From: Zhihao Cheng chengzhihao1@huawei.com
maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9MWEQ CVE: NA
Reference: https://lore.kernel.org/lkml/20240410073751.2522830-8-chengzhihao1@huawei.co...
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There is a potential space leak problem when powercut happens in linking tmpfile, in which case, inode node (with nlink=0) and its' data nodes can be found from tnc (on flash), but there are no dentries related to the inode, so the file is invisible but takes free space. Detailed process is shown as: ubifs_tmpfile ubifs_jnl_update // Add bud A into log area ubifs_add_orphan // Add inode into orphan list
P1 P2 ubifs_link ubifs_delete_orphan // Delete inode from orphan list, then inode won't // be written into orphan area, there is no chance // to delete inode by replaying orphan. commit // bud A won't be replayed in next mounting
powercut <<
ubifs_jnl_update // Link inode to dentry
The root cause is that orphan entry deletion and journal writing(for link) are interrupted by commit, which makes the two operations are not atomic. Fix it by doing ubifs_delete_orphan under the protection of c->commit_sem within ubifs_jnl_update. This is also a preparation to support all creating new files by orphan inode.
v1 is https://lore.kernel.org/linux-mtd/20200701093227.674945-1-chengzhihao1@huawe...
Fixes: 32fe905c17f0 ("ubifs: Fix O_TMPFILE corner case in ubifs_link()") Link: https://bugzilla.kernel.org/show_bug.cgi?id=208405 Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Conflicts: fs/ubifs/dir.c Signed-off-by: ZhaoLong Wang wangzhaolong1@huawei.com --- fs/ubifs/dir.c | 22 ++++++++-------------- fs/ubifs/journal.c | 6 +++++- fs/ubifs/ubifs.h | 2 +- fs/ubifs/xattr.c | 2 +- 4 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 3cb5ce49a232..5b7e1d469a8b 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -325,7 +325,7 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode, dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -478,7 +478,7 @@ static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry, mutex_unlock(&ui->ui_mutex);
lock_2_inodes(dir, inode); - err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); @@ -759,17 +759,13 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
lock_2_inodes(dir, inode);
- /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */ - if (inode->i_nlink == 0) - ubifs_delete_orphan(c, inode->i_ino); - inc_nlink(inode); ihold(inode); inode->i_ctime = current_time(inode); dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, inode->i_nlink == 1); if (err) goto out_cancel; unlock_2_inodes(dir, inode); @@ -783,8 +779,6 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; drop_nlink(inode); - if (inode->i_nlink == 0) - ubifs_add_orphan(c, inode->i_ino); unlock_2_inodes(dir, inode); ubifs_release_budget(c, &req); iput(inode); @@ -843,7 +837,7 @@ static int ubifs_unlink(struct inode *dir, struct dentry *dentry) dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); @@ -946,7 +940,7 @@ static int ubifs_rmdir(struct inode *dir, struct dentry *dentry) dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0, 0); if (err) goto out_cancel; unlock_2_inodes(dir, inode); @@ -1019,7 +1013,7 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); if (err) { ubifs_err(c, "cannot create directory, error %d", err); goto out_cancel; @@ -1112,7 +1106,7 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); @@ -1212,7 +1206,7 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, dir->i_size += sz_change; dir_ui->ui_size = dir->i_size; dir->i_mtime = dir->i_ctime = inode->i_ctime; - err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); + err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0, 0); if (err) goto out_cancel; mutex_unlock(&dir_ui->ui_mutex); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8607db74a07d..dfbedbf0dc42 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -643,6 +643,7 @@ static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent) * @inode: inode to update * @deletion: indicates a directory entry deletion i.e unlink or rmdir * @xent: non-zero if the directory entry is an extended attribute entry + * @delete_orphan: indicates an orphan entry deletion for @inode * * This function updates an inode by writing a directory entry (or extended * attribute entry), the inode itself, and the parent directory inode (or the @@ -664,7 +665,7 @@ static void set_dent_cookie(struct ubifs_info *c, struct ubifs_dent_node *dent) */ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, const struct fscrypt_name *nm, const struct inode *inode, - int deletion, int xent) + int deletion, int xent, int delete_orphan) { int err, dlen, ilen, len, lnum, ino_offs, dent_offs, orphan_added = 0; int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir); @@ -806,6 +807,9 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, if (err) goto out_ro;
+ if (delete_orphan) + ubifs_delete_orphan(c, inode->i_ino); + finish_reservation(c); spin_lock(&ui->ui_lock); ui->synced_i_size = ui->ui_size; diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 672345efb8f2..69f2916b3ff3 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1766,7 +1766,7 @@ int ubifs_consolidate_log(struct ubifs_info *c); /* journal.c */ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir, const struct fscrypt_name *nm, const struct inode *inode, - int deletion, int xent); + int deletion, int xent, int delete_orphan); int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode, const union ubifs_key *key, const void *buf, int len); int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode); diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c index 81efe638acd5..725d4260ac20 100644 --- a/fs/ubifs/xattr.c +++ b/fs/ubifs/xattr.c @@ -149,7 +149,7 @@ static int create_xattr(struct ubifs_info *c, struct inode *host, if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) host_ui->flags |= UBIFS_CRYPT_FL;
- err = ubifs_jnl_update(c, host, nm, inode, 0, 1); + err = ubifs_jnl_update(c, host, nm, inode, 0, 1, 0); if (err) goto out_cancel; ubifs_set_inode_flags(host);