag is set. The I/O mode is thus selected at open time and is not changed for an already-open file: a later change to the attribute takes effect on the next open. The specification permits this -- a client that has already opened a file MAY continue with its existing caching behavior and apply the updated attribute to subsequent operations (Section 5). The delegation interaction in Section 4.3 was considered: it permits read caching to remain when another NFSv4.2 mechanism, such as a delegation, already ensures a consistent view of the file. That relaxation is optional ("may remain appropriate") and read-only -- it does not relax write-behind suppression (Section 4.1) or the WRITE durability invariant (Section 4.2). This implementation deliberately does not take it: an uncacheable file is opened O_DIRECT regardless of any delegation held, which is compliant (read caching is simply suppressed more aggressively than the Section 4.3 minimum) and avoids decoupling read vs write caching behind a single open flag. Relaxing reads under a delegation is left as a possible future optimization. Section 6 observes the benefit holds "for applications that issue well-formed I/O requests". That alignment caveat does not constrain the Linux NFS client's over-the-wire path: the client readily issues misaligned I/O using O_DIRECT over SunRPC to the remote NFS server. The only place a fallback from O_DIRECT to buffered I/O for misaligned I/O applies is NFS LOCALIO (fs/nfs/localio.c), which detects non-DIO-aligned I/O and falls back internally; that path is unaffected by this change. Link: https://datatracker.ietf.org/doc/draft-ietf-nfsv4-uncacheable-files/ Signed-off-by: Mike Snitzer <snitzer@kernel.org> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> 
Honor the per-file UNCACHEABLE_FILE_DATA attribute by transparently
opening such regular files with O_DIRECT, so reads and writes bypass the
page cache as the attribute requires, without the application having to
request O_DIRECT itself.

This follows the model the specification describes: the attribute is
"similar in intent to O_DIRECT" and clients "retain flexibility in how
they satisfy the requirements" (draft-ietf-nfsv4-uncacheable-files
Section 4.4, "Relationship to Direct I/O"), and its Implementation
Status (Section 6) describes a prototype Linux client that "treats the
attribute as an indication to use O_DIRECT-like behavior for file
access".

Introduce an NFS_CONTEXT_O_DIRECT open-context flag: nfs4_atomic_open()
sets it when the resolved inode has uncacheable_file_data set (and the
open is not O_APPEND), and the open paths nfs_atomic_open() and
nfs4_file_open() apply O_DIRECT to the file when the flag is set.

The I/O mode is thus selected at open time and is not changed for an
already-open file: a later change to the attribute takes effect on the
next open.  The specification permits this -- a client that has already
opened a file MAY continue with its existing caching behavior and apply
the updated attribute to subsequent operations (Section 5).

The delegation interaction in Section 4.3 was considered: it permits read
caching to remain when another NFSv4.2 mechanism, such as a delegation,
already ensures a consistent view of the file.  That relaxation is
optional ("may remain appropriate") and read-only -- it does not relax
write-behind suppression (Section 4.1) or the WRITE durability invariant
(Section 4.2).  This implementation deliberately does not take it: an
uncacheable file is opened O_DIRECT regardless of any delegation held,
which is compliant (read caching is simply suppressed more aggressively
than the Section 4.3 minimum) and avoids decoupling read vs write caching
behind a single open flag.  Relaxing reads under a delegation is left as
a possible future optimization.

Section 6 observes the benefit holds "for applications that issue
well-formed I/O requests".  That alignment caveat does not constrain the
Linux NFS client's over-the-wire path: the client readily issues
misaligned I/O using O_DIRECT over SunRPC to the remote NFS server.  The
only place a fallback from O_DIRECT to buffered I/O for misaligned I/O
applies is NFS LOCALIO (fs/nfs/localio.c), which detects non-DIO-aligned
I/O and falls back internally; that path is unaffected by this change.

Link: https://datatracker.ietf.org/doc/draft-ietf-nfsv4-uncacheable-files/

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
nfs4.2: add UNCACHEABLE_FILE_DATA attribute support 2026-08-17T16:02:07+00:00 Tom Haynes loghyr@hammerspace.com 2026-07-27T21:09:38+00:00 86ff1842795b3e51f526460b1d701d48fdee49b8 Recognize the NFSv4.2 per-file UNCACHEABLE_FILE_DATA attribute (attr 87, draft-ietf-nfsv4-uncacheable-files): decode it via GETATTR, track per- exported-filesystem support, and record on the inode whether a regular file's data must not be cached. Acting on the attribute (opening such files O_DIRECT) is done by a subsequent change. If the NFSv4 server reports a regular file's UNCACHEABLE_FILE_DATA as true, it indicates the file's data must not be cached; the client records this in NFS_I(inode)->uncacheable_file_data for use by the I/O paths. The UNCACHEABLE_FILE_DATA attribute applies only to regular files (NF4REG); per the draft a server MUST reject a query of it on any other object type with NFS4ERR_INVAL. A subsequent commit gates the client accordingly. Link: https://datatracker.ietf.org/doc/draft-ietf-nfsv4-uncacheable-files/ Signed-off-by: Tom Haynes <loghyr@hammerspace.com> [snitzer: adapt Tom's original code focused on metadata for ABE] Co-developed-by: Mike Snitzer <snitzer@hammerspace.com> Signed-off-by: Mike Snitzer <snitzer@hammerspace.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> 
Recognize the NFSv4.2 per-file UNCACHEABLE_FILE_DATA attribute (attr 87,
draft-ietf-nfsv4-uncacheable-files): decode it via GETATTR, track per-
exported-filesystem support, and record on the inode whether a regular
file's data must not be cached.  Acting on the attribute (opening such
files O_DIRECT) is done by a subsequent change.

If the NFSv4 server reports a regular file's UNCACHEABLE_FILE_DATA as
true, it indicates the file's data must not be cached; the client records
this in NFS_I(inode)->uncacheable_file_data for use by the I/O paths.

The UNCACHEABLE_FILE_DATA attribute applies only to regular files
(NF4REG); per the draft a server MUST reject a query of it on any other
object type with NFS4ERR_INVAL.  A subsequent commit gates the client
accordingly.

Link: https://datatracker.ietf.org/doc/draft-ietf-nfsv4-uncacheable-files/

Signed-off-by: Tom Haynes <loghyr@hammerspace.com>
[snitzer: adapt Tom's original code focused on metadata for ABE]
Co-developed-by: Mike Snitzer <snitzer@hammerspace.com>
Signed-off-by: Mike Snitzer <snitzer@hammerspace.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
nfs: remove fileid field from struct nfs_inode 2026-06-08T14:21:54+00:00 Jeff Layton jlayton@kernel.org 2026-05-12T16:12:45+00:00 bd5e6b056bd0900d8efde90da7a5877dc50842c7 Now that all NFS client code uses inode->i_ino directly to store and access the 64-bit NFS fileid, the separate fileid field in struct nfs_inode is unused. Remove it to save 8 bytes per NFS inode. Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> 
Now that all NFS client code uses inode->i_ino directly to store and
access the 64-bit NFS fileid, the separate fileid field in struct
nfs_inode is unused. Remove it to save 8 bytes per NFS inode.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
nfs: replace NFS_FILEID() and nfsi->fileid with inode->i_ino 2026-06-08T14:21:54+00:00 Jeff Layton jlayton@kernel.org 2026-05-12T16:12:44+00:00 2026c8a96afe6e5783497860c4af0a0e1a53991b Now that inode->i_ino stores the full 64-bit NFS fileid, replace all uses of NFS_FILEID(), set_nfs_fileid(), and direct nfsi->fileid accesses with inode->i_ino throughout the NFS client. Remove the NFS_FILEID() and set_nfs_fileid() helper functions from include/linux/nfs_fs.h since they are no longer needed. Also fix two pre-existing truncation bugs in nfs4trace.h where fileid trace fields were declared as u32 instead of u64. Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> 
Now that inode->i_ino stores the full 64-bit NFS fileid, replace all
uses of NFS_FILEID(), set_nfs_fileid(), and direct nfsi->fileid
accesses with inode->i_ino throughout the NFS client.

Remove the NFS_FILEID() and set_nfs_fileid() helper functions from
include/linux/nfs_fs.h since they are no longer needed.

Also fix two pre-existing truncation bugs in nfs4trace.h where fileid
trace fields were declared as u32 instead of u64.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
nfs: remove nfs_compat_user_ino64() and deprecate enable_ino64 2026-06-08T14:21:54+00:00 Jeff Layton jlayton@kernel.org 2026-05-12T16:12:43+00:00 0e06a884f5ba6226829441bfc656ff9f5e9e90ac Now that inode->i_ino stores the full 64-bit NFS fileid, the nfs_compat_user_ino64() function is no longer needed. generic_fillattr() already copies inode->i_ino into stat->ino, so the explicit override in nfs_getattr() is also redundant. Also remove the now-unused nfs_fileid_to_ino_t() and nfs_fattr_to_ino_t() helper functions that were used to XOR-fold 64-bit fileids into the old unsigned long i_ino. Keep the enable_ino64 module parameter as a deprecated stub that accepts but ignores the value, logging a notice when set. This avoids breaking existing configurations that pass nfs.enable_ino64 on the kernel command line or in modprobe.d. Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> 
Now that inode->i_ino stores the full 64-bit NFS fileid, the
nfs_compat_user_ino64() function is no longer needed.
generic_fillattr() already copies inode->i_ino into stat->ino, so the
explicit override in nfs_getattr() is also redundant.

Also remove the now-unused nfs_fileid_to_ino_t() and
nfs_fattr_to_ino_t() helper functions that were used to XOR-fold
64-bit fileids into the old unsigned long i_ino.

Keep the enable_ino64 module parameter as a deprecated stub that
accepts but ignores the value, logging a notice when set. This avoids
breaking existing configurations that pass nfs.enable_ino64 on the
kernel command line or in modprobe.d.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
nfs: store the full NFS fileid in inode->i_ino 2026-06-08T14:21:54+00:00 Jeff Layton jlayton@kernel.org 2026-05-12T16:12:42+00:00 0cad7630425f4c9ee0dfa376ff8bf60c88ff2566 Now that inode->i_ino is a 64-bit value, store the full NFS fileid in it directly instead of an XOR-folded hash. This makes NFS_FILEID() and set_nfs_fileid() operate on inode->i_ino rather than the separate nfsi->fileid field. Since iget5_locked() and ilookup5() now accept a u64 hashval, pass the full fileid as the hash parameter directly. Convert direct nfsi->fileid accesses in nfs_check_inode_attributes(), nfs_update_inode(), and nfs_same_file() to use inode->i_ino. Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> 
Now that inode->i_ino is a 64-bit value, store the full NFS fileid in
it directly instead of an XOR-folded hash. This makes NFS_FILEID() and
set_nfs_fileid() operate on inode->i_ino rather than the separate
nfsi->fileid field.

Since iget5_locked() and ilookup5() now accept a u64 hashval, pass the
full fileid as the hash parameter directly.

Convert direct nfsi->fileid accesses in nfs_check_inode_attributes(),
nfs_update_inode(), and nfs_same_file() to use inode->i_ino.

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
NFS: fix writeback in presence of errors 2026-04-22T12:53:23+00:00 Olga Kornievskaia okorniev@redhat.com 2026-04-13T22:24:23+00:00 5d3869a41f3608101c00ff9c9c7c2364c555fa65 After running xfstest generic/751, in certain conditions, can have a writeback IO stuck while experiencing one of the two patterns. Pattern#1: writeback IO experiences ENOSPC on an offset smaller than the filesize. Example, write offset=0 len=4096 how=unstable OK write offset=8192 len=4096 how=unstable OK write offset=12288 len=4096 how=unstable ENOSPC write offset=4096 len=4096 how=unstable ENOSPC client sends a commit and receives a verifier which is different from the last successful write. It marks pages dirty and writeback retries. But it again send writes unstable and gets into the same pattern, running into the ENOSPC error and sending a commit because writes were sent at unstable. Pattern#2: an unstable write followed by a short write and ENOSPC. write offset=0 len=4096 how=unstable OK write offset=4096 len=4096 how=unstable returns OK but count=100 write offset=4197 len=3996 how=stable returns ENOSPC client send a commit and receives a verifier different from the last unstable write. The same behaviour is retried in a loop. Instead, this patch proposes to identify those conditions and mark requests to be done synchronously instead. Previous solution tried to mark it in the nfs_page, however that's not persistent thus instead mark it in the nfs_open_context. Furthermore, the same problem occurs during localio code path so recognize that IO needs to be done sync in that case as well. Signed-off-by: Olga Kornievskaia <okorniev@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> 
After running xfstest generic/751, in certain conditions, can have
a writeback IO stuck while experiencing one of the two patterns.

Pattern#1: writeback IO experiences ENOSPC on an offset smaller
than the filesize. Example,
write offset=0 len=4096 how=unstable OK
write offset=8192 len=4096 how=unstable OK
write offset=12288 len=4096 how=unstable ENOSPC
write offset=4096 len=4096 how=unstable ENOSPC
client sends a commit and receives a verifier which is different
from the last successful write. It marks pages dirty and writeback
retries. But it again send writes unstable and gets into the same
pattern, running into the ENOSPC error and sending a commit because
writes were sent at unstable.

Pattern#2: an unstable write followed by a short write and ENOSPC.
write offset=0 len=4096 how=unstable OK
write offset=4096 len=4096 how=unstable returns OK but count=100
write offset=4197 len=3996 how=stable returns ENOSPC
client send a commit and receives a verifier different from
the last unstable write. The same behaviour is retried in a loop.

Instead, this patch proposes to identify those conditions and mark
requests to be done synchronously instead. Previous solution tried
to mark it in the nfs_page, however that's not persistent thus
instead mark it in the nfs_open_context.

Furthermore, the same problem occurs during localio code path so
recognize that IO needs to be done sync in that case as well.

Signed-off-by: Olga Kornievskaia <okorniev@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
NFS: Fix a deadlock involving nfs_release_folio() 2026-01-05T04:03:24+00:00 Trond Myklebust trond.myklebust@hammerspace.com 2025-12-31T16:42:31+00:00 cce0be6eb4971456b703aaeafd571650d314bcca Wang Zhaolong reports a deadlock involving NFSv4.1 state recovery waiting on kthreadd, which is attempting to reclaim memory by calling nfs_release_folio(). The latter cannot make progress due to state recovery being needed. It seems that the only safe thing to do here is to kick off a writeback of the folio, without waiting for completion, or else kicking off an asynchronous commit. Reported-by: Wang Zhaolong <wangzhaolong@huaweicloud.com> Fixes: 96780ca55e3c ("NFS: fix up nfs_release_folio() to try to release the page") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> 
Wang Zhaolong reports a deadlock involving NFSv4.1 state recovery
waiting on kthreadd, which is attempting to reclaim memory by calling
nfs_release_folio(). The latter cannot make progress due to state
recovery being needed.

It seems that the only safe thing to do here is to kick off a writeback
of the folio, without waiting for completion, or else kicking off an
asynchronous commit.

Reported-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Fixes: 96780ca55e3c ("NFS: fix up nfs_release_folio() to try to release the page")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>