NFS: Readdir plus in v4
By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.
To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files. Without readdir plus, I see this:
n files | 100 | 1,000 | 10,000 | 100,000 | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access | 3 | 1 | 1 | 4 | 31
getattr | 2 | 1 | 1 | 1 | 1
lookup | 104 | 1,003 | 10,003 | 100,003 | 1,000,003
readdir | 2 | 16 | 158 | 1,575 | 15,749
total | 111 | 1,021 | 10,163 | 101,583 | 1,015,784
With readdir plus enabled, I see this:
n files | 100 | 1,000 | 10,000 | 100,000 | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access | 3 | 1 | 1 | 1 | 7
getattr | 2 | 1 | 1 | 1 | 1
lookup | 4 | 3 | 3 | 3 | 3
readdir | 6 | 62 | 630 | 6,300 | 62,993
total | 15 | 67 | 635 | 6,305 | 63,004
Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index b7eff20..ccfb1c92 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1385,12 +1385,20 @@
static void encode_readdir(struct xdr_stream *xdr, const struct nfs4_readdir_arg *readdir, struct rpc_rqst *req, struct compound_hdr *hdr)
{
- uint32_t attrs[2] = {
- FATTR4_WORD0_RDATTR_ERROR|FATTR4_WORD0_FILEID,
- FATTR4_WORD1_MOUNTED_ON_FILEID,
- };
+ uint32_t attrs[2] = {0, 0};
__be32 *p;
+ if (readdir->plus) {
+ attrs[0] |= FATTR4_WORD0_TYPE|FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE|
+ FATTR4_WORD0_FSID|FATTR4_WORD0_FILEHANDLE;
+ attrs[1] |= FATTR4_WORD1_MODE|FATTR4_WORD1_NUMLINKS|FATTR4_WORD1_OWNER|
+ FATTR4_WORD1_OWNER_GROUP|FATTR4_WORD1_RAWDEV|
+ FATTR4_WORD1_SPACE_USED|FATTR4_WORD1_TIME_ACCESS|
+ FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY;
+ }
+ attrs[0] |= FATTR4_WORD0_RDATTR_ERROR|FATTR4_WORD0_FILEID;
+ attrs[1] |= FATTR4_WORD1_MOUNTED_ON_FILEID;
+
p = reserve_space(xdr, 12+NFS4_VERIFIER_SIZE+20);
*p++ = cpu_to_be32(OP_READDIR);
p = xdr_encode_hyper(p, readdir->cookie);
@@ -1398,11 +1406,15 @@
*p++ = cpu_to_be32(readdir->count >> 1); /* We're not doing readdirplus */
*p++ = cpu_to_be32(readdir->count);
*p++ = cpu_to_be32(2);
- /* Switch to mounted_on_fileid if the server supports it */
- if (readdir->bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)
- attrs[0] &= ~FATTR4_WORD0_FILEID;
- else
- attrs[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID;
+
+ if (!readdir->plus) {
+ /* Switch to mounted_on_fileid if the server supports it */
+ if (readdir->bitmask[1] & FATTR4_WORD1_MOUNTED_ON_FILEID)
+ attrs[0] &= ~FATTR4_WORD0_FILEID;
+ else
+ attrs[1] &= ~FATTR4_WORD1_MOUNTED_ON_FILEID;
+ }
+
*p++ = cpu_to_be32(attrs[0] & readdir->bitmask[0]);
*p = cpu_to_be32(attrs[1] & readdir->bitmask[1]);
hdr->nops++;
@@ -5768,7 +5780,8 @@
}
#endif /* CONFIG_NFS_V4_1 */
-__be32 *nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
+__be32 *nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
+ struct nfs_server *server, int plus)
{
uint32_t bitmap[2] = {0};
uint32_t len;
@@ -5824,24 +5837,10 @@
goto out_overflow;
len = XDR_QUADLEN(ntohl(*p++)); /* attribute buffer length */
if (len > 0) {
- if (bitmap[0] & FATTR4_WORD0_RDATTR_ERROR) {
- bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR;
- /* Ignore the return value of rdattr_error for now */
- p = xdr_inline_decode(xdr, 4);
- if (unlikely(!p))
- goto out_overflow;
- }
- if (bitmap[0] == 0 && bitmap[1] == FATTR4_WORD1_MOUNTED_ON_FILEID) {
- p = xdr_inline_decode(xdr, 8);
- if (unlikely(!p))
- goto out_overflow;
- xdr_decode_hyper(p, &entry->ino);
- } else if (bitmap[0] == FATTR4_WORD0_FILEID) {
- p = xdr_inline_decode(xdr, 8);
- if (unlikely(!p))
- goto out_overflow;
- xdr_decode_hyper(p, &entry->ino);
- }
+ if (decode_getfattr_attrs(xdr, bitmap, entry->fattr, entry->fh, server, 1) < 0)
+ goto out_overflow;
+ if (entry->fattr->valid & NFS_ATTR_FATTR_FILEID)
+ entry->ino = entry->fattr->fileid;
}
p = xdr_inline_peek(xdr, 8);
