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* Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds2017-05-061-15/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang <yizhan@redhat.com> - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...
| * Revert "block: use DAX for partition table reads"Dan Williams2017-04-251-15/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d1a5f2b4d8a1 ("block: use DAX for partition table reads") was part of a stalled effort to allow dax mappings of block devices. Since then the device-dax mechanism has filled the role of dax-mapping static device ranges. Now that we are moving ->direct_access() from a block_device operation to a dax_inode operation we would need block devices to map and carry their own dax_inode reference. Unless / until we decide to revive dax mapping of raw block devices through the dax_inode scheme, there is no need to carry read_dax_sector(). Its removal in turn allows for the removal of bdev_direct_access() and should have been included in commit 223757016837 ("block_dev: remove DAX leftovers"). Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* | block: get rid of blk_integrity_revalidate()Ilya Dryomov2017-04-211-1/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk") introduced blk_integrity_revalidate(), which seems to assume ownership of the stable pages flag and unilaterally clears it if no blk_integrity profile is registered: if (bi->profile) disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; else disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; It's called from revalidate_disk() and rescan_partitions(), making it impossible to enable stable pages for drivers that support partitions and don't use blk_integrity: while the call in revalidate_disk() can be trivially worked around (see zram, which doesn't support partitions and hence gets away with zram_revalidate_disk()), rescan_partitions() can be triggered from userspace at any time. This breaks rbd, where the ceph messenger is responsible for generating/verifying CRCs. Since blk_integrity_{un,}register() "must" be used for (un)registering the integrity profile with the block layer, move BDI_CAP_STABLE_WRITES setting there. This way drivers that call blk_integrity_register() and use integrity infrastructure won't interfere with drivers that don't but still want stable pages. Fixes: 25520d55cdb6 ("block: Inline blk_integrity in struct gendisk") Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 4.4+, needs backporting Tested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Rename blk_queue_zone_size and bdev_zone_sizeDamien Le Moal2017-01-121-7/+7
| | | | | | | | | | | | | | | | | All block device data fields and functions returning a number of 512B sectors are by convention named xxx_sectors while names in the form xxx_size are generally used for a number of bytes. The blk_queue_zone_size and bdev_zone_size functions were not following this convention so rename them. No functional change is introduced by this patch. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Collapsed the two patches, they were nonsensically split and broke bisection. Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Check partition alignment on zoned block devicesDamien Le Moal2016-12-011-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | Both blkdev_report_zones and blkdev_reset_zones can operate on a partition of a zoned block device. However, the first and last zones reported for a partition make sense only if the partition start sector and size are aligned on the device zone size. The same applies for zone reset. Resetting the first or the last zone of a partition straddling zones may impact neighboring partitions. Finally, if a partition start sector is not at the beginning of a sequential zone, it will be impossible to write to the first sectors of the partition on a host-managed device. Avoid all these problems and incoherencies by ignoring partitions that are not zone aligned. Note: Even with CONFIG_BLK_DEV_ZONED disabled, bdev_is_zoned() will report the correct disk zoning type (host-aware, host-managed or none) but bdev_zone_size() will always return 0 for zoned block devices (i.e. the zone size is unknown). So test this as a way to ensure that a zoned block device is being handled as such. As a result, for a host-aware devices, unaligned zone partitions will be accepted with CONFIG_BLK_DEV_ZONED disabled. That is, the disk will be treated as a regular block device (as it should). If zoned block device support is enabled, only aligned partitions will be accepted. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block/partition-generic.c: Remove a set-but-not-used variableBart Van Assche2016-06-141-3/+0
| | | | | | | | A value is assigned to the variable 'info' but that value is never used. Hence remove the variable 'info'. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2016-04-161-3/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block fixes from Jens Axboe: "A few fixes for the current series. This contains: - Two fixes for NVMe: One fixes a reset race that can be triggered by repeated insert/removal of the module. The other fixes an issue on some platforms, where we get probe timeouts since legacy interrupts isn't working. This used not to be a problem since we had the worker thread poll for completions, but since that was killed off, it means those poor souls can't successfully probe their NVMe device. Use a proper IRQ check and probe (msi-x -> msi ->legacy), like most other drivers to work around this. Both from Keith. - A loop corruption issue with offset in iters, from Ming Lei. - A fix for not having the partition stat per cpu ref count initialized before sending out the KOBJ_ADD, which could cause user space to access the counter prior to initialization. Also from Ming Lei. - A fix for using the wrong congestion state, from Kaixu Xia" * 'for-linus' of git://git.kernel.dk/linux-block: block: loop: fix filesystem corruption in case of aio/dio NVMe: Always use MSI/MSI-x interrupts NVMe: Fix reset/remove race writeback: fix the wrong congested state variable definition block: partition: initialize percpuref before sending out KOBJ_ADD
| * block: partition: initialize percpuref before sending out KOBJ_ADDMing Lei2016-03-301-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The initialization of partition's percpu_ref should have been done before sending out KOBJ_ADD uevent, which may cause userspace to read partition table. So the uninitialized percpu_ref may be accessed in data path. This patch fixes this issue reported by Naveen. Reported-by: Naveen Kaje <nkaje@codeaurora.org> Tested-by: Naveen Kaje <nkaje@codeaurora.org> Fixes: 6c71013ecb7e2(block: partition: convert percpu ref) Cc: <stable@vger.kernel.org> # v4.3+ Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* | mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov2016-04-041-4/+4
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: partition: add partition specific uevent callbacks for partition infoSan Mehat2016-03-161-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch has been carried in the Android tree for quite some time and is one of the few patches required to get a mainline kernel up and running with an exsiting Android userspace. So I wanted to submit it for review and consideration if it should be merged. For partitions, add new uevent parameters 'PARTN' which specifies the partitions index in the table, and 'PARTNAME', which specifies PARTNAME specifices the partition name of a partition device. Android's userspace uses this for creating device node links from the partition name and number, ie: /dev/block/platform/soc/by-name/system or /dev/block/platform/soc/by-num/p1 One can see its usage here: https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#355 and https://android.googlesource.com/platform/system/core/+/master/init/devices.cpp#494 [john.stultz@linaro.org: dropped NPARTS and reworded commit message for context] Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Rom Lemarchand <romlem@google.com> Cc: Android Kernel Team <kernel-team@android.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: <harald@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: use DAX for partition table readsDan Williams2016-01-301-3/+15
| | | | | | | | | | | | | | | | Avoid populating pagecache when the block device is in DAX mode. Otherwise these page cache entries collide with the fsync/msync implementation and break data durability guarantees. Cc: Jan Kara <jack@suse.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Return EBUSY from BLKRRPART for mounted whole-dev fsEric Sandeen2015-11-261-1/+1
| | | | | | | | | | | | | | | Today, blockdev --rereadpt /dev/sda will fail with EBUSY if any partition of sda is mounted (and will fail with EINVAL if pointed at a partition). But it will pass if the entire block device is formatted with a filesystem and mounted. I don't think this makes sense; partitioning should surely not ever change out from under a mounted device. So check for bdev->bd_super, and fail that with -EBUSY as well. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Inline blk_integrity in struct gendiskMartin K. Petersen2015-10-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up until now the_integrity profile has been dynamically allocated and attached to struct gendisk after the disk has been made active. This causes problems because NVMe devices need to register the profile prior to the partition table being read due to a mandatory metadata buffer requirement. In addition, DM goes through hoops to deal with preallocating, but not initializing integrity profiles. Since the integrity profile is small (4 bytes + a pointer), Christoph suggested moving it to struct gendisk proper. This requires several changes: - Moving the blk_integrity definition to genhd.h. - Inlining blk_integrity in struct gendisk. - Removing the dynamic allocation code. - Adding helper functions which allow gendisk to set up and tear down the integrity sysfs dir when a disk is added/deleted. - Adding a blk_integrity_revalidate() callback for updating the stable pages bdi setting. - The calls that depend on whether a device has an integrity profile or not now key off of the bi->profile pointer. - Simplifying the integrity support routines in DM (Mike Snitzer). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reported-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: partition: convert percpu refMing Lei2015-07-171-4/+5
| | | | | | | | | | | | Percpu refcount is the perfect match for partition's case, and the conversion is quite straight. With the convertion, one pair of atomic inc/dec can be saved for accounting block I/O, which is run in hot path of block I/O. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: partition: introduce hd_free_part()Ming Lei2015-07-171-2/+1
| | | | | | | | So the helper can be used in both generic partition case and part0 case. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
* block: Fix dev_t minor allocation lifetimeKeith Busch2014-09-031-1/+1
| | | | | | | | | | | | | Releases the dev_t minor when all references are closed to prevent another device from acquiring the same major/minor. Since the partition's release may be invoked from call_rcu's soft-irq context, the ext_dev_idr's mutex had to be replaced with a spinlock so as not so sleep. Signed-off-by: Keith Busch <keith.busch@intel.com> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
* Revert "loop: cleanup partitions when detaching loop device"Jens Axboe2013-04-081-1/+0
| | | | | | | | | | | | | This reverts commit 8761a3dc1f07b163414e2215a2cadbb4cfe2a107. There are situations where the destruction path is called with the bdev->bd_mutex already held, which then deadlocks in loop_clr_fd(). The normal partition cleanup does a trylock() on the mutex, but it'd be nice to have a more bullet proof method in loop. So punt this more involved fix to the next merge window, and just back out this buggy fix for now. Signed-off-by: Jens Axboe <axboe@kernel.dk>
* loop: cleanup partitions when detaching loop devicePhillip Susi2013-03-221-0/+1
| | | | | | | | | | | | | | | Any partitions added by user space to the loop device were being left in place after detaching the loop device. This was because the detach path issued a BLKRRPART to clean up partitions if LO_FLAGS_PARTSCAN was set, meaning that the partitions were auto scanned on attach. Replace this BLKRRPART with code that unconditionally cleans up partitions on detach instead. Signed-off-by: Phillip Susi <psusi@ubuntu.com> Modified by Jens to export delete_partition(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block/partitions: optimize memory allocation in check_partition()Ming Lei2013-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently, sizeof(struct parsed_partitions) may be 64KB in 32bit arch, so it is easy to trigger page allocation failure by check_partition, especially in hotplug block device situation(such as, USB mass storage, MMC card, ...), and Felipe Balbi has observed the failure. This patch does below optimizations on the allocation of struct parsed_partitions to try to address the issue: - make parsed_partitions.parts as pointer so that the pointed memory can fit in 32KB buffer, then approximate 32KB memory can be saved - vmalloc the buffer pointed by parsed_partitions.parts because 32KB is still a bit big for kmalloc - given that many devices have the partition count limit, so only allocate disk_max_parts() partitions instead of 256 partitions always Signed-off-by: Ming Lei <ming.lei@canonical.com> Reported-by: Felipe Balbi <balbi@ti.com> Cc: Jens Axboe <axboe@kernel.dk> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: fix ext_devt_idr handlingTomas Henzl2013-02-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While adding and removing a lot of disks disks and partitions this sometimes shows up: WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: sysfs: cannot create duplicate filename '/dev/block/259:751' Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan] Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1 Call Trace: warn_slowpath_common+0x87/0xc0 warn_slowpath_fmt+0x46/0x50 sysfs_add_one+0xc9/0x130 sysfs_do_create_link+0x12b/0x170 sysfs_create_link+0x13/0x20 device_add+0x317/0x650 idr_get_new+0x13/0x50 add_partition+0x21c/0x390 rescan_partitions+0x32b/0x470 sd_open+0x81/0x1f0 [sd_mod] __blkdev_get+0x1b6/0x3c0 blkdev_get+0x10/0x20 register_disk+0x155/0x170 add_disk+0xa6/0x160 sd_probe_async+0x13b/0x210 [sd_mod] add_wait_queue+0x46/0x60 async_thread+0x102/0x250 default_wake_function+0x0/0x20 async_thread+0x0/0x250 kthread+0x96/0xa0 child_rip+0xa/0x20 kthread+0x0/0xa0 child_rip+0x0/0x20 This most likely happens because dev_t is freed while the number is still used and idr_get_new() is not protected on every use. The fix adds a mutex where it wasn't before and moves the dev_t free function so it is called after device del. Signed-off-by: Tomas Henzl <thenzl@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: add partition resize function to blkpg ioctlVivek Goyal2012-08-011-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new operation code (BLKPG_RESIZE_PARTITION) to the BLKPG ioctl that allows altering the size of an existing partition, even if it is currently in use. This patch converts hd_struct->nr_sects into sequence counter because One might extend a partition while IO is happening to it and update of nr_sects can be non-atomic on 32bit machines with 64bit sector_t. This can lead to issues like reading inconsistent size of a partition. Sequence counter have been used so that readers don't have to take bdev mutex lock as we call sector_in_part() very frequently. Now all the access to hd_struct->nr_sects should happen using sequence counter read/update helper functions part_nr_sects_read/part_nr_sects_write. There is one exception though, set_capacity()/get_capacity(). I think theoritically race should exist there too but this patch does not modify set_capacity()/get_capacity() due to sheer number of call sites and I am afraid that change might break something. I have left that as a TODO item. We can handle it later if need be. This patch does not introduce any new races as such w.r.t set_capacity()/get_capacity(). v2: Add CONFIG_LBDAF test to UP preempt case as suggested by Phillip. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Phillip Susi <psusi@ubuntu.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Fix NULL pointer dereference in sd_revalidate_diskJun'ichi Nomura2012-03-021-8/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 2.6.39 (1196f8b), when a driver returns -ENOMEDIUM for open(), __blkdev_get() calls rescan_partitions() to remove in-kernel partition structures and raise KOBJ_CHANGE uevent. However it ends up calling driver's revalidate_disk without open and could cause oops. In the case of SCSI: process A process B ---------------------------------------------- sys_open __blkdev_get sd_open returns -ENOMEDIUM scsi_remove_device <scsi_device torn down> rescan_partitions sd_revalidate_disk <oops> Oopses are reported here: http://marc.info/?l=linux-scsi&m=132388619710052 This patch separates the partition invalidation from rescan_partitions() and use it for -ENOMEDIUM case. Reported-by: Huajun Li <huajun.li.lee@gmail.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* separate partition format handling from generic codeAl Viro2012-01-041-0/+537
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>