diff options
| author | Scott Mayhew <smayhew@redhat.com> | 2024-05-23 15:01:22 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-07-25 09:49:12 +0200 |
| commit | 72118292631de3bdf974301270a96c905d67ec04 (patch) | |
| tree | b62bb05cba7c173f5e5c2d091a330f4fb2a8c4ff /fs/nfs/dir.c | |
| parent | f1e52990b002f666d3a23f9726f730fc27fa44db (diff) | |
nfs: don't invalidate dentries on transient errors
[ Upstream commit 0c8c7c559740d2d8b66048162af6c4dba8f0c88c ]
This is a slight variation on a patch previously proposed by Neil Brown
that never got merged.
Prior to commit 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()"),
any error from nfs_lookup_verify_inode() other than -ESTALE would result
in nfs_lookup_revalidate() returning that error (-ESTALE is mapped to
zero).
Since that commit, all errors result in nfs_lookup_revalidate()
returning zero, resulting in dentries being invalidated where they
previously were not (particularly in the case of -ERESTARTSYS).
Fix it by passing the actual error code to nfs_lookup_revalidate_done(),
and leaving the decision on whether to map the error code to zero or
one to nfs_lookup_revalidate_done().
A simple reproducer is to run the following python code in a
subdirectory of an NFS mount (not in the root of the NFS mount):
---8<---
import os
import multiprocessing
import time
if __name__=="__main__":
multiprocessing.set_start_method("spawn")
count = 0
while True:
try:
os.getcwd()
pool = multiprocessing.Pool(10)
pool.close()
pool.terminate()
count += 1
except Exception as e:
print(f"Failed after {count} iterations")
print(e)
break
---8<---
Prior to commit 5ceb9d7fdaaf, the above code would run indefinitely.
After commit 5ceb9d7fdaaf, it fails almost immediately with -ENOENT.
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/nfs/dir.c')
| -rw-r--r-- | fs/nfs/dir.c | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index a5a4d9422d6e..70660ff248b7 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1615,7 +1615,16 @@ nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry, switch (error) { case 1: break; - case 0: + case -ETIMEDOUT: + if (inode && (IS_ROOT(dentry) || + NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)) + error = 1; + break; + case -ESTALE: + case -ENOENT: + error = 0; + fallthrough; + default: /* * We can't d_drop the root of a disconnected tree: * its d_hash is on the s_anon list and d_drop() would hide @@ -1670,18 +1679,8 @@ static int nfs_lookup_revalidate_dentry(struct inode *dir, dir_verifier = nfs_save_change_attribute(dir); ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr); - if (ret < 0) { - switch (ret) { - case -ESTALE: - case -ENOENT: - ret = 0; - break; - case -ETIMEDOUT: - if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL) - ret = 1; - } + if (ret < 0) goto out; - } /* Request help from readdirplus */ nfs_lookup_advise_force_readdirplus(dir, flags); @@ -1725,7 +1724,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct inode *inode; - int error; + int error = 0; nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); inode = d_inode(dentry); @@ -1770,7 +1769,7 @@ out_valid: out_bad: if (flags & LOOKUP_RCU) return -ECHILD; - return nfs_lookup_revalidate_done(dir, dentry, inode, 0); + return nfs_lookup_revalidate_done(dir, dentry, inode, error); } static int |