linux-toradex.git/fs/ext4/namei.c, branch v5.5

ext4: fix unused-but-set-variable warning in ext4_add_entry()

2019-12-22T02:00:53+00:00

Warning is found when compile with "-Wunused-but-set-variable":

fs/ext4/namei.c: In function ‘ext4_add_entry’:
fs/ext4/namei.c:2167:23: warning: variable ‘sbi’ set but not used
[-Wunused-but-set-variable]
  struct ext4_sb_info *sbi;
                       ^~~
Fix this by moving the variable @sbi under CONFIG_UNICODE.

Signed-off-by: Yunfeng Ye 
Reviewed-by: Ritesh Harjani 
Link: https://lore.kernel.org/r/cb5eb904-224a-9701-c38f-cb23514b1fff@huawei.com
Signed-off-by: Theodore Ts'o

ext4: fix ext4_empty_dir() for directories with holes

2019-12-14T22:22:45+00:00

Function ext4_empty_dir() doesn't correctly handle directories with
holes and crashes on bh->b_data dereference when bh is NULL. Reorganize
the loop to use 'offset' variable all the times instead of comparing
pointers to current direntry with bh->b_data pointer. Also add more
strict checking of '.' and '..' directory entries to avoid entering loop
in possibly invalid state on corrupted filesystems.

References: CVE-2019-19037
CC: stable@vger.kernel.org
Fixes: 4e19d6b65fb4 ("ext4: allow directory holes")
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20191202170213.4761-2-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: work around deleting a file with i_nlink == 0 safely

2019-11-19T17:25:21+00:00

If the file system is corrupted such that a file's i_links_count is
too small, then it's possible that when unlinking that file, i_nlink
will already be zero.  Previously we were working around this kind of
corruption by forcing i_nlink to one; but we were doing this before
trying to delete the directory entry --- and if the file system is
corrupted enough that ext4_delete_entry() fails, then we exit with
i_nlink elevated, and this causes the orphan inode list handling to be
FUBAR'ed, such that when we unmount the file system, the orphan inode
list can get corrupted.

A better way to fix this is to simply skip trying to call drop_nlink()
if i_nlink is already zero, thus moving the check to the place where
it makes the most sense.

https://bugzilla.kernel.org/show_bug.cgi?id=205433

Link: https://lore.kernel.org/r/20191112032903.8828-1-tytso@mit.edu
Signed-off-by: Theodore Ts'o 
Cc: stable@kernel.org
Reviewed-by: Andreas Dilger

ext4: Do not iput inode under running transaction

2019-11-05T17:13:25+00:00

When ext4_mkdir(), ext4_symlink(), ext4_create(), or ext4_mknod() fail
to add entry into directory, it ends up dropping freshly created inode
under the running transaction and thus inode truncation happens under
that transaction. That breaks assumptions that evict() does not get
called from a transaction context and at least in ext4_symlink() case it
can result in inode eviction deadlocking in inode_wait_for_writeback()
when flush worker finds symlink inode, starts to write it back and
blocks on starting a transaction. So change the code in ext4_mkdir() and
ext4_add_nondir() to drop inode reference only after the transaction is
stopped. We also have to add inode to the orphan list in that case as
otherwise the inode would get leaked in case we crash before inode
deletion is committed.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20191105164437.32602-5-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: Move marking of handle as sync to ext4_add_nondir()

2019-11-05T17:13:25+00:00

Every caller of ext4_add_nondir() marks handle as sync if directory has
DIRSYNC set. Move this marking to ext4_add_nondir() so reduce some
duplication.

Signed-off-by: Jan Kara 
Link: https://lore.kernel.org/r/20191105164437.32602-4-jack@suse.cz
Signed-off-by: Theodore Ts'o

ext4: fix kernel oops caused by spurious casefold flag

2019-09-03T05:43:17+00:00

If an directory has the a casefold flag set without the casefold
feature set, s_encoding will not be initialized, and this will cause
the kernel to dereference a NULL pointer.  In addition to adding
checks to avoid these kernel oops, attempts to load inodes with the
casefold flag when the casefold feature is not enable will cause the
file system to be declared corrupted.

Signed-off-by: Theodore Ts'o

ext4: fix coverity warning on error path of filename setup

2019-07-02T21:56:12+00:00

Fix the following coverity warning reported by Dan Carpenter:

fs/ext4/namei.c:1311 ext4_fname_setup_ci_filename()
	  warn: 'cf_name->len' unsigned <= 0

Fixes: 3ae72562ad91 ("ext4: optimize case-insensitive lookups")
Signed-off-by: Gabriel Krisman Bertazi 
Signed-off-by: Theodore Ts'o 
Reported-by: Dan Carpenter

ext4: rename htree_inline_dir_to_tree() to ext4_inlinedir_to_tree()

2019-06-22T01:57:00+00:00

Clean up namespace pollution by the inline_data code.

Signed-off-by: Theodore Ts'o

ext4: refactor initialize_dirent_tail()

2019-06-21T20:31:47+00:00

Move the calculation of the location of the dirent tail into
initialize_dirent_tail().  Also prefix the function with ext4_ to fix
kernel namepsace polution.

Signed-off-by: Theodore Ts'o

ext4: rename "dirent_csum" functions to use "dirblock"

2019-06-21T19:49:26+00:00

Functions such as ext4_dirent_csum_verify() and ext4_dirent_csum_set()
don't actually operate on a directory entry, but a directory block.
And while they take a struct ext4_dir_entry *dirent as an argument, it
had better be the first directory at the beginning of the direct
block, or things will go very wrong.

Rename the following functions so that things make more sense, and
remove a lot of confusing casts along the way:

   ext4_dirent_csum_verify	 -> ext4_dirblock_csum_verify
   ext4_dirent_csum_set		 -> ext4_dirblock_csum_set
   ext4_dirent_csum		 -> ext4_dirblock_csum
   ext4_handle_dirty_dirent_node -> ext4_handle_dirty_dirblock

Signed-off-by: Theodore Ts'o