Commit Graph

295 Commits

Author SHA1 Message Date
Jens Axboe
7dcda1c96d fs: export empty_aops
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>
2011-04-05 23:51:48 +02:00
Linus Torvalds
6c51038900 Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block
* '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}
2011-03-24 10:16:26 -07:00
Linus Torvalds
fdc0ad80a4 Merge branch 'for-linus' of git://git.infradead.org/ubi-2.6
* 'for-linus' of git://git.infradead.org/ubi-2.6:
  UBIFS: fix assertion warning and refine comments
  UBIFS: kill CONFIG_UBIFS_FS_DEBUG_CHKS
  UBIFS: use GFP_NOFS properly
  UBI: use GFP_NOFS properly
2011-03-24 08:22:34 -07:00
Artem Bityutskiy
6ed09c34b7 UBIFS: fix assertion warning and refine comments
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>
2011-03-24 16:16:18 +02:00
Artem Bityutskiy
9d523cafbe UBIFS: kill CONFIG_UBIFS_FS_DEBUG_CHKS
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>
2011-03-24 16:16:08 +02:00
Artem Bityutskiy
fc5e58c0c4 UBIFS: use GFP_NOFS properly
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>
2011-03-24 16:14:26 +02:00
Serge E. Hallyn
2e14967075 userns: rename is_owner_or_cap to inode_owner_or_capable
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>
2011-03-23 19:47:13 -07:00
Linus Torvalds
8f627a8a88 Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* '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
  ...
2011-03-18 10:50:27 -07:00
Artem Bityutskiy
5d630e4328 UBIFS: clean-up commentaries
Clean-up commentaries in debug.h and remove references to non-existing
symblols.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-16 14:05:25 +02:00
Artem Bityutskiy
7c83cc91ab UBIFS: save 128KiB or more RAM
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>
2011-03-16 14:05:25 +02:00
Artem Bityutskiy
f5cf319cf3 UBIFS: allocate orphans scan buffer on demand
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>
2011-03-16 14:05:25 +02:00
Artem Bityutskiy
cab95d446c UBIFS: allocate lpt dump buffer on demand
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>
2011-03-16 14:05:25 +02:00
Artem Bityutskiy
6fb324a4b0 UBIFS: allocate ltab checking buffer on demand
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>
2011-03-16 14:05:24 +02:00
Artem Bityutskiy
cd5f7485bb UBIFS: allocate scanning buffer on demand
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>
2011-03-16 14:05:24 +02:00
Artem Bityutskiy
73d9aec3fd UBIFS: allocate dump buffer on demand
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>
2011-03-16 14:05:24 +02:00
Aneesh Kumar K.V
f17b604207 fs: Remove i_nlink check from file system link callback
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>
2011-03-15 02:21:44 -04:00
Artem Bityutskiy
2bcf002159 UBIFS: do not check data crc by default
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>
2011-03-11 10:52:07 +02:00
Artem Bityutskiy
cce3f612fe UBIFS: simplify UBIFS Kconfig menu
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>
2011-03-11 10:52:07 +02:00
Artem Bityutskiy
6342aaebda UBIFS: print max. index node size
Improve debugging messages by printing the maximum index node size
on mount.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-03-11 10:52:07 +02:00
Matthew L. Creech
d882962f6a UBIFS: handle allocation failures in UBIFS write path
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>
2011-03-11 10:52:07 +02:00
Jens Axboe
7eaceaccab block: remove per-queue plugging
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>
2011-03-10 08:52:07 +01:00
Artem Bityutskiy
2765df7da5 UBIFS: use max_write_size during recovery
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>
2011-03-08 10:12:49 +02:00
Artem Bityutskiy
6c7f74f703 UBIFS: use max_write_size for write-buffers
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>
2011-03-08 10:12:49 +02:00
Artem Bityutskiy
3c89f396dc UBIFS: introduce write-buffer size field
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>
2011-03-08 10:12:49 +02:00
Artem Bityutskiy
ca2ec61d15 UBI: incorporate LEB offset information
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>
2011-03-08 10:12:48 +02:00
Artem Bityutskiy
3e8e2e0c8d UBIFS: incorporate maximum write size
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>
2011-03-08 10:12:48 +02:00
Artem Bityutskiy
10ac279702 UBIFS: fix LEB number in printk
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>
2011-02-08 17:26:32 +02:00
Vasiliy Kulikov
8c559d30b4 UBIFS: restrict world-writable debugfs files
Don't allow everybody to dump sensitive information about filesystems.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06 18:59:31 +02:00
Artem Bityutskiy
be7b42a5cb UBIFS: describe UBIFS recovery logic some more
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>
2011-02-06 18:59:30 +02:00
Artem Bityutskiy
822ed64c5b UBIFS: remove double semicolon
Just a tiny clean-up - remove ;;

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2011-02-06 15:08:02 +02:00
Artem Bityutskiy
944fdef52c UBIFS: do not start the commit if there is nothing to commit
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>
2011-01-25 10:21:13 +02:00
Artem Bityutskiy
18d1d7fbcc UBIFS: introduce mounting flag
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>
2011-01-17 23:24:30 +02:00
Artem Bityutskiy
d8cdda3efb UBIFS: re-arrange variables in ubifs_info
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>
2011-01-17 23:24:30 +02:00
Nick Piggin
fa0d7e3de6 fs: icache RCU free inodes
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>
2011-01-07 17:50:26 +11:00
Al Viro
157d81e7ff convert ubifs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:36 -04:00
Al Viro
7de9c6ee3e new helper: ihold()
Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Linus Torvalds
06d362931a Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6
* '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
2010-10-22 16:34:03 -07:00
Artem Bityutskiy
6599fcbd01 UBIFS: do not allocate unneeded scan buffer
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>
2010-10-21 11:15:19 +03:00
Artem Bityutskiy
3601ba2735 UBIFS: do not forget to cancel timers
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>
2010-10-21 11:15:18 +03:00
Artem Bityutskiy
39037559e6 UBIFS: remove a bit of unneeded code
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>
2010-10-21 11:15:18 +03:00
Artem Bityutskiy
7d08ae3c92 UBIFS: add a commentary about log recovery
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>
2010-10-17 15:57:40 +03:00
Arnd Bergmann
6038f373a3 llseek: automatically add .llseek fop
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>
2010-10-15 15:53:27 +02:00
Steffen Sledz
54dd55a406 UBIFS: avoid kernel error if ubifs superblock read fails
.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>
2010-09-28 09:46:30 +03:00
Artem Bityutskiy
2ef13294d2 UBIFS: introduce new flags for RO mounts
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>
2010-09-19 21:07:58 +03:00
Artem Bityutskiy
2680d722bf UBIFS: introduce new flag for RO due to errors
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>
2010-09-17 17:08:09 +03:00
Vasiliy Kulikov
8c893a5545 UBIFS: check return code of pnode_lookup
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>
2010-09-07 12:10:43 +03:00
Vasiliy Kulikov
0e54c8992a UBIFS: check return code of ubifs_lpt_lookup
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>
2010-09-07 12:09:41 +03:00
Artem Bityutskiy
3a8fa0ed3e UBIFS: improve error reporting when reading bad node
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>
2010-08-30 10:19:09 +03:00
Artem Bityutskiy
3bb66b47a4 UBIFS: introduce list sorting debugging checks
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>
2010-08-30 10:19:09 +03:00
Artem Bityutskiy
1a9476a770 UBIFS: fix assertion warnings in comparison function
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>
2010-08-30 10:19:08 +03:00