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| author | Kinglong Mee <kinglongmee@gmail.com> | 2023-07-21 04:23:00 +0300 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2023-08-24 20:24:15 +0300 |
| commit | 14e7316a3c73cf45cef4422549f3585fc1c53521 (patch) | |
| tree | d164fc619ab7a124734e91a3037ec4e59d3aab7b /fs/nfs/dir.c | |
| parent | 08b45fcb2d4675f6182fe0edc0d8b1fe604051fa (diff) | |
| download | linux-14e7316a3c73cf45cef4422549f3585fc1c53521.tar.xz | |
nfs: fix redundant readdir request after get eof
When a directory contains 17 files (except . and ..), nfs client sends
a redundant readdir request after get eof.
A simple reproduce,
At NFS server, create a directory with 17 files under exported directory.
# mkdir test
# cd test
# for i in {0..16} ; do touch $i; done
At NFS client, no matter mounting through nfsv3 or nfsv4,
does ls (or ll) at the created test directory.
A tshark output likes following (for nfsv4),
# tshark -i eth0 tcp port 2049 -Tfields -e ip.src -e ip.dst -e nfs -e nfs.cookie4
srcip dstip SEQUENCE, PUTFH, READDIR 0
dstip srcip SEQUENCE PUTFH READDIR 909539109313539306,2108391201987888856,2305312124304486544,2566335452463141496,2978225129081509984,4263037479923412583,4304697173036510679,4666703455469210097,4759208201298769007,4776701232145978803,5338408478512081262,5949498658935544804,5971526429894832903,6294060338267709855,6528840566229532529,8600463293536422524,9223372036854775807
srcip dstip
srcip dstip SEQUENCE, PUTFH, READDIR 9223372036854775807
dstip srcip SEQUENCE PUTFH READDIR
The READDIR with cookie 9223372036854775807(0x7FFFFFFFFFFFFFFF) is redundant.
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/dir.c')
| -rw-r--r-- | fs/nfs/dir.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8f3112e71a6a..e6a51fd94fea 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1089,6 +1089,17 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc, for (i = desc->cache_entry_index; i < array->size; i++) { struct nfs_cache_array_entry *ent; + /* + * nfs_readdir_handle_cache_misses return force clear at + * (cache_misses > NFS_READDIR_CACHE_MISS_THRESHOLD) for + * readdir heuristic, NFS_READDIR_CACHE_MISS_THRESHOLD + 1 + * entries need be emitted here. + */ + if (first_emit && i > NFS_READDIR_CACHE_MISS_THRESHOLD + 2) { + desc->eob = true; + break; + } + ent = &array->array[i]; if (!dir_emit(desc->ctx, ent->name, ent->name_len, nfs_compat_user_ino64(ent->ino), ent->d_type)) { @@ -1107,10 +1118,6 @@ static void nfs_do_filldir(struct nfs_readdir_descriptor *desc, desc->ctx->pos = desc->dir_cookie; else desc->ctx->pos++; - if (first_emit && i > NFS_READDIR_CACHE_MISS_THRESHOLD + 1) { - desc->eob = true; - break; - } } if (array->folio_is_eof) desc->eof = !desc->eob; |