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2016-01-12Merge branch 'work.misc' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of stuff. That probably should've been 5 or 6 separate branches, but by the time I'd realized how large and mixed that bag had become it had been too close to -final to play with rebasing. Some fs/namei.c cleanups there, memdup_user_nul() introduction and switching open-coded instances, burying long-dead code, whack-a-mole of various kinds, several new helpers for ->llseek(), assorted cleanups and fixes from various people, etc. One piece probably deserves special mention - Neil's lookup_one_len_unlocked(). Similar to lookup_one_len(), but gets called without ->i_mutex and tries to avoid ever taking it. That, of course, means that it's not useful for any directory modifications, but things like getting inode attributes in nfds readdirplus are fine with that. I really should've asked for moratorium on lookup-related changes this cycle, but since I hadn't done that early enough... I *am* asking for that for the coming cycle, though - I'm going to try and get conversion of i_mutex to rwsem with ->lookup() done under lock taken shared. There will be a patch closer to the end of the window, along the lines of the one Linus had posted last May - mechanical conversion of ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/ inode_is_locked()/inode_lock_nested(). To quote Linus back then: ----- | This is an automated patch using | | sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/' | sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/' | sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[ ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/' | sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/' | sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/' | | with a very few manual fixups ----- I'm going to send that once the ->i_mutex-affecting stuff in -next gets mostly merged (or when Linus says he's about to stop taking merges)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) nfsd: don't hold i_mutex over userspace upcalls fs:affs:Replace time_t with time64_t fs/9p: use fscache mutex rather than spinlock proc: add a reschedule point in proc_readfd_common() logfs: constify logfs_block_ops structures fcntl: allow to set O_DIRECT flag on pipe fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE fs: xattr: Use kvfree() [s390] page_to_phys() always returns a multiple of PAGE_SIZE nbd: use ->compat_ioctl() fs: use block_device name vsprintf helper lib/vsprintf: add %*pg format specifier fs: use gendisk->disk_name where possible poll: plug an unused argument to do_poll amdkfd: don't open-code memdup_user() cdrom: don't open-code memdup_user() rsxx: don't open-code memdup_user() mtip32xx: don't open-code memdup_user() [um] mconsole: don't open-code memdup_user_nul() [um] hostaudio: don't open-code memdup_user() ...
2016-01-04dm-bufio: virt_to_phys() doesn't change remainder modulo PAGE_SIZEAl Viro1-1/+1
... so virt_to_phys(p) & (PAGE_SIZE - 1) is a very odd way to spell offset_in_page(p). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-10dm bufio: use BUG_ON instead of conditional call to BUGAnup Limbu1-2/+1
Signed-off-by: Anup Limbu <anuplimbu14@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm bufio: store stacktrace in buffers to help find buffer leaksMikulas Patocka1-1/+38
The option DM_DEBUG_BLOCK_STACK_TRACING is moved from persistent-data directory to device mapper directory because it will now be used by persistent-data and bufio. When the option is enabled, each bufio buffer stores the stacktrace of the last dm_bufio_get(), dm_bufio_read() or dm_bufio_new() call that increased the hold count to 1. The buffer's stacktrace is printed if the buffer was not released before the bufio client is destroyed. When DM_DEBUG_BLOCK_STACK_TRACING is enabled, any bufio buffer leaks are considered warnings - i.e. the kernel continues afterwards. If not enabled, buffer leaks are considered BUGs and the kernel with crash. Reasoning on this disposition is: if we only ever warned on buffer leaks users would generally ignore them and the problematic code would never get fixed. Successfully used to find source of bufio leaks fixed with commit fce079f63c3 ("dm btree: fix bufio buffer leaks in dm_btree_del() error path"). Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-12-10dm bufio: return NULL to improve code clarityMikulas Patocka1-1/+1
A small code cleanup in new_read() - return NULL instead of b (although b is NULL at this point). This function is not returning pointer to the buffer, it is returning a pointer to the bufffer's data, thus it makes no sense to return the variable b. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-10-31dm: convert ffs to __ffsMikulas Patocka1-5/+5
ffs counts bit starting with 1 (for the least significant bit), __ffs counts bits starting with 0. This patch changes various occurrences of ffs to __ffs and removes subtraction of 1 from the result. Note that __ffs (unlike ffs) is not defined when called with zero argument, but it is not called with zero argument in any of these cases. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-10-31dm: drop NULL test before kmem_cache_destroy() and mempool_destroy()Julia Lawall1-6/+2
Remove DM's unneeded NULL tests before calling these destroy functions, now that they check for NULL, thanks to these v4.3 commits: 3942d2991 ("mm/slab_common: allow NULL cache pointer in kmem_cache_destroy()") 4e3ca3e03 ("mm/mempool: allow NULL `pool' pointer in mempool_destroy()") The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x; @@ -if (x != NULL) \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-10/+16
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-09dm bufio: fix time comparison to use time_after_eq()Asaf Vertz1-1/+2
To be future-proof and for better readability the time comparison is modified to use time_after_eq() instead of plain, error-prone math. Signed-off-by: Asaf Vertz <asaf.vertz@tandemg.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-12-08Merge tag 'dm-3.19-changes' of ↵Linus Torvalds1-78/+148
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - Significant DM thin-provisioning performance improvements to meet performance requirements that were requested by the Gluster distributed filesystem. Specifically, dm-thinp now takes care to aggregate IO that will be issued to the same thinp block before issuing IO to the underlying devices. This really helps improve performance on HW RAID6 devices that have a writeback cache because it avoids RMW in the HW RAID controller. - Some stable fixes: fix leak in DM bufio if integrity profiles were enabled, use memzero_explicit in DM crypt to avoid any potential for information leak, and a DM cache fix to properly mark a cache block dirty if it was promoted to the cache via the overwrite optimization. - A few simple DM persistent data library fixes - DM cache multiqueue policy block promotion improvements. - DM cache discard improvements that take advantage of range (multiblock) discard support in the DM bio-prison. This allows for much more efficient bulk discard processing (e.g. when mkfs.xfs discards the entire device). - Some small optimizations in DM core and RCU deference cleanups - DM core changes to suspend/resume code to introduce the new internal suspend/resume interface that the DM thin-pool target now uses to suspend/resume active thin devices when the thin-pool must suspend/resume. This avoids forcing userspace to track all active thin volumes in a thin-pool when the thin-pool is suspended for the purposes of metadata or data space resize. * tag 'dm-3.19-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (49 commits) dm crypt: use memzero_explicit for on-stack buffer dm space map metadata: fix sm_bootstrap_get_count() dm space map metadata: fix sm_bootstrap_get_nr_blocks() dm bufio: fix memleak when using a dm_buffer's inline bio dm cache: fix spurious cell_defer when dealing with partial block at end of device dm cache: dirty flag was mistakenly being cleared when promoting via overwrite dm cache: only use overwrite optimisation for promotion when in writeback mode dm cache: discard block size must be a multiple of cache block size dm cache: fix a harmless race when working out if a block is discarded dm cache: when reloading a discard bitset allow for a different discard block size dm cache: fix some issues with the new discard range support dm array: if resizing the array is a noop set the new root to the old one dm: use rcu_dereference_protected instead of rcu_dereference dm thin: fix pool_io_hints to avoid looking at max_hw_sectors dm thin: suspend/resume active thin devices when reloading thin-pool dm: enhance internal suspend and resume interface dm thin: do not allow thin device activation while pool is suspended dm: add presuspend_undo hook to target_type dm: return earlier from dm_blk_ioctl if target doesn't implement .ioctl dm thin: remove stale 'trim' message in block comment above pool_message ...
2014-12-01dm bufio: fix memleak when using a dm_buffer's inline bioDarrick J. Wong1-1/+19
When dm-bufio sets out to use the bio built into a struct dm_buffer to issue an IO, it needs to call bio_reset after it's done with the bio so that we can free things attached to the bio such as the integrity payload. Therefore, inject our own endio callback to take care of the bio_reset after calling submit_io's end_io callback. Test case: 1. modprobe scsi_debug delay=0 dif=1 dix=199 ato=1 dev_size_mb=300 2. Set up a dm-bufio client, e.g. dm-verity, on the scsi_debug device 3. Repeatedly read metadata and watch kmalloc-192 leak! Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-11-13Merge tag 'dm-3.18-fixes' of ↵Linus Torvalds1-6/+6
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper fixes from Mike Snitzer: - stable fix for dm-thin that avoids normal IO racing with discard - stable fix for a dm-cache related bug in dm-btree walking code that results from using very large fast device (eg 4T) with a very small cache blocksize (eg 32K) -- this is a very uncommon configuration - a couple fixes for dm-raid (one for stable and the other addresses a crash in 3.18-rc1 code) - stable fix for dm-thinp that addresses a very rare dm-bufio bug having to do with memory reclaimation (via shrinker) when using dm-thinp ontop of loopback devices - fix a leak in dm-stripe target constructor's error path * tag 'dm-3.18-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm btree: fix a recursion depth bug in btree walking code dm thin: grab a virtual cell before looking up the mapping dm raid: fix inaccessible superblocks causing oops in configure_discard_support dm raid: ensure superblock's size matches device's logical block size dm bufio: change __GFP_IO to __GFP_FS in shrinker callbacks dm stripe: fix potential for leak in stripe_ctr error path
2014-11-10dm bufio: evict buffers that are past the max age but retain some buffersJoe Thornber1-34/+75
These changes help keep metadata backed by dm-bufio in-core longer which fixes reports of metadata churn in the face of heavy random IO workloads. Before, bufio evicted all buffers older than DM_BUFIO_DEFAULT_AGE_SECS. Having a device (e.g. dm-thinp or dm-cache) lose all metadata just because associated buffers had been idle for some time is unfriendly. Now, the user may now configure the number of bytes that bufio retains using the 'retain_bytes' module parameter. The default is 256K. Also, the DM_BUFIO_WORK_TIMER_SECS and DM_BUFIO_DEFAULT_AGE_SECS defaults were quite low so increase them (to 30 and 300 respectively). Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-11-10dm bufio: switch from a huge hash table to an rbtreeJoe Thornber1-43/+54
Converting over to using an rbtree eliminates a fixed 8MB allocation from vmalloc space for the hash table. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-10-18Merge tag 'dm-3.18' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device-mapper updates from Mike Snitzer: "I rebased the DM tree ontop of linux-block.git's 'for-3.18/core' at the beginning of October because DM core now depends on the newly introduced bioset_create_nobvec() interface. Summary: - fix DM's long-standing excessive use of memory by leveraging the new bioset_create_nobvec() interface when creating the DM's bioset - fix a few bugs in dm-bufio and dm-log-userspace - add DM core support for a DM multipath use-case that requires loading DM tables that contain devices that have failed (by allowing active and inactive DM tables to share dm_devs) - add discard support to the DM raid target; like MD raid456 the user must opt-in to raid456 discard support be specifying the devices_handle_discard_safely=Y module param" * tag 'dm-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm log userspace: fix memory leak in dm_ulog_tfr_init failure path dm bufio: when done scanning return from __scan immediately dm bufio: update last_accessed when relinking a buffer dm raid: add discard support for RAID levels 4, 5 and 6 dm raid: add discard support for RAID levels 1 and 10 dm: allow active and inactive tables to share dm_devs dm mpath: stop queueing IO when no valid paths exist dm: use bioset_create_nobvec() dm: remove nr_iovecs parameter from alloc_tio()
2014-10-17dm bufio: change __GFP_IO to __GFP_FS in shrinker callbacksMikulas Patocka1-6/+6
The shrinker uses gfp flags to indicate what kind of operation can the driver wait for. If __GFP_IO flag is present, the driver can wait for block I/O operations, if __GFP_FS flag is present, the driver can wait on operations involving the filesystem. dm-bufio tested for __GFP_IO. However, dm-bufio can run on a loop block device that makes calls into the filesystem. If __GFP_IO is present and __GFP_FS isn't, dm-bufio could still block on filesystem operations if it runs on a loop block device. The change from __GFP_IO to __GFP_FS supposedly fixes one observed (though unreproducible) deadlock involving dm-bufio and loop device. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
2014-10-05dm bufio: when done scanning return from __scan immediatelyMikulas Patocka1-2/+2
When __scan frees the required number of buffer entries that the shrinker requested (nr_to_scan becomes zero) it must return. Before this fix the __scan code exited only the inner loop and continued in the outer loop -- which could result in reduced performance due to extra buffers being freed (e.g. unnecessarily evicted thinp metadata needing to be synchronously re-read into bufio's cache). Also, move dm_bufio_cond_resched to __scan's inner loop, so that iterating the bufio client's lru lists doesn't result in scheduling latency. Reported-by: Joe Thornber <thornber@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.2+
2014-10-05dm bufio: update last_accessed when relinking a bufferJoe Thornber1-0/+1
The 'last_accessed' member of the dm_buffer structure was only set when the the buffer was created. This led to each buffer being discarded after dm_bufio_max_age time even if it was used recently. In practice this resulted in all thinp metadata being evicted soon after being read -- this is particularly problematic for metadata intensive workloads like multithreaded small random IO. 'last_accessed' is now updated each time the buffer is moved to the head of the LRU list, so the buffer is now properly discarded if it was not used in dm_bufio_max_age time. Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.2+
2014-09-19sched, cleanup, treewide: Remove set_current_state(TASK_RUNNING) after ↵Kirill Tkhai1-1/+0
schedule() schedule(), io_schedule() and schedule_timeout() always return with TASK_RUNNING state set, so one more setting is unnecessary. (All places in patch are visible good, only exception is kiblnd_scheduler() from: drivers/staging/lustre/lnet/klnds/o2iblnd/o2iblnd_cb.c Its schedule() is one line above standard 3 lines of unified diff) No places where set_current_state() is used for mb(). Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1410529254.3569.23.camel@tkhai Cc: Alasdair Kergon <agk@redhat.com> Cc: Anil Belur <askb23@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: David Howells <dhowells@redhat.com> Cc: Dmitry Eremin <dmitry.eremin@intel.com> Cc: Frank Blaschka <blaschka@linux.vnet.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Isaac Huang <he.huang@intel.com> Cc: James E.J. Bottomley <JBottomley@parallels.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: J. Bruce Fields <bfields@fieldses.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Liang Zhen <liang.zhen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masaru Nomura <massa.nomura@gmail.com> Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: Oleg Drokin <green@linuxhacker.ru> Cc: Peng Tao <bergwolf@gmail.com> Cc: Richard Weinberger <richard@nod.at> Cc: Robert Love <robert.w.love@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Cc: Ursula Braun <ursula.braun@de.ibm.com> Cc: Zi Shen Lim <zlim.lnx@gmail.com> Cc: devel@driverdev.osuosl.org Cc: dm-devel@redhat.com Cc: dri-devel@lists.freedesktop.org Cc: fcoe-devel@open-fcoe.org Cc: jfs-discussion@lists.sourceforge.net Cc: linux390@de.ibm.com Cc: linux-afs@lists.infradead.org Cc: linux-cris-kernel@axis.com Cc: linux-kernel@vger.kernel.org Cc: linux-nfs@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linux-raid@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linux-scsi@vger.kernel.org Cc: qla2xxx-upstream@qlogic.com Cc: user-mode-linux-devel@lists.sourceforge.net Cc: user-mode-linux-user@lists.sourceforge.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-04Merge branch 'sched-core-for-linus' of ↵Linus Torvalds1-27/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Move the nohz kick code out of the scheduler tick to a dedicated IPI, from Frederic Weisbecker. This necessiated quite some background infrastructure rework, including: * Clean up some irq-work internals * Implement remote irq-work * Implement nohz kick on top of remote irq-work * Move full dynticks timer enqueue notification to new kick * Move multi-task notification to new kick * Remove unecessary barriers on multi-task notification - Remove proliferation of wait_on_bit() action functions and allow wait_on_bit_action() functions to support a timeout. (Neil Brown) - Another round of sched/numa improvements, cleanups and fixes. (Rik van Riel) - Implement fast idling of CPUs when the system is partially loaded, for better scalability. (Tim Chen) - Restructure and fix the CPU hotplug handling code that may leave cfs_rq and rt_rq's throttled when tasks are migrated away from a dead cpu. (Kirill Tkhai) - Robustify the sched topology setup code. (Peterz Zijlstra) - Improve sched_feat() handling wrt. static_keys (Jason Baron) - Misc fixes. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits) sched/fair: Fix 'make xmldocs' warning caused by missing description sched: Use macro for magic number of -1 for setparam sched: Robustify topology setup sched: Fix sched_setparam() policy == -1 logic sched: Allow wait_on_bit_action() functions to support a timeout sched: Remove proliferation of wait_on_bit() action functions sched/numa: Revert "Use effective_load() to balance NUMA loads" sched: Fix static_key race with sched_feat() sched: Remove extra static_key*() function indirection sched/rt: Fix replenish_dl_entity() comments to match the current upstream code sched: Transform resched_task() into resched_curr() sched/deadline: Kill task_struct->pi_top_task sched: Rework check_for_tasks() sched/rt: Enqueue just unthrottled rt_rq back on the stack in __disable_runtime() sched/fair: Disable runtime_enabled on dying rq sched/numa: Change scan period code to match intent sched/numa: Rework best node setting in task_numa_migrate() sched/numa: Examine a task move when examining a task swap sched/numa: Simplify task_numa_compare() sched/numa: Use effective_load() to balance NUMA loads ...
2014-08-01dm bufio: fully initialize shrinkerGreg Thelen1-1/+1
1d3d4437eae1 ("vmscan: per-node deferred work") added a flags field to struct shrinker assuming that all shrinkers were zero filled. The dm bufio shrinker is not zero filled, which leaves arbitrary kmalloc() data in flags. So far the only defined flags bit is SHRINKER_NUMA_AWARE. But there are proposed patches which add other bits to shrinker.flags (e.g. memcg awareness). Rather than simply initializing the shrinker, this patch uses kzalloc() when allocating the dm_bufio_client to ensure that the embedded shrinker and any other similar structures are zeroed. This fixes theoretical over aggressive shrinking of dm bufio objects. If the uninitialized dm_bufio_client.shrinker.flags contains SHRINKER_NUMA_AWARE then shrink_slab() would call the dm shrinker for each numa node rather than just once. This has been broken since 3.12. Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # v3.12+
2014-07-16sched: Remove proliferation of wait_on_bit() action functionsNeilBrown1-27/+14
The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-18arch: Mass conversion of smp_mb__*()Peter Zijlstra1-4/+4
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-30Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull core block IO changes from Jens Axboe: "The major piece in here is the immutable bio_ve series from Kent, the rest is fairly minor. It was supposed to go in last round, but various issues pushed it to this release instead. The pull request contains: - Various smaller blk-mq fixes from different folks. Nothing major here, just minor fixes and cleanups. - Fix for a memory leak in the error path in the block ioctl code from Christian Engelmayer. - Header export fix from CaiZhiyong. - Finally the immutable biovec changes from Kent Overstreet. This enables some nice future work on making arbitrarily sized bios possible, and splitting more efficient. Related fixes to immutable bio_vecs: - dm-cache immutable fixup from Mike Snitzer. - btrfs immutable fixup from Muthu Kumar. - bio-integrity fix from Nic Bellinger, which is also going to stable" * 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits) xtensa: fixup simdisk driver to work with immutable bio_vecs block/blk-mq-cpu.c: use hotcpu_notifier() blk-mq: for_each_* macro correctness block: Fix memory leak in rw_copy_check_uvector() handling bio-integrity: Fix bio_integrity_verify segment start bug block: remove unrelated header files and export symbol blk-mq: uses page->list incorrectly blk-mq: use __smp_call_function_single directly btrfs: fix missing increment of bi_remaining Revert "block: Warn and free bio if bi_end_io is not set" block: Warn and free bio if bi_end_io is not set blk-mq: fix initializing request's start time block: blk-mq: don't export blk_mq_free_queue() block: blk-mq: make blk_sync_queue support mq block: blk-mq: support draining mq queue dm cache: increment bi_remaining when bi_end_io is restored block: fixup for generic bio chaining block: Really silence spurious compiler warnings block: Silence spurious compiler warnings block: Kill bio_pair_split() ...
2014-01-14dm snapshot: use dm-bufio prefetchMikulas Patocka1-2/+12
This patch modifies dm-snapshot so that it prefetches the buffers when loading the exceptions. The number of buffers read ahead is specified in the DM_PREFETCH_CHUNKS macro. The current value for DM_PREFETCH_CHUNKS (12) was found to provide the best performance on a single 15k SCSI spindle. In the future we may modify this default or make it configurable. Also, introduce the function dm_bufio_set_minimum_buffers to setup bufio's number of internal buffers before freeing happens. dm-bufio may hold more buffers if enough memory is available. There is no guarantee that the specified number of buffers will be available - if you need a guarantee, use the argument reserved_buffers for dm_bufio_client_create. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2014-01-14dm snapshot: use dm-bufioMikulas Patocka1-0/+22
Use dm-bufio for initial loading of the exceptions. Introduce a new function dm_bufio_forget that frees the given buffer. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-12-31Merge tag 'v3.13-rc6' into for-3.14/coreJens Axboe1-0/+5
Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c
2013-12-10dm bufio: initialize read-only module parametersMikulas Patocka1-0/+5
Some module parameters in dm-bufio are read-only. These parameters inform the user about memory consumption. They are not supposed to be changed by the user. However, despite being read-only, these parameters can be set on modprobe or insmod command line, for example: modprobe dm-bufio current_allocated_bytes=12345 The kernel doesn't expect that these variables can be non-zero at module initialization and if the user sets them, it results in BUG. This patch initializes the variables in the module init routine, so that user-supplied values are ignored. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org # 3.2+
2013-11-23block: Abstract out bvec iteratorKent Overstreet1-1/+1
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
2013-09-10drivers: convert shrinkers to new count/scan APIDave Chinner1-25/+39
Convert the driver shrinkers to the new API. Most changes are compile tested only because I either don't have the hardware or it's staging stuff. FWIW, the md and android code is pretty good, but the rest of it makes me want to claw my eyes out. The amount of broken code I just encountered is mind boggling. I've added comments explaining what is broken, but I fear that some of the code would be best dealt with by being dragged behind the bike shed, burying in mud up to it's neck and then run over repeatedly with a blunt lawn mower. Special mention goes to the zcache/zcache2 drivers. They can't co-exist in the build at the same time, they are under different menu options in menuconfig, they only show up when you've got the right set of mm subsystem options configured and so even compile testing is an exercise in pulling teeth. And that doesn't even take into account the horrible, broken code... [glommer@openvz.org: fixes for i915, android lowmem, zcache, bcache] Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Glauber Costa <glommer@openvz.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Kent Overstreet <koverstreet@google.com> Cc: John Stultz <john.stultz@linaro.org> Cc: David Rientjes <rientjes@google.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Rientjes <rientjes@google.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: J. Bruce Fields <bfields@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Thomas Hellstrom <thellstrom@vmware.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-10dm bufio: submit writes outside lockMikulas Patocka1-15/+58
This patch changes dm-bufio so that it submits write I/Os outside of the lock. If the number of submitted buffers is greater than the number of requests on the target queue, submit_bio blocks. We want to block outside of the lock to improve latency of other threads that may need the lock. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-07-10dm: use __GFP_HIGHMEM in __vmallocMikulas Patocka1-1/+1
Use __GFP_HIGHMEM in __vmalloc. Pages allocated with __vmalloc can be allocated in high memory that is not directly mapped to kernel space, so use __GFP_HIGHMEM just like vmalloc does. This patch reduces memory pressure slightly because pages can be allocated in the high zone. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-05-10dm bufio: avoid a possible __vmalloc deadlockMikulas Patocka1-1/+23
This patch uses memalloc_noio_save to avoid a possible deadlock in dm-bufio. (it could happen only with large block size, at most PAGE_SIZE << MAX_ORDER (typically 8MiB). __vmalloc doesn't fully respect gfp flags. The specified gfp flags are used for allocation of requested pages, structures vmap_area, vmap_block and vm_struct and the radix tree nodes. However, the kernel pagetables are allocated always with GFP_KERNEL. Thus the allocation of pagetables can recurse back to the I/O layer and cause a deadlock. This patch uses the function memalloc_noio_save to set per-process PF_MEMALLOC_NOIO flag and the function memalloc_noio_restore to restore it. When this flag is set, all allocations in the process are done with implied GFP_NOIO flag, thus the deadlock can't happen. This should be backported to stable kernels, but they don't have the PF_MEMALLOC_NOIO flag and memalloc_noio_save/memalloc_noio_restore functions. So, PF_MEMALLOC should be set and restored instead. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@kernel.org Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-03-20dm verity: avoid deadlockMikulas Patocka1-0/+2
A deadlock was found in the prefetch code in the dm verity map function. This patch fixes this by transferring the prefetch to a worker thread and skipping it completely if kmalloc fails. If generic_make_request is called recursively, it queues the I/O request on the current->bio_list without making the I/O request and returns. The routine making the recursive call cannot wait for the I/O to complete. The deadlock occurs when one thread grabs the bufio_client mutex and waits for an I/O to complete but the I/O is queued on another thread's current->bio_list and is waiting to get the mutex held by the first thread. The fix recognises that prefetching is not essential. If memory can be allocated, it queues the prefetch request to the worker thread, but if not, it does nothing. Signed-off-by: Paul Taysom <taysom@chromium.org> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
2013-03-01dm bufio: use WRITE_FLUSH instead of REQ_FLUSHMikulas Patocka1-1/+1
Use WRITE_FLUSH instead of REQ_FLUSH for submitted requests to make it consistent with the rest of the kernel. There is no functional change. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2013-02-27hlist: drop the node parameter from iteratorsSasha Levin1-2/+1
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-12dm: use ACCESS_ONCE for sysfs valuesMikulas Patocka1-7/+3
Use the ACCESS_ONCE macro in dm-bufio and dm-verity where a variable can be modified asynchronously (through sysfs) and we want to prevent compiler optimizations that assume that the variable hasn't changed. (See Documentation/atomic_ops.txt.) Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-10-12dm bufio: use list_moveWei Yongjun1-2/+1
Use list_move() instead of list_del() + list_add(). spatch with a semantic match was used to find this. (http://coccinelle.lip6.fr/) Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-28dm bufio: prefetchMikulas Patocka1-26/+82
This patch introduces a new function dm_bufio_prefetch. It prefetches the specified range of blocks into dm-bufio cache without waiting for i/o completion. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-02-03dm-bufio.c: there's no need to include linux/version.hJesper Juhl1-1/+0
As 'make versioncheck' points out, drivers/md/dm-bufio.c has no need to include linux/version.h, so this patch removes the unneeded include. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-11-07device-mapper: dm-bufio.c needs to include module.hStephen Rothwell1-0/+1
since it uses the module facilities. Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31dm: add bufioMikulas Patocka1-0/+1699
The dm-bufio interface allows you to do cached I/O on devices, holding recently-read blocks in memory and performing delayed writes. We don't use buffer cache or page cache already present in the kernel, because: * we need to handle block sizes larger than a page * we can't allocate memory to perform reads or we'd have deadlocks Currently, when a cache is required, we limit its size to a fraction of available memory. Usage can be viewed and changed in /sys/module/dm_bufio/parameters/ . The first user is thin provisioning, but more dm users are planned. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>