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| author | Paul Aurich <paul@darkrain42.org> | 2024-11-20 08:01:54 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-27 11:09:03 +0100 |
| commit | b8ced2b9a23a1a2c1e0ed8d0d02512e51bdf38da (patch) | |
| tree | 26809f2230ff0d70e5bf4b6187906f9ad79cbc9f /fs | |
| parent | aaaa689aa29d96b74f8aaddb51bd1aa4658020bd (diff) | |
| download | linux-b8ced2b9a23a1a2c1e0ed8d0d02512e51bdf38da.tar.gz linux-b8ced2b9a23a1a2c1e0ed8d0d02512e51bdf38da.tar.bz2 linux-b8ced2b9a23a1a2c1e0ed8d0d02512e51bdf38da.zip | |
smb: Log an error when close_all_cached_dirs fails
commit a2182743a8b4969481f64aec4908ff162e8a206c upstream.
Under low-memory conditions, close_all_cached_dirs() can't move the
dentries to a separate list to dput() them once the locks are dropped.
This will result in a "Dentry still in use" error, so add an error
message that makes it clear this is what happened:
[ 495.281119] CIFS: VFS: \\otters.example.com\share Out of memory while dropping dentries
[ 495.281595] ------------[ cut here ]------------
[ 495.281887] BUG: Dentry ffff888115531138{i=78,n=/} still in use (2) [unmount of cifs cifs]
[ 495.282391] WARNING: CPU: 1 PID: 2329 at fs/dcache.c:1536 umount_check+0xc8/0xf0
Also, bail out of looping through all tcons as soon as a single
allocation fails, since we're already in trouble, and kmalloc() attempts
for subseqeuent tcons are likely to fail just like the first one did.
Signed-off-by: Paul Aurich <paul@darkrain42.org>
Acked-by: Bharath SM <bharathsm@microsoft.com>
Suggested-by: Ruben Devos <rdevos@oxya.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/smb/client/cached_dir.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c index 749794667295..d64742ba371a 100644 --- a/fs/smb/client/cached_dir.c +++ b/fs/smb/client/cached_dir.c @@ -484,8 +484,17 @@ void close_all_cached_dirs(struct cifs_sb_info *cifs_sb) spin_lock(&cfids->cfid_list_lock); list_for_each_entry(cfid, &cfids->entries, entry) { tmp_list = kmalloc(sizeof(*tmp_list), GFP_ATOMIC); - if (tmp_list == NULL) - break; + if (tmp_list == NULL) { + /* + * If the malloc() fails, we won't drop all + * dentries, and unmounting is likely to trigger + * a 'Dentry still in use' error. + */ + cifs_tcon_dbg(VFS, "Out of memory while dropping dentries\n"); + spin_unlock(&cfids->cfid_list_lock); + spin_unlock(&cifs_sb->tlink_tree_lock); + goto done; + } spin_lock(&cfid->fid_lock); tmp_list->dentry = cfid->dentry; cfid->dentry = NULL; @@ -497,6 +506,7 @@ void close_all_cached_dirs(struct cifs_sb_info *cifs_sb) } spin_unlock(&cifs_sb->tlink_tree_lock); +done: list_for_each_entry_safe(tmp_list, q, &entry, entry) { list_del(&tmp_list->entry); dput(tmp_list->dentry); |