[PATCH] NFSD: Protect against filesystem freezing
From: Chuck Lever <cel@kernel.org>
Date: 2023-03-06 15:45:16
Subsystem:
filesystems (vfs and infrastructure), kernel nfsd, sunrpc, and lockd servers, the rest · Maintainers:
Alexander Viro, Christian Brauner, Chuck Lever, Jeff Layton, Linus Torvalds
From: Chuck Lever <chuck.lever@oracle.com> Flole observes this WARNING on occasion: [1210423.486503] WARNING: CPU: 8 PID: 1524732 at fs/ext4/ext4_jbd2.c:75 ext4_journal_check_start+0x68/0xb0 Reported-by: <redacted> Suggested-by: Jan Kara <jack@suse.cz> Link: https://bugzilla.kernel.org/show_bug.cgi?id=217123 Fixes: 73da852e3831 ("nfsd: use vfs_iter_read/write") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- fs/nfsd/vfs.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 21d5209f6e04..ba34a31a7c70 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c@@ -1104,7 +1104,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, since = READ_ONCE(file->f_wb_err); if (verf) nfsd_copy_write_verifier(verf, nn); + file_start_write(file); host_err = vfs_iter_write(file, &iter, &pos, flags); + file_end_write(file); if (host_err < 0) { nfsd_reset_write_verifier(nn); trace_nfsd_writeverf_reset(nn, rqstp, host_err);