diff options
| author | Kees Cook <keescook@chromium.org> | 2020-05-05 04:41:30 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2020-05-12 18:15:29 +0200 |
| commit | 7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a (patch) | |
| tree | 12faf3065122ed0a2c716ca09ec13042997c4f2c /fs/pstore/inode.c | |
| parent | pstore: Add proper unregister lock checking (diff) | |
| download | linux-7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a.tar.xz linux-7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a.zip | |
pstore: Refactor pstorefs record list removal
The "unlink" handling should perform list removal (which can also make
sure records don't get double-erased), and the "evict" handling should
be responsible only for memory freeing.
Link: https://lore.kernel.org/lkml/20200506152114.50375-8-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'fs/pstore/inode.c')
| -rw-r--r-- | fs/pstore/inode.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 92ebcc75434f..5f08b21b7a46 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -177,10 +177,21 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) { struct pstore_private *p = d_inode(dentry)->i_private; struct pstore_record *record = p->record; + int rc = 0; if (!record->psi->erase) return -EPERM; + /* Make sure we can't race while removing this file. */ + mutex_lock(&records_list_lock); + if (!list_empty(&p->list)) + list_del_init(&p->list); + else + rc = -ENOENT; + mutex_unlock(&records_list_lock); + if (rc) + return rc; + mutex_lock(&record->psi->read_mutex); record->psi->erase(record); mutex_unlock(&record->psi->read_mutex); @@ -193,12 +204,7 @@ static void pstore_evict_inode(struct inode *inode) struct pstore_private *p = inode->i_private; clear_inode(inode); - if (p) { - mutex_lock(&records_list_lock); - list_del(&p->list); - mutex_unlock(&records_list_lock); - free_pstore_private(p); - } + free_pstore_private(p); } static const struct inode_operations pstore_dir_inode_operations = { @@ -417,6 +423,7 @@ static void pstore_kill_sb(struct super_block *sb) { kill_litter_super(sb); pstore_sb = NULL; + INIT_LIST_HEAD(&records_list); } static struct file_system_type pstore_fs_type = { |