From 29361590ed10fe5db2b02574b19d3ed8afec5bf4 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Tue, 18 Feb 2020 18:07:57 -0600
Subject: [PATCH] cifs: do not ignore the SYNC flags in getattr
Check the AT_STATX_FORCE_SYNC flag and force an attribute
revalidation if requested by the caller, and if the caller
specificies AT_STATX_DONT_SYNC only revalidate cached attributes
if required. In addition do not flush writes in getattr (which
can be expensive) if size or timestamps not requested by the
caller.
Signed-off-by: Steve French <stfrench@microsoft.com>
---
fs/cifs/inode.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
@@ -2148,8 +2148,9 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
* We need to be sure that all dirty pages are written and the server
* has actual ctime, mtime and file length.
*/
- if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
- inode->i_mapping->nrpages != 0) {
+ if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_SIZE)) &&
+ !CIFS_CACHE_READ(CIFS_I(inode)) &&
+ inode->i_mapping && inode->i_mapping->nrpages != 0) {
rc = filemap_fdatawait(inode->i_mapping);
if (rc) {
mapping_set_error(inode->i_mapping, rc);
@@ -2157,9 +2158,20 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
}
}
- rc = cifs_revalidate_dentry_attr(dentry);
- if (rc)
- return rc;
+ if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_FORCE_SYNC)
+ CIFS_I(inode)->time = 0; /* force revalidate */
+
+ /*
+ * If the caller doesn't require syncing, only sync if
+ * necessary (e.g. due to earlier truncate or setattr
+ * invalidating the cached metadata)
+ */
+ if (((flags & AT_STATX_SYNC_TYPE) != AT_STATX_DONT_SYNC) ||
+ (CIFS_I(inode)->time == 0)) {
+ rc = cifs_revalidate_dentry_attr(dentry);
+ if (rc)
+ return rc;
+ }
generic_fillattr(inode, stat);
stat->blksize = cifs_sb->bsize;
--
2.20.1
cifs.ko should not ignore the SYNC flags in getattr Check the AT_STATX_FORCE_SYNC flag and force an attribute revalidation if requested by the caller, and if the caller specificies AT_STATX_DONT_SYNC only revalidate cached attributes if required. In addition do not flush writes in getattr (which can be expensive) if size or timestamps not requested by the caller.