This commits refactors and cleans up 'ubifs_rcvry_gc_commit()' which was quite
untidy, also removes the commentary which was not 100% correct.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Split the 'ubifs_rcvry_gc_commit()' function and introduce a 'grab_empty_leb()'
heler. This cleans 'ubifs_rcvry_gc_commit()' a little and makes it a bit less
of spagetti.
Also, add a commentary which explains why it is crucial to first search for an
empty LEB and then run commit.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When UBIFS is in the failure mode (used for power cut emulation testing) we for
some reasons do not dump the stack in many places, e.g., in assertions.
Probably at early days we had too many of them and disabled this to make the
development easier, but then never enabled. Nowadays I sometimes observe
assertion failures during power cut testing, but the useful stackdump is not
printed, which is bad. This patch makes UBIFS always print the stackdump when
debugging is enabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
If we fail to recover the gc_lnum we just return an error and it then
it is difficult to figure out why this happened. This patch adds useful
debugging information which should make it easier to debug the failure.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch removes a piece of code in 'ubifs_rcvry_gc_commit()' which is never
executed. We call 'ubifs_find_dirty_leb()' function with min_space =
wbuf->offs, so if it returns us an LEB, it is guaranteed to have at lease
'wbuf->offs' bytes of free+dirty space. So we can remove the subsequent code
which deals with "returned LEB has less than 'wbuf->offs' bytes of free+dirty
space". This simplifies 'ubifs_rcvry_gc_commit()' a little.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We have duplicated code in 'ubifs_garbage_collect()' and
'ubifs_rcvry_gc_commit()', which is about handling the special case of free
LEB. In both cases we just want to garbage-collect the LEB using
'ubifs_garbage_collect_leb()'.
This patch teaches 'ubifs_garbage_collect_leb()' to handle free LEB's so that
the caller does not have to do this and the duplicated code is removed.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Remove the following commentary from 'ubifs_file_mmap()':
/* 'generic_file_mmap()' takes care of NOMMU case */
I do not understand what it means, and I could not find anything relater to
NOMMU in 'generic_file_mmap()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch is a tiny improvement which removes few bytes of code.
UBIFS debugfs files are non-seekable and the file position is ignored,
so do not increase it in the write handler.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The 'dbg_dump_lprop()' is trying to detect journal head LEBs when printing,
so it looks at the write-buffers. However, if we are in R/O mode, we
de-allocate the write-buffers, so 'dbg_dump_lprop()' oopses. This patch fixes
the issue.
Note, this patch is not critical, it is only about the debugging code path, and
it is unlikely that anyone but UBIFS developers would ever hit this issue.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We have our own flags indicating R/O mode, and c->ro_mode is equivalent
to MS_RDONLY. Let's be consistent and use UBIFS flags everywhere.
This patch is just a minor cleanup.
Additionally, add a comment that we are surprised with VFS behavior -
as a reminder to look at this some day.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When the debugging failure emulation is enabled and UBIFS decides to
emulate an I/O error, it uses EIO error code. In which case UBIFS
switches into R/O mode later on. The for the user-space is that when
a failure is emulated, the file-system sometimes returns EIO and
sometimes EROFS. This makes it more difficult to implement user-space
tests for the failure mode. Let's be consistent and return EROFS in
all the cases.
This patch is an improvement for the debugging code and does not affect
the functionality at all.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is just a tiny clean-up patch. The variable name for empty address
space operations is "empty_aops". Let's use consistent names for empty
inode and file operations: "empty_iops" and "empty_fops", instead of
inconsistent "none_inode_operations" and "none_file_operations".
Artem: re-write the commit message.
Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Try to improve UBIFS testing coverage by randomly picking LEBs to
store in lsave, rather than picking them optimally. Create a debugging
version of 'populate_lsave()' for these purposes and enable it when
general debugging self-checks are enabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
UBIFS can force itself to use the 'in-the-gaps' commit method - the last resort
method which is normally invoced very very rarely. Currently this "force
int-the-gaps" debugging feature is a separate test mode. But it is a bit saner
to make it to be the "general" self-test check instead.
This patch is just a clean-up which should make the debugging code look a bit
nicer and easier to use - we have way too many debugging options.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch improves the 'dbg_check_space_info()' function which checks
whether the amount of space before re-mounting and after re-mounting
is the same (remounting from R/O to R/W modes and vice-versa).
The problem is that 'dbg_check_space_info()' does not save the budgeting
information before re-mounting, so when an error is reported, we do not
know why the amount of free space changed.
This patches makes the following changes:
1. Teaches 'dbg_dump_budg()' function to accept a 'struct ubifs_budg_info'
argument and print out the this argument. This way we may ask it to
print any saved budgeting info, no only the current one.
2. Accordingly changes all the callers of 'dbg_dump_budg()' to comply with
the changed interface.
3. Introduce a 'saved_bi' (saved budgeting info) field to
'struct ubifs_debug_info' and save the budgeting info before re-mounting
there.
4. Change 'dbg_check_space_info()' and make it print both old and new
budgeting information.
5. Additionally, save 'c->igx_gc_cnt' and print it if and error happens. This
value contributes to the amount of free space, so we have to print it.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Re-arrange the budget dump and make sure we first dump all
the 'struct ubifs_budg_info' fields, and then the other information.
Additionally, print the 'uncommitted_idx' variable.
This change is required for to the following dumping function
enhancement where it will be possible to dump saved
'struct ubifs_budg_info' objects, not only the current one.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The current 'dbg_dump_budg()' calling convention is that the
'c->space_lock' spinlock is held. However, none of the callers
actually use it from contects which have 'c->space_lock' locked,
so all callers have to explicitely lock and unlock the spinlock.
This is not very sensible convention. This patch changes it and
makes 'dbg_dump_budg()' lock the spinlock instead of imposing this
to the callers. This simplifies the code a little.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch separates out all the budgeting-related information
from 'struct ubifs_info' to 'struct ubifs_budg_info'. This way the
code looks a bit cleaner. However, the main driver for this is
that we want to save budgeting information and print it later,
so a separate data structure for this is helpful.
This patch is a preparation for the further debugging output
improvements.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
There was an attempt to standartize various "__attribute__" and
other macros in order to have potentially portable and more
consistent code, see commit 82ddcb0405.
Note, that commit refers Rober Love's blog post, but the URL
is broken, the valid URL is:
http://blog.rlove.org/2005/10/with-little-help-from-your-compiler.html
Moreover, nowadays checkpatch.pl warns about using
__attribute__((packed)):
"WARNING: __packed is preferred over __attribute__((packed))"
It is not a big deal for UBIFS to use __packed, so let's do it.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Fix several minor stylistic issues:
* lines longer than 80 characters
* space before closing parenthesis ')'
* spaces in the indentations
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Turn the debufs files UBIFS maintains into non-seekable. Indeed, none
of them is supposed to be seek'ed.
Do this by making the '.lseek()' handler to be 'no_llseek()' and by
using 'nonseekable_open()' in the '.open()' operation.
This does mean an API break but this debugging API is only used by a couple
of test scripts which do not rely in the 'llseek()' operation.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is the second fix of the following symptom:
UBIFS error (pid 34456): could not find an empty LEB
which sometimes happens after power cuts when we mount the file-system - UBIFS
refuses it with the above error message which comes from the
'ubifs_rcvry_gc_commit()' function. I can reproduce this using the integck test
with the UBIFS power cut emulation enabled.
Analysis of the problem.
Currently UBIFS replay seeks the journal heads to the last _replayed_ bud.
But the buds are replayed out-of-order, so the replay basically seeks journal
heads to the "random" bud belonging to this head, and not to the _last_ one.
The result of this is that the GC head may be seeked to a full LEB with no free
space, or very little free space. And 'ubifs_rcvry_gc_commit()' tries to find a
fully or mostly dirty LEB to match the current GC head (because we need to
garbage-collect that dirty LEB at one go, because we do not have @c->gc_lnum).
So 'ubifs_find_dirty_leb()' fails and we fall back to finding an empty LEB and
also fail. As a result - recovery fails and mounting fails.
This patch teaches the replay to initialize the GC heads exactly to the latest
buds, i.e. the buds which have the largest sequence number in corresponding
log reference nodes.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
Currently UBIFS has a small optimization - it frees write-buffers when it is
re-mounted from R/W mode to R/O mode. Of course, when it is mounted R/O, it
does not allocate write-buffers as well.
This optimization is nice but it leads to subtle problems and complications
in recovery, which I can reproduce using the integck test. The symptoms are
that after a power cut the file-system cannot be mounted if we first mount
it R/O, and then re-mount R/W - 'ubifs_rcvry_gc_commit()' prints:
UBIFS error (pid 34456): could not find an empty LEB
Analysis of the problem.
When mounting R/W, the reply process sets journal heads to buds [1], but
when mounting R/O - it does not do this, because the write-buffers are not
allocated. So 'ubifs_rcvry_gc_commit()' works completely differently for the
same file-system but for the following 2 cases:
1. mounting R/W after a power cut and recover
2. mounting R/O after a power cut, re-mounting R/W and run deferred recovery
In the former case, we have journal heads seeked to the a bud, in the latter
case, they are non-seeked (wbuf->lnum == -1). So in the latter case we do not
try to recover the GC LEB by garbage-collecting to the GC head, but we just
try to find an empty LEB, and there may be no empty LEBs, so we just fail.
On the other hand, in the former case (mount R/W), we are able to make a GC LEB
(@c->gc_lnum) by garbage-collecting.
Thus, let's remove this small nice optimization and always allocate
write-buffers. This should not make too big difference - we have only 3
of them, each of max. write unit size, which is usually 2KiB. So this is
about 6KiB of RAM for the typical case, and only when mounted R/O.
[1]: Note, currently the replay process is setting (seeking) the journal heads
to _some_ buds, not necessarily to the buds which had been the journal heads
before the power cut happened. This will be fixed separately.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
This patch fixes the following symptoms:
1. Unmount UBIFS cleanly.
2. Start mounting UBIFS R/W and have a power cut immediately
3. Start mounting UBIFS R/O, this succeeds
4. Try to re-mount UBIFS R/W - this fails immediately or later on,
because UBIFS will write the master node to the flash area
which has been written before.
The analysis of the problem:
1. UBIFS is unmounted cleanly, both copies of the master node are clean.
2. UBIFS is being mounter R/W, starts changing master node copy 1, and
a power cut happens. The copy N1 becomes corrupted.
3. UBIFS is being mounted R/O. It notices the copy N1 is corrupted and
reads copy N2. Copy N2 is clean.
4. Because of R/O mode, UBIFS cannot recover copy 1.
5. The mount code (ubifs_mount()) sees that the master node is clean,
so it decides that no recovery is needed.
6. We are re-mounting R/W. UBIFS believes no recovery is needed and
starts updating the master node, but copy N1 is still corrupted
and was not recovered!
Fix this problem by marking the master node as dirty every time we
recover it and we are in R/O mode. This forces further recovery and
the UBIFS cleans-up the corruptions and recovers the copy N1 when
re-mounting R/W later.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
When UBIFS switches to R/O mode because it detects I/O failures, then
when we unmount, we still may have allocated budget, and the assertions
which verify that we have not budget will fire. But it is expected to
have the budget in case of I/O failures, so the assertion warnings will
be false. Suppress them for the I/O failure case.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes UBIFS mount failure when the debugging support is enabled,
we are recovering from a power cut, we were first mounter R/O and we are
re-mounting R/W. In this case we should not assume that the amount of free
space before we have re-mounted R/W and after are equivalent, because
when we have mounted R/O the file-system is in a non-committed state so
the amount of free space is slightly smaller, due to the fact that we cannot
predict the amount of free space precisely before we commit.
This patch fixes the issue by skipping the debugging check in case of
recovery. This issue was reported by Caizhiyong <caizhiyong@huawei.com>
here: http://thread.gmane.org/gmane.linux.drivers.mtd/34350/focus=34387
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reported-by: Caizhiyong <caizhiyong@huawei.com>
Cc: stable@kernel.org [2.6.30+]
When compiling UBIFS with CONFIG_UBIFS_FS_DEBUG not set,
gcc-4.5.2 generates a slew of "warning: statement with no effect"
on references to non-void functions defined as 0.
To avoid these warnings, replace #defines with dummy inline functions.
Artem: massage the patch a bit, also remove the duplicate
'dbg_check_lprops()' prototype.
Signed-off-by: Maksim Rayskiy <maksim.rayskiy@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes severe UBIFS bug: UBIFS oopses when we 'fsync()' an
file on R/O-mounter file-system. We (the UBIFS authors) incorrectly
thought that VFS would not propagate 'fsync()' down to the file-system
if it is read-only, but this is not the case.
It is easy to exploit this bug using the following simple perl script:
use strict;
use File::Sync qw(fsync sync);
die "File path is not specified" if not defined $ARGV[0];
my $path = $ARGV[0];
open FILE, "<", "$path" or die "Cannot open $path: $!";
fsync(\*FILE) or die "cannot fsync $path: $!";
close FILE or die "Cannot close $path: $!";
Thanks to Reuben Dowle <Reuben.Dowle@navico.com> for reporting about this
issue.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reported-by: Reuben Dowle <Reuben.Dowle@navico.com>
Cc: stable@kernel.org
* 'for-linus' of git://git.infradead.org/ubifs-2.6:
UBI: do not select KALLSYMS_ALL
UBI: do not compare array with NULL
UBI: check if we are in RO mode in the erase routine
UBIFS: fix debugging failure in dbg_check_space_info
UBIFS: fix error path in dbg_debugfs_init_fs
UBIFS: unify error path dbg_debugfs_init_fs
UBIFS: do not select KALLSYMS_ALL
UBIFS: fix assertion warnings
UBIFS: fix oops on error path in read_pnode
UBIFS: do not read flash unnecessarily
With the ->sync_page() hook gone, we have a few users that
add their own static address_space_operations without any
functions defined.
fs/inode.c already has an empty_aops that it uses for init
purposes. Lets export that and use it in the places where
an otherwise empty aops was defined.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch fixes a debugging failure with which looks like this:
UBIFS error (pid 32313): dbg_check_space_info: free space changed from 6019344 to 6022654
The reason for this failure is described in the comment this patch adds
to the code. But in short - 'c->freeable_cnt' may be different before
and after re-mounting, and this is normal. So the debugging code should
make sure that free space calculations do not depend on 'c->freeable_cnt'.
A similar issue has been reported here:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/034647.html
This patch should fix it.
For the -stable guys: this patch is only relevant for kernels 2.6.30
onwards.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org [2.6.30+]
The debug interface is substandard and on error returns either
NULL or an error code packed in the pointer. So using "IS_ERR"
for the pointers returned by debugfs function is incorrect.
Instead, we should use IS_ERR_OR_NULL.
This path is an improved vestion of the original patch from
Phil Carmody.
Reported-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
This is just a small clean-up patch which simlifies and unifies the
error path in the dbg_debugfs_init_fs(). We have common error path
for all failure cases in this function except of the very first
case. And this patch makes the first failure case use the same
error path as the other cases by using the 'fname' and 'dent'
variables.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
All UBIFS needs is to make sure we stacktraces when UBIFS debugging
is enabled. It is enough to select KALLSYMS for this, KALLSYMS_ALL
is not necessary. Moreover, Randy Dunlap reported that UBIFS causes
the following Kconfig dependency warning:
warning: (UBIFS_FS_DEBUG && LOCKDEP && LATENCYTOP) selects KALLSYMS_ALL
which has unmet direct dependencies (DEBUG_KERNEL && KALLSYMS)
The reason is that KALLSYMS_ALL requires DEBUG_KERNEL and KALLSYMS, so
ideally, to select KALLSYMS_ALL we'd need to select DEBUG_KERNEL and
KALLSYMS first.
This seems to be too much to select. The easiest way to go is to forget
about KALLSYMS_ALL and just select KALLSYMS when UBIFS debugging is
enabled - that should be enough for stackdumps.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
This patch fixes UBIFS assertion warnings like:
UBIFS assert failed in ubifs_leb_unmap at 135 (pid 29365)
Pid: 29365, comm: integck Tainted: G I 2.6.37-ubi-2.6+ #34
Call Trace:
[<ffffffffa047c663>] ubifs_lpt_init+0x95e/0x9ee [ubifs]
[<ffffffffa04623a7>] ubifs_remount_fs+0x2c7/0x762 [ubifs]
[<ffffffff810f066e>] do_remount_sb+0xb6/0x101
[<ffffffff81106ff4>] ? do_mount+0x191/0x78e
[<ffffffff811070bb>] do_mount+0x258/0x78e
[<ffffffff810da1e8>] ? alloc_pages_current+0xa2/0xc5
[<ffffffff81107674>] sys_mount+0x83/0xbd
[<ffffffff81009a12>] system_call_fastpath+0x16/0x1b
They happen when we re-mount from R/O mode to R/W mode. While
re-mounting, we write to the media, but we still have the c->ro_mount
flag set. The fix is very simple - just clear the flag before
starting re-mounting R/W.
These warnings are caused by the following commit:
2ef13294d2
For -stable guys: this bug was introduced in 2.6.38, this is materieal
for 2.6.38-stable.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org [2.6.38]
Thanks to coverity which spotted that UBIFS will oops if 'kmalloc()'
in 'read_pnode()' fails and we dereference a NULL 'pnode' pointer
when we 'goto out'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
This fix makes the 'dbg_check_old_index()' function return
immediately if debugging is disabled, instead of executing
incorrect 'goto out' which causes UBIFS to:
1. Allocate memory
2. Read the flash
On every commit. OK, we do not commit that often, but it is
still silly to do unneeded I/O anyway.
Credits to coverity for spotting this silly issue.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: stable@kernel.org
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
Documentation/iostats.txt: bit-size reference etc.
cfq-iosched: removing unnecessary think time checking
cfq-iosched: Don't clear queue stats when preempt.
blk-throttle: Reset group slice when limits are changed
blk-cgroup: Only give unaccounted_time under debug
cfq-iosched: Don't set active queue in preempt
block: fix non-atomic access to genhd inflight structures
block: attempt to merge with existing requests on plug flush
block: NULL dereference on error path in __blkdev_get()
cfq-iosched: Don't update group weights when on service tree
fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
block: Require subsystems to explicitly allocate bio_set integrity mempool
jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
fs: make fsync_buffers_list() plug
mm: make generic_writepages() use plugging
blk-cgroup: Add unaccounted time to timeslice_used.
block: fixup plugging stubs for !CONFIG_BLOCK
block: remove obsolete comments for blkdev_issue_zeroout.
blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
...
Fix up conflicts in fs/{aio.c,super.c}
This patch fixes the following UBIFS assertion warning:
UBIFS assert failed in do_readpage at 115 (pid 199)
[<b00321b8>] (unwind_backtrace+0x0/0xdc) from [<af025118>]
(do_readpage+0x108/0x594 [ubifs])
[<af025118>] (do_readpage+0x108/0x594 [ubifs]) from [<af025764>]
(ubifs_write_end+0x1c0/0x2e8 [ubifs])
[<af025764>] (ubifs_write_end+0x1c0/0x2e8 [ubifs]) from
[<b00a0164>] (generic_file_buffered_write+0x18c/0x270)
[<b00a0164>] (generic_file_buffered_write+0x18c/0x270) from
[<b00a08d4>] (__generic_file_aio_write+0x478/0x4c0)
[<b00a08d4>] (__generic_file_aio_write+0x478/0x4c0) from
[<b00a0984>] (generic_file_aio_write+0x68/0xc8)
[<b00a0984>] (generic_file_aio_write+0x68/0xc8) from
[<af024a78>] (ubifs_aio_write+0x178/0x1d8 [ubifs])
[<af024a78>] (ubifs_aio_write+0x178/0x1d8 [ubifs]) from
[<b00d104c>] (do_sync_write+0xb0/0x100)
[<b00d104c>] (do_sync_write+0xb0/0x100) from [<b00d1abc>]
(vfs_write+0xac/0x154)
[<b00d1abc>] (vfs_write+0xac/0x154) from [<b00d1c10>]
(sys_write+0x3c/0x68)
[<b00d1c10>] (sys_write+0x3c/0x68) from [<b002d9a0>]
(ret_fast_syscall+0x0/0x2c)
The 'PG_checked' flag is used to indicate that the page does not
supposedly exist on the media (e.g., a hole or a page beyond the
inode size), so it requires slightly bigger budget, because we have
to account the indexing size increase. And this flag basically
tells that the budget for this page has to be "new page budget".
The "new page budget" is slightly bigger than the "existing page
budget".
The 'do_readpage()' function has the following assertion which
sometimes is hit: 'ubifs_assert(!PageChecked(page))'. Obviously,
the meaning of this assertion is: "I should not be asked to read
a page which does not exist on the media".
However, in 'ubifs_write_begin()' we have a small "trick". Notice,
that VFS may write pages which were not read yet, so the page data
were not loaded from the media to the page cache yet. If VFS tells
that it is going to change only some part of the page, we obviously
have to load it from the media. However, if VFS tells that it is
going to change whole page, we do not read it from the media for
optimization purposes.
However, since we do not read it, we do not know if it exists on
the media or not (a hole, etc). So we set the 'PG_checked' flag
to this page to force bigger budget, just in case.
So 'ubifs_write_begin()' sets 'PG_checked'. Then we are in
'ubifs_write_end()'. And VFS tells us: "hey, for some reasons I
changed my mind and did not change whole page". Frankly, I do not
know why this happens, but I hit this somehow on an ARM platform.
And this is extremely rare.
So in this case UBIFS does the following:
1. Cancels allocated budget.
2. Loads the page from the media by calling 'do_readpage()'.
3. Asks VFS to repeat the whole write operation from the very
beginning (call '->write_begin() again, etc).
And the assertion warning is hit at the step 2 - remember we have
the 'PG_checked' set for this page, and 'do_readpage()' does not
like this. So this patch fixes the problem by adding step 1.5 and
cleaning the 'PG_checked' before calling 'do_readpage()'.
All in all, this patch does not fix any functionality issue, but it
silences UBIFS false positive warning which may happen in very very
rare cases.
And while on it, this patch also improves a commentary which explains
the reasons of setting the 'PG_checked' flag for the page. The old
commentary was a bit difficult to understand.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Simplify UBIFS configuration menu and kill the option to enable self-check
compile-time. We do not really need this because we can do this run-time
using the module parameters or the corresponding sysfs interfaces. And
there is a value in simplifying the kernel configuration menu which becomes
increasingly large.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes a brown-paperbag bug which was introduced by me:
I used incorrect "GFP_KERNEL | GFP_NOFS" allocation flags to make
sure my allocations do not cause write-back. But the correct form
is "GFP_NOFS".
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
And give it a kernel-doc comment.
[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (25 commits)
UBIFS: clean-up commentaries
UBIFS: save 128KiB or more RAM
UBIFS: allocate orphans scan buffer on demand
UBIFS: allocate lpt dump buffer on demand
UBIFS: allocate ltab checking buffer on demand
UBIFS: allocate scanning buffer on demand
UBIFS: allocate dump buffer on demand
UBIFS: do not check data crc by default
UBIFS: simplify UBIFS Kconfig menu
UBIFS: print max. index node size
UBIFS: handle allocation failures in UBIFS write path
UBIFS: use max_write_size during recovery
UBIFS: use max_write_size for write-buffers
UBIFS: introduce write-buffer size field
UBI: incorporate LEB offset information
UBIFS: incorporate maximum write size
UBI: provide LEB offset information
UBI: incorporate maximum write size
UBIFS: fix LEB number in printk
UBIFS: restrict world-writable debugfs files
...
When debugging is enabled, we allocate a buffer of PEB size for
various debugging purposes. However, now all users of this buffer
are gone and we can safely remove it and save 128KiB or more RAM.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'dbg_scan_orphans()', dynamically allocate it when needed. The intend
is to get rid of the pre-allocated 'c->dbg->buf' buffer and save
128KiB of RAM (or more if PEB size is larger). Indeed, currently we
allocate this memory even if the user never enables any self-check,
which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'dump_lpt_leb()', dynamically allocate it when needed. The intend
is to get rid of the pre-allocated 'c->dbg->buf' buffer and save
128KiB of RAM (or more if PEB size is larger). Indeed, currently we
allocate this memory even if the user never enables any self-check,
which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'dbg_check_ltab_lnum()', dynamically allocate it when needed. The
intend is to get rid of the pre-allocated 'c->dbg->buf' buffer and
save 128KiB of RAM (or more if PEB size is larger). Indeed,
currently we allocate this memory even if the user never enables
any self-check, which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'scan_check_cb()', dynamically allocate it when needed. The intend
is to get rid of the pre-allocated 'c->dbg->buf' buffer and save
128KiB of RAM (or more if PEB size is larger). Indeed, currently we
allocate this memory even if the user never enables any self-check,
which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'dbg_dump_leb()', dynamically allocate it when needed. The intend
is to get rid of the pre-allocated 'c->dbg->buf' buffer and save
128KiB of RAM (or more if PEB size is larger). Indeed, currently we
allocate this memory even if the user never enables any self-check,
which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Now that VFS check for inode->i_nlink == 0 and returns proper
error, remove similar check from file system
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Change the default UBIFS behavior WRT data CRC checking. Currently,
UBIFS checks data CRC when reading, which slows it down quite a bit,
and this is the default option. However, it looks like in average
user does not need this feature and would prefer faster read speed
over extra reliability. And this seems to be de-facto standard that
file-systems do not check data CRC every time they read from the
media.
Thus, make UBIFS default behavior so that it does not check data
CRC. This corresponds to the no_chk_data_crc mount option. Those users
who need extra protection can always enable it using the chk_data_crc
option.
Please, read more information about this feature here:
http://www.linux-mtd.infradead.org/doc/ubifs.html#L_checksumming
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Remove debug message level and debug checks Kconfig options as they
proved to be useless anyway. We have sysfs interface which we can
use for fine-grained debugging messages and checks selection, see
Documentation/filesystems/ubifs.txt for mode details.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Running kernel 2.6.37, my PPC-based device occasionally gets an
order-2 allocation failure in UBIFS, which causes the root FS to
become unwritable:
kswapd0: page allocation failure. order:2, mode:0x4050
Call Trace:
[c787dc30] [c00085b8] show_stack+0x7c/0x194 (unreliable)
[c787dc70] [c0061aec] __alloc_pages_nodemask+0x4f0/0x57c
[c787dd00] [c0061b98] __get_free_pages+0x20/0x50
[c787dd10] [c00e4f88] ubifs_jnl_write_data+0x54/0x200
[c787dd50] [c00e82d4] do_writepage+0x94/0x198
[c787dd90] [c00675e4] shrink_page_list+0x40c/0x77c
[c787de40] [c0067de0] shrink_inactive_list+0x1e0/0x370
[c787de90] [c0068224] shrink_zone+0x2b4/0x2b8
[c787df00] [c0068854] kswapd+0x408/0x5d4
[c787dfb0] [c0037bcc] kthread+0x80/0x84
[c787dff0] [c000ef44] kernel_thread+0x4c/0x68
Similar problems were encountered last April by Tomasz Stanislawski:
http://patchwork.ozlabs.org/patch/50965/
This patch implements Artem's suggested fix: fall back to a
mutex-protected static buffer, allocated at mount time. I tested it
by forcing execution down the failure path, and didn't see any ill
effects.
Artem: massaged the patch a little, improved it so that we'd not
allocate the write reserve buffer when we are in R/O mode.
Signed-off-by: Matthew L. Creech <mlcreech@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
When recovering from unclean reboots UBIFS scans the journal and checks nodes.
If a corrupted node is found, UBIFS tries to check if this is the last node
in the LEB or not. This is is done by checking if there only 0xFF bytes
starting from the next min. I/O unit. However, since now we write in
c->max_write_size, we should actually check for 0xFFs starting from the
next max. write unit.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Switch write-buffers from 'c->min_io_size' to 'c->max_write_size' which
presumably has to be more write speed-efficient. However, when write-buffer
is synchronized, write only the the min. I/O units which contain the
data, do not write whole write-buffer. This is more space-efficient.
Additionally, this patch takes into account that the LEB might not start
from the max. write unit-aligned address.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Currently we assume write-buffer size is always min_io_size. But
this is about to change and write-buffers may be of variable size.
Namely, they will be of max_write_size at the beginning, but will
get smaller when we are approaching the end of LEB.
This is a preparation patch which introduces 'size' field in
the write-buffer structure which carries the current write-buffer
size.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Incorporate the LEB offset information into UBIFS. We'll use this
information in one of the next patches to figure out what are the
max. write size offsets relative to the PEB. So this patch is just
a preparation.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Incorporate maximum write size into the UBIFS description data
structure. This patch just introduces new 'c->max_write_size'
and 'c->max_write_shift' fields as a preparation for the following
patches.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is a minor patch which fixes the LEB number we print when
corrupted empty space is found.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch adds more commentaries about UBIFS recovery logic which should
explain the famous UBIFS "corrupt empty space" errors.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes suboptimal UBIFS 'sync_fs()' implementation which causes
flash I/O even if the file-system is synchronized. E.g., a 'printk()'
in the MTD erasure function (e.g., 'nand_erase_nand()') can show that
for every 'sync' shell command UBIFS erases at least one eraseblock.
So '$ while true; do sync; done' will cause huge amount of flash I/O.
The reason for this is that UBIFS commits in 'sync_fs()', and starts the
commit even if there is nothing to commit, e.g., it anyway changes the
log. This patch adds a check in the 'do_commit()' UBIFS functions which
prevents the commit if there is nothing to commit.
Reported-by: Hans J. Koch <hjk@linutronix.de>
Tested-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is a preparational patch which removes the 'c->always_chk_crc' which was
set during mounting and remounting to R/W mode and introduces 'c->mounting'
flag which is set when mounting. Now the 'c->always_chk_crc' flag is the
same as 'c->remounting_rw && c->mounting'.
This patch is a preparation for the next one which will need to know when we
are mounting and remounting to R/W mode, which is exactly what
'c->always_chk_crc' effectively is, but its name does not suite the
next patch. The other possibility would be to just re-name it, but then
we'd end up with less logical flags coverage.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is a cosmetic patch which re-arranges variables in 'struct ubifs_info'
so that all boolean-like variables which are only changed during mounting or
re-mounting to R/W mode are places together. Then they are turned into
bit-fields, which makes the structure a little bit smaller.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBIFS: do not allocate unneeded scan buffer
UBIFS: do not forget to cancel timers
UBIFS: remove a bit of unneeded code
UBIFS: add a commentary about log recovery
UBIFS: avoid kernel error if ubifs superblock read fails
UBIFS: introduce new flags for RO mounts
UBIFS: introduce new flag for RO due to errors
UBIFS: check return code of pnode_lookup
UBIFS: check return code of ubifs_lpt_lookup
UBIFS: improve error reporting when reading bad node
UBIFS: introduce list sorting debugging checks
UBIFS: fix assertion warnings in comparison function
UBIFS: mark unused key objects as invalid
UBIFS: do not write rubbish into truncation scanning node
UBIFS: improve assertion in node comparison functions
UBIFS: do not use key type in list_sort
UBIFS: do not look up truncation nodes
UBIFS: fix assertion warning
UBIFS: do not treat ENOSPC specially
UBIFS: switch to RO mode after synchronizing
In 'ubifs_replay_journal()' we allocate 'sbuf' for scanning the log.
However, we already have 'c->sbuf' for these purposes, so do not
allocate yet another one. This reduces UBIFS memory consumption while
recovering.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is a bug-fix: when we unmount, and we are currently in R/O
mode because of an error - we do not sync write-buffers, which
means we also do not cancel write-buffer timers we may possibly
have armed. This patch fixes the issue.
The issue can easily be reproduced by enabling UBIFS failure debug
mode (echo 4 > /sys/module/ubifs/parameters/debug_tsts) and
unmounting as soon as a failure happen. At some point the system
oopses because we have an armed hrtimer but UBIFS is unmounted
already.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This is a clean-up patch which:
1. Removes explicite 'hrtimer_cancel()' after 'ubifs_wbuf_sync()' in
'ubifs_remount_ro()', because the timers will be canceled by
'ubifs_wbuf_sync()', no need to cancel them for the second time.
2. Remove "if (c->jheads)" check from 'ubifs_put_super()', because
at journal heads must always be allocated there, since we checked
earlier that we were mounted R/W, and the olny situation when
journal heads are not allocated is when mounter or re-mounted R/O.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Add a commentary which elaborates that 'ubifs_recover_log_leb()' recovers only
the last log LEB, not any. Also remove some unneeded newlines.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.
The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.
New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time. Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.
The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.
Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.
Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.
===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
// but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}
@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}
@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}
@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
*off = E
|
*off += E
|
func(..., off, ...)
|
E = *off
)
...+>
}
@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}
@ fops0 @
identifier fops;
@@
struct file_operations fops = {
...
};
@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
.llseek = llseek_f,
...
};
@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
.read = read_f,
...
};
@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
.write = write_f,
...
};
@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
.open = open_f,
...
};
// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
... .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};
@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
... .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};
// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
... .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};
// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};
// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};
@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+ .llseek = default_llseek, /* write accesses f_pos */
};
// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////
@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
.write = write_f,
.read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};
@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};
@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};
@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
.get_sb is called on mounts with automatic fs detection too, so this
function should print an error if it cannot read the superblock in
debug mode only (new behaviour conforms the other fs types)
Signed-off-by: Steffen Sledz <sledz@dresearch.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Commit 2fde99cb55 "UBIFS: mark VFS SB RO too"
introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the
VFS superblock when it switches to R/O mode due to an error. This was done
to make VFS show the R/O UBIFS flag in /proc/mounts.
However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this
flag can only change when we re-mount. For example, 'ubifs_put_super()'.
This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when
we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O).
This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'.
This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to
'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write
anything if the FS was mounter R/O.
All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed
and now we test the 'c->ro_mount' flag instead, because it preserves the
original UBIFS mount type, unlike the 'MS_RDONLY' flag.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The R/O state may have various reasons:
1. The UBI volume is R/O
2. The FS is mounted R/O
3. The FS switched to R/O mode because of an error
However, in UBIFS we have only one variable which represents cases
1 and 3 - 'c->ro_media'. Indeed, we set this to 1 if we switch to
R/O mode due to an error, and then we test it in many places to
make sure that we stop writing as soon as the error happens.
But this is very unclean. One consequence of this, for example, is
that in 'ubifs_remount_fs()' we use 'c->ro_media' to check whether
we are in R/O mode because on an error, and we print a message
in this case. However, if we are in R/O mode because the media
is R/O, our message is bogus.
This patch introduces new flag - 'c->ro_error' which is set when
we switch to R/O mode because of an error. It also changes all
"if (c->ro_media)" checks to "if (c->ro_error)" checks, because
this is what the checks actually mean. We do not need to check
for 'c->ro_media' because if the UBI volume is in R/O mode, we
do not allow R/W mounting, and now writes can happen. This is
guaranteed by VFS. But it is good to double-check this, so this
patch also adds many "ubifs_assert(!c->ro_media)" checks.
In the 'ubifs_remount_fs()' function this patch makes a bit more
changes - it fixes the error messages as well.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Function pnode_lookup may return ERR_PTR(...). Check for it.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Function ubifs_lpt_lookup may return ERR_PTR(...). Check for it.
[Tweaked by Artem Bityutskiy]
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When an error happens during validation of read node, the typical situation is that
the LEB we read is unmapped (due to some bug). It is handy to include the mapping
status into the error message.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The UBIFS bug in the GC list sorting comparison functions inspired
me to write internal debugging check functions which verify that
the list of nodes is sorted properly.
So, this patch implements 2 new debugging functions:
o 'dbg_check_data_nodes_order()' - check order of data nodes list
o 'dbg_check_nondata_nodes_order()' - check order of non-data nodes list
The debugging functions are executed only if general UBIFS debugging checks are
enabled. And they are compiled out if UBIFS debugging is disabled.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When running the integrity test ('integck' from mtd-utils) on current
UBIFS on 2.6.35, I see that assertions in UBIFS 'list_sort()' comparison
functions trigger sometimes, e.g.:
UBIFS assert failed in data_nodes_cmp at 132 (pid 28311)
My investigation showed that this happens when 'list_sort()' calls the 'cmp()'
function with equivalent arguments. In this case, the 'struct list_head'
parameter, passed to 'cmp()' is bogus, and it does not belong to any element in
the original list.
And this issue seems to be introduced by commit:
commit 835cc0c847
Author: Don Mullis <don.mullis@gmail.com>
Date: Fri Mar 5 13:43:15 2010 -0800
It is easy to work around the issue by doing:
if (a == b)
return 0;
in UBIFS. It works, but 'lib_sort()' should nevertheless be fixed. Although it
is harmless to have this piece of code in UBIFS.
This patch adds that code to both UBIFS 'cmp()' functions:
'data_nodes_cmp()' and 'nondata_nodes_cmp()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When scanning the flash, UBIFS builds a list of flash nodes of type
'struct ubifs_scan_node'. Each scanned node has a 'snod->key' field. This field
is valid for most of the nodes, but invalid for some node type, e.g., truncation
nodes. It is safer to explicitly initialize such keys to something invalid,
rather than leaving them initialized to all zeros, which has key type of
UBIFS_INO_KEY.
This patch introduces new "fake" key type UBIFS_INVALID_KEY and initializes
unused 'snod->key' objects to this type. It also adds debugging assertions in
the TNC code to make sure no one ever tries to look these nodes up in the TNC.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
In the scanning code, in 'ubifs_add_snod()', we write rubbish into
'snod->key', because we assume that on-flash truncation nodes have a key, but
they do not. If the other parts of UBIFS then mistakenly try to look-up
the truncation node key (they should not do this, but may do because of a bug),
we can succeed and corrupt TNC. It looks like we did have such a situation in
'sort_nodes()' in gc.c.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Improve assertions in gc.c in the comparison functions for 'list_sort()': check
key types _and_ node types.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
In comparison function for 'list_sort()' we use key type to distinguish between
node types. However, we have a bit simper way to detect node type -
'snod->type'. This more logical to use, comparing to decoding key types. Also
allows to get rid of 2 local variables.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When moving nodes in GC, do not try to look up truncation nodes in TNC,
because they do not exist there. This would be harmless, because the TNC
look-up would fail, if we did not have bug 'ubifs_add_snod()' which reads
garbage into 'snod->key'. But in any case, it is less error prone to
explicitly ignore everything but inode, data, dentry and xentry nodes.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes the following false assertion warning:
UBIFS assert failed in data_nodes_cmp at 130 (pid 15107)
The assertion was wrong because it did not take into account that the
node can be an xentry.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
'ubifs_garbage_collect_leb()' should never return '-ENOSPC', and if it
does, this is an error. Thus, do not treat this error code specially.
'-EAGAIN' is a special error code, but not '-ENOSPC'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
In 'ubifs_garbage_collect()' on error path, we first switch to R/O mode, and
then synchronize write-buffers (to make sure no data are lost). But the GC
write-buffer synchronization will fail, because we are already in R/O mode.
This patch re-orders this and makes sure we first synchronize the write-buffer,
and then switch to R/O mode.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits)
no need for list_for_each_entry_safe()/resetting with superblock list
Fix sget() race with failing mount
vfs: don't hold s_umount over close_bdev_exclusive() call
sysv: do not mark superblock dirty on remount
sysv: do not mark superblock dirty on mount
btrfs: remove junk sb_dirt change
BFS: clean up the superblock usage
AFFS: wait for sb synchronization when needed
AFFS: clean up dirty flag usage
cifs: truncate fallout
mbcache: fix shrinker function return value
mbcache: Remove unused features
add f_flags to struct statfs(64)
pass a struct path to vfs_statfs
update VFS documentation for method changes.
All filesystems that need invalidate_inode_buffers() are doing that explicitly
convert remaining ->clear_inode() to ->evict_inode()
Make ->drop_inode() just return whether inode needs to be dropped
fs/inode.c:clear_inode() is gone
fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
...
Fix up trivial conflicts in fs/nilfs2/super.c
Make sure we check the truncate constraints early on in ->setattr by adding
those checks to inode_change_ok. Also clean up and document inode_change_ok
to make this obvious.
As a fallout we don't have to call inode_newsize_ok from simple_setsize and
simplify it down to a truncate_setsize which doesn't return an error. This
simplifies a lot of setattr implementations and means we use truncate_setsize
almost everywhere. Get rid of fat_setsize now that it's trivial and mark
ext2_setsize static to make the calling convention obvious.
Keep the inode_newsize_ok in vmtruncate for now as all callers need an
audit for its removal anyway.
Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
needs a deeper audit, but that is left for later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
