Commit graph

565612 commits

Author SHA1 Message Date
Chao Yu
b3cba4ddf8 f2fs: measure inode.i_blocks as generic filesystem
Both in memory or on disk, generic filesystems record i_blocks with
512bytes sized sector count, also VFS sub module such as disk quota
follows this rule, but f2fs records it with 4096bytes sized block
count, this difference leads to that once we use dquota's function
which inc/dec iblocks, it will make i_blocks of f2fs being inconsistent
between in memory and on disk.

In order to resolve this issue, this patch changes to make in-memory
i_blocks of f2fs recording sector count instead of block count,
meanwhile leaving on-disk i_blocks recording block count.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:56 -07:00
Chao Yu
8a4c673301 f2fs: set CP_TRIMMED_FLAG correctly
Don't set CP_TRIMMED_FLAG for non-zoned block device or discard
unsupported device, it can avoid to trigger unneeded checkpoint for
that kind of device.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:55 -07:00
Eric Biggers
4e968ec7cb f2fs: require key for truncate(2) of encrypted file
Currently, filesystems allow truncate(2) on an encrypted file without
the encryption key.  However, it's impossible to correctly handle the
case where the size being truncated to is not a multiple of the
filesystem block size, because that would require decrypting the final
block, zeroing the part beyond i_size, then encrypting the block.

As other modifications to encrypted file contents are prohibited without
the key, just prohibit truncate(2) as well, making it fail with ENOKEY.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:53 -07:00
Chao Yu
06fc88a60d f2fs: move sysfs code from super.c to fs/f2fs/sysfs.c
Codes related to sysfs and procfs are dispersive and mixed with sb
related codes, but actually these codes are independent from others,
so split them from super.c, and reorgnize and manger them in sysfs.c.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

 Conflicts:
	fs/f2fs/super.c
2017-07-13 16:56:51 -07:00
Chao Yu
1fb6bf71cd f2fs: clean up sysfs codes
Just cleanup.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:49 -07:00
Chao Yu
b9ee759fbc f2fs: fix wrong error number of fill_super
This patch fixes incorrect error number in error path of fill_super.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:47 -07:00
Chao Yu
47871a830a f2fs: fix to show injection rate in ->show_options
If fault injection functionality is enabled, show additional injection
rate in ->show_options.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:46 -07:00
Christophe JAILLET
fb35965422 f2fs: Fix a return value in case of error in 'f2fs_fill_super'
err must be set to -ENOMEM, otherwise we return 0.

Fixes: a912b54d3aaa0 ("f2fs: split bio cache")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:44 -07:00
Tiezhu Yang
e1640316b9 f2fs: use proper variable name
It is better to use variable name "inline_dentry" instead of "dentry_blk"
when data type is "struct f2fs_inline_dentry". This patch has no functional
changes, just to make code more readable especially when call the function
make_dentry_ptr_inline() and f2fs_convert_inline_dir().

Signed-off-by: Tiezhu Yang <kernelpatch@126.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:42 -07:00
Chao Yu
82aed6f9d7 f2fs: fix to avoid panic when encountering corrupt node
With fault_injection option, generic/361 of fstests will complain us
with below message:

Call Trace:
 get_node_page+0x12/0x20 [f2fs]
 f2fs_iget+0x92/0x7d0 [f2fs]
 f2fs_fill_super+0x10fb/0x15e0 [f2fs]
 mount_bdev+0x184/0x1c0
 f2fs_mount+0x15/0x20 [f2fs]
 mount_fs+0x39/0x150
 vfs_kern_mount+0x67/0x110
 do_mount+0x1bb/0xc70
 SyS_mount+0x83/0xd0
 do_syscall_64+0x6e/0x160
 entry_SYSCALL64_slow_path+0x25/0x25

Since mkfs loop device in f2fs partition can be failed silently due to
checkpoint error injection, so root inode page can be corrupted, in order
to avoid needless panic, in get_node_page, it's better to leave message
and return error to caller, and let fsck repaire it later.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:41 -07:00
Chao Yu
958022601a f2fs: don't track newly allocated nat entry in list
We will never persist newly allocated nat entries during checkpoint(), so
we don't need to track such nat entries in nat dirty list in order to
avoid:
- more latency during traversing dirty list;
- sorting nat sets incorrectly due to recording wrong entry_cnt in nat
entry set.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:39 -07:00
Chao Yu
f3fb4448d8 f2fs: add f2fs_bug_on in __remove_discard_cmd
Recently, discard related codes have changed a lot, so add f2fs_bug_on to
detect potential bug.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:37 -07:00
Chao Yu
4798bcc808 f2fs: introduce __wait_one_discard_bio
In order to avoid copied codes.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:36 -07:00
Qiuyang Sun
11de19dfa7 f2fs: dax: fix races between page faults and truncating pages
Currently in F2FS, page faults and operations that truncate the pagecahe
or data blocks, are completely unsynchronized. This can result in page
fault faulting in a page into a range that we are changing after
truncating, and thus we can end up with a page mapped to disk blocks that
will be shortly freed. Filesystem corruption will shortly follow.

This patch fixes the problem by creating new rw semaphore i_mmap_sem in
f2fs_inode_info and grab it for functions removing blocks from extent tree
and for read over page faults. The mechanism is similar to that in ext4.

Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

 Conflicts:
	fs/f2fs/file.c
2017-07-13 16:56:34 -07:00
Fan Li
9ddde7dfd1 f2fs: simplify the way of calulating next nat address
The index of segment which the next nat block is in has only one different
bit than the current one, so to get the next nat address, we can simply
alter that one bit.

Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:32 -07:00
Jin Qian
1479b6ffeb f2fs: sanity check size of nat and sit cache
Make sure number of entires doesn't exceed max journal size.

Cc: stable@vger.kernel.org
Signed-off-by: Jin Qian <jinqian@android.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:30 -07:00
Yunlei He
83f42def8a f2fs: fix a panic caused by NULL flush_cmd_control
Mount fs with option noflush_merge, boot failed for illegal address
fcc in function f2fs_issue_flush:

        if (!test_opt(sbi, FLUSH_MERGE)) {
                ret = submit_flush_wait(sbi);
                atomic_inc(&fcc->issued_flush);   ->  Here, fcc illegal
                return ret;
        }

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:29 -07:00
Zhang Shengju
0a3354135a f2fs: remove the unnecessary cast for PTR_ERR
It's not necessary to specify 'int' casting for PTR_ERR.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:27 -07:00
Jaegeuk Kim
97c0717bd0 f2fs: remove false-positive bug_on
For example,

f2fs_create
 - new_node_page is failed
 - handle_failed_inode
  - skip to add it into orphan list, since ni.blk_addr == NULL_ADDR
   : set_inode_flag(inode, FI_FREE_NID)

f2fs_evict_inode
 - EIO due to fault injection
 - f2fs_bug_on() is triggered

So, we don't need to call f2fs_bug_on in this case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:25 -07:00
Damien Le Moal
46281c4ef5 f2fs: Do not issue small discards in LFS mode
clear_prefree_segments() issues small discards after discarding full
segments. These small discards may not be section aligned, so not zone
aligned on a zoned block device, causing __f2fs_iissue_discard_zone() to fail.
Fix this by not issuing small discards for a volume mounted with the BLKZONED
feature enabled.

Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:24 -07:00
Eric Biggers
6dbf9cbf28 f2fs: don't bother checking for encryption key in ->write_iter()
Since only an open file can be written to, and we only allow open()ing
an encrypted file when its key is available, there is no need to check
for the key again before permitting each ->write_iter().

This code was also broken in that it wouldn't actually have failed if
the key was in fact unavailable.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:22 -07:00
Eric Biggers
f4afd85fc4 f2fs: don't bother checking for encryption key in ->mmap()
Since only an open file can be mmap'ed, and we only allow open()ing an
encrypted file when its key is available, there is no need to check for
the key again before permitting each mmap().

This f2fs copy of this code was also broken in that it wouldn't actually
have failed if the key was in fact unavailable.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:20 -07:00
Chao Yu
b3df3669b7 f2fs: wait discard IO completion without cmd_lock held
Wait discard IO completion outside cmd_lock to avoid long latency
of holding cmd_lock in IO busy scenario.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:19 -07:00
Chao Yu
aa9d75d2f5 f2fs: wake up all waiters in f2fs_submit_discard_endio
There could be more than one waiter waiting discard IO completion, so we
need use complete_all() instead of complete() in f2fs_submit_discard_endio
to avoid hungtask.

Fixes: 	ec9895add2c5 ("f2fs: don't hold cmd_lock during waiting discard
command")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:17 -07:00
Chao Yu
732de6bf9e f2fs: show more info if fail to issue discard
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:15 -07:00
Chao Yu
843d3364d7 f2fs: introduce io_list for serialize data/node IOs
Serialize data/node IOs by using fifo list instead of mutex lock,
it will help to enhance concurrency of f2fs, meanwhile keeping LFS
IO semantics.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:13 -07:00
Chao Yu
f152939829 f2fs: split wio_mutex
Split wio_mutex to adjust different temperature bio cache.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:11 -07:00
Yunlei He
b89cdaf6b9 f2fs: combine huge num of discard rb tree consistence checks
Came across a hungtask caused by huge number of rb tree traversing
during adding discard addrs in cp. This patch combine these consistence
checks and move it to discard thread.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:10 -07:00
Yunlei He
e2b2bed096 f2fs: fix a bug caused by NULL extent tree
Thread A:					Thread B:

-f2fs_remount
    -sbi->mount_opt.opt = 0;
						<--- -f2fs_iget
						         -do_read_inode
							     -f2fs_init_extent_tree
							         -F2FS_I(inode)->extent_tree is NULL
        -default_options && parse_options
	    -remount return
						<---  -f2fs_map_blocks
						          -f2fs_lookup_extent_tree
                                                              -f2fs_bug_on(sbi, !et);

The same problem with f2fs_new_inode.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:08 -07:00
Jaegeuk Kim
842ce444fd f2fs: try to freeze in gc and discard threads
This allows to freeze gc and discard threads.

Cc: stable@vger.kernel.org
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:06 -07:00
Yunlei He
800a48334f f2fs: add a new function get_ssr_cost
This patch add a new method get_ssr_cost to select
SSR segment more accurately.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:04 -07:00
Hou Pengyang
a34df1bce7 f2fs: declare load_free_nid_bitmap static
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:03 -07:00
Jaegeuk Kim
5d6951b8e1 f2fs: avoid f2fs_lock_op for IPU writes
Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp):            Process B:
f2fs_lock_all(sbi)
                        get_dnode_of_data <---- lock dn.node_page
flush_nodes             f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:56:01 -07:00
Jaegeuk Kim
a3b6a40969 f2fs: split bio cache
Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

 Conflicts:
	include/trace/events/f2fs.h
2017-07-13 16:55:59 -07:00
Jaegeuk Kim
e61d650436 f2fs: use fio instead of multiple parameters
This patch just changes using fio instead of parameters.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:58 -07:00
Jaegeuk Kim
4a6ac1475b f2fs: remove unnecessary read cases in merged IO flow
Merged IO flow doesn't need to care about read IOs.

f2fs_submit_merged_bio -> f2fs_submit_merged_write
f2fs_submit_merged_bios -> f2fs_submit_merged_writes
f2fs_submit_merged_bio_cond -> f2fs_submit_merged_write_cond

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:56 -07:00
Jaegeuk Kim
74683b0ea0 f2fs: use f2fs_submit_page_bio for ra_meta_pages
This patch avoids to use f2fs_submit_merged_bio for read, which was the only
read case.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:54 -07:00
Weichao Guo
71a2058ae6 f2fs: make sure f2fs_gc returns consistent errno
By default, f2fs_gc returns -EINVAL in general error cases, e.g., no victim
was selected. However, the default errno may be overwritten in two cases:
gc_more and BG_GC -> FG_GC. We should return consistent errno in such cases.

Signed-off-by: Weichao Guo <guoweichao@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:53 -07:00
Jaegeuk Kim
34c2b318e3 f2fs: load inode's flag from disk
This patch fixes missing inode flag loaded from disk, reported by Tom.

[tom@localhost ~]$ sudo mount /dev/loop0 /mnt/
[tom@localhost ~]$ sudo chown tom:tom /mnt/
[tom@localhost ~]$ touch /mnt/testfile
[tom@localhost ~]$ sudo chattr +i /mnt/testfile
[tom@localhost ~]$ echo test > /mnt/testfile
bash: /mnt/testfile: Operation not permitted
[tom@localhost ~]$ rm /mnt/testfile
rm: cannot remove '/mnt/testfile': Operation not permitted
[tom@localhost ~]$ sudo umount /mnt/
[tom@localhost ~]$ sudo mount /dev/loop0 /mnt/
[tom@localhost ~]$ lsattr /mnt/testfile
----i-------------- /mnt/testfile
[tom@localhost ~]$ echo test > /mnt/testfile
[tom@localhost ~]$ rm /mnt/testfile
[tom@localhost ~]$ sudo umount /mnt/

Cc: stable@vger.kernel.org
Reported-by: Tom Yan <tom.ty89@outlook.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:51 -07:00
Jin Qian
cc46114919 f2fs: sanity check checkpoint segno and blkoff
Make sure segno and blkoff read from raw image are valid.

Cc: stable@vger.kernel.org
Signed-off-by: Jin Qian <jinqian@google.com>
[Jaegeuk Kim: adjust minor coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-13 16:55:49 -07:00
Jaegeuk Kim
6190400da0 f2fs, block_dump: give WRITE direction to submit_bio
The block_dump in submit_bio uses rw, instead of bio->bi_rw.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-07 13:06:40 -07:00
Eric Biggers
a156aa8444 fscrypt: correct collision claim for digested names
As I noted on the mailing list, it's easier than I originally thought to
create intentional collisions in the digested names.  Unfortunately it's
not too easy to solve this, so for now just fix the comment to not lie.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:56 -07:00
Eric Biggers
a1425ed239 f2fs: switch to using fscrypt_match_name()
Switch f2fs directory searches to use the fscrypt_match_name() helper
function.  There should be no functional change.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:55 -07:00
Eric Biggers
8c66df6c7a fscrypt: introduce helper function for filename matching
Introduce a helper function fscrypt_match_name() which tests whether a
fscrypt_name matches a directory entry.  Also clean up the magic numbers
and document things properly.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:55 -07:00
Eric Biggers
48c7f9c819 fscrypt: fix context consistency check when key(s) unavailable
To mitigate some types of offline attacks, filesystem encryption is
designed to enforce that all files in an encrypted directory tree use
the same encryption policy (i.e. the same encryption context excluding
the nonce).  However, the fscrypt_has_permitted_context() function which
enforces this relies on comparing struct fscrypt_info's, which are only
available when we have the encryption keys.  This can cause two
incorrect behaviors:

1. If we have the parent directory's key but not the child's key, or
   vice versa, then fscrypt_has_permitted_context() returned false,
   causing applications to see EPERM or ENOKEY.  This is incorrect if
   the encryption contexts are in fact consistent.  Although we'd
   normally have either both keys or neither key in that case since the
   master_key_descriptors would be the same, this is not guaranteed
   because keys can be added or removed from keyrings at any time.

2. If we have neither the parent's key nor the child's key, then
   fscrypt_has_permitted_context() returned true, causing applications
   to see no error (or else an error for some other reason).  This is
   incorrect if the encryption contexts are in fact inconsistent, since
   in that case we should deny access.

To fix this, retrieve and compare the fscrypt_contexts if we are unable
to set up both fscrypt_infos.

While this slightly hurts performance when accessing an encrypted
directory tree without the key, this isn't a case we really need to be
optimizing for; access *with* the key is much more important.
Furthermore, the performance hit is barely noticeable given that we are
already retrieving the fscrypt_context and doing two keyring searches in
fscrypt_get_encryption_info().  If we ever actually wanted to optimize
this case we might start by caching the fscrypt_contexts.

Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:54 -07:00
Joe Richey
171695f2ab fscrypt: Move key structure and constants to uapi
This commit exposes the necessary constants and structures for a
userspace program to pass filesystem encryption keys into the keyring.
The fscrypt_key structure was already part of the kernel ABI, this
change just makes it so programs no longer have to redeclare these
structures (like e4crypt in e2fsprogs currently does).

Note that we do not expose the other FS_*_KEY_SIZE constants as they are
not necessary. Only XTS is supported for contents_encryption_mode, so
currently FS_MAX_KEY_SIZE bytes of key material must always be passed to
the kernel.

This commit also removes __packed from fscrypt_key as it does not
contain any implicit padding and does not refer to an on-disk structure.

Signed-off-by: Joe Richey <joerichey@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:53 -07:00
Eric Biggers
c24873a651 fscrypt: remove fscrypt_symlink_data_len()
fscrypt_symlink_data_len() is never called and can be removed.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 18:10:52 -07:00
Eric Biggers
31469fc248 fscrypt: remove unnecessary checks for NULL operations
The functions in fs/crypto/*.c are only called by filesystems configured
with encryption support.  Since the ->get_context(), ->set_context(),
and ->empty_dir() operations are always provided in that case (and must
be, otherwise there would be no way to get/set encryption policies, or
in the case of ->get_context() even access encrypted files at all),
there is no need to check for these operations being NULL and we can
remove these unneeded checks.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-05-08 17:36:10 -07:00
Eric Biggers
0addb61dc7 fscrypt: eliminate ->prepare_context() operation
The only use of the ->prepare_context() fscrypt operation was to allow
ext4 to evict inline data from the inode before ->set_context().
However, there is no reason why this cannot be done as simply the first
step in ->set_context(), and in fact it makes more sense to do it that
way because then the policy modes and flags get validated before any
real work is done.  Therefore, merge ext4_prepare_context() into
ext4_set_context(), and remove ->prepare_context().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

 Conflicts:
	fs/ext4/super.c
2017-05-08 17:35:42 -07:00
Eric Biggers
e9dbf926ed fscrypt: remove broken support for detecting keyring key revocation
Filesystem encryption ostensibly supported revoking a keyring key that
had been used to "unlock" encrypted files, causing those files to become
"locked" again.  This was, however, buggy for several reasons, the most
severe of which was that when key revocation happened to be detected for
an inode, its fscrypt_info was immediately freed, even while other
threads could be using it for encryption or decryption concurrently.
This could be exploited to crash the kernel or worse.

This patch fixes the use-after-free by removing the code which detects
the keyring key having been revoked, invalidated, or expired.  Instead,
an encrypted inode that is "unlocked" now simply remains unlocked until
it is evicted from memory.  Note that this is no worse than the case for
block device-level encryption, e.g. dm-crypt, and it still remains
possible for a privileged user to evict unused pages, inodes, and
dentries by running 'sync; echo 3 > /proc/sys/vm/drop_caches', or by
simply unmounting the filesystem.  In fact, one of those actions was
already needed anyway for key revocation to work even somewhat sanely.
This change is not expected to break any applications.

In the future I'd like to implement a real API for fscrypt key
revocation that interacts sanely with ongoing filesystem operations ---
waiting for existing operations to complete and blocking new operations,
and invalidating and sanitizing key material and plaintext from the VFS
caches.  But this is a hard problem, and for now this bug must be fixed.

This bug affected almost all versions of ext4, f2fs, and ubifs
encryption, and it was potentially reachable in any kernel configured
with encryption support (CONFIG_EXT4_ENCRYPTION=y,
CONFIG_EXT4_FS_ENCRYPTION=y, CONFIG_F2FS_FS_ENCRYPTION=y, or
CONFIG_UBIFS_FS_ENCRYPTION=y).  Note that older kernels did not use the
shared fs/crypto/ code, but due to the potential security implications
of this bug, it may still be worthwhile to backport this fix to them.

Fixes: b7236e21d5 ("ext4 crypto: reorganize how we store keys in the inode")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Michael Halcrow <mhalcrow@google.com>
2017-05-08 17:33:50 -07:00