Pull core block IO changes from Jens Axboe:
"The major piece in here is the immutable bio_ve series from Kent, the
rest is fairly minor. It was supposed to go in last round, but
various issues pushed it to this release instead. The pull request
contains:
- Various smaller blk-mq fixes from different folks. Nothing major
here, just minor fixes and cleanups.
- Fix for a memory leak in the error path in the block ioctl code
from Christian Engelmayer.
- Header export fix from CaiZhiyong.
- Finally the immutable biovec changes from Kent Overstreet. This
enables some nice future work on making arbitrarily sized bios
possible, and splitting more efficient. Related fixes to immutable
bio_vecs:
- dm-cache immutable fixup from Mike Snitzer.
- btrfs immutable fixup from Muthu Kumar.
- bio-integrity fix from Nic Bellinger, which is also going to stable"
* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
xtensa: fixup simdisk driver to work with immutable bio_vecs
block/blk-mq-cpu.c: use hotcpu_notifier()
blk-mq: for_each_* macro correctness
block: Fix memory leak in rw_copy_check_uvector() handling
bio-integrity: Fix bio_integrity_verify segment start bug
block: remove unrelated header files and export symbol
blk-mq: uses page->list incorrectly
blk-mq: use __smp_call_function_single directly
btrfs: fix missing increment of bi_remaining
Revert "block: Warn and free bio if bi_end_io is not set"
block: Warn and free bio if bi_end_io is not set
blk-mq: fix initializing request's start time
block: blk-mq: don't export blk_mq_free_queue()
block: blk-mq: make blk_sync_queue support mq
block: blk-mq: support draining mq queue
dm cache: increment bi_remaining when bi_end_io is restored
block: fixup for generic bio chaining
block: Really silence spurious compiler warnings
block: Silence spurious compiler warnings
block: Kill bio_pair_split()
...
The local variable 'pos' in nilfs_ioctl_wrap_copy function can overflow if
a large number was passed to argv->v_index from userspace and the sum of
argv->v_index and argv->v_nmembs exceeds the maximum value of __u64 type
integer (= ~(__u64)0 = 18446744073709551615).
Here, argv->v_index is a 64-bit width argument to specify the start
position of target data items (such as segment number, checkpoint number,
or virtual block address of nilfs), and argv->v_nmembs gives the total
number of the items that userland programs (such as lssu, lscp, or
cleanerd) want to get information about, which also gives the maximum
element count of argv->v_base[] array.
nilfs_ioctl_wrap_copy() calls dofunc() repeatedly and increments the
position variable 'pos' at the end of each iteration if dofunc() itself
didn't update 'pos':
if (pos == ppos)
pos += n;
This patch prevents the overflow here by rejecting pairs of a start
position (argv->v_index) and a total count (argv->v_nmembs) which leads to
the overflow.
[konishi.ryusuke@lab.ntt.co.jp: fix signedness issue]
Signed-off-by: Wenliang Fan <fanwlexca@gmail.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a bug in the function nilfs_segctor_collect, which results in
active data being written to a segment, that is marked as clean. It is
possible, that this segment is selected for a later segment
construction, whereby the old data is overwritten.
The problem shows itself with the following kernel log message:
nilfs_sufile_do_cancel_free: segment 6533 must be clean
Usually a few hours later the file system gets corrupted:
NILFS: bad btree node (blocknr=8748107): level = 0, flags = 0x0, nchildren = 0
NILFS error (device sdc1): nilfs_bmap_last_key: broken bmap (inode number=114660)
The issue can be reproduced with a file system that is nearly full and
with the cleaner running, while some IO intensive task is running.
Although it is quite hard to reproduce.
This is what happens:
1. The cleaner starts the segment construction
2. nilfs_segctor_collect is called
3. sc_stage is on NILFS_ST_SUFILE and segments are freed
4. sc_stage is on NILFS_ST_DAT current segment is full
5. nilfs_segctor_extend_segments is called, which
allocates a new segment
6. The new segment is one of the segments freed in step 3
7. nilfs_sufile_cancel_freev is called and produces an error message
8. Loop around and the collection starts again
9. sc_stage is on NILFS_ST_SUFILE and segments are freed
including the newly allocated segment, which will contain active
data and can be allocated at a later time
10. A few hours later another segment construction allocates the
segment and causes file system corruption
This can be prevented by simply reordering the statements. If
nilfs_sufile_cancel_freev is called before nilfs_segctor_extend_segments
the freed segments are marked as dirty and cannot be allocated any more.
Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Reviewed-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many NILFS2 users were reported about strange file system corruption
(for example):
NILFS: bad btree node (blocknr=185027): level = 0, flags = 0x0, nchildren = 768
NILFS error (device sda4): nilfs_bmap_last_key: broken bmap (inode number=11540)
But such error messages are consequence of file system's issue that takes
place more earlier. Fortunately, Jerome Poulin <jeromepoulin@gmail.com>
and Anton Eliasson <devel@antoneliasson.se> were reported about another
issue not so recently. These reports describe the issue with segctor
thread's crash:
BUG: unable to handle kernel paging request at 0000000000004c83
IP: nilfs_end_page_io+0x12/0xd0 [nilfs2]
Call Trace:
nilfs_segctor_do_construct+0xf25/0x1b20 [nilfs2]
nilfs_segctor_construct+0x17b/0x290 [nilfs2]
nilfs_segctor_thread+0x122/0x3b0 [nilfs2]
kthread+0xc0/0xd0
ret_from_fork+0x7c/0xb0
These two issues have one reason. This reason can raise third issue
too. Third issue results in hanging of segctor thread with eating of
100% CPU.
REPRODUCING PATH:
One of the possible way or the issue reproducing was described by
Jermoe me Poulin <jeromepoulin@gmail.com>:
1. init S to get to single user mode.
2. sysrq+E to make sure only my shell is running
3. start network-manager to get my wifi connection up
4. login as root and launch "screen"
5. cd /boot/log/nilfs which is a ext3 mount point and can log when NILFS dies.
6. lscp | xz -9e > lscp.txt.xz
7. mount my snapshot using mount -o cp=3360839,ro /dev/vgUbuntu/root /mnt/nilfs
8. start a screen to dump /proc/kmsg to text file since rsyslog is killed
9. start a screen and launch strace -f -o find-cat.log -t find
/mnt/nilfs -type f -exec cat {} > /dev/null \;
10. start a screen and launch strace -f -o apt-get.log -t apt-get update
11. launch the last command again as it did not crash the first time
12. apt-get crashes
13. ps aux > ps-aux-crashed.log
13. sysrq+W
14. sysrq+E wait for everything to terminate
15. sysrq+SUSB
Simplified way of the issue reproducing is starting kernel compilation
task and "apt-get update" in parallel.
REPRODUCIBILITY:
The issue is reproduced not stable [60% - 80%]. It is very important to
have proper environment for the issue reproducing. The critical
conditions for successful reproducing:
(1) It should have big modified file by mmap() way.
(2) This file should have the count of dirty blocks are greater that
several segments in size (for example, two or three) from time to time
during processing.
(3) It should be intensive background activity of files modification
in another thread.
INVESTIGATION:
First of all, it is possible to see that the reason of crash is not valid
page address:
NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82
NILFS [nilfs_segctor_complete_write]:2101 segbuf->sb_segnum 6783
Moreover, value of b_page (0x1a82) is 6786. This value looks like segment
number. And b_blocknr with b_size values look like block numbers. So,
buffer_head's pointer points on not proper address value.
Detailed investigation of the issue is discovered such picture:
[-----------------------------SEGMENT 6783-------------------------------]
NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111149024, segbuf->sb_segnum 6783
[-----------------------------SEGMENT 6784-------------------------------]
NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff8802174a6798, bh->b_assoc_buffers.prev ffff880221cffee8
NILFS [nilfs_segctor_do_construct]:2336 nilfs_segctor_assign
NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 1, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6784
NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111150080, segbuf->sb_segnum 6784, segbuf->sb_nbio 0
[----------] ditto
NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111164416, segbuf->sb_segnum 6784, segbuf->sb_nbio 15
[-----------------------------SEGMENT 6785-------------------------------]
NILFS [nilfs_segctor_do_construct]:2310 nilfs_segctor_begin_construction
NILFS [nilfs_segctor_do_construct]:2321 nilfs_segctor_collect
NILFS [nilfs_lookup_dirty_data_buffers]:782 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
NILFS [nilfs_lookup_dirty_data_buffers]:783 bh->b_assoc_buffers.next ffff880219277e80, bh->b_assoc_buffers.prev ffff880221cffc88
NILFS [nilfs_segctor_do_construct]:2367 nilfs_segctor_update_segusage
NILFS [nilfs_segctor_do_construct]:2371 nilfs_segctor_prepare_write
NILFS [nilfs_segctor_do_construct]:2376 nilfs_add_checksums_on_logs
NILFS [nilfs_segctor_do_construct]:2381 nilfs_segctor_write
NILFS [nilfs_segbuf_submit_bh]:575 bh->b_count 2, bh->b_page ffffea000709b000, page->index 0, i_ino 1033103, i_size 25165824
NILFS [nilfs_segbuf_submit_bh]:576 segbuf->sb_segnum 6785
NILFS [nilfs_segbuf_submit_bh]:577 bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8
NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111165440, segbuf->sb_segnum 6785, segbuf->sb_nbio 0
[----------] ditto
NILFS [nilfs_segbuf_submit_bio]:464 bio->bi_sector 111177728, segbuf->sb_segnum 6785, segbuf->sb_nbio 12
NILFS [nilfs_segctor_do_construct]:2399 nilfs_segctor_wait
NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6783
NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6784
NILFS [nilfs_segbuf_wait]:676 segbuf->sb_segnum 6785
NILFS [nilfs_segctor_complete_write]:2100 bh->b_count 0, bh->b_blocknr 13895680, bh->b_size 13897727, bh->b_page 0000000000001a82
BUG: unable to handle kernel paging request at 0000000000001a82
IP: [<ffffffffa024d0f2>] nilfs_end_page_io+0x12/0xd0 [nilfs2]
Usually, for every segment we collect dirty files in list. Then, dirty
blocks are gathered for every dirty file, prepared for write and
submitted by means of nilfs_segbuf_submit_bh() call. Finally, it takes
place complete write phase after calling nilfs_end_bio_write() on the
block layer. Buffers/pages are marked as not dirty on final phase and
processed files removed from the list of dirty files.
It is possible to see that we had three prepare_write and submit_bio
phases before segbuf_wait and complete_write phase. Moreover, segments
compete between each other for dirty blocks because on every iteration
of segments processing dirty buffer_heads are added in several lists of
payload_buffers:
[SEGMENT 6784]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880218bcdf50
[SEGMENT 6785]: bh->b_assoc_buffers.next ffff880218a0d5f8, bh->b_assoc_buffers.prev ffff880222cc7ee8
The next pointer is the same but prev pointer has changed. It means
that buffer_head has next pointer from one list but prev pointer from
another. Such modification can be made several times. And, finally, it
can be resulted in various issues: (1) segctor hanging, (2) segctor
crashing, (3) file system metadata corruption.
FIX:
This patch adds:
(1) setting of BH_Async_Write flag in nilfs_segctor_prepare_write()
for every proccessed dirty block;
(2) checking of BH_Async_Write flag in
nilfs_lookup_dirty_data_buffers() and
nilfs_lookup_dirty_node_buffers();
(3) clearing of BH_Async_Write flag in nilfs_segctor_complete_write(),
nilfs_abort_logs(), nilfs_forget_buffer(), nilfs_clear_dirty_page().
Reported-by: Jerome Poulin <jeromepoulin@gmail.com>
Reported-by: Anton Eliasson <devel@antoneliasson.se>
Cc: Paul Fertser <fercerpav@gmail.com>
Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp>
Cc: Piotr Szymaniak <szarpaj@grubelek.pl>
Cc: Juan Barry Manuel Canham <Linux@riotingpacifist.net>
Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com>
Cc: Elmer Zhang <freeboy6716@gmail.com>
Cc: Kenneth Langga <klangga@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs pile 1 from Al Viro:
"Unfortunately, this merge window it'll have a be a lot of small piles -
my fault, actually, for not keeping #for-next in anything that would
resemble a sane shape ;-/
This pile: assorted fixes (the first 3 are -stable fodder, IMO) and
cleanups + %pd/%pD formats (dentry/file pathname, up to 4 last
components) + several long-standing patches from various folks.
There definitely will be a lot more (starting with Miklos'
check_submount_and_drop() series)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
direct-io: Handle O_(D)SYNC AIO
direct-io: Implement generic deferred AIO completions
add formats for dentry/file pathnames
kvm eventfd: switch to fdget
powerpc kvm: use fdget
switch fchmod() to fdget
switch epoll_ctl() to fdget
switch copy_module_from_fd() to fdget
git simplify nilfs check for busy subtree
ibmasmfs: don't bother passing superblock when not needed
don't pass superblock to hypfs_{mkdir,create*}
don't pass superblock to hypfs_diag_create_files
don't pass superblock to hypfs_vm_create_files()
oprofile: get rid of pointless forward declarations of struct super_block
oprofilefs_create_...() do not need superblock argument
oprofilefs_mkdir() doesn't need superblock argument
don't bother with passing superblock to oprofile_create_stats_files()
oprofile: don't bother with passing superblock to ->create_files()
don't bother passing sb to oprofile_create_files()
coh901318: don't open-code simple_read_from_buffer()
...
Fix the issue with improper counting number of flying bio requests for
BIO_EOPNOTSUPP error detection case.
The sb_nbio must be incremented exactly the same number of times as
complete() function was called (or will be called) because
nilfs_segbuf_wait() will call wail_for_completion() for the number of
times set to sb_nbio:
do {
wait_for_completion(&segbuf->sb_bio_event);
} while (--segbuf->sb_nbio > 0);
Two functions complete() and wait_for_completion() must be called the
same number of times for the same sb_bio_event. Otherwise,
wait_for_completion() will hang or leak.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cp_inodes_count and cp_blocks_count are represented as __le64 type in
on-disk structure (struct nilfs_checkpoint). But analogous fields in
in-core structure (struct nilfs_root) are represented by atomic_t type.
This patch replaces atomic_t on atomic64_t type in representation of
inodes_count and blocks_count fields in struct nilfs_root.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Joern Engel <joern@logfs.org>
Cc: Clemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current
used inodes count as total file nodes in file system (f_files):
df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 2 2 0 100% /mnt/nilfs2
This patch implements real calculation of free inodes count. First of
all, it is calculated total file nodes in file system as
(desc_blocks_count * groups_per_desc_block * entries_per_group). Then, it
is calculated free inodes count as difference the total file nodes and
used inodes count. As a result, we have such output for NILFS2:
df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/loop0 4194304 2114701 2079603 51% /mnt/nilfs2
Reported-by: Clemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nilfs2: fix issue of nilfs_set_page_dirty for page at EOF boundary
DESCRIPTION:
There are use-cases when NILFS2 file system (formatted with block size
lesser than 4 KB) can be remounted in RO mode because of encountering of
"broken bmap" issue.
The issue was reported by Anthony Doggett <Anthony2486@interfaces.org.uk>:
"The machine I've been trialling nilfs on is running Debian Testing,
Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc
version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.35-2), but I've
also reproduced it (identically) with Debian Unstable amd64 and Debian
Experimental (using the 3.8-trunk kernel). The problematic partitions
were formatted with "mkfs.nilfs2 -b 1024 -B 8192"."
SYMPTOMS:
(1) System log contains error messages likewise:
[63102.496756] nilfs_direct_assign: invalid pointer: 0
[63102.496786] NILFS error (device dm-17): nilfs_bmap_assign: broken bmap (inode number=28)
[63102.496798]
[63102.524403] Remounting filesystem read-only
(2) The NILFS2 file system is remounted in RO mode.
REPRODUSING PATH:
(1) Create volume group with name "unencrypted" by means of vgcreate utility.
(2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>):
----------------[BEGIN SCRIPT]--------------------
VG=unencrypted
lvcreate --size 2G --name ntest $VG
mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest
mkdir /var/tmp/n
mkdir /var/tmp/n/ntest
mount /dev/mapper/$VG-ntest /var/tmp/n/ntest
mkdir /var/tmp/n/ntest/thedir
cd /var/tmp/n/ntest/thedir
sleep 2
date
darcs init
sleep 2
dmesg|tail -n 5
date
darcs whatsnew || true
date
sleep 2
dmesg|tail -n 5
----------------[END SCRIPT]--------------------
REPRODUCIBILITY: 100%
INVESTIGATION:
As it was discovered, the issue takes place during segment
construction after executing such sequence of user-space operations:
open("_darcs/index", O_RDWR|O_CREAT|O_NOCTTY, 0666) = 7
fstat(7, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
ftruncate(7, 60)
The error message "NILFS error (device dm-17): nilfs_bmap_assign: broken
bmap (inode number=28)" takes place because of trying to get block
number for third block of the file with logical offset #3072 bytes. As
it is possible to see from above output, the file has 60 bytes of the
whole size. So, it is enough one block (1 KB in size) allocation for
the whole file. Trying to operate with several blocks instead of one
takes place because of discovering several dirty buffers for this file
in nilfs_segctor_scan_file() method.
The root cause of this issue is in nilfs_set_page_dirty function which
is called just before writing to an mmapped page.
When nilfs_page_mkwrite function handles a page at EOF boundary, it
fills hole blocks only inside EOF through __block_page_mkwrite().
The __block_page_mkwrite() function calls set_page_dirty() after filling
hole blocks, thus nilfs_set_page_dirty function (=
a_ops->set_page_dirty) is called. However, the current implementation
of nilfs_set_page_dirty() wrongly marks all buffers dirty even for page
at EOF boundary.
As a result, buffers outside EOF are inconsistently marked dirty and
queued for write even though they are not mapped with nilfs_get_block
function.
FIX:
This modifies nilfs_set_page_dirty() not to mark hole blocks dirty.
Thanks to Vyacheslav Dubeyko for his effort on analysis and proposals
for this issue.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reported-by: Anthony Doggett <Anthony2486@interfaces.org.uk>
Reported-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
page->mapping->host cannot be NULL in nilfs_writepage(), so remove the
unneeded test.
The fixes the smatch warning: "fs/nilfs2/inode.c:211 nilfs_writepage()
error: we previously assumed 'inode' could be null (see line 195)".
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The NILFS2 driver remounts itself in RO mode in the case of discovering
metadata corruption (for example, discovering a broken bmap). But
usually, this takes place when there have been file system operations
before remounting in RO mode.
Thereby, NILFS2 driver can be in RO mode with presence of dirty pages in
modified inodes' address spaces. It results in flush kernel thread's
infinite trying to flush dirty pages in RO mode. As a result, it is
possible to see such side effects as: (1) flush kernel thread occupies
50% - 99% of CPU time; (2) system can't be shutdowned without manual
power switch off.
SYMPTOMS:
(1) System log contains error message: "Remounting filesystem read-only".
(2) The flush kernel thread occupies 50% - 99% of CPU time.
(3) The system can't be shutdowned without manual power switch off.
REPRODUCTION PATH:
(1) Create volume group with name "unencrypted" by means of vgcreate utility.
(2) Run script (prepared by Anthony Doggett <Anthony2486@interfaces.org.uk>):
----------------[BEGIN SCRIPT]--------------------
#!/bin/bash
VG=unencrypted
#apt-get install nilfs-tools darcs
lvcreate --size 2G --name ntest $VG
mkfs.nilfs2 -b 1024 -B 8192 /dev/mapper/$VG-ntest
mkdir /var/tmp/n
mkdir /var/tmp/n/ntest
mount /dev/mapper/$VG-ntest /var/tmp/n/ntest
mkdir /var/tmp/n/ntest/thedir
cd /var/tmp/n/ntest/thedir
sleep 2
date
darcs init
sleep 2
dmesg|tail -n 5
date
darcs whatsnew || true
date
sleep 2
dmesg|tail -n 5
----------------[END SCRIPT]--------------------
(3) Try to shutdown the system.
REPRODUCIBILITY: 100%
FIX:
This patch implements checking mount state of NILFS2 driver in
nilfs_writepage(), nilfs_writepages() and nilfs_mdt_write_page()
methods. If it is detected the RO mount state then all dirty pages are
simply discarded with warning messages is written in system log.
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Anthony Doggett <Anthony2486@interfaces.org.uk>
Cc: ARAI Shun-ichi <hermes@ceres.dti.ne.jp>
Cc: Piotr Szymaniak <szarpaj@grubelek.pl>
Cc: Zahid Chowdhury <zahid.chowdhury@starsolutions.com>
Cc: Elmer Zhang <freeboy6716@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.
A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.
Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.
Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.
This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.
This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.
After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
Merge misc patches from Andrew Morton:
- Florian has vanished so I appear to have become fbdev maintainer
again :(
- Joel and Mark are distracted to welcome to the new OCFS2 maintainer
- The backlight queue
- Small core kernel changes
- lib/ updates
- The rtc queue
- Various random bits
* akpm: (164 commits)
rtc: rtc-davinci: use devm_*() functions
rtc: rtc-max8997: use devm_request_threaded_irq()
rtc: rtc-max8907: use devm_request_threaded_irq()
rtc: rtc-da9052: use devm_request_threaded_irq()
rtc: rtc-wm831x: use devm_request_threaded_irq()
rtc: rtc-tps80031: use devm_request_threaded_irq()
rtc: rtc-lp8788: use devm_request_threaded_irq()
rtc: rtc-coh901331: use devm_clk_get()
rtc: rtc-vt8500: use devm_*() functions
rtc: rtc-tps6586x: use devm_request_threaded_irq()
rtc: rtc-imxdi: use devm_clk_get()
rtc: rtc-cmos: use dev_warn()/dev_dbg() instead of printk()/pr_debug()
rtc: rtc-pcf8583: use dev_warn() instead of printk()
rtc: rtc-sun4v: use pr_warn() instead of printk()
rtc: rtc-vr41xx: use dev_info() instead of printk()
rtc: rtc-rs5c313: use pr_err() instead of printk()
rtc: rtc-at91rm9200: use dev_dbg()/dev_err() instead of printk()/pr_debug()
rtc: rtc-rs5c372: use dev_dbg()/dev_warn() instead of printk()/pr_debug()
rtc: rtc-ds2404: use dev_err() instead of printk()
rtc: rtc-efi: use dev_err()/dev_warn()/pr_err() instead of printk()
...
