Support statx() mask and query flags parameters

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@primarydata.com>
This commit is contained in:
Trond Myklebust 2018-01-04 17:46:09 -05:00
parent 8634ef5e05
commit 9ccee940bd
1 changed files with 37 additions and 11 deletions

View File

@ -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 +765,42 @@ 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;
request_mask &= ~STATX_ATIME;
if (need_atime || nfs_need_revalidate_inode(inode)) {
struct nfs_server *server = NFS_SERVER(inode);
/* 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|NFS_INO_INVALID_LABEL);
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) {
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;