Support the query flags AT_STATX_FORCE_SYNC by forcing an attribute
revalidation, and AT_STATX_DONT_SYNC by returning cached attributes
only.
Use the mask to optimise away server revalidation for attributes
that are not being requested by the user.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
v2:
- Respect the attribute cache timeout.
- Unless AT_STATX_DONT_SYNC is set, we must only return attributes
that have been duly revalidated.
fs/nfs/inode.c | 51 ++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 38 insertions(+), 13 deletions(-)
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index b112002dbdb2..c2c8bb7755ad 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -735,12 +735,20 @@ int nfs_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
- int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
+ struct nfs_server *server = NFS_SERVER(inode);
+ unsigned long cache_validity;
int err = 0;
+ bool force_sync = query_flags & AT_STATX_FORCE_SYNC;
+ bool do_update = false;
trace_nfs_getattr_enter(inode);
+
+ if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync)
+ goto out_no_update;
+
/* Flush out writes to the server in order to update c/mtime. */
- if (S_ISREG(inode->i_mode)) {
+ if ((request_mask & (STATX_CTIME|STATX_MTIME)) &&
+ S_ISREG(inode->i_mode)) {
err = filemap_write_and_wait(inode->i_mapping);
if (err)
goto out;
@@ -757,24 +765,41 @@ int nfs_getattr(const struct path *path, struct kstat *stat,
*/
if ((path->mnt->mnt_flags & MNT_NOATIME) ||
((path->mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))
- need_atime = 0;
-
- if (need_atime || nfs_need_revalidate_inode(inode)) {
- struct nfs_server *server = NFS_SERVER(inode);
-
+ request_mask &= ~STATX_ATIME;
+
+ /* Is the user requesting attributes that might need revalidation? */
+ if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
+ STATX_MTIME|STATX_UID|STATX_GID|
+ STATX_SIZE|STATX_BLOCKS)))
+ goto out_no_revalidate;
+
+ /* Check whether the cached attributes are stale */
+ do_update |= force_sync || nfs_attribute_cache_expired(inode);
+ cache_validity = READ_ONCE(NFS_I(inode)->cache_validity);
+ do_update |= cache_validity & NFS_INO_INVALID_ATTR;
+ if (request_mask & STATX_ATIME)
+ do_update |= cache_validity & NFS_INO_INVALID_ATIME;
+ if (request_mask & (STATX_CTIME|STATX_MTIME))
+ do_update |= cache_validity & NFS_INO_REVAL_PAGECACHE;
+ if (do_update) {
+ /* Update the attribute cache */
if (!(server->flags & NFS_MOUNT_NOAC))
nfs_readdirplus_parent_cache_miss(path->dentry);
else
nfs_readdirplus_parent_cache_hit(path->dentry);
err = __nfs_revalidate_inode(server, inode);
+ if (err)
+ goto out;
} else
nfs_readdirplus_parent_cache_hit(path->dentry);
- if (!err) {
- generic_fillattr(inode, stat);
- stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
- if (S_ISDIR(inode->i_mode))
- stat->blksize = NFS_SERVER(inode)->dtsize;
- }
+out_no_revalidate:
+ /* Only return attributes that were revalidated. */
+ stat->result_mask &= request_mask;
+out_no_update:
+ generic_fillattr(inode, stat);
+ stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
+ if (S_ISDIR(inode->i_mode))
+ stat->blksize = NFS_SERVER(inode)->dtsize;
out:
trace_nfs_getattr_exit(inode, err);
return err;
--
2.14.3
--
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