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| author | Theodore Ts'o <tytso@mit.edu> | 2014-10-05 22:56:00 -0400 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-11-13 19:02:34 +0100 |
| commit | bead15b503cf4007a0383f6e8a7409569c41a546 (patch) | |
| tree | 381148640feaec910b546a6e0efbf374f8b7be1e | |
| parent | 147261f789cb5b1f0d62459f849c18dea7ada958 (diff) | |
| download | lwn-bead15b503cf4007a0383f6e8a7409569c41a546.tar.gz lwn-bead15b503cf4007a0383f6e8a7409569c41a546.zip | |
ext4: add ext4_iget_normal() which is to be used for dir tree lookups
commit f4bb2981024fc91b23b4d09a8817c415396dbabb upstream.
If there is a corrupted file system which has directory entries that
point at reserved, metadata inodes, prohibit them from being used by
treating them the same way we treat Boot Loader inodes --- that is,
mark them to be bad inodes. This prohibits them from being opened,
deleted, or modified via chmod, chown, utimes, etc.
In particular, this prevents a corrupted file system which has a
directory entry which points at the journal inode from being deleted
and its blocks released, after which point Much Hilarity Ensues.
Reported-by: Sami Liedes <sami.liedes@iki.fi>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | fs/ext4/ext4.h | 1 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 7 | ||||
| -rw-r--r-- | fs/ext4/namei.c | 4 | ||||
| -rw-r--r-- | fs/ext4/super.c | 2 |
4 files changed, 11 insertions, 3 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 54d94db2cf03..4eca63f8314a 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2093,6 +2093,7 @@ int do_journal_get_write_access(handle_t *handle, #define CONVERT_INLINE_DATA 2 extern struct inode *ext4_iget(struct super_block *, unsigned long); +extern struct inode *ext4_iget_normal(struct super_block *, unsigned long); extern int ext4_write_inode(struct inode *, struct writeback_control *); extern int ext4_setattr(struct dentry *, struct iattr *); extern int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 474b9eafee43..a43859ca3184 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4251,6 +4251,13 @@ bad_inode: return ERR_PTR(ret); } +struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino) +{ + if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO) + return ERR_PTR(-EIO); + return ext4_iget(sb, ino); +} + static int ext4_inode_blocks_set(handle_t *handle, struct ext4_inode *raw_inode, struct ext4_inode_info *ei) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 5a0408d7b114..8e000a058958 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1430,7 +1430,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi dentry->d_name.name); return ERR_PTR(-EIO); } - inode = ext4_iget(dir->i_sb, ino); + inode = ext4_iget_normal(dir->i_sb, ino); if (inode == ERR_PTR(-ESTALE)) { EXT4_ERROR_INODE(dir, "deleted inode referenced: %u", @@ -1461,7 +1461,7 @@ struct dentry *ext4_get_parent(struct dentry *child) return ERR_PTR(-EIO); } - return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino)); + return d_obtain_alias(ext4_iget_normal(child->d_inode->i_sb, ino)); } /* diff --git a/fs/ext4/super.c b/fs/ext4/super.c index cf3068a50b48..2914dc7ce9e8 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -977,7 +977,7 @@ static struct inode *ext4_nfs_get_inode(struct super_block *sb, * Currently we don't know the generation for parent directory, so * a generation of 0 means "accept any" */ - inode = ext4_iget(sb, ino); + inode = ext4_iget_normal(sb, ino); if (IS_ERR(inode)) return ERR_CAST(inode); if (generation && inode->i_generation != generation) { |