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>
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 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>
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>
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>
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>
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Lots of filesystems calls vmtruncate despite not implementing the old
->truncate method. Switch them to use simple_setsize and add some
comments about the truncate code where it seems fitting.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Improve 'dbg_dump_lprop()' and print dark and dead space there,
decode flags, and journal heads.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The journal head names and numbers are part of the UBIFS format, so
they should be in the ubifs-media.h.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
At the moment UBIFS print large and scary error messages and
flash dumps in case of nearly any corruption, even if it is
a recoverable corruption. For example, if the master node is
corrupted, ubifs_scan() prints error dumps, then UBIFS recovers
just fine and goes on.
This patch makes UBIFS print scary error messages only in
real cases, which are not recoverable. It adds 'quiet' argument
to the 'ubifs_scan()' function, so the caller may ask 'ubi_scan()'
not to print error messages if the caller is able to do recovery.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Adrian Hunter <Adrian.Hunter@nokia.com>
This patch adds the following minor optimization:
1. If write-buffer does not use the timer, indicate it with the
wbuf->no_timer variable, instead of using the wbuf->softlimit
variable. This is better because wbuf->softlimit is of ktime_t
type, and the ktime_to_ns function contains 64-bit multiplication.
2. Do not call the 'hrtimer_cancel()' function for write-buffers
which do not use timers.
3. Do not cancel the timer in 'ubifs_put_super()' because the
synchronization function does this.
This patch also removes a confusing comment.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
UBIFS uses timers for write-buffer write-back. It is not
crucial for us to write-back exactly on time. We are fine
to write-back a little earlier or later. And this means
we may optimize UBIFS timer so that it could be groped
with a close timer event, so that the CPU would not be
waken up just to do the write back. This is optimization
to lessen power consumption, which is important in
embedded devices UBIFS is used for.
hrtimers have a nice feature: they are effectively range
timers, and we may defind the soft and hard limits for
it. Standard timers do not have these feature. They may
only be made deferrable, but this means there is effectively
no hard limit. So, we will better use hrtimers.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Now UBIFS is supported by u-boot. If we ever decide to change the
media format, then people will have to upgrade their u-boots to
mount new format images. However, very often it is possible to
preserve R/O forward-compatibility, even though the write
forward-compatibility is not preserved.
This patch introduces a new super-block field which stores the
R/O compatibility version.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: Adrian Hunter <Adrian.Hunter@nokia.com>
This patch introduces a helpful @c->idx_leb_size variable.
The patch also fixes some spelling issues and makes comments
use "LEB" instead of "eraseblock", which is more correct.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Make 'ubifs_find_free_space()' return offset where free space starts,
rather than the amount of free space. This is just more appropriat
for its caller.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This UBIFS feature has never worked properly, and it was a mistake
to add it because we simply have no use-cases. So, lets still accept
the fast_unmount mount option, but ignore it. This does not change
much, because UBIFS commit in sync_fs anyway, and sync_fs is called
while unmounting.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
- preserve the idx_gc list - it will be needed in the same
state, should UBIFS be remounted rw again
- prevent remounting ro if we have switched to read only
mode (due to a fatal error)
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When data CRC checking is disabled, UBIFS returns incorrect return
code from the 'try_read_node()' function (0 instead of 1, which means
CRC error), which make the caller re-read the data node again, but using
a different code patch, so the second read is fine. Thus, we read the
same node twice. And the result of this is that UBIFS is slower
with no_chk_data_crc option than it is with chk_data_crc option.
This patches fixes the problem.
Reported-by: Reuben Dowle <Reuben.Dowle@navico.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When mounting read-only the orphan area head is
not initialized. It must be initialized when
remounting read/write, but it was not. This patch
fixes that.
[Artem: sorry, added comment tweaking noise]
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We observe space corrupted accounting when re-mounting. So add some
debbugging checks to catch problems like this.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
When freeing the c->idx_lebs list, we have to release the LEBs as well,
because we might be called from mount to read-only mode code. Otherwise
the LEBs stay taken forever, which may cause problems when we re-mount
back ro RW mode.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
These are mostly long lines and wrong indentation warning
fixes. But also there are two volatile variables and
checkpatch.pl complains about them:
WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
+ volatile int gc_seq;
WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
+ volatile int gced_lnum;
Well, we anyway use smp_wmb() for c->gc_seq and c->gced_lnum, so
these 'volatile' modifiers can be just dropped.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Take into account that 2 eraseblocks are never available because
they are reserved for the index. This gives more realistic count
of FS blocks.
To avoid future confusions like this, introduce a constant.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This patch fixes the following section mismatch:
WARNING: fs/ubifs/ubifs.o(.init.text+0xec): Section mismatch in reference from the function init_module() to the function .exit.text:ubifs_compressors_exit()
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We need to have a possibility to see various UBIFS variables
and ask UBIFS to dump various information. Debugfs is what
we need.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Introduce a new data structure which contains all debugging
stuff inside. This is cleaner than having debugging stuff
directly in 'c'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
It is very handy to be able to change default UBIFS compressor
via mount options. Introduce -o compr=<name> mount option support.
Currently only "none", "lzo" and "zlib" compressors are supported.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Save a 4 bytes of RAM per 'struct inode' by stroring inode
compression type in bit-filed, instead of using 'int'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
To avoid memory allocation failure during bulk-read, pre-allocate
a bulk-read buffer, so that if there is only one bulk-reader at
a time, it would just use the pre-allocated buffer and would not
do any memory allocation. However, if there are more than 1 bulk-
reader, then only one reader would use the pre-allocated buffer,
while the other reader would allocate the buffer for itself.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Bulk-read allocates 128KiB or more using kmalloc. The allocation
starts failing often when the memory gets fragmented. UBIFS still
works fine in this case, because it falls-back to standard
(non-optimized) read method, though. This patch teaches bulk-read
to allocate exactly the amount of memory it needs, instead of
allocating 128KiB every time.
This patch is also a preparation to the further fix where we'll
have a pre-allocated bulk-read buffer as well. For example, now
the @bu object is prepared in 'ubifs_bulk_read()', so we could
path either pre-allocated or allocated information to
'ubifs_do_bulk_read()' later. Or teaching 'ubifs_do_bulk_read()'
not to allocate 'bu->buf' if it is already there.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Bulk-read allocates a lot of memory with 'kmalloc()', and when it
is/gets fragmented 'kmalloc()' fails with a scarry warning. But
because bulk-read is just an optimization, UBIFS keeps working fine.
Supress the warning by passing __GFP_NOWARN option to 'kmalloc()'.
This patch also introduces a macro for the magic 128KiB constant.
This is just neater.
Note, this is not really fixes the problem we had, but just hides
the warnings. The further patches fix the problem.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Also add debugging checks for LPT size and separate
out c->check_lpt_free from unrelated bitfields.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
We cannot store bit-fields together if the processes which
change them may race, unless we serialize them.
Thus, move the nospc and nospc_rp bit-fields eway from
the mount option/constant bit-fields, to avoid races.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
