Commit 79566ef0 authored Jun 25, 2016 by Trond Myklebust

NFS: Getattr doesn't require data sync semantics

When retrieving stat() information, NFS unfortunately does require us to
sync writes to disk in order to ensure that mtime and ctime are up to
date. However we shouldn't have to ensure that those writes are persisted.

Relaxing that requirement does mean that we may see an mtime/ctime change
if the server reboots and forces us to replay all writes.

The exception to this rule are pNFS clients that are required to send
layoutcommit, however that is dealt with by the call to pnfs_sync_inode()
in _nfs_revalidate_inode().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

parent 651b0e70

fs/nfs/inode.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -661,9 +661,7 @@ int nfs_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat)
		trace_nfs_getattr_enter(inode);
		/* Flush out writes to the server in order to update c/mtime. */
		if (S_ISREG(inode->i_mode)) {
		inode_lock(inode);
		err = nfs_sync_inode(inode);
		inode_unlock(inode);
		err = filemap_write_and_wait(inode->i_mapping);
		if (err)
		goto out;
		}

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