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authorKees Cook <keescook@chromium.org>2020-05-04 19:41:30 -0700
committerKees Cook <keescook@chromium.org>2020-05-12 09:15:29 -0700
commit7a0ad546847a23f92f5e227fa8e4578eaa3a8d0a (patch)
tree12faf3065122ed0a2c716ca09ec13042997c4f2c /fs/pstore
parent6248a0666c8a408dcc5bd952536274d5bd0f02cb (diff)
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')
-rw-r--r--fs/pstore/inode.c19
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 = {