Commit Graph

50492 Commits

Author SHA1 Message Date
Al Viro
ca1579f6c6 Merge remote-tracking branch 'jl/locks-4.13' into work.misc-set_fs 2017-06-26 23:52:33 -04:00
Will Deacon
3edb1dd13c Merge branch 'aarch64/for-next/ras-apei' into aarch64/for-next/core
Merge in arm64 ACPI RAS support (APEI/GHES) from Tyler Baicar.
2017-06-26 10:54:27 +01:00
Brian Foster
39775431f8 xfs: free uncommitted transactions during log recovery
Log recovery allocates in-core transaction and member item data
structures on-demand as it processes the on-disk log. Transactions
are allocated on first encounter on-disk and stored in a hash table
structure where they are easily accessible for subsequent lookups.
Transaction items are also allocated on demand and are attached to
the associated transactions.

When a commit record is encountered in the log, the transaction is
committed to the fs and the in-core structures are freed. If a
filesystem crashes or shuts down before all in-core log buffers are
flushed to the log, however, not all transactions may have commit
records in the log. As expected, the modifications in such an
incomplete transaction are not replayed to the fs. The in-core data
structures for the partial transaction are never freed, however,
resulting in a memory leak.

Update xlog_do_recovery_pass() to first correctly initialize the
hash table array so empty lists can be distinguished from populated
lists on function exit. Update xlog_recover_free_trans() to always
remove the transaction from the list prior to freeing the associated
memory. Finally, walk the hash table of transaction lists as the
last step before it goes out of scope and free any transactions that
may remain on the lists. This prevents a memory leak of partial
transactions in the log.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-24 10:11:41 -07:00
Ingo Molnar
1bc3cd4dfa Merge branch 'linus' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-24 08:57:20 +02:00
Eric Biggers
c250b7dd8e fscrypt: make ->dummy_context() return bool
This makes it consistent with ->is_encrypted(), ->empty_dir(), and
fscrypt_dummy_context_enabled().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 20:11:50 -04:00
Daniel Walter
b7e7cf7a66 fscrypt: add support for AES-128-CBC
fscrypt provides facilities to use different encryption algorithms which
are selectable by userspace when setting the encryption policy. Currently,
only AES-256-XTS for file contents and AES-256-CBC-CTS for file names are
implemented. This is a clear case of kernel offers the mechanism and
userspace selects a policy. Similar to what dm-crypt and ecryptfs have.

This patch adds support for using AES-128-CBC for file contents and
AES-128-CBC-CTS for file name encryption. To mitigate watermarking
attacks, IVs are generated using the ESSIV algorithm. While AES-CBC is
actually slightly less secure than AES-XTS from a security point of view,
there is more widespread hardware support. Using AES-CBC gives us the
acceptable performance while still providing a moderate level of security
for persistent storage.

Especially low-powered embedded devices with crypto accelerators such as
CAAM or CESA often only support AES-CBC. Since using AES-CBC over AES-XTS
is basically thought of a last resort, we use AES-128-CBC over AES-256-CBC
since it has less encryption rounds and yields noticeable better
performance starting from a file size of just a few kB.

Signed-off-by: Daniel Walter <dwalter@sigma-star.at>
[david@sigma-star.at: addressed review comments]
Signed-off-by: David Gstir <david@sigma-star.at>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 20:05:07 -04:00
Eric Biggers
27e47a6342 fscrypt: inline fscrypt_free_filename()
fscrypt_free_filename() only needs to do a kfree() of crypto_buf.name,
which works well as an inline function.  We can skip setting the various
pointers to NULL, since no user cares about it (the name is always freed
just before it goes out of scope).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 19:59:08 -04:00
Eric Biggers
63136858ae ext4: 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>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 19:48:44 -04:00
Eric Biggers
66e0aaadce ext4: 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().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 19:41:38 -04:00
Linus Torvalds
337c6ba2d8 Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
 "8 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  fs/exec.c: account for argv/envp pointers
  ocfs2: fix deadlock caused by recursive locking in xattr
  slub: make sysfs file removal asynchronous
  lib/cmdline.c: fix get_options() overflow while parsing ranges
  fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
  autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL
  mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge vmap mappings
  mm, thp: remove cond_resched from __collapse_huge_page_copy
2017-06-23 16:30:52 -07:00
Kees Cook
98da7d0885 fs/exec.c: account for argv/envp pointers
When limiting the argv/envp strings during exec to 1/4 of the stack limit,
the storage of the pointers to the strings was not included.  This means
that an exec with huge numbers of tiny strings could eat 1/4 of the stack
limit in strings and then additional space would be later used by the
pointers to the strings.

For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721
single-byte strings would consume less than 2MB of stack, the max (8MB /
4) amount allowed, but the pointers to the strings would consume the
remaining additional stack space (1677721 * 4 == 6710884).

The result (1677721 + 6710884 == 8388605) would exhaust stack space
entirely.  Controlling this stack exhaustion could result in
pathological behavior in setuid binaries (CVE-2017-1000365).

[akpm@linux-foundation.org: additional commenting from Kees]
Fixes: b6a2fea393 ("mm: variable length argument support")
Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-23 16:15:56 -07:00
Eric Ren
8818efaaac ocfs2: fix deadlock caused by recursive locking in xattr
Another deadlock path caused by recursive locking is reported.  This
kind of issue was introduced since commit 743b5f1434 ("ocfs2: take
inode lock in ocfs2_iop_set/get_acl()").  Two deadlock paths have been
fixed by commit b891fa5024 ("ocfs2: fix deadlock issue when taking
inode lock at vfs entry points").  Yes, we intend to fix this kind of
case in incremental way, because it's hard to find out all possible
paths at once.

This one can be reproduced like this.  On node1, cp a large file from
home directory to ocfs2 mountpoint.  While on node2, run
setfacl/getfacl.  Both nodes will hang up there.  The backtraces:

On node1:
  __ocfs2_cluster_lock.isra.39+0x357/0x740 [ocfs2]
  ocfs2_inode_lock_full_nested+0x17d/0x840 [ocfs2]
  ocfs2_write_begin+0x43/0x1a0 [ocfs2]
  generic_perform_write+0xa9/0x180
  __generic_file_write_iter+0x1aa/0x1d0
  ocfs2_file_write_iter+0x4f4/0xb40 [ocfs2]
  __vfs_write+0xc3/0x130
  vfs_write+0xb1/0x1a0
  SyS_write+0x46/0xa0

On node2:
  __ocfs2_cluster_lock.isra.39+0x357/0x740 [ocfs2]
  ocfs2_inode_lock_full_nested+0x17d/0x840 [ocfs2]
  ocfs2_xattr_set+0x12e/0xe80 [ocfs2]
  ocfs2_set_acl+0x22d/0x260 [ocfs2]
  ocfs2_iop_set_acl+0x65/0xb0 [ocfs2]
  set_posix_acl+0x75/0xb0
  posix_acl_xattr_set+0x49/0xa0
  __vfs_setxattr+0x69/0x80
  __vfs_setxattr_noperm+0x72/0x1a0
  vfs_setxattr+0xa7/0xb0
  setxattr+0x12d/0x190
  path_setxattr+0x9f/0xb0
  SyS_setxattr+0x14/0x20

Fix this one by using ocfs2_inode_{lock|unlock}_tracker, which is
exported by commit 439a36b8ef ("ocfs2/dlmglue: prepare tracking logic
to avoid recursive cluster lock").

Link: http://lkml.kernel.org/r/20170622014746.5815-1-zren@suse.com
Fixes: 743b5f1434 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()")
Signed-off-by: Eric Ren <zren@suse.com>
Reported-by: Thomas Voegtle <tv@lio96.de>
Tested-by: Thomas Voegtle <tv@lio96.de>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-23 16:15:55 -07:00
Jan Kara
1eb643d02b fs/dax.c: fix inefficiency in dax_writeback_mapping_range()
dax_writeback_mapping_range() fails to update iteration index when
searching radix tree for entries needing cache flushing.  Thus each
pagevec worth of entries is searched starting from the start which is
inefficient and prone to livelocks.  Update index properly.

Link: http://lkml.kernel.org/r/20170619124531.21491-1-jack@suse.cz
Fixes: 9973c98ecf ("dax: add support for fsync/sync")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-23 16:15:55 -07:00
NeilBrown
9fa4eb8e49 autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL
If a positive status is passed with the AUTOFS_DEV_IOCTL_FAIL ioctl,
autofs4_d_automount() will return

   ERR_PTR(status)

with that status to follow_automount(), which will then dereference an
invalid pointer.

So treat a positive status the same as zero, and map to ENOENT.

See comment in systemd src/core/automount.c::automount_send_ready().

Link: http://lkml.kernel.org/r/871sqwczx5.fsf@notabene.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.com>
Cc: Ian Kent <raven@themaw.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-23 16:15:55 -07:00
Linus Torvalds
7b249bdc3d Merge tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
 "I have one more bugfix for you for 4.12-rc7 to fix a disk corruption
  problem:

   - don't allow swapon on files on the realtime device, because the
     swap code will swap pages out to blocks on the data device, thereby
     corrupting the filesystem"

* tag 'xfs-4.12-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: don't allow bmap on rt files
2017-06-23 12:23:06 -07:00
Jeff Mahoney
08db141b53 reiserfs: fix race in prealloc discard
The main loop in __discard_prealloc is protected by the reiserfs write lock
which is dropped across schedules like the BKL it replaced.  The problem is
that it checks the value, calls a routine that schedules, and then adjusts
the state.  As a result, two threads that are calling
reiserfs_prealloc_discard at the same time can race when one calls
reiserfs_free_prealloc_block, the lock is dropped, and the other calls
reiserfs_free_prealloc_block with the same block number.  In the right
circumstances, it can cause the prealloc count to go negative.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-06-23 09:40:30 +02:00
Jeff Mahoney
54930dfeb4 reiserfs: don't preallocate blocks for extended attributes
Most extended attributes will fit in a single block.  More importantly,
we drop the reference to the inode while holding the transaction open
so the preallocated blocks aren't released.  As a result, the inode
may be evicted before it's removed from the transaction's prealloc list
which can cause memory corruption.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2017-06-23 09:40:24 +02:00
Chao Yu
1ea1516fbb ext4: check return value of kstrtoull correctly in reserved_clusters_store
kstrtoull returns 0 on success, however, in reserved_clusters_store we
will return -EINVAL if kstrtoull returns 0, it makes us fail to update
reserved_clusters value through sysfs.

Fixes: 76d33bca55
Cc: stable@vger.kernel.org # 4.4
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 01:08:22 -04:00
Darrick J. Wong
4a4956249d ext4: fix off-by-one fsmap error on 1k block filesystems
For 1k-block filesystems, the filesystem starts at block 1, not block 0.
This fact is recorded in s_first_data_block, so use that to bump up the
start_fsb before we start querying the filesystem for its space map.
Without this, ext4/026 fails on 1k block ext4 because various functions
(notably ext4_get_group_no_and_offset) don't know what to do with an
fsblock that is "before" the start of the filesystem and return garbage
results (blockgroup 2^32-1, etc.) that confuse fsmap.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 00:58:57 -04:00
Theodore Ts'o
bdddf34279 ext4: return EFSBADCRC if a bad checksum error is found in ext4_find_entry()
Previously a bad directory block with a bad checksum is skipped; we
should be returning EFSBADCRC (aka EBADMSG).

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23 00:47:05 -04:00
Khazhismel Kumykov
6febe6f253 ext4: return EIO on read error in ext4_find_entry
Previously, a read error would be ignored and we would eventually return
NULL from ext4_find_entry, which signals "no such file or directory". We
should be returning EIO.

Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
2017-06-23 00:29:05 -04:00
Eric Biggers
9ce0151a47 ext4: forbid encrypting root directory
Currently it's possible to encrypt all files and directories on an ext4
filesystem by deleting everything, including lost+found, then setting an
encryption policy on the root directory.  However, this is incompatible
with e2fsck because e2fsck expects to find, create, and/or write to
lost+found and does not have access to any encryption keys.  Especially
problematic is that if e2fsck can't find lost+found, it will create it
without regard for whether the root directory is encrypted.  This is
wrong for obvious reasons, and it causes a later run of e2fsck to
consider the lost+found directory entry to be corrupted.

Encrypting the root directory may also be of limited use because it is
the "all-or-nothing" use case, for which dm-crypt can be used instead.
(By design, encryption policies are inherited and cannot be overridden;
so the root directory having an encryption policy implies that all files
and directories on the filesystem have that same encryption policy.)

In any case, encrypting the root directory is broken currently and must
not be allowed; so start returning an error if userspace requests it.
For now only do this in ext4, because f2fs and ubifs do not appear to
have the lost+found requirement.  We could move it into
fscrypt_ioctl_set_policy() later if desired, though.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
2017-06-23 00:10:36 -04:00
Daeho Jeong
a015434480 ext4: send parallel discards on commit completions
Now, when we mount ext4 filesystem with '-o discard' option, we have to
issue all the discard commands for the blocks to be deallocated and
wait for the completion of the commands on the commit complete phase.
Because this procedure might involve a lot of sequential combinations of
issuing discard commands and waiting for that, the delay of this
procedure might be too much long, even to 17.0s in our test,
and it results in long commit delay and fsync() performance degradation.

To reduce this kind of delay, instead of adding callback for each
extent and handling all of them in a sequential manner on commit phase,
we instead add a separate list of extents to free to the superblock and
then process this list at once after transaction commits so that
we can issue all the discard commands in a parallel manner like XFS
filesystem.

Finally, we could enhance the discard command handling performance.
The result was such that 17.0s delay of a single commit in the worst
case has been enhanced to 4.8s.

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Hobin Woo <hobin.woo@samsung.com>
Tested-by: Kitae Lee <kitae87.lee@samsung.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2017-06-22 23:54:33 -04:00
Jan Kara
3abb1a0fc2 ext4: avoid unnecessary stalls in ext4_evict_inode()
These days inode reclaim calls evict_inode() only when it has no pages
in the mapping.  In that case it is not necessary to wait for transaction
commit in ext4_evict_inode() as there can be no pages waiting to be
committed.  So avoid unnecessary transaction waiting in that case.

We still have to keep the check for the case where ext4_evict_inode()
gets called from other paths (e.g. umount) where inode still can have
some page cache pages.

Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 23:49:46 -04:00
Linus Torvalds
a38371cba6 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
 "Various small fixes for stable"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: Fix some return values in case of error in 'crypt_message'
  cifs: remove redundant return in cifs_creation_time_get
  CIFS: Improve readdir verbosity
  CIFS: check if pages is null rather than bv for a failed allocation
  CIFS: Set ->should_dirty in cifs_user_readv()
2017-06-22 11:16:55 -07:00
Tahsin Erdogan
cdb7ee4c63 ext4: add nombcache mount option
The main purpose of mb cache is to achieve deduplication in
extended attributes. In use cases where opportunity for deduplication
is unlikely, it only adds overhead.

Add a mount option to explicitly turn off mb cache.

Suggested-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:55:14 -04:00
Tahsin Erdogan
b9fc761ea2 ext4: strong binding of xattr inode references
To verify that a xattr entry is not pointing to the wrong xattr inode,
we currently check that the target inode has EXT4_EA_INODE_FL flag set and
also the entry size matches the target inode size.

For stronger validation, also incorporate crc32c hash of the value into
the e_hash field. This is done regardless of whether the entry lives in
the inode body or external attribute block.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:53:15 -04:00
Tahsin Erdogan
daf8328172 ext4: eliminate xattr entry e_hash recalculation for removes
When an extended attribute block is modified, ext4_xattr_hash_entry()
recalculates e_hash for the entry that is pointed by s->here. This  is
unnecessary if the modification is to remove an entry.

Currently, if the removed entry is the last one and there are other
entries remaining, hash calculation targets the just erased entry which
has been filled with zeroes and effectively does nothing.  If the removed
entry is not the last one and there are more entries, this time it will
recalculate hash on the next entry which is totally unnecessary.

Fix these by moving the decision on when to recalculate hash to
ext4_xattr_set_entry().

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:52:03 -04:00
Tahsin Erdogan
9c6e7853c5 ext4: reserve space for xattr entries/names
New ea_inode feature allows putting large xattr values into external
inodes.  struct ext4_xattr_entry and the attribute name however have to
remain in the inode extra space or external attribute block.  Once that
space is exhausted, no further entries can be added.  Some of that space
could also be used by values that fit in there at the time of addition.

So, a single xattr entry whose value barely fits in the external block
could prevent further entries being added.

To mitigate the problem, this patch introduces a notion of reserved
space in the external attribute block that cannot be used by value data.
This reserve is enforced when ea_inode feature is enabled.  The amount
of reserve is arbitrarily chosen to be min(block_size/8, 1024).  The
table below shows how much space is reserved for each block size and the
guaranteed mininum number of entries that can be placed in the external
attribute block.

block size     reserved bytes  entries (name length = 16)
 1k            128              3
 2k            256              7
 4k            512             15
 8k            1024            31
16k            1024            31
32k            1024            31
64k            1024            31

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:48:53 -04:00
Tahsin Erdogan
7a9ca53aea quota: add get_inode_usage callback to transfer multi-inode charges
Ext4 ea_inode feature allows storing xattr values in external inodes to
be able to store values that are bigger than a block in size. Ext4 also
has deduplication support for these type of inodes. With deduplication,
the actual storage waste is eliminated but the users of such inodes are
still charged full quota for the inodes as if there was no sharing
happening in the background.

This design requires ext4 to manually charge the users because the
inodes are shared.

An implication of this is that, if someone calls chown on a file that
has such references we need to transfer the quota for the file and xattr
inodes. Current dquot_transfer() function implicitly transfers one inode
charge. With ea_inode feature, we would like to transfer multiple inode
charges.

Add get_inode_usage callback which can interrogate the total number of
inodes that were charged for a given inode.

[ Applied fix from Colin King to make sure the 'ret' variable is
  initialized on the successful return path.  Detected by
  CoverityScan, CID#1446616 ("Uninitialized scalar variable") --tytso]

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jan Kara <jack@suse.cz>
2017-06-22 11:46:48 -04:00
Tahsin Erdogan
dec214d00e ext4: xattr inode deduplication
Ext4 now supports xattr values that are up to 64k in size (vfs limit).
Large xattr values are stored in external inodes each one holding a
single value. Once written the data blocks of these inodes are immutable.

The real world use cases are expected to have a lot of value duplication
such as inherited acls etc. To reduce data duplication on disk, this patch
implements a deduplicator that allows sharing of xattr inodes.

The deduplication is based on an in-memory hash lookup that is a best
effort sharing scheme. When a xattr inode is read from disk (i.e.
getxattr() call), its crc32c hash is added to a hash table. Before
creating a new xattr inode for a value being set, the hash table is
checked to see if an existing inode holds an identical value. If such an
inode is found, the ref count on that inode is incremented. On value
removal the ref count is decremented and if it reaches zero the inode is
deleted.

The quota charging for such inodes is manually managed. Every reference
holder is charged the full size as if there was no sharing happening.
This is consistent with how xattr blocks are also charged.

[ Fixed up journal credits calculation to handle inline data and the
  rare case where an shared xattr block can get freed when two thread
  race on breaking the xattr block sharing. --tytso ]

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:44:55 -04:00
Tahsin Erdogan
30a7eb970c ext4: cleanup transaction restarts during inode deletion
During inode deletion, the number of journal credits that will be
needed is hard to determine.  For that reason we have journal
extend/restart calls in several places.  Whenever a transaction is
restarted, filesystem must be in a consistent state because there is
no atomicity guarantee beyond a restart call.

Add ext4_xattr_ensure_credits() helper function which takes care of
journal extend/restart logic.  It also handles getting jbd2 write
access and dirty metadata calls.  This function is called at every
iteration of handling an ea_inode reference.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:42:09 -04:00
Tahsin Erdogan
02749a4c20 ext4: add ext4_is_quota_file()
IS_NOQUOTA() indicates whether quota is disabled for an inode. Ext4
also uses it to check whether an inode is for a quota file. The
distinction currently doesn't matter because quota is disabled only
for the quota files. When we start disabling quota for other inodes
in the future, we will want to make the distinction clear.

Replace IS_NOQUOTA() call with ext4_is_quota_file() at places where
we are checking for quota files.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:31:25 -04:00
Tahsin Erdogan
47387409ee ext2, ext4: make mb block cache names more explicit
There will be a second mb_cache instance that tracks ea_inodes. Make
existing names more explicit so that it is clear that they refer to
xattr block cache.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 11:28:55 -04:00
Tahsin Erdogan
c07dfcb458 mbcache: make mbcache naming more generic
Make names more generic so that mbcache usage is not limited to
block sharing. In a subsequent patch in the series
("ext4: xattr inode deduplication"), we start using the mbcache code
for sharing xattr inodes. With that patch, old mb_cache_entry.e_block
field could be holding either a block number or an inode number.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 10:29:53 -04:00
Tahsin Erdogan
b6d9029df0 ext4: move struct ext4_xattr_inode_array to xattr.h
Since this is a xattr specific data structure it is cleaner to keep it in
xattr header file.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 10:28:38 -04:00
Tahsin Erdogan
0421a189bc ext4: modify ext4_xattr_ino_array to hold struct inode *
Tracking struct inode * rather than the inode number eliminates the
repeated ext4_xattr_inode_iget() call later. The second call cannot
fail in practice but still requires explanation when it wants to ignore
the return value. Avoid the trouble and make things simple.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-22 10:26:31 -04:00
Darrick J. Wong
eb5e248d50 xfs: don't allow bmap on rt files
bmap returns a dumb LBA address but not the block device that goes with
that LBA.  Swapfiles don't care about this and will blindly assume that
the data volume is the correct blockdev, which is totally bogus for
files on the rt subvolume.  This results in the swap code doing IOs to
arbitrary locations on the data device(!) if the passed in mapping is a
realtime file, so just turn off bmap for rt files.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-06-21 20:27:35 -07:00
Tahsin Erdogan
c1a5d5f6ab ext4: improve journal credit handling in set xattr paths
Both ext4_set_acl() and ext4_set_context() need to be made aware of
ea_inode feature when it comes to credits calculation.

Also add a sufficient credits check in ext4_xattr_set_handle() right
after xattr write lock is grabbed. Original credits calculation is done
outside the lock so there is a possiblity that the initially calculated
credits are not sufficient anymore.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:28:40 -04:00
Tahsin Erdogan
65d3000520 ext4: ext4_xattr_delete_inode() should return accurate errors
In a few places the function returns without trying to pass the actual
error code to the caller. Fix those.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:24:38 -04:00
Tahsin Erdogan
b347e2bcd1 ext4: retry storing value in external inode with xattr block too
When value size is <= EXT4_XATTR_MIN_LARGE_EA_SIZE(), and it
doesn't fit in either inline or xattr block, a second try is made to
store it in an external inode while storing the entry itself in inline
area. There should also be an attempt to store the entry in xattr block.

This patch adds a retry loop to do that. It also makes the caller the
sole decider on whether to store a value in an external inode.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:20:32 -04:00
Tahsin Erdogan
b315529891 ext4: fix credits calculation for xattr inode
When there is no space for a value in xattr block, it may be stored
in an xattr inode even if the value length is less than
EXT4_XATTR_MIN_LARGE_EA_SIZE(). So the current assumption in credits
calculation is wrong.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:16:20 -04:00
Tahsin Erdogan
7cec191894 ext4: fix ext4_xattr_cmp()
When a xattr entry refers to an external inode, the value data is not
available in the inline area so we should not attempt to read it using
value offset.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:14:30 -04:00
Tahsin Erdogan
f6109100ba ext4: fix ext4_xattr_move_to_block()
When moving xattr entries from inline area to a xattr block, entries
that refer to external xattr inodes need special handling because
value data is not available in the inline area but rather should be
read from its external inode.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:11:54 -04:00
Tahsin Erdogan
9bb21cedda ext4: fix ext4_xattr_make_inode_space() value size calculation
ext4_xattr_make_inode_space() is interested in calculating the inline
space used in an inode. When a xattr entry refers to an external inode
the value size indicates the external inode size, not the value size in
the inline area. Change the function to take this into account.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:05:44 -04:00
Tahsin Erdogan
0bd454c04f ext4: ext4_xattr_value_same() should return false for external data
ext4_xattr_value_same() is used as a quick optimization in case the new
xattr value is identical to the previous value. When xattr value is
stored in a xattr inode the check becomes expensive so it is better to
just assume that they are not equal.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 22:02:06 -04:00
Tahsin Erdogan
990461dd85 ext4: add missing le32_to_cpu(e_value_inum) conversions
Two places in code missed converting xattr inode number using
le32_to_cpu().

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 21:59:30 -04:00
Tahsin Erdogan
9096669332 ext4: clean up ext4_xattr_inode_get()
The input and output values of *size parameter are equal on successful
return from ext4_xattr_inode_get().  On error return, the callers ignore
the output value so there is no need to update it.

Also check for NULL return from ext4_bread().  If the actual xattr inode
size happens to be smaller than the expected size, ext4_bread() may
return NULL which would indicate data corruption.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 21:57:36 -04:00
Tahsin Erdogan
bab79b0499 ext4: change ext4_xattr_inode_iget() signature
In general, kernel functions indicate success/failure through their return
values. This function returns the status as an output parameter and reserves
the return value for the inode. Make it follow the general convention.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 21:49:53 -04:00
Tahsin Erdogan
0eefb10758 ext4: extended attribute value size limit is enforced by vfs
EXT4_XATTR_MAX_LARGE_EA_SIZE definition in ext4 is currently unused.
Besides, vfs enforces its own 64k limit which makes the 1MB limit in
ext4 redundant. Remove it.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-21 21:41:37 -04:00