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* mtd: blkdevs: fix potential deadlock + lockdep warningsBrian Norris2015-10-301-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 073db4a51ee4 ("mtd: fix: avoid race condition when accessing mtd->usecount") fixed a race condition but due to poor ordering of the mutex acquisition, introduced a potential deadlock. The deadlock can occur, for example, when rmmod'ing the m25p80 module, which will delete one or more MTDs, along with any corresponding mtdblock devices. This could potentially race with an acquisition of the block device as follows. -> blktrans_open() -> mutex_lock(&dev->lock); -> mutex_lock(&mtd_table_mutex); -> del_mtd_device() -> mutex_lock(&mtd_table_mutex); -> blktrans_notify_remove() -> del_mtd_blktrans_dev() -> mutex_lock(&dev->lock); This is a classic (potential) ABBA deadlock, which can be fixed by making the A->B ordering consistent everywhere. There was no real purpose to the ordering in the original patch, AFAIR, so this shouldn't be a problem. This ordering was actually already present in del_mtd_blktrans_dev(), for one, where the function tried to ensure that its caller already held mtd_table_mutex before it acquired &dev->lock: if (mutex_trylock(&mtd_table_mutex)) { mutex_unlock(&mtd_table_mutex); BUG(); } So, reverse the ordering of acquisition of &dev->lock and &mtd_table_mutex so we always acquire mtd_table_mutex first. Snippets of the lockdep output follow: # modprobe -r m25p80 [ 53.419251] [ 53.420838] ====================================================== [ 53.427300] [ INFO: possible circular locking dependency detected ] [ 53.433865] 4.3.0-rc6 #96 Not tainted [ 53.437686] ------------------------------------------------------- [ 53.444220] modprobe/372 is trying to acquire lock: [ 53.449320] (&new->lock){+.+...}, at: [<c043fe4c>] del_mtd_blktrans_dev+0x80/0xdc [ 53.457271] [ 53.457271] but task is already holding lock: [ 53.463372] (mtd_table_mutex){+.+.+.}, at: [<c0439994>] del_mtd_device+0x18/0x100 [ 53.471321] [ 53.471321] which lock already depends on the new lock. [ 53.471321] [ 53.479856] [ 53.479856] the existing dependency chain (in reverse order) is: [ 53.487660] -> #1 (mtd_table_mutex){+.+.+.}: [ 53.492331] [<c043fc5c>] blktrans_open+0x34/0x1a4 [ 53.497879] [<c01afce0>] __blkdev_get+0xc4/0x3b0 [ 53.503364] [<c01b0bb8>] blkdev_get+0x108/0x320 [ 53.508743] [<c01713c0>] do_dentry_open+0x218/0x314 [ 53.514496] [<c0180454>] path_openat+0x4c0/0xf9c [ 53.519959] [<c0182044>] do_filp_open+0x5c/0xc0 [ 53.525336] [<c0172758>] do_sys_open+0xfc/0x1cc [ 53.530716] [<c000f740>] ret_fast_syscall+0x0/0x1c [ 53.536375] -> #0 (&new->lock){+.+...}: [ 53.540587] [<c063f124>] mutex_lock_nested+0x38/0x3cc [ 53.546504] [<c043fe4c>] del_mtd_blktrans_dev+0x80/0xdc [ 53.552606] [<c043f164>] blktrans_notify_remove+0x7c/0x84 [ 53.558891] [<c04399f0>] del_mtd_device+0x74/0x100 [ 53.564544] [<c043c670>] del_mtd_partitions+0x80/0xc8 [ 53.570451] [<c0439aa0>] mtd_device_unregister+0x24/0x48 [ 53.576637] [<c046ce6c>] spi_drv_remove+0x1c/0x34 [ 53.582207] [<c03de0f0>] __device_release_driver+0x88/0x114 [ 53.588663] [<c03de19c>] device_release_driver+0x20/0x2c [ 53.594843] [<c03dd9e8>] bus_remove_device+0xd8/0x108 [ 53.600748] [<c03dacc0>] device_del+0x10c/0x210 [ 53.606127] [<c03dadd0>] device_unregister+0xc/0x20 [ 53.611849] [<c046d878>] __unregister+0x10/0x20 [ 53.617211] [<c03da868>] device_for_each_child+0x50/0x7c [ 53.623387] [<c046eae8>] spi_unregister_master+0x58/0x8c [ 53.629578] [<c03e12f0>] release_nodes+0x15c/0x1c8 [ 53.635223] [<c03de0f8>] __device_release_driver+0x90/0x114 [ 53.641689] [<c03de900>] driver_detach+0xb4/0xb8 [ 53.647147] [<c03ddc78>] bus_remove_driver+0x4c/0xa0 [ 53.652970] [<c00cab50>] SyS_delete_module+0x11c/0x1e4 [ 53.658976] [<c000f740>] ret_fast_syscall+0x0/0x1c [ 53.664621] [ 53.664621] other info that might help us debug this: [ 53.664621] [ 53.672979] Possible unsafe locking scenario: [ 53.672979] [ 53.679169] CPU0 CPU1 [ 53.683900] ---- ---- [ 53.688633] lock(mtd_table_mutex); [ 53.692383] lock(&new->lock); [ 53.698306] lock(mtd_table_mutex); [ 53.704658] lock(&new->lock); [ 53.707946] [ 53.707946] *** DEADLOCK *** Fixes: 073db4a51ee4 ("mtd: fix: avoid race condition when accessing mtd->usecount") Reported-by: Felipe Balbi <balbi@ti.com> Tested-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com> Cc: <stable@vger.kernel.org>
* mtd: blktrans: fix multiplication overflowPeng Fan2015-09-281-1/+1
| | | | | | | | | | | | | | | | | | | | In drivers/mtd/mtd_blkdevs.c: 406 set_capacity(gd, (new->size * tr->blksize) >> 9); The type of new->size is unsigned long and the type of tr->blksize is int, the result of 'new->size * tr->blksize' may exceed ULONG_MAX on 32bit machines. I use nand chip MT29F32G08CBADBWP which is 4GB and the parameters passed to kernel is 'mtdparts=gpmi-nand:-(user)', the whole nand chip will be treated as a 4GB mtd partition. new->size is 0x800000 and tr->blksize is 0x200, 'new->size * tr->blksize' however is 0. This is what we do not want to see. Using type cast u64 to fix the multiplication overflow issue. Signed-off-by: Peng Fan <van.freenix@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds2015-09-021-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
| * block: have drivers use blk_queue_max_discard_sectors()Jens Axboe2015-07-171-1/+1
| | | | | | | | | | | | | | | | | | | | Some drivers use it now, others just set the limits field manually. But in preparation for splitting this into a hard and soft limit, ensure that they all call the proper function for setting the hw limit for discards. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | mtd: blkdevs: fix switch-bool compilation warningTomer Barletz2015-08-251-6/+2
|/ | | | | | | | With gcc 5.1 I get: warning: switch condition has boolean value [-Wswitch-bool] Signed-off-by: Tomer Barletz <barletz@gmail.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* mtd: blktrans: use better error code for unimplemented ioctl()Brian Norris2015-05-211-1/+1
| | | | | | | | | | | | | | In commit 50183936254b ("mtd: blktrans: change blktrans_getgeo return value") we fixed the problem that ioctl(HDIO_GETGEO) might return 0 (success) for mtdblock devices which did not implement the feature and would leave a blank (zero) result. But now, let's get the error code right. Other code paths on this ioctl tend to use -ENOTTY to notify the user that the ioctl() is not supported for the device, so let's use that instead of -EOPNOTSUPP. Suggested-by: Richard Weinberger <richard@nod.at> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* mtd: blktrans: change blktrans_getgeo return valueWenlin Kang2015-05-211-1/+1
| | | | | | | | | | | | | Modify function blktrans_getgeo()'s return value to -EOPNOTSUPP when dev->tr->getgeo == NULL. We shouldn't make the return value to 0 when dev->tr->getgeo == NULL, because the function blktrans_getgeo() has an output value "hd_geometry" which is usually used by some application, if returns 0 (i.e., "success"), it will make some application get the wrong information. Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* mtd: fix: avoid race condition when accessing mtd->usecountBrian Norris2015-05-121-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On A MIPS 32-cores machine a BUG_ON was triggered because some acesses to mtd->usecount were done without taking mtd_table_mutex. kernel: Call Trace: kernel: [<ffffffff80401818>] __put_mtd_device+0x20/0x50 kernel: [<ffffffff804086f4>] blktrans_release+0x8c/0xd8 kernel: [<ffffffff802577e0>] __blkdev_put+0x1a8/0x200 kernel: [<ffffffff802579a4>] blkdev_close+0x1c/0x30 kernel: [<ffffffff8022006c>] __fput+0xac/0x250 kernel: [<ffffffff80171208>] task_work_run+0xd8/0x120 kernel: [<ffffffff8012c23c>] work_notifysig+0x10/0x18 kernel: kernel: Code: 2442ffff ac8202d8 000217fe <00020336> dc820128 10400003 00000000 0040f809 00000000 kernel: ---[ end trace 080fbb4579b47a73 ]--- Fixed by taking the mutex in blktrans_open and blktrans_release. Note that this locking is already suggested in include/linux/mtd/blktrans.h: struct mtd_blktrans_ops { ... /* Called with mtd_table_mutex held; no race with add/remove */ int (*open)(struct mtd_blktrans_dev *dev); void (*release)(struct mtd_blktrans_dev *dev); ... }; But we weren't following it. Originally reported by (and patched by) Zhang and Giuseppe, independently. Improved and rewritten. Cc: stable@vger.kernel.org Reported-by: Zhang Xingcai <zhangxingcai@huawei.com> Reported-by: Giuseppe Cantavenera <giuseppe.cantavenera.ext@nokia.com> Tested-by: Giuseppe Cantavenera <giuseppe.cantavenera.ext@nokia.com> Acked-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* mtd: blkdevs: remove dead codeBrian Norris2015-03-111-3/+0
| | | | | | | | | The only exit (break) from the preceding loop is nested within a condition which yields req == NULL. This code is dead. Coverity CID #752669 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* block: disable entropy contributions for nonrot devicesMike Snitzer2014-10-041-0/+1
| | | | | | | | | | | | | | | | | | | | | Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set QUEUE_FLAG_NONROT. Historically, all block devices have automatically made entropy contributions. But as previously stated in commit e2e1a148 ("block: add sysfs knob for turning off disk entropy contributions"): - On SSD disks, the completion times aren't as random as they are for rotational drives. So it's questionable whether they should contribute to the random pool in the first place. - Calling add_disk_randomness() has a lot of overhead. There are more reliable sources for randomness than non-rotational block devices. From a security perspective it is better to err on the side of caution than to allow entropy contributions from unreliable "random" sources. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge tag 'for-linus-20140610' of git://git.infradead.org/linux-mtdLinus Torvalds2014-06-111-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull MTD updates from Brian Norris: - refactor m25p80.c driver for use as a general SPI NOR framework for other drivers which may speak to SPI NOR flash without providing full SPI support (i.e., not part of drivers/spi/) - new Freescale QuadSPI driver (utilizing new SPI NOR framework) - updates for the STMicro "FSM" SPI NOR driver - fix sync/flush behavior on mtd_blkdevs - fixup subpage write support on a few NAND drivers - correct the MTD OOB test for odd-sized OOB areas - add BCH-16 support for OMAP NAND - fix warnings and trivial refactoring - utilize new ECC DT bindings in pxa3xx NAND driver - new LPDDR NVM driver - address a few assorted bugs caught by Coverity - add new imx6sx support for GPMI NAND - use a bounce buffer for NAND when non-DMA-able buffers are used * tag 'for-linus-20140610' of git://git.infradead.org/linux-mtd: (77 commits) mtd: gpmi: add gpmi support for imx6sx mtd: maps: remove check for CONFIG_MTD_SUPERH_RESERVE mtd: bf5xx_nand: use the managed version of kzalloc mtd: pxa3xx_nand: make the driver work on big-endian systems mtd: nand: omap: fix omap_calculate_ecc_bch() for-loop error mtd: nand: r852: correct write_buf loop bounds mtd: nand_bbt: handle error case for nand_create_badblock_pattern() mtd: nand_bbt: remove unused variable mtd: maps: sc520cdp: fix warnings mtd: slram: fix unused variable warning mtd: pfow: remove unused variable mtd: lpddr: fix Kconfig dependency, for I/O accessors mtd: nand: pxa3xx: Add supported ECC strength and step size to the DT binding mtd: nand: pxa3xx: Use ECC strength and step size devicetree binding mtd: nand: pxa3xx: Clean pxa_ecc_init() error handling mtd: nand: Warn the user if the selected ECC strength is too weak mtd: nand: omap: Documentation: How to select correct ECC scheme for your device ? mtd: nand: omap: add support for BCH16_ECC - NAND driver updates mtd: nand: omap: add support for BCH16_ECC - ELM driver updates mtd: nand: omap: add support for BCH16_ECC - GPMC driver updates ...
| * mtd: mtd_blkdevs: handle REQ_FLUSH request and do explicit flush of ↵Roman Peniaev2014-04-151-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | writeback buffer mtd_blkdevs is device with volatile cache (writeback buffer), so it should support REQ_FLUSH to do explicit flush. Without this patch 'sync' does not guarantee that writeback buffer will be flushed on disk in case of power off, e.g.: $ cp some_file /mnt $ sync ### POWER OFF In case of this sequence writeback buffer will not be flushed on disk. This patch fixes this behaviour and explicitly reports to block layer that flush requests are being supported. Signed-off-by: Roman Peniaev <r.peniaev@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: linux-mtd@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* | block: remove struct request buffer memberJens Axboe2014-04-151-2/+1
|/ | | | | | | | | | | | | | | This was used in the olden days, back when onions were proper yellow. Basically it mapped to the current buffer to be transferred. With highmem being added more than a decade ago, most drivers map pages out of a bio, and rq->buffer isn't pointing at anything valid. Convert old style drivers to just use bio_data(). For the discard payload use case, just reference the page in the bio. Signed-off-by: Jens Axboe <axboe@fb.com>
* mtd: delete non-required instances of include <linux/init.h>Paul Gortmaker2014-03-101-1/+0
| | | | | | | | | | | | | | None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Cc: David Woodhouse <dwmw2@infradead.org> Cc: Brian Norris <computersforpeace@gmail.com> Cc: linux-mtd@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> [Brian: dropped one incorrect hunk] Signed-off-by: Brian Norris <computersforpeace@gmail.com>
* block_device_operations->release() should return voidAl Viro2013-05-071-3/+2
| | | | | | | | | The value passed is 0 in all but "it can never happen" cases (and those only in a couple of drivers) *and* it would've been lost on the way out anyway, even if something tried to pass something meaningful. Just don't bother. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mtd_blktrans_ops->release() should return voidAl Viro2013-05-051-4/+4
| | | | | | | Both existing instances always return 0 and even if they didn't, the value would be lost on the way out. Just don't bother... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mtd: mtd_blkdevs: Replace request handler kthread with a workqueueEzequiel Garcia2012-11-211-32/+15
| | | | | | | | | | | | | | | | | | | By replacing a kthread with a workqueue, the code is now a bit clearer. There's also a slight reduction of code size (numbers apply for x86): Before: text data bss dec hex filename 3248 36 0 3284 cd4 drivers/mtd/mtd_blkdevs.o After: text data bss dec hex filename 3150 36 0 3186 c72 drivers/mtd/mtd_blkdevs.o Due to lack of real hardware, tests have been performed on an emulated environment with mtdswap and mtdblock over nandsim devices. Some real testing should be done, before merging this patch. Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* mtd: mtd_blkdev: Use a different name for block_device_operations variableEzequiel Garcia2012-11-211-2/+2
| | | | | | | | | struct mtd_blktrans_ops is a type, and mtd_blktrans_ops is a variable. To improve code clarity it's better to not use the same names, so we just change the latter. Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
* mtd: mtdblock: call mtd_sync() only if opened for writeAlexander Stein2012-03-271-0/+1
| | | | | | | | | | | | | | Because it is useless to call it if the device is opened in R/O mode, and also harmful: on CFI NOR flash it may block for long time waiting for erase operations to complete is another partition with a R/W file-system on this chip. Artem Bityutskiy: write commit message, amend the patch to match the latest tree (we use mtd_sync(), not mtd->sync() nowadays). Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: mtd_blkdevs: don't increase 'open' count on error pathBrian Norris2012-01-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some error paths in mtd_blkdevs were fixed in the following commit: commit 94735ec4044a6d318b83ad3c5794e931ed168d10 mtd: mtd_blkdevs: fix error path in blktrans_open But on these error paths, the block device's `dev->open' count is already incremented before we check for errors. This meant that, while the error path was handled correctly on the first time through blktrans_open(), the device is erroneously considered already open on the second time through. This problem can be seen, for instance, when a UBI volume is simultaneously mounted as a UBIFS partition and read through its corresponding gluebi mtdblockX device. This results in blktrans_open() passing its error checks (with `dev->open > 0') without actually having a handle on the device. Here's a summarized log of the actions and results with nandsim: # modprobe nandsim # modprobe mtdblock # modprobe gluebi # modprobe ubifs # ubiattach /dev/ubi_ctrl -m 0 ... # ubimkvol /dev/ubi0 -N test -s 16MiB ... # mount -t ubifs ubi0:test /mnt # ls /dev/mtdblock* /dev/mtdblock0 /dev/mtdblock1 # cat /dev/mtdblock1 > /dev/null cat: can't open '/dev/mtdblock4': Device or resource busy # cat /dev/mtdblock1 > /dev/null CPU 0 Unable to handle kernel paging request at virtual address fffffff0, epc == 8031536c, ra == 8031f280 Oops[#1]: ... Call Trace: [<8031536c>] ubi_leb_read+0x14/0x164 [<8031f280>] gluebi_read+0xf0/0x148 [<802edba8>] mtdblock_readsect+0x64/0x198 [<802ecfe4>] mtd_blktrans_thread+0x330/0x3f4 [<8005be98>] kthread+0x88/0x90 [<8000bc04>] kernel_thread_helper+0x10/0x18 Cc: stable@kernel.org [3.0+] Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: mark block device queue as non-rotationalDan McGee2011-10-141-0/+2
| | | | | | | This is similar to what the nbd driver does, among others. Signed-off-by: Dan McGee <dpmcgee@gmail.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
* mtd: mtd_blkdevs: fix error path in blktrans_openArtem Bityutskiy2011-05-251-3/+21
| | | | | | | | | | | | | | | | | | The 'blktrans_open()' does not handle possible '__get_mtd_device()' failures because it does not check the error code. Moreover, the 'dev->tr->open()' failures are not handled correctly because in this case the function just goes ahead and gets the mtd device, then returns an error. But Instead, it should _not_ try to get the mtd device, then it should put back the module and the kref. This patch fixes the issue. Note, I only compile-tested it. This patch was inspired by a bug report about a similar issue in 2.6.34 kernels sent by Mike Turner <admin@islandsoftware.co.uk> to the MTD mailing list: http://lists.infradead.org/pipermail/linux-mtd/2011-April/034980.html Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge branch 'master' of ↵Artem Bityutskiy2011-03-251-3/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1 * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits) [media] rc: update for bitop name changes fs: simplify iget & friends fs: pull inode->i_lock up out of writeback_single_inode fs: rename inode_lock to inode_hash_lock fs: move i_wb_list out from under inode_lock fs: move i_sb_list out from under inode_lock fs: remove inode_lock from iput_final and prune_icache fs: Lock the inode LRU list separately fs: factor inode disposal fs: protect inode->i_state with inode->i_lock lib, arch: add filter argument to show_mem and fix private implementations SLUB: Write to per cpu data when allocating it slub: Fix debugobjects with lockless fastpath autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd() autofs4 - remove autofs4_lock autofs4 - fix d_manage() return on rcu-walk autofs4 - fix autofs4_expire_indirect() traversal autofs4 - fix dentry leak in autofs4_expire_direct() autofs4 - reinstate last used update on access vfs - check non-mountpoint dentry might block in __follow_mount_rcu() ... NOTE! This merge commit was created to fix compilation error. The block tree was merged upstream and removed the 'elv_queue_empty()' function which the new 'mtdswap' driver is using. So a simple merge of the mtd tree with upstream does not compile. And the mtd tree has already be published, so re-basing it is not an option. To fix this unfortunate situation, I had to merge upstream into the mtd-2.6.git tree without committing, put the fixup patch on top of this, and then commit this. The result is that we do not have commits which do not compile. In other words, this merge commit "merges" 3 things: the MTD tree, the upstream tree, and the fixup patch.
* | mtd_blkdevs: Set the maximum discards sizeJarkko Lavinen2011-03-111-3/+4
| | | | | | | | | | | | | | | | Set max_discard_sectors to UINT_MAX. Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com> Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd_blkdevs: Add background processing supportJarkko Lavinen2011-03-111-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new background method into mtd_blktrans_ops, add background support into mtd_blktrans_thread(), and add mtd_blktrans_cease_background(). If the mtd blktrans dev has the background support, the thread will call background function when the request queue becomes empty. The background operation may run as long as needs to until mtd_blktrans_cease_background() tells to stop. Signed-off-by: Jarkko Lavinen <jarkko.lavinen@nokia.com> Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd: mtd_blkdevs: local symbols should be staticH Hartley Sweeten2011-03-111-2/+2
|/ | | | | | | | | The function blktrans_dev_release and blktrans_dev_put are only used locally in this file and should be static. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: mtd_blkdevs: fix double free on error pathMaxim Levitsky2011-03-111-1/+0
| | | | | | | | | | | | | | | | This one liner patch fixes double free that will occur if add_mtd_blktrans_dev fails. On failure it frees the input argument, but all its users also free it on error which is natural thing to do. Thus don't free it. All credit for finding that bug belongs to reporters of the bug in the android bugzilla http://code.google.com/p/android/issues/detail?id=13761 Commit message tweaked by Artem. Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Cc: stable@kernel.org
* mtd: Remove redundant mutex from mtd_blkdevs.cDavid Woodhouse2010-10-301-7/+0
| | | | | | | | | | | In commit 2a48fc0ab24241755dc93bfd4f01d68efab47f5a ('block: autoconvert trivial BKL users to private mutex'), Arnd replaced the BKL usage with a mutex. However, Maxim has already provided a better fix in commit 480792b7bf188c29b8d4b10fee65c3a06ec5dbf7 ('mtd: blktrans: kill BKL'), which was simply to remove the BKL without replacing it — since he'd already made it do all necessary locking for itself. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge branch 'master' of ↵David Woodhouse2010-10-301-1/+7
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git Conflicts: drivers/mtd/mtd_blkdevs.c Merge Grant's device-tree bits so that we can apply the subsequent fixes. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| * block: autoconvert trivial BKL users to private mutexArnd Bergmann2010-10-051-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The block device drivers have all gained new lock_kernel calls from a recent pushdown, and some of the drivers were already using the BKL before. This turns the BKL into a set of per-driver mutexes. Still need to check whether this is safe to do. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de>
* | MTD: Fix wrong check register_blkdev return valueFrank Li2010-10-301-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | register_blkdev return 1..255 when major = 0. if (ret ) { printk(KERN_WARNING "Unable to register %s block device on major %d: %d\n", tr->name, tr->major, ret); mutex_unlock(&mtd_table_mutex); return ret; } Above code will return fail when register_blkdev return allocated major number. Signed-off-by: Frank Li <Frank.Li@freescale.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd: blktrans: fix a race vs kthread_stopMaxim Levitsky2010-10-251-0/+4
| | | | | | | | | | | | | | | | | | There is small race window that could make kthread_stop hang forever. I found that while hacking the IR subsystem. Signed-off-by: Maxim Levitsky <maximlevisky@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd: blktrans: kill BKLMaxim Levitsky2010-10-251-6/+0
| | | | | | | | | | | | | | | | | | It not needed, because I already added locking for all fops methods. Signed-off-by: Maxim Levitsky <maximlevisky@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd: allow to unload the mtdtrans module if its block devices aren't openMaxim Levitsky2010-10-251-28/+24
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now it once again possible to remove mtdtrans module. You still need to ensure that block devices of that module aren't mounted. This is due to the fact that as long as a block device is open, it still exists, therefore if we were to allow module removal, this block device might became used again. This time in addition to code review, I also made the code pass some torture tests like module reload in a loop + read in a loop + card insert/removal all at same time. The blktrans_open/blktrans_release don't take the mtd table lock because: While device is added (that includes execution of add_mtd_blktrans_dev) the lock is already taken Now suppose the device will never be removed. In this case even if we have changes in mtd table, the entry that we need will stay exactly the same. (Note that we don't look at table at all, just following private pointer of block device). Now suppose that someone tries to remove the mtd device. This will be propagated to trans driver which _ought_ to call del_mtd_blktrans_dev which will take the per device lock, release the mtd device and set trans->mtd = NULL. >From this point on, following opens won't even be able to know anything about that mtd device (which at that point is likely not to exist) Also the same care is taken not to trip over NULL mtd pointer in blktrans_dev_release. Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Tested-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2010-08-101-4/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits) block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n xen-blkfront: fix missing out label blkdev: fix blkdev_issue_zeroout return value block: update request stacking methods to support discards block: fix missing export of blk_types.h writeback: fix bad _bh spinlock nesting drbd: revert "delay probes", feature is being re-implemented differently drbd: Initialize all members of sync_conf to their defaults [Bugz 315] drbd: Disable delay probes for the upcomming release writeback: cleanup bdi_register writeback: add new tracepoints writeback: remove unnecessary init_timer call writeback: optimize periodic bdi thread wakeups writeback: prevent unnecessary bdi threads wakeups writeback: move bdi threads exiting logic to the forker thread writeback: restructure bdi forker loop a little writeback: move last_active to bdi writeback: do not remove bdi from bdi_list writeback: simplify bdi code a little writeback: do not lose wake-ups in bdi threads ... Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and drivers/scsi/scsi_error.c as per Jens.
| * block: push down BKL into .open and .releaseArnd Bergmann2010-08-071-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The open and release block_device_operations are currently called with the BKL held. In order to change that, we must first make sure that all drivers that currently rely on this have no regressions. This blindly pushes the BKL into all .open and .release operations for all block drivers to prepare for the next step. The drivers can subsequently replace the BKL with their own locks or remove it completely when it can be shown that it is not needed. The functions blkdev_get and blkdev_put are the only remaining users of the big kernel lock in the block layer, besides a few uses in the ioctl code, none of which need to serialize with blkdev_{get,put}. Most of these two functions is also under the protection of bdev->bd_mutex, including the actual calls to ->open and ->release, and the common code does not access any global data structures that need the BKL. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * block: push down BKL into .locked_ioctlArnd Bergmann2010-08-071-1/+4
| | | | | | | | | | | | | | | | | | | | | | As a preparation for the removal of the big kernel lock in the block layer, this removes the BKL from the common ioctl handling code, moving it into every single driver still using it. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
| * block: remove wrappers for request type/flagsChristoph Hellwig2010-08-071-2/+2
| | | | | | | | | | | | | | | | | | Remove all the trivial wrappers for the cmd_type and cmd_flags fields in struct requests. This allows much easier grepping for different request types instead of unwinding through macros. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* | mtd: Update copyright noticesDavid Woodhouse2010-08-081-2/+16
| | | | | | | | Signed-off-by: David Woodhouse <dwmw2@infradead.org>
* | mtd: blkdevs: fix crash related to sysfs attributes.Maxim Levitsky2010-08-061-3/+4
| | | | | | | | | | | | | | | | Remove the attributes group before disk to avoid use after free Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | mtd: return success on blktrans_ioctlDan Carpenter2010-08-021-0/+1
|/ | | | | | | | | There was a break missing so we returned -ENOTTY on success instead of zero. This was introduced by 048d8719956: "mtd: blktrans: Hotplug fixes" Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: blktrans: do blk_cleanup_queue when it is really safe to do soMaxim Levitsky2010-03-081-1/+1
| | | | | | | | | I was calling it in del_mtd_blktrans_dev, but ->request_fn could still be running at that point, thus defer this call to blktrans_dev_release Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: Few follow up cleanups for Smartmedia/xD supportMaxim Levitsky2010-02-261-2/+4
| | | | | | | | | | * Test results of few functions that were declared with __must_check * Fix bogus gcc warning about uinitialized variable 'ret' * Remove unused variable from mtdblock_remove_dev * Don't use deprecated DMA_32BIT_MASK Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: blktrans: allow FTL drivers to export sysfs attributesMaxim Levitsky2010-02-261-0/+8
| | | | | | | | | | | This patch adds an ability to export sysfs attributes below the block disk device. This can be used to pass the udev an information about the FTL and could include the vendor, serial, version, etc... Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: blktrans: Hotplug fixesMaxim Levitsky2010-02-261-54/+148
| | | | | | | | | | | | | | | | | | | * Add locking where it was missing. * Don't do a get_mtd_device in blktrans_open because it would lead to a deadlock; instead do that in add_mtd_blktrans_dev. * Only free the mtd_blktrans_dev structure when the last user exits. * Flush request queue on device removal. * Track users, and call tr->release in del_mtd_blktrans_dev Due to that ->open and release aren't called more that once. Now it is safe to call del_mtd_blktrans_dev while the device is still in use. Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: blktrans: remove mtd_blkcore_priv, switch to per device queue and threadMaxim Levitsky2010-02-261-66/+58
| | | | | | | | | This is the biggest change. To make hotplug possible, and this layer clean, the mtd_blktrans_dev now contains everything for a single mtd block translation device. Also removed some very old leftovers. Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: Raise limit on block device minor numbersBen Hutchings2010-02-251-2/+5
| | | | | | | | | | | add_mtd_blktrans_dev() imposes a maximum of 257 devices per block translator. This was presumably meant to prevent overflow back in the days of 8-bit minor numbers. Instead, check against MINORMASK and the limits of the partition naming scheme. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* mtd: Introduce and use iteration macro for reading the MTD device tableBen Hutchings2010-02-251-5/+5
| | | | | | Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* Merge git://git.infradead.org/mtd-2.6Linus Torvalds2009-12-161-4/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.infradead.org/mtd-2.6: (90 commits) jffs2: Fix long-standing bug with symlink garbage collection. mtd: OneNAND: Fix test of unsigned in onenand_otp_walk() mtd: cfi_cmdset_0002, fix lock imbalance Revert "mtd: move mxcnd_remove to .exit.text" mtd: m25p80: add support for Macronix MX25L4005A kmsg_dump: fix build for CONFIG_PRINTK=n mtd: nandsim: add support for 4KiB pages mtd: mtdoops: refactor as a kmsg_dumper mtd: mtdoops: make record size configurable mtd: mtdoops: limit the maximum mtd partition size mtd: mtdoops: keep track of used/unused pages in an array mtd: mtdoops: several minor cleanups core: Add kernel message dumper to call on oopses and panics mtd: add ARM pismo support mtd: pxa3xx_nand: Fix PIO data transfer mtd: nand: fix multi-chip suspend problem mtd: add support for switching old SST chips into QRY mode mtd: fix M29W800D dev_id and uaddr mtd: don't use PF_MEMALLOC mtd: Add bad block table overrides to Davinci NAND driver ... Fixed up conflicts (mostly trivial) in drivers/mtd/devices/m25p80.c drivers/mtd/maps/pcmciamtd.c drivers/mtd/nand/pxa3xx_nand.c kernel/printk.c
| * mtd: don't use PF_MEMALLOCKOSAKI Motohiro2009-11-301-3/+0
| | | | | | | | | | | | | | | | | | Non MM subsystem must not use PF_MEMALLOC. Memory reclaim need few memory, anyone must not prevent it. Otherwise the system cause mysterious hang-up and/or OOM Killer invokation. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>