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-rw-r--r--fs/f2fs/dir.c34
-rw-r--r--fs/f2fs/f2fs.h1
2 files changed, 30 insertions, 5 deletions
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 827c5daef4fc..54aa30ee028f 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -207,9 +207,13 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
f2fs_put_page(dentry_page, 0);
}
- if (!de && room && F2FS_I(dir)->chash != namehash) {
- F2FS_I(dir)->chash = namehash;
- F2FS_I(dir)->clevel = level;
+ /* This is to increase the speed of f2fs_create */
+ if (!de && room) {
+ F2FS_I(dir)->task = current;
+ if (F2FS_I(dir)->chash != namehash) {
+ F2FS_I(dir)->chash = namehash;
+ F2FS_I(dir)->clevel = level;
+ }
}
return de;
@@ -643,14 +647,34 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name,
struct inode *inode, nid_t ino, umode_t mode)
{
struct fscrypt_name fname;
+ struct page *page = NULL;
+ struct f2fs_dir_entry *de = NULL;
int err;
err = fscrypt_setup_filename(dir, name, 0, &fname);
if (err)
return err;
- err = __f2fs_do_add_link(dir, &fname, inode, ino, mode);
-
+ /*
+ * An immature stakable filesystem shows a race condition between lookup
+ * and create. If we have same task when doing lookup and create, it's
+ * definitely fine as expected by VFS normally. Otherwise, let's just
+ * verify on-disk dentry one more time, which guarantees filesystem
+ * consistency more.
+ */
+ if (current != F2FS_I(dir)->task) {
+ de = __f2fs_find_entry(dir, &fname, &page);
+ F2FS_I(dir)->task = NULL;
+ }
+ if (de) {
+ f2fs_dentry_kunmap(dir, page);
+ f2fs_put_page(page, 0);
+ err = -EEXIST;
+ } else if (IS_ERR(page)) {
+ err = PTR_ERR(page);
+ } else {
+ err = __f2fs_do_add_link(dir, &fname, inode, ino, mode);
+ }
fscrypt_free_filename(&fname);
return err;
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 28e954080890..7b5e287ac127 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -459,6 +459,7 @@ struct f2fs_inode_info {
atomic_t dirty_pages; /* # of dirty pages */
f2fs_hash_t chash; /* hash value of given file name */
unsigned int clevel; /* maximum level of given file name */
+ struct task_struct *task; /* lookup and create consistency */
nid_t i_xattr_nid; /* node id that contains xattrs */
loff_t last_disk_size; /* lastly written file size */