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authorFrank van der Linden <fllinden@amazon.com>2020-06-23 22:39:04 +0000
committerTrond Myklebust <trond.myklebust@hammerspace.com>2020-07-13 17:52:46 -0400
commit95ad37f90c338e3fd4abf61cecfe02b6f3e080f0 (patch)
treecc65ec6496ed30eb9a48cf2eeda6e19be734c65f /fs/nfs/nfs42proc.c
parent012a211abd5db098094ce429de5f046368391e68 (diff)
NFSv4.2: add client side xattr caching.
Implement client side caching for NFSv4.2 extended attributes. The cache is a per-inode hashtable, with name/value entries. There is one special entry for the listxattr cache. NFS inodes have a pointer to a cache structure. The cache structure is allocated on demand, freed when the cache is invalidated. Memory shrinkers keep the size in check. Large entries (> PAGE_SIZE) are collected by a separate shrinker, and freed more aggressively than others. Signed-off-by: Frank van der Linden <fllinden@amazon.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Diffstat (limited to 'fs/nfs/nfs42proc.c')
-rw-r--r--fs/nfs/nfs42proc.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index 8c2e52bc986a..e200522469af 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -1182,6 +1182,18 @@ static ssize_t _nfs42_proc_getxattr(struct inode *inode, const char *name,
if (ret < 0)
return ret;
+ /*
+ * Normally, the caching is done one layer up, but for successful
+ * RPCS, always cache the result here, even if the caller was
+ * just querying the length, or if the reply was too big for
+ * the caller. This avoids a second RPC in the case of the
+ * common query-alloc-retrieve cycle for xattrs.
+ *
+ * Note that xattr_len is always capped to XATTR_SIZE_MAX.
+ */
+
+ nfs4_xattr_cache_add(inode, name, NULL, pages, res.xattr_len);
+
if (buflen) {
if (res.xattr_len > buflen)
return -ERANGE;