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2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-10-31oom: fix race while temporarily setting current's oom_score_adjDavid Rientjes
test_set_oom_score_adj() was introduced in 72788c385604 ("oom: replace PF_OOM_ORIGIN with toggling oom_score_adj") to temporarily elevate current's oom_score_adj for ksm and swapoff without requiring an additional per-process flag. Using that function to both set oom_score_adj to OOM_SCORE_ADJ_MAX and then reinstate the previous value is racy since it's possible that userspace can set the value to something else itself before the old value is reinstated. That results in userspace setting current's oom_score_adj to a different value and then the kernel immediately setting it back to its previous value without notification. To fix this, a new compare_swap_oom_score_adj() function is introduced with the same semantics as the compare and swap CAS instruction, or CMPXCHG on x86. It is used to reinstate the previous value of oom_score_adj if and only if the present value is the same as the old value. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: delete various needless include <linux/module.h>Paul Gortmaker
There is nothing modular in these files, and no reason to drag in all the 357 headers that module.h brings with it, since it just slows down compiles. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-08-03mm: let swap use exceptional entriesHugh Dickins
If swap entries are to be stored along with struct page pointers in a radix tree, they need to be distinguished as exceptional entries. Most of the handling of swap entries in radix tree will be contained in shmem.c, but a few functions in filemap.c's common code need to check for their appearance: find_get_page(), find_lock_page(), find_get_pages() and find_get_pages_contig(). So as not to slow their fast paths, tuck those checks inside the existing checks for unlikely radix_tree_deref_slot(); except for find_lock_page(), where it is an added test. And make it a BUG in find_get_pages_tag(), which is not applied to tmpfs files. A part of the reason for eliminating shmem_readpage() earlier, was to minimize the places where common code would need to allow for swap entries. The swp_entry_t known to swapfile.c must be massaged into a slightly different form when stored in the radix tree, just as it gets massaged into a pte_t when stored in page tables. In an i386 kernel this limits its information (type and page offset) to 30 bits: given 32 "types" of swapfile and 4kB pagesize, that's a maximum swapfile size of 128GB. Which is less than the 512GB we previously allowed with X86_PAE (where the swap entry can occupy the entire upper 32 bits of a pte_t), but not a new limitation on 32-bit without PAE; and there's not a new limitation on 64-bit (where swap filesize is already limited to 16TB by a 32-bit page offset). Thirty areas of 128GB is probably still enough swap for a 64GB 32-bit machine. Provide swp_to_radix_entry() and radix_to_swp_entry() conversions, and enforce filesize limit in read_swap_header(), just as for ptes. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-20fs: seq_file - add event counter to simplify poll() supportKay Sievers
Moving the event counter into the dynamically allocated 'struc seq_file' allows poll() support without the need to allocate its own tracking structure. All current users are switched over to use the new counter. Requested-by: Andrew Morton akpm@linux-foundation.org Acked-by: NeilBrown <neilb@suse.de> Tested-by: Lucas De Marchi lucas.demarchi@profusion.mobi Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-06-27mm: move shmem prototypes to shmem_fs.hHugh Dickins
Before adding any more global entry points into shmem.c, gather such prototypes into shmem_fs.h. Remove mm's own declarations from swap.h, but for now leave the ones in mm.h: because shmem_file_setup() and shmem_zero_setup() are called from various places, and we should not force other subsystems to update immediately. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25oom: replace PF_OOM_ORIGIN with toggling oom_score_adjDavid Rientjes
There's a kernel-wide shortage of per-process flags, so it's always helpful to trim one when possible without incurring a significant penalty. It's even more important when you're planning on adding a per- process flag yourself, which I plan to do shortly for transparent hugepages. PF_OOM_ORIGIN is used by ksm and swapoff to prefer current since it has a tendency to allocate large amounts of memory and should be preferred for killing over other tasks. We'd rather immediately kill the task making the errant syscall rather than penalizing an innocent task. This patch removes PF_OOM_ORIGIN since its behavior is equivalent to setting the process's oom_score_adj to OOM_SCORE_ADJ_MAX. The process's old oom_score_adj is stored and then set to OOM_SCORE_ADJ_MAX during the time it used to have PF_OOM_ORIGIN. The old value is then reinstated when the process should no longer be considered a high priority for oom killing. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Izik Eidus <ieidus@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-24Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits) Documentation/iostats.txt: bit-size reference etc. cfq-iosched: removing unnecessary think time checking cfq-iosched: Don't clear queue stats when preempt. blk-throttle: Reset group slice when limits are changed blk-cgroup: Only give unaccounted_time under debug cfq-iosched: Don't set active queue in preempt block: fix non-atomic access to genhd inflight structures block: attempt to merge with existing requests on plug flush block: NULL dereference on error path in __blkdev_get() cfq-iosched: Don't update group weights when on service tree fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away block: Require subsystems to explicitly allocate bio_set integrity mempool jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging fs: make fsync_buffers_list() plug mm: make generic_writepages() use plugging blk-cgroup: Add unaccounted time to timeslice_used. block: fixup plugging stubs for !CONFIG_BLOCK block: remove obsolete comments for blkdev_issue_zeroout. blktrace: Use rq->cmd_flags directly in blk_add_trace_rq. ... Fix up conflicts in fs/{aio.c,super.c}
2011-03-23memcg: fix ugly initialization of return value is in callerKAMEZAWA Hiroyuki
Remove initialization of vaiable in caller of memory cgroup function. Actually, it's return value of memcg function but it's initialized in caller. Some memory cgroup uses following style to bring the result of start function to the end function for avoiding races. mem_cgroup_start_A(&(*ptr)) /* Something very complicated can happen here. */ mem_cgroup_end_A(*ptr) In some calls, *ptr should be initialized to NULL be caller. But it's ugly. This patch fixes that *ptr is initialized by _start function. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23sys_swapon: fix inode lockingCesar Eduardo Barros
A conflict between 52c50567d8ab ("mm: swap: unlock swapfile inode mutex before closing file on bad swapfiles") and 83ef99befc32 ("sys_swapon: remove did_down variable") caused a double unlock of the inode mutex (once in bad_swap: before the filp_close, once at the end just before returning). The patch which added the extra unlock cleared did_down to avoid unlocking twice, but the other patch removed the did_down variable. To fix, set inode to NULL after the first unlock, since it will be used after that point only for the final unlock. While checking this patch, I found a path which could unlock without locking, in case the same inode was added as a swapfile twice. To fix, move the setting of the inode variable further down, to just before claim_swapfile, which will lock the inode before doing anything else. Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Eric B Munson <emunson@mgebm.net> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22mm: remove inline from scan_swap_map()Cesar Eduardo Barros
scan_swap_map() is a large function (224 lines), with several loops and a complex control flow involving several gotos. Given all that, it is a bit silly that it is marked as inline. The compiler agrees with me: on a x86-64 compile, it did not inline the function. Remove the "inline" and let the compiler decide instead. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: separate final enabling of the swapfileCesar Eduardo Barros
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(). Move this code to a separate function, and use it both in sys_swapon and sys_swapoff. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapoff: change order to match sys_swaponCesar Eduardo Barros
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(), except for the order of the operations within the lock. Since the order should not matter, arbitrarily change sys_swapoff to match sys_swapon, in preparation to making both share the same code. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: move printk outside lockCesar Eduardo Barros
The block in sys_swapon which does the final adjustments to the swap_info_struct and to swap_list is the same as the block which re-inserts it again at sys_swapoff on failure of try_to_unuse(). To be able to make both share the same code, move the printk() call in the middle of it to just after it. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: remove nr_good_pages variableCesar Eduardo Barros
It still exists within setup_swap_map_and_extents(), but after it nr_good_pages == p->pages. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: simplify error flow in setup_swap_map_and_extents()Cesar Eduardo Barros
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: separate parsing of bad blocks and extentsCesar Eduardo Barros
Move the code which parses the bad block list and the extents to a separate function. Only code movement, no functional changes. This change uses the fact that, after the success path, nr_good_pages == p->pages. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: call swap_cgroup_swapon() earlierCesar Eduardo Barros
The call to swap_cgroup_swapon is in the middle of loading the swap map and extents. As it only does memory allocation and does not depend on the swapfile layout (map/extents), it can be called earlier (or later). Move it to just after the allocation of swap_map, since it is conceptually similar (allocates a map). Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: simplify error flow in read_swap_header()Cesar Eduardo Barros
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: separate parsing of swapfile headerCesar Eduardo Barros
Move the code which parses and checks the swapfile header (except for the bad block list) to a separate function. Only code movement, no functional changes. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: move setting of swapfilepages near useCesar Eduardo Barros
There is no reason I can see to read inode->i_size long before it is needed. Move its read to just before it is needed, to reduce the variable lifetime. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: simplify error flow in claim_swapfile()Cesar Eduardo Barros
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: separate bdev claim and inode lockCesar Eduardo Barros
Move the code which claims the bdev (S_ISBLK) or locks the inode (S_ISREG) to a separate function. Only code movement, no functional changes. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: use a single error labelCesar Eduardo Barros
sys_swapon currently has two error labels, bad_swap and bad_swap_2. bad_swap does the same as bad_swap_2 plus destroy_swap_extents() and swap_cgroup_swapoff(); both are noops in the places where bad_swap_2 is jumped to. With a single extra test for inode (matching the one in the S_ISREG case below), all the error paths in the function can go to bad_swap. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: do only cleanup in the cleanup blocksCesar Eduardo Barros
The only way error is 0 in the cleanup blocks is when the function is returning successfully. In this case, the cleanup blocks were setting S_SWAPFILE in the S_ISREG case. But this is not a cleanup. Move the setting of S_SWAPFILE to just before the "goto out;" to make this more clear. At this point, we do not need to test for inode because it will never be NULL. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: remove bdev variableCesar Eduardo Barros
The bdev variable is always equivalent to (S_ISBLK(inode->i_mode) ? p->bdev : NULL), as long as it being set is moved to a bit earlier. Use this fact to remove the bdev variable. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: move setting of error nearer useCesar Eduardo Barros
Move the setting of the error variable nearer the goto in a few places. Avoids calling PTR_ERR() if not IS_ERR() in two places, and makes the error condition more explicit in two other places. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: remove did_down variableCesar Eduardo Barros
Since mutex_lock(&inode->i_mutex) is called just after setting inode, did_down is always equivalent to (inode && S_ISREG(inode->i_mode)). Use this fact to remove the did_down variable. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: remove initial value of name variableCesar Eduardo Barros
Now there is nothing which jumps to the cleanup blocks before the name variable is set. There is no need to set it initially to NULL anymore. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: simplify error flow in alloc_swap_info()Cesar Eduardo Barros
Since there is no cleanup to do, there is no reason to jump to a label. Return directly instead. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: simplify error return from swap_info allocationCesar Eduardo Barros
At this point in sys_swapon, there is nothing to free. Return directly instead of jumping to the cleanup block at the end of the function. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: separate swap_info allocationCesar Eduardo Barros
Move the swap_info allocation to its own function. Only code movement, no functional changes. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: do not depend on "type" after allocationCesar Eduardo Barros
Within sys_swapon, after the swap_info entry has been allocated, we always have type == p->type and swap_info[type] == p. Use this fact to reduce the dependency on the "type" local variable within the function, as a preparation to move the allocation of the swap_info entry to a separate function. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujisu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: remove changelog from function commentCesar Eduardo Barros
Changelogs belong in the git history instead of in the source code. Also, "The swapon system call" is redundant with "SYSCALL_DEFINE2(swapon, ...)". Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Gaah. That's a _historical_ comment. But the patch-series depends on removal ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22sys_swapon: use vzalloc() instead of vmalloc/memsetCesar Eduardo Barros
This patch series refactors the sys_swapon function. sys_swapon is currently a very large function, with 313 lines (more than 12 25-line screens), which can make it a bit hard to read. This patch series reduces this size by half, by extracting large chunks of related code to new helper functions. One of these chunks of code was nearly identical to the part of sys_swapoff which is used in case of a failure return from try_to_unuse(), so this patch series also makes both share the same code. As a side effect of all this refactoring, the compiled code gets a bit smaller (from v1 of this patch series): text data bss dec hex filename 14012 944 276 15232 3b80 mm/swapfile.o.before 13941 944 276 15161 3b39 mm/swapfile.o.after This patch: Use vzalloc() instead of vmalloc/memset. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net> Tested-by: Eric B Munson <emunson@mgebm.net> Acked-by: Eric B Munson <emunson@mgebm.net> Reviewed-by: Pekka Enberg <penberg@kernel.org> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22mm: swap: unlock swapfile inode mutex before closing file on bad swapfilesMel Gorman
If an administrator tries to swapon a file backed by NFS, the inode mutex is taken (as it is for any swapfile) but later identified to be a bad swapfile due to the lack of bmap and tries to cleanup. During cleanup, an attempt is made to close the file but with inode->i_mutex still held. Closing an NFS file syncs it which tries to acquire the inode mutex leading to deadlock. If lockdep is enabled the following appears on the console; ============================================= [ INFO: possible recursive locking detected ] 2.6.38-rc8-autobuild #1 --------------------------------------------- swapon/2192 is trying to acquire lock: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: vfs_fsync_range+0x47/0x7c but task is already holding lock: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7 other info that might help us debug this: 1 lock held by swapon/2192: #0: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7 stack backtrace: Pid: 2192, comm: swapon Not tainted 2.6.38-rc8-autobuild #1 Call Trace: __lock_acquire+0x2eb/0x1623 find_get_pages_tag+0x14a/0x174 pagevec_lookup_tag+0x25/0x2e vfs_fsync_range+0x47/0x7c lock_acquire+0xd3/0x100 vfs_fsync_range+0x47/0x7c nfs_flush_one+0x0/0xdf [nfs] mutex_lock_nested+0x40/0x2b1 vfs_fsync_range+0x47/0x7c vfs_fsync_range+0x47/0x7c vfs_fsync+0x1c/0x1e nfs_file_flush+0x64/0x69 [nfs] filp_close+0x43/0x72 sys_swapon+0xa39/0xae7 sysret_check+0x2e/0x69 system_call_fastpath+0x16/0x1b This patch releases the mutex if its held before calling filep_close() so swapon fails as expected without deadlock when the swapfile is backed by NFS. If accepted for 2.6.39, it should also be considered a -stable candidate for 2.6.38 and 2.6.37. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@kernel.org> [2.6.37+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-10Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe
Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-02-24mm: fix refcounting in swaponMiklos Szeredi
Grab a reference to bdev before calling blkdev_get(), which expects the refcount to be already incremented and either returns success or decrements the refcount and returns an error. The bug was introduced by e525fd89 (block: make blkdev_get/put() handle exclusive access), which didn't take into account this behavior of blkdev_get(). Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: split_huge_page pagingAndrea Arcangeli
Paging logic that splits the page before it is unmapped and added to swap to ensure backwards compatibility with the legacy swap code. Eventually swap should natively pageout the hugepages to increase performance and decrease seeking and fragmentation of swap space. swapoff can just skip over huge pmd as they cannot be part of swap yet. In add_to_swap be careful to split the page only if we got a valid swap entry so we don't split hugepages with a full swap. In theory we could split pages before isolating them during the lru scan, but for khugepaged to be safe, I'm relying on either mmap_sem write mode, or PG_lock taken, so split_huge_page has to run either with mmap_sem read/write mode or PG_lock taken. Calling it from isolate_lru_page would make locking more complicated, in addition to that split_huge_page would deadlock if called by __isolate_lru_page because it has to take the lru lock to add the tail pages. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-13block: make blkdev_get/put() handle exclusive accessTejun Heo
Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-10-26/proc/swaps: support pollingKay Sievers
System management wants to subscribe to changes in swap configuration. Make /proc/swaps pollable like /proc/mounts. [akpm@linux-foundation.org: document proc_poll_event] Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Acked-by: Greg KH <greg@kroah.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-16block: remove BLKDEV_IFL_WAITChristoph Hellwig
All the blkdev_issue_* helpers can only sanely be used for synchronous caller. To issue cache flushes or barriers asynchronously the caller needs to set up a bio by itself with a completion callback to move the asynchronous state machine ahead. So drop the BLKDEV_IFL_WAIT flag that is always specified when calling blkdev_issue_* and also remove the now unused flags argument to blkdev_issue_flush and blkdev_issue_zeroout. For blkdev_issue_discard we need to keep it for the secure discard flag, which gains a more descriptive name and loses the bitops vs flag confusion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10swap: do not send discards as barriersChristoph Hellwig
The swap code already uses synchronous discards, no need to add I/O barriers. tj: superflous newlines removed. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Hugh Dickins <hughd@google.com> Tested-by: Nigel Cunningham <nigel@tuxonice.net> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-09swap: discard while swapping only if SWAP_FLAG_DISCARDHugh Dickins
Tests with recent firmware on Intel X25-M 80GB and OCZ Vertex 60GB SSDs show a shift since I last tested in December: in part because of firmware updates, in part because of the necessary move from barriers to awaiting completion at the block layer. While discard at swapon still shows as slightly beneficial on both, discarding 1MB swap cluster when allocating is now disadvanteous: adds 25% overhead on Intel, adds 230% on OCZ (YMMV). Surrender: discard as presently implemented is more hindrance than help for swap; but might prove useful on other devices, or with improvements. So continue to do the discard at swapon, but make discard while swapping conditional on a SWAP_FLAG_DISCARD to sys_swapon() (which has been using only the lower 16 bits of int flags). We can add a --discard or -d to swapon(8), and a "discard" to swap in /etc/fstab: matching the mount option for btrfs, ext4, fat, gfs2, nilfs2. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Nigel Cunningham <nigel@tuxonice.net> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09swap: do not send discards as barriersChristoph Hellwig
The swap code already uses synchronous discards, no need to add I/O barriers. This fixes the worst of the terrible slowdown in swap allocation for hibernation, reported on 2.6.35 by Nigel Cunningham; but does not entirely eliminate that regression. [tj@kernel.org: superflous newlines removed] Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Nigel Cunningham <nigel@tuxonice.net> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Jens Axboe <jaxboe@fusionio.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09swap: prevent reuse during hibernationHugh Dickins
Move the hibernation check from scan_swap_map() into try_to_free_swap(): to catch not only the common case when hibernation's allocation itself triggers swap reuse, but also the less likely case when concurrent page reclaim (shrink_page_list) might happen to try_to_free_swap from a page. Hibernation already clears __GFP_IO from the gfp_allowed_mask, to stop reclaim from going to swap: check that to prevent swap reuse too. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Andrea Gelmini <andrea.gelmini@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Nigel Cunningham <nigel@tuxonice.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09swap: revert special hibernation allocationHugh Dickins
Please revert 2.6.36-rc commit d2997b1042ec150616c1963b5e5e919ffd0b0ebf "hibernation: freeze swap at hibernation". It complicated matters by adding a second swap allocation path, just for hibernation; without in any way fixing the issue that it was intended to address - page reclaim after fixing the hibernation image might free swap from a page already imaged as swapcache, letting its swap be reallocated to store a different page of the image: resulting in data corruption if the imaged page were freed as clean then swapped back in. Pages freed to si->swap_map were still in danger of being reallocated by the alternative allocation path. I guess it inadvertently fixed slow SSD swap allocation for hibernation, as reported by Nigel Cunningham: by missing out the discards that occur on the usual swap allocation path; but that was unintentional, and needs a separate fix. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Andrea Gelmini <andrea.gelmini@gmail.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Nigel Cunningham <nigel@tuxonice.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09hibernation: freeze swap at hibernationKAMEZAWA Hiroyuki
When taking a memory snapshot in hibernate_snapshot(), all (directly called) memory allocations use GFP_ATOMIC. Hence swap misusage during hibernation never occurs. But from a pessimistic point of view, there is no guarantee that no page allcation has __GFP_WAIT. It is better to have a global indication "we enter hibernation, don't use swap!". This patch tries to freeze new-swap-allocation during hibernation. (All user processes are frozenm so swapin is not a concern). This way, no updates will happen to swap_map[] between hibernate_snapshot() and save_image(). Swap is thawed when swsusp_free() is called. We can be assured that swap corruption will not occur. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Hugh Dickins <hughd@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Ondrej Zary <linux@rainbow-software.org> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>