kernel/linux.git/fs/nfs/write.c, branch v6.12.80

NFS: Fix a deadlock involving nfs_release_folio()

2026-01-23T10:18:36+00:00

[ Upstream commit 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 Fixes: 96780ca55e3c ("NFS: fix up nfs_release_folio() to try to release the page") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFS: check if suid/sgid was cleared after a write as needed

2025-11-24T09:35:48+00:00

[ Upstream commit 9ff022f3820a31507cb93be6661bf5f3ca0609a4 ] I noticed xfstests generic/193 and generic/355 started failing against knfsd after commit e7a8ebc305f2 ("NFSD: Offer write delegation for OPEN with OPEN4_SHARE_ACCESS_WRITE"). I ran those same tests against ONTAP (which has had write delegation support for a lot longer than knfsd) and they fail there too... so while it's a new failure against knfsd, it isn't an entirely new failure. Add the NFS_INO_REVAL_FORCED flag so that the presence of a delegation doesn't keep the inode from being revalidated to fetch the updated mode. Signed-off-by: Scott Mayhew Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin

NFS: nfs_invalidate_folio() must observe the offset and size arguments

2025-09-19T14:35:44+00:00

[ Upstream commit b7b8574225e9d2b5f1fb5483886ab797892f43b5 ] If we're truncating part of the folio, then we need to write out the data on the part that is not covered by the cancellation. Fixes: d47992f86b30 ("mm: change invalidatepage prototype to accept length") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

NFS: Fix a race when updating an existing write

2025-08-28T14:31:05+00:00

commit 76d2e3890fb169168c73f2e4f8375c7cc24a765e upstream. After nfs_lock_and_join_requests() tests for whether the request is still attached to the mapping, nothing prevents a call to nfs_inode_remove_request() from succeeding until we actually lock the page group. The reason is that whoever called nfs_inode_remove_request() doesn't necessarily have a lock on the page group head. So in order to avoid races, let's take the page group lock earlier in nfs_lock_and_join_requests(), and hold it across the removal of the request in nfs_inode_remove_request(). Reported-by: Jeff Layton Tested-by: Joe Quanaim Tested-by: Andrew Steffen Reviewed-by: Jeff Layton Fixes: bd37d6fce184 ("NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

nfs: Add missing release on error in nfs_lock_and_join_requests()

2025-04-10T12:39:28+00:00

[ Upstream commit 8e5419d6542fdf2dca9a0acdef2b8255f0e4ba69 ] Call nfs_release_request() on this error path before returning. Fixes: c3f2235782c3 ("nfs: fold nfs_folio_find_and_lock_request into nfs_lock_and_join_requests") Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/3aaaa3d5-1c8a-41e4-98c7-717801ddd171@stanley.mountain Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

Revert "nfs: don't reuse partially completed requests in nfs_lock_and_join_requests"

2024-12-05T13:03:05+00:00

[ Upstream commit 66f9dac9077c9c063552e465212abeb8f97d28a7 ] This reverts commit b571cfcb9dcac187c6d967987792d37cb0688610. This patch appears to assume that if one request is complete, then the others will complete too before unlocking. That is not a valid assumption, since other requests could hit a non-fatal error or a short write that would cause them not to complete. Reported-by: Igor Raits Link: https://bugzilla.kernel.org/show_bug.cgi?id=219508 Fixes: b571cfcb9dca ("nfs: don't reuse partially completed requests in nfs_lock_and_join_requests") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin

nfs: enable localio for non-pNFS IO

2024-09-23T19:03:30+00:00

Try a local open of the file being written to, and if it succeeds, then use localio to issue IO. Signed-off-by: Trond Myklebust Signed-off-by: Mike Snitzer Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs: add LOCALIO support

2024-09-23T19:03:30+00:00

Add client support for bypassing NFS for localhost reads, writes, and commits. This is only useful when the client and the server are running on the same host. nfs_local_probe() is stubbed out, later commits will enable client and server handshake via a Linux-only LOCALIO auxiliary RPC protocol. This has dynamic binding with the nfsd module (via nfs_localio module which is part of nfs_common). LOCALIO will only work if nfsd is already loaded. The "localio_enabled" nfs kernel module parameter can be used to disable and enable the ability to use LOCALIO support. CONFIG_NFS_LOCALIO enables NFS client support for LOCALIO. Lastly, LOCALIO uses an nfsd_file to initiate all IO. To make proper use of nfsd_file (and nfsd's filecache) its lifetime (duration before nfsd_file_put is called) must extend until after commit, read and write operations. So rather than immediately drop the nfsd_file reference in nfs_local_open_fh(), that doesn't happen until nfs_local_pgio_release() for read/write and not until nfs_local_release_commit_data() for commit. The same applies to the reference held on nfsd's nn->nfsd_serv. Both objects' lifetimes and associated references are managed through calls to nfs_to->nfsd_file_put_local(). Signed-off-by: Weston Andros Adamson Signed-off-by: Trond Myklebust Co-developed-by: Mike Snitzer Signed-off-by: Mike Snitzer Signed-off-by: NeilBrown # nfs_open_local_fh Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs: pass struct nfsd_file to nfs_init_pgio and nfs_init_commit

2024-09-23T19:03:30+00:00

The nfsd_file will be passed, in future commits, by callers that enable LOCALIO support (for both regular NFS and pNFS IO). [Derived from patch authored by Weston Andros Adamson, but switched from passing struct file to struct nfsd_file] Signed-off-by: Mike Snitzer Reviewed-by: NeilBrown Reviewed-by: Jeff Layton Signed-off-by: Anna Schumaker

nfs: add 'noalignwrite' option for lock-less 'lost writes' prevention

2024-09-23T19:03:13+00:00

There are some applications that write to predefined non-overlapping file offsets from multiple clients and therefore don't need to rely on file locking. However, if these applications want non-aligned offsets and sizes they need to either use locks or risk data corruption, as the NFS client defaults to extending writes to whole pages. This commit adds a new mount option `noalignwrite`, which allows to turn that off and avoid the need of locking, as long as these applications don't overlap on offsets. Signed-off-by: Dan Aloni Reviewed-by: Jeff Layton Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Signed-off-by: Anna Schumaker