nfsd: use vfs_fsync_range(), not O_SYNC, for stable writes (face1502) · Commits · 戴 / test

NFSv4 shares the same struct file across multiple writes. (And we'd like NFSv2 and NFSv3 to do that as well some day.) So setting O_SYNC on the struct file as a way to request a synchronous write doesn't work. Instead, do a vfs_fsync_range() in that case. Reported-by:

Peter Staubach <pstaubach@exagrid.com> Signed-off-by:

J. Bruce Fields <bfields@redhat.com>

fs/nfsd/vfs.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -1024,11 +1024,6 @@ nfsd_vfs_write(struct svc_rqst rqstp, struct svc_fh fhp, struct file *file,

		if (!EX_ISSYNC(exp))
		stable = 0;
		if (stable && !use_wgather) {
		spin_lock(&file->f_lock);
		file->f_flags \|= O_SYNC;
		spin_unlock(&file->f_lock);
		}

		/* Write the data. */
		oldfs = get_fs(); set_fs(KERNEL_DS);
		@@ -1044,8 +1039,12 @@ nfsd_vfs_write(struct svc_rqst rqstp, struct svc_fh fhp, struct file *file,
		if (inode->i_mode & (S_ISUID \| S_ISGID))
		kill_suid(dentry);

		if (stable && use_wgather)
		if (stable) {
		if (use_wgather)
		host_err = wait_for_concurrent_writes(file);
		else
		host_err = vfs_fsync_range(file, offset, offset+*cnt, 0);
		}

		out_nfserr:
		dprintk("nfsd: write complete host_err=%d\n", host_err);

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