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| author | Chuck Lever <chuck.lever@oracle.com> | 2026-04-19 14:53:07 -0400 |
|---|---|---|
| committer | Chuck Lever <chuck.lever@oracle.com> | 2026-05-28 11:31:26 -0400 |
| commit | e654b5a8c968f54323ffeaa1e1a796e3bf40b2bf (patch) | |
| tree | feb63564e61b0904fe25be98f4d2fd6426aba623 /fs | |
| parent | 083eabeaf4c707909cd07187f4bf49ccd0d3c4f1 (diff) | |
| download | linux-next-history-e654b5a8c968f54323ffeaa1e1a796e3bf40b2bf.tar.gz | |
NFSD: Close cached file handles when revoking export state
When NFSD_CMD_UNLOCK_EXPORT revokes NFSv4 state for an export path,
GC-managed nfsd_file entries for files under that path may remain
in the file cache. These cached handles hold the underlying
filesystem busy, preventing a subsequent unmount.
Add nfsd_file_close_export(), which walks the nfsd_file hash table
and closes GC-eligible entries whose underlying file resides on the
same filesystem and is a descendant of the export path. Because
nfsd_file entries do not carry an export reference, the ancestry
check uses is_subdir() on the file's dentry. False positives --
closing a cached handle that did not originate from the target
export -- are harmless; the handle is simply reopened on the next
access.
The handler calls nfsd_file_close_export() before revoking NFSv4
state, mirroring the order used by NFSD_CMD_UNLOCK_FILESYSTEM
(which cancels copies and releases NLM locks before revoking
state). Both calls run under nfsd_mutex.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nfsd/filecache.c | 46 | ||||
| -rw-r--r-- | fs/nfsd/filecache.h | 1 | ||||
| -rw-r--r-- | fs/nfsd/nfsctl.c | 5 |
3 files changed, 50 insertions, 2 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index 1e2b38ed1d35d..24511c3208db9 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -724,6 +724,52 @@ nfsd_file_close_inode_sync(struct inode *inode) nfsd_file_dispose_list(&dispose); } +/** + * nfsd_file_close_export - close cached file handles for an export + * @net: net namespace in which to operate + * @path: export path whose cached files should be closed + * + * Close out GC-managed nfsd_file entries whose underlying file is on + * the same filesystem as, and a descendant of, @path. nfsd_file + * entries do not carry an export reference, so the check uses the + * file's dentry ancestry. False positives (closing a cached handle + * that did not originate from the target export) are harmless -- the + * handle is simply reopened on the next access. + * + * Called from the NFSD_CMD_UNLOCK_EXPORT handler before revoking + * NFSv4 state, to ensure that cached file handles do not hold the + * filesystem busy. + */ +void nfsd_file_close_export(struct net *net, const struct path *path) +{ + struct rhashtable_iter iter; + struct nfsd_file *nf; + LIST_HEAD(dispose); + + rhltable_walk_enter(&nfsd_file_rhltable, &iter); + do { + rhashtable_walk_start(&iter); + + nf = rhashtable_walk_next(&iter); + while (!IS_ERR_OR_NULL(nf)) { + if (nf->nf_net == net && + test_bit(NFSD_FILE_GC, &nf->nf_flags) && + nf->nf_file && + file_inode(nf->nf_file)->i_sb == + path->dentry->d_sb && + is_subdir(nf->nf_file->f_path.dentry, + path->dentry)) + nfsd_file_cond_queue(nf, &dispose); + nf = rhashtable_walk_next(&iter); + } + + rhashtable_walk_stop(&iter); + } while (nf == ERR_PTR(-EAGAIN)); + rhashtable_walk_exit(&iter); + + nfsd_file_dispose_list(&dispose); +} + static int nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg, void *data) diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h index b383dbc5b9218..683b6437cacc2 100644 --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -70,6 +70,7 @@ struct net *nfsd_file_put_local(struct nfsd_file __rcu **nf); struct nfsd_file *nfsd_file_get(struct nfsd_file *nf); struct file *nfsd_file_file(struct nfsd_file *nf); void nfsd_file_close_inode_sync(struct inode *inode); +void nfsd_file_close_export(struct net *net, const struct path *path); void nfsd_file_net_dispose(struct nfsd_net *nn); bool nfsd_file_is_cached(struct inode *inode); __be32 nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp, diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 3b16a1d8ef2ed..3da4264d38bed 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2379,9 +2379,10 @@ int nfsd_nl_unlock_export_doit(struct sk_buff *skb, struct genl_info *info) return error; mutex_lock(&nfsd_mutex); - if (nn->nfsd_serv) + if (nn->nfsd_serv) { + nfsd_file_close_export(net, &path); nfsd4_revoke_export_states(nn, &path); - else + } else error = -EINVAL; mutex_unlock(&nfsd_mutex); |