f2fs: fix multiple f2fs_add_link() calls having same name

am: d00d1b71d9

Change-Id: I2a53ea79d79f68575a8024b4d2e7ae6caa3f574d
This commit is contained in:
Jaegeuk Kim
2017-03-12 08:31:21 +00:00
committed by android-build-merger
2 changed files with 30 additions and 5 deletions

View File

@@ -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;
}

View File

@@ -431,6 +431,7 @@ 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 */
unsigned long long xattr_ver; /* cp version of xattr modification */
loff_t last_disk_size; /* lastly written file size */