kernel/linux.git/fs/nfs/write.c, branch v6.18.21

NFS: Fix a deadlock involving nfs_release_folio()

2026-01-23T10:21:13+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

2025-10-13T18:33:00+00:00

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

NFSv4/flexfiles: Use ds_commit_idx when marking a write commit

2025-09-26T19:30:20+00:00

Correct this path to use ds_commit_idx. Another noop preparation change. In current code commit_idx == mirror_idx but when striping is enabled that will not be true. Signed-off-by: Jonathan Curley Signed-off-by: Anna Schumaker

NFS: Enable use of the RWF_DONTCACHE flag on the NFS client

2025-09-23T17:29:50+00:00

The NFS client needs to defer dropbehind until after any writes to the folio have been persisted on the server. Since this may be a 2 step process, use folio_end_writeback_no_dropbehind() to allow release of the writeback flag, and then call folio_end_dropbehind() once the COMMIT is done. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

sunrpc: remove dfprintk_cont() and dfprintk_rcu_cont()

2025-09-23T17:28:19+00:00

KERN_CONT hails from a simpler time, when SMP wasn't the norm. These days, it doesn't quite work right since another printk() can always race in between the first one and the one being "continued". Nothing calls dprintk_rcu_cont(), so just remove it. The only caller of dprintk_cont() is in nfs_commit_release_pages(). Just use a normal dprintk() there instead, since this is not SMP-safe anyway. Signed-off-by: Jeff Layton Reviewed-by: Chuck Lever Reviewed-by: Simon Horman Signed-off-by: Anna Schumaker

nfs: add tracepoints to nfs_writepages()

2025-09-23T17:28:19+00:00

Show the inode info and requested range. Signed-off-by: Jeff Layton Reviewed-by: Benjamin Coddington Signed-off-by: Anna Schumaker

nfs: more in-depth tracing of writepage events

2025-09-23T17:28:19+00:00

Add tracepoints to nfs_writepage_setup() and nfs_do_writepage(). Signed-off-by: Jeff Layton Reviewed-by: Benjamin Coddington Signed-off-by: Anna Schumaker

nfs: new tracepoints around write handling

2025-09-23T17:28:19+00:00

New start and done tracepoints for: nfs_update_folio() nfs_write_begin() nfs_write_end() nfs_try_to_update_request() Signed-off-by: Jeff Layton Reviewed-by: Benjamin Coddington Signed-off-by: Anna Schumaker

NFS: Fix the marking of the folio as up to date

2025-09-06T20:51:26+00:00

Since all callers of nfs_page_group_covers_page() have already ensured that there is only one group member, all that is required is to check that the entire folio contains dirty data. Signed-off-by: Trond Myklebust

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

2025-09-06T20:51:26+00:00

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