- 31 10月, 2008 1 次提交
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由 Alan Cox 提交于
Junjiro R. Okajima reported a problem where knfsd crashes if you are using it to export shmemfs objects and run strict overcommit. In this situation the current->mm based modifier to the overcommit goes through a NULL pointer. We could simply check for NULL and skip the modifier but we've caught other real bugs in the past from mm being NULL here - cases where we did need a valid mm set up (eg the exec bug about a year ago). To preserve the checks and get the logic we want shuffle the checking around and add a new helper to the vm_ security wrappers Also fix a current->mm reference in nommu that should use the passed mm [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix build] Reported-by: NJunjiro R. Okajima <hooanon05@yahoo.co.jp> Acked-by: NJames Morris <jmorris@namei.org> Signed-off-by: NAlan Cox <alan@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 10月, 2008 3 次提交
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由 Lee Schermerhorn 提交于
Shmem segments locked into memory via shmctl(SHM_LOCKED) should not be kept on the normal LRU, since scanning them is a waste of time and might throw off kswapd's balancing algorithms. Place them on the unevictable LRU list instead. Use the AS_UNEVICTABLE flag to mark address_space of SHM_LOCKed shared memory regions as unevictable. Then these pages will be culled off the normal LRU lists during vmscan. Add new wrapper function to clear the mapping's unevictable state when/if shared memory segment is munlocked. Add 'scan_mapping_unevictable_page()' to mm/vmscan.c to scan all pages in the shmem segment's mapping [struct address_space] for evictability now that they're no longer locked. If so, move them to the appropriate zone lru list. Changes depend on [CONFIG_]UNEVICTABLE_LRU. [kosaki.motohiro@jp.fujitsu.com: revert shm change] Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NKosaki Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rik van Riel 提交于
Split the LRU lists in two, one set for pages that are backed by real file systems ("file") and one for pages that are backed by memory and swap ("anon"). The latter includes tmpfs. The advantage of doing this is that the VM will not have to scan over lots of anonymous pages (which we generally do not want to swap out), just to find the page cache pages that it should evict. This patch has the infrastructure and a basic policy to balance how much we scan the anon lists and how much we scan the file lists. The big policy changes are in separate patches. [lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset] [kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru] [kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page] [hugh@veritas.com: memcg swapbacked pages active] [hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED] [akpm@linux-foundation.org: fix /proc/vmstat units] [nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration] [kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo] [kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()] Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NLee Schermerhorn <Lee.Schermerhorn@hp.com> Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rik van Riel 提交于
Define page_file_cache() function to answer the question: is page backed by a file? Originally part of Rik van Riel's split-lru patch. Extracted to make available for other, independent reclaim patches. Moved inline function to linux/mm_inline.h where it will be needed by subsequent "split LRU" and "noreclaim" patches. Unfortunately this needs to use a page flag, since the PG_swapbacked state needs to be preserved all the way to the point where the page is last removed from the LRU. Trying to derive the status from other info in the page resulted in wrong VM statistics in earlier split VM patchsets. The total number of page flags in use on a 32 bit machine after this patch is 19. [akpm@linux-foundation.org: fix up out-of-order merge fallout] [hugh@veritas.com: splitlru: shmem_getpage SetPageSwapBacked sooner[ Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: NMinChan Kim <minchan.kim@gmail.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 18 10月, 2008 1 次提交
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由 Keith Packard 提交于
GEM needs to create shmem files to back buffer objects. Though currently creation of files for objects could have been driven from userland, the modesetting work will require allocation of buffer objects before userland is running, for boot-time message display. Signed-off-by: NEric Anholt <eric@anholt.net> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: NDave Airlie <airlied@redhat.com>
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- 13 10月, 2008 1 次提交
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由 Mimi Zohar 提交于
Discussion on the mailing list questioned the use of these magic values in userspace, concluding these values are already exported to userspace via statfs and their correct/incorrect usage is left up to the userspace application. - Move special fs magic number definitions to magic.h - Add magic.h include Signed-off-by: NMimi Zohar <zohar@us.ibm.com> Reviewed-by: NJames Morris <jmorris@namei.org> Signed-off-by: NJames Morris <jmorris@namei.org>
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- 05 8月, 2008 1 次提交
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由 Nick Piggin 提交于
Converting page lock to new locking bitops requires a change of page flag operation naming, so we might as well convert it to something nicer (!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked). This also facilitates lockdeping of page lock. Signed-off-by: NNick Piggin <npiggin@suse.de> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NPeter Zijlstra <peterz@infradead.org> Acked-by: NAndrew Morton <akpm@linux-foundation.org> Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 29 7月, 2008 1 次提交
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由 Hugh Dickins 提交于
SuSE's insserve initscript ordering program hits kernel BUG at mm/shmem.c:814 on 2.6.26. It's using posix_fadvise on directories, and the shmem_readpage method added in 2.6.23 is letting POSIX_FADV_WILLNEED allocate useless pages to a tmpfs directory, incrementing i_blocks count but never decrementing it. Fix this by assigning shmem_aops (pointing to readpage and writepage and set_page_dirty) only when it's needed, on a regular file or a long symlink. Many thanks to Kel for outstanding bugreport and steps to reproduce it. Reported-by: NKel Modderman <kel@otaku42.de> Tested-by: NKel Modderman <kel@otaku42.de> Signed-off-by: NHugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 27 7月, 2008 2 次提交
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由 Alexey Dobriyan 提交于
Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Acked-by: NPekka Enberg <penberg@cs.helsinki.fi> Acked-by: NChristoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Nick Piggin 提交于
If we can be sure that elevating the page_count on a pagecache page will pin it, we can speculatively run this operation, and subsequently check to see if we hit the right page rather than relying on holding a lock or otherwise pinning a reference to the page. This can be done if get_page/put_page behaves consistently throughout the whole tree (ie. if we "get" the page after it has been used for something else, we must be able to free it with a put_page). Actually, there is a period where the count behaves differently: when the page is free or if it is a constituent page of a compound page. We need an atomic_inc_not_zero operation to ensure we don't try to grab the page in either case. This patch introduces the core locking protocol to the pagecache (ie. adds page_cache_get_speculative, and tweaks some update-side code to make it work). Thanks to Hugh for pointing out an improvement to the algorithm setting page_count to zero when we have control of all references, in order to hold off speculative getters. [kamezawa.hiroyu@jp.fujitsu.com: fix migration_entry_wait()] [hugh@veritas.com: fix add_to_page_cache] [akpm@linux-foundation.org: repair a comment] Signed-off-by: NNick Piggin <npiggin@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Acked-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 26 7月, 2008 2 次提交
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由 KAMEZAWA Hiroyuki 提交于
A new call, mem_cgroup_shrink_usage() is added for shmem handling and relacing non-standard usage of mem_cgroup_charge/uncharge. Now, shmem calls mem_cgroup_charge() just for reclaim some pages from mem_cgroup. In general, shmem is used by some process group and not for global resource (like file caches). So, it's reasonable to reclaim pages from mem_cgroup where shmem is mainly used. [hugh@veritas.com: shmem_getpage release page sooner] [hugh@veritas.com: mem_cgroup_shrink_usage css_put] Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KAMEZAWA Hiroyuki 提交于
memcg: performance improvements Patch Description 1/5 ... remove refcnt fron page_cgroup patch (shmem handling is fixed) 2/5 ... swapcache handling patch 3/5 ... add helper function for shmem's memory reclaim patch 4/5 ... optimize by likely/unlikely ppatch 5/5 ... remove redundunt check patch (shmem handling is fixed.) Unix bench result. == 2.6.26-rc2-mm1 + memory resource controller Execl Throughput 2915.4 lps (29.6 secs, 3 samples) C Compiler Throughput 1019.3 lpm (60.0 secs, 3 samples) Shell Scripts (1 concurrent) 5796.0 lpm (60.0 secs, 3 samples) Shell Scripts (8 concurrent) 1097.7 lpm (60.0 secs, 3 samples) Shell Scripts (16 concurrent) 565.3 lpm (60.0 secs, 3 samples) File Read 1024 bufsize 2000 maxblocks 1022128.0 KBps (30.0 secs, 3 samples) File Write 1024 bufsize 2000 maxblocks 544057.0 KBps (30.0 secs, 3 samples) File Copy 1024 bufsize 2000 maxblocks 346481.0 KBps (30.0 secs, 3 samples) File Read 256 bufsize 500 maxblocks 319325.0 KBps (30.0 secs, 3 samples) File Write 256 bufsize 500 maxblocks 148788.0 KBps (30.0 secs, 3 samples) File Copy 256 bufsize 500 maxblocks 99051.0 KBps (30.0 secs, 3 samples) File Read 4096 bufsize 8000 maxblocks 2058917.0 KBps (30.0 secs, 3 samples) File Write 4096 bufsize 8000 maxblocks 1606109.0 KBps (30.0 secs, 3 samples) File Copy 4096 bufsize 8000 maxblocks 854789.0 KBps (30.0 secs, 3 samples) Dc: sqrt(2) to 99 decimal places 126145.2 lpm (30.0 secs, 3 samples) INDEX VALUES TEST BASELINE RESULT INDEX Execl Throughput 43.0 2915.4 678.0 File Copy 1024 bufsize 2000 maxblocks 3960.0 346481.0 875.0 File Copy 256 bufsize 500 maxblocks 1655.0 99051.0 598.5 File Copy 4096 bufsize 8000 maxblocks 5800.0 854789.0 1473.8 Shell Scripts (8 concurrent) 6.0 1097.7 1829.5 ========= FINAL SCORE 991.3 == 2.6.26-rc2-mm1 + this set == Execl Throughput 3012.9 lps (29.9 secs, 3 samples) C Compiler Throughput 981.0 lpm (60.0 secs, 3 samples) Shell Scripts (1 concurrent) 5872.0 lpm (60.0 secs, 3 samples) Shell Scripts (8 concurrent) 1120.3 lpm (60.0 secs, 3 samples) Shell Scripts (16 concurrent) 578.0 lpm (60.0 secs, 3 samples) File Read 1024 bufsize 2000 maxblocks 1003993.0 KBps (30.0 secs, 3 samples) File Write 1024 bufsize 2000 maxblocks 550452.0 KBps (30.0 secs, 3 samples) File Copy 1024 bufsize 2000 maxblocks 347159.0 KBps (30.0 secs, 3 samples) File Read 256 bufsize 500 maxblocks 314644.0 KBps (30.0 secs, 3 samples) File Write 256 bufsize 500 maxblocks 151852.0 KBps (30.0 secs, 3 samples) File Copy 256 bufsize 500 maxblocks 101000.0 KBps (30.0 secs, 3 samples) File Read 4096 bufsize 8000 maxblocks 2033256.0 KBps (30.0 secs, 3 samples) File Write 4096 bufsize 8000 maxblocks 1611814.0 KBps (30.0 secs, 3 samples) File Copy 4096 bufsize 8000 maxblocks 847979.0 KBps (30.0 secs, 3 samples) Dc: sqrt(2) to 99 decimal places 128148.7 lpm (30.0 secs, 3 samples) INDEX VALUES TEST BASELINE RESULT INDEX Execl Throughput 43.0 3012.9 700.7 File Copy 1024 bufsize 2000 maxblocks 3960.0 347159.0 876.7 File Copy 256 bufsize 500 maxblocks 1655.0 101000.0 610.3 File Copy 4096 bufsize 8000 maxblocks 5800.0 847979.0 1462.0 Shell Scripts (8 concurrent) 6.0 1120.3 1867.2 ========= FINAL SCORE 1004.6 This patch: Remove refcnt from page_cgroup(). After this, * A page is charged only when !page_mapped() && no page_cgroup is assigned. * Anon page is newly mapped. * File page is added to mapping->tree. * A page is uncharged only when * Anon page is fully unmapped. * File page is removed from LRU. There is no change in behavior from user's view. This patch also removes unnecessary calls in rmap.c which was used only for refcnt mangement. [akpm@linux-foundation.org: fix warning] [hugh@veritas.com: fix shmem_unuse_inode charging] Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 7月, 2008 1 次提交
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由 Hugh Dickins 提交于
We have a request for tmpfs to support the AIO interface: easily done, no more than replacing the old shmem_file_read by shmem_file_aio_read, cribbed from generic_file_aio_read. (In 2.6.25 its write side was already changed to use generic_file_aio_write.) Incorporate cleanups from Andrew Morton and Harvey Harrison. Tests out fine with LTP's ltp-aiodio.sh, given hacks (not included) to support O_DIRECT. tmpfs cannot honestly support O_DIRECT: its cache-avoiding-IO nature is at odds with direct IO-avoiding-cache. Signed-off-by: NHugh Dickins <hugh@veritas.com> Tested-by: NLawrence Greenfield <leg@google.com> Cc: Christoph Rohland <hans-christoph.rohland@sap.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Zach Brown <zach.brown@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 30 4月, 2008 1 次提交
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由 Miklos Szeredi 提交于
Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB. If this flag is set, then don't update the per-bdi writeback stats from test_set_page_writeback() and test_clear_page_writeback(). Misc cleanups: - convert bdi_cap_writeback_dirty() and friends to static inline functions - create a flag that includes all three dirty/writeback related flags, since almst all users will want to have them toghether Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 28 4月, 2008 9 次提交
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由 Lee Schermerhorn 提交于
This patch replaces the mempolicy mode, mode_flags, and nodemask in the shmem_sb_info struct with a struct mempolicy pointer, initialized to NULL. This removes dependency on the details of mempolicy from shmem.c and hugetlbfs inode.c and simplifies the interfaces. mpol_parse_str() in mempolicy.c is changed to return, via a pointer to a pointer arg, a struct mempolicy pointer on success. For MPOL_DEFAULT, the returned pointer is NULL. Further, mpol_parse_str() now takes a 'no_context' argument that causes the input nodemask to be stored in the w.user_nodemask of the created mempolicy for use when the mempolicy is installed in a tmpfs inode shared policy tree. At that time, any cpuset contextualization is applied to the original input nodemask. This preserves the previous behavior where the input nodemask was stored in the superblock. We can think of the returned mempolicy as "context free". Because mpol_parse_str() is now calling mpol_new(), we can remove from mpol_to_str() the semantic checks that mpol_new() already performs. Add 'no_context' parameter to mpol_to_str() to specify that it should format the nodemask in w.user_nodemask for 'bind' and 'interleave' policies. Change mpol_shared_policy_init() to take a pointer to a "context free" struct mempolicy and to create a new, "contextualized" mempolicy using the mode, mode_flags and user_nodemask from the input mempolicy. Note: we know that the mempolicy passed to mpol_to_str() or mpol_shared_policy_init() from a tmpfs superblock is "context free". This is currently the only instance thereof. However, if we found more uses for this concept, and introduced any ambiguity as to whether a mempolicy was context free or not, we could add another internal mode flag to identify context free mempolicies. Then, we could remove the 'no_context' argument from mpol_to_str(). Added shmem_get_sbmpol() to return a reference counted superblock mempolicy, if one exists, to pass to mpol_shared_policy_init(). We must add the reference under the sb stat_lock to prevent races with replacement of the mpol by remount. This reference is removed in mpol_shared_policy_init(). [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: another build fix] [akpm@linux-foundation.org: yet another build fix] Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Lee Schermerhorn 提交于
mm/shmem.c currently contains functions to parse and display memory policy strings for the tmpfs 'mpol' mount option. Move this to mm/mempolicy.c with the rest of the mempolicy support. With subsequent patches, we'll be able to remove knowledge of the details [mode, flags, policy, ...] completely from shmem.c 1) replace shmem_parse_mpol() in mm/shmem.c with mpol_parse_str() in mm/mempolicy.c. Rework to use the policy_types[] array [used by mpol_to_str()] to look up mode by name. 2) use mpol_to_str() to format policy for shmem_show_mpol(). mpol_to_str() expects a pointer to a struct mempolicy, so temporarily construct one. This will be replaced with a reference to a struct mempolicy in the tmpfs superblock in a subsequent patch. NOTE 1: I changed mpol_to_str() to use a colon ':' rather than an equal sign '=' as the nodemask delimiter to match mpol_parse_str() and the tmpfs/shmem mpol mount option formatting that now uses mpol_to_str(). This is a user visible change to numa_maps, but then the addition of the mode flags already changed the display. It makes sense to me to have the mounts and numa_maps display the policy in the same format. However, if anyone objects strongly, I can pass the desired nodemask delimeter as an arg to mpol_to_str(). Note 2: Like show_numa_map(), I don't check the return code from mpol_to_str(). I do use a longer buffer than the one provided by show_numa_map(), which seems to have sufficed so far. Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Lee Schermerhorn 提交于
After further discussion with Christoph Lameter, it has become clear that my earlier attempts to clean up the mempolicy reference counting were a bit of overkill in some areas, resulting in superflous ref/unref in what are usually fast paths. In other areas, further inspection reveals that I botched the unref for interleave policies. A separate patch, suitable for upstream/stable trees, fixes up the known errors in the previous attempt to fix reference counting. This patch reworks the memory policy referencing counting and, one hopes, simplifies the code. Maybe I'll get it right this time. See the update to the numa_memory_policy.txt document for a discussion of memory policy reference counting that motivates this patch. Summary: Lookup of mempolicy, based on (vma, address) need only add a reference for shared policy, and we need only unref the policy when finished for shared policies. So, this patch backs out all of the unneeded extra reference counting added by my previous attempt. It then unrefs only shared policies when we're finished with them, using the mpol_cond_put() [conditional put] helper function introduced by this patch. Note that shmem_swapin() calls read_swap_cache_async() with a dummy vma containing just the policy. read_swap_cache_async() can call alloc_page_vma() multiple times, so we can't let alloc_page_vma() unref the shared policy in this case. To avoid this, we make a copy of any non-null shared policy and remove the MPOL_F_SHARED flag from the copy. This copy occurs before reading a page [or multiple pages] from swap, so the overhead should not be an issue here. I introduced a new static inline function "mpol_cond_copy()" to copy the shared policy to an on-stack policy and remove the flags that would require a conditional free. The current implementation of mpol_cond_copy() assumes that the struct mempolicy contains no pointers to dynamically allocated structures that must be duplicated or reference counted during copy. Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Lee Schermerhorn 提交于
This is a change that was requested some time ago by Mel Gorman. Makes sense to me, so here it is. Note: I retain the name "mpol_free_shared_policy()" because it actually does free the shared_policy, which is NOT a reference counted object. However, ... The mempolicy object[s] referenced by the shared_policy are reference counted, so mpol_put() is used to release the reference held by the shared_policy. The mempolicy might not be freed at this time, because some task attached to the shared object associated with the shared policy may be in the process of allocating a page based on the mempolicy. In that case, the task performing the allocation will hold a reference on the mempolicy, obtained via mpol_shared_policy_lookup(). The mempolicy will be freed when all tasks holding such a reference have called mpol_put() for the mempolicy. Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Lee Schermerhorn 提交于
Parsing of new mode flags in the tmpfs mpol mount option is slightly broken: Setting a valid flag works OK: #mount -o remount,mpol=bind=static:1-2 /dev/shm #mount ... tmpfs on /dev/shm type tmpfs (rw,mpol=bind=static:1-2) ... However, we can't remove them or change them, once we've set a valid flag: #mount -o remount,mpol=bind:1-2 /dev/shm #mount ... tmpfs on /dev/shm type tmpfs (rw,mpol=bind:1-2) ... It SAYS it removed it, but that's just a copy of the input string. If we now try to set it to a different flag, we get: #mount -o remount,mpol=bind=relative:1-2 /dev/shm mount: /dev/shm not mounted already, or bad option And on the console, we see: tmpfs: Bad value 'bind' for mount option 'mpol' ^ lost remainder of string Furthermore, bogus flags are accepted with out error. Granted, they are a no-op: #mount -o remount,mpol=interleave=foo:0-3 /dev/shm #mount ... tmpfs on /dev/shm type tmpfs (rw,mpol=interleave=foo:0-3) Again, that's just a copy of the input string shown by the mount command. This patch fixes the behavior by pre-zeroing the flags so that only one of the mutually exclusive flags can be set at one time. It also reports an error when an unrecognized flag is specified. The check for both flags being set is removed because it can't happen with this implementation. If we ever want to support multiple non-exclusive flags, this area will need rework and we will need to check that any mutually exclusive flags aren't specified. Signed-off-by: NLee Schermerhorn <lee.schermerhorn@hp.com> Cc: David Rientjes <rientjes@google.com> Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: Eric Whitney <eric.whitney@hp.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
Adds another optional mode flag, MPOL_F_RELATIVE_NODES, that specifies nodemasks passed via set_mempolicy() or mbind() should be considered relative to the current task's mems_allowed. When the mempolicy is created, the passed nodemask is folded and mapped onto the current task's mems_allowed. For example, consider a task using set_mempolicy() to pass MPOL_INTERLEAVE | MPOL_F_RELATIVE_NODES with a nodemask of 1-3. If current's mems_allowed is 4-7, the effected nodemask is 5-7 (the second, third, and fourth node of mems_allowed). If the same task is attached to a cpuset, the mempolicy nodemask is rebound each time the mems are changed. Some possible rebinds and results are: mems result 1-3 1-3 1-7 2-4 1,5-6 1,5-6 1,5-7 5-7 Likewise, the zonelist built for MPOL_BIND acts on the set of zones assigned to the resultant nodemask from the relative remap. In the MPOL_PREFERRED case, the preferred node is remapped from the currently effected nodemask to the relative nodemask. This mempolicy mode flag was conceived of by Paul Jackson <pj@sgi.com>. Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
Add an optional mempolicy mode flag, MPOL_F_STATIC_NODES, that suppresses the node remap when the policy is rebound. Adds another member to struct mempolicy, nodemask_t user_nodemask, as part of a union with cpuset_mems_allowed: struct mempolicy { ... union { nodemask_t cpuset_mems_allowed; nodemask_t user_nodemask; } w; } that stores the the nodemask that the user passed when he or she created the mempolicy via set_mempolicy() or mbind(). When using MPOL_F_STATIC_NODES, which is passed with any mempolicy mode, the user's passed nodemask intersected with the VMA or task's allowed nodes is always used when determining the preferred node, setting the MPOL_BIND zonelist, or creating the interleave nodemask. This happens whenever the policy is rebound, including when a task's cpuset assignment changes or the cpuset's mems are changed. This creates an interesting side-effect in that it allows the mempolicy "intent" to lie dormant and uneffected until it has access to the node(s) that it desires. For example, if you currently ask for an interleaved policy over a set of nodes that you do not have access to, the mempolicy is not created and the task continues to use the previous policy. With this change, however, it is possible to create the same mempolicy; it is only effected when access to nodes in the nodemask is acquired. It is also possible to mount tmpfs with the static nodemask behavior when specifying a node or nodemask. To do this, simply add "=static" immediately following the mempolicy mode at mount time: mount -o remount mpol=interleave=static:1-3 Also removes mpol_check_policy() and folds its logic into mpol_new() since it is now obsoleted. The unused vma_mpol_equal() is also removed. Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
With the evolution of mempolicies, it is necessary to support mempolicy mode flags that specify how the policy shall behave in certain circumstances. The most immediate need for mode flag support is to suppress remapping the nodemask of a policy at the time of rebind. Both the mempolicy mode and flags are passed by the user in the 'int policy' formal of either the set_mempolicy() or mbind() syscall. A new constant, MPOL_MODE_FLAGS, represents the union of legal optional flags that may be passed as part of this int. Mempolicies that include illegal flags as part of their policy are rejected as invalid. An additional member to struct mempolicy is added to support the mode flags: struct mempolicy { ... unsigned short policy; unsigned short flags; } The splitting of the 'int' actual passed by the user is done in sys_set_mempolicy() and sys_mbind() for their respective syscalls. This is done by intersecting the actual with MPOL_MODE_FLAGS, rejecting the syscall of there are additional flags, and storing it in the new 'flags' member of struct mempolicy. The intersection of the actual with ~MPOL_MODE_FLAGS is stored in the 'policy' member of the struct and all current users of pol->policy remain unchanged. The union of the policy mode and optional mode flags is passed back to the user in get_mempolicy(). This combination of mode and flags within the same actual does not break userspace code that relies on get_mempolicy(&policy, ...) and either switch (policy) { case MPOL_BIND: ... case MPOL_INTERLEAVE: ... }; statements or if (policy == MPOL_INTERLEAVE) { ... } statements. Such applications would need to use optional mode flags when calling set_mempolicy() or mbind() for these previously implemented statements to stop working. If an application does start using optional mode flags, it will need to mask the optional flags off the policy in switch and conditional statements that only test mode. An additional member is also added to struct shmem_sb_info to store the optional mode flags. [hugh@veritas.com: shmem mpol: fix build warning] Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
The mempolicy mode constants, MPOL_DEFAULT, MPOL_PREFERRED, MPOL_BIND, and MPOL_INTERLEAVE, are better declared as part of an enum since they are sequentially numbered and cannot be combined. The policy member of struct mempolicy is also converted from type short to type unsigned short. A negative policy does not have any legitimate meaning, so it is possible to change its type in preparation for adding optional mode flags later. The equivalent member of struct shmem_sb_info is also changed from int to unsigned short. For compatibility, the policy formal to get_mempolicy() remains as a pointer to an int: int get_mempolicy(int *policy, unsigned long *nmask, unsigned long maxnode, unsigned long addr, unsigned long flags); although the only possible values is the range of type unsigned short. Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: NDavid Rientjes <rientjes@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 3月, 2008 1 次提交
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由 Randy Dunlap 提交于
Convert tiny-shmem.c function comments to kernel-doc. Add parameters and convert/fix other kernel-doc in shmem.c. Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 3月, 2008 1 次提交
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由 Hugh Dickins 提交于
My memcgroup patch to fix hang with shmem/tmpfs added NULL page handling to mem_cgroup_charge_common. It seemed convenient at the time, but hard to justify now: there's a perfectly appropriate swappage to charge and uncharge instead, this is not on any hot path through shmem_getpage, and no performance hit was observed from the slight extra overhead. So revert that NULL page handling from mem_cgroup_charge_common; and make it clearer by bringing page_cgroup_assign_new_page_cgroup into its body - that was a helper I found more of a hindrance to understanding. Signed-off-by: NHugh Dickins <hugh@veritas.com> Cc: David Rientjes <rientjes@google.com> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hirokazu Takahashi <taka@valinux.co.jp> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 2月, 2008 2 次提交
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由 Andrew Morton 提交于
Documentation/SubmitCheckist, please. Cc: Hugh Dickins <hugh@veritas.com> Cc: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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Add .show_options super operation to tmpfs. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 2月, 2008 1 次提交
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由 Hugh Dickins 提交于
The memcgroup regime relies upon a cgroup reclaiming pages from itself within add_to_page_cache: which may involve some waiting. Whereas shmem and tmpfs rely upon using add_to_page_cache while holding a spinlock: when it cannot wait. The consequence is that when a cgroup reaches its limit, shmem_getpage just hangs - unless there is outside memory pressure too, neither kswapd nor radix_tree_preload get it out of the retry loop. In most cases we can mem_cgroup_cache_charge the page waitably first, to attach the page_cgroup in advance, so add_to_page_cache will do no more than increment a count; then mem_cgroup_uncharge_page after (in both success and failure cases) to balance the books again. And where there used to be a congestion_wait for kswapd (recently made redundant by radix_tree_preload), use mem_cgroup_cache_charge with NULL page to go through a cycle of allocation and freeing, without accounting to any particular page, and without updating the statistics vector. This brings the cgroup below its limit so the next try usually succeeds. Signed-off-by: NHugh Dickins <hugh@veritas.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 2月, 2008 12 次提交
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由 David P. Quigley 提交于
This patch modifies the interface to inode_getsecurity to have the function return a buffer containing the security blob and its length via parameters instead of relying on the calling function to give it an appropriately sized buffer. Security blobs obtained with this function should be freed using the release_secctx LSM hook. This alleviates the problem of the caller having to guess a length and preallocate a buffer for this function allowing it to be used elsewhere for Labeled NFS. The patch also removed the unused err parameter. The conversion is similar to the one performed by Al Viro for the security_getprocattr hook. Signed-off-by: NDavid P. Quigley <dpquigl@tycho.nsa.gov> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Chris Wright <chrisw@sous-sol.org> Acked-by: NJames Morris <jmorris@namei.org> Acked-by: NSerge Hallyn <serue@us.ibm.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Intensive swapoff testing shows shmem_unuse spinning on an entry in shmem_swaplist pointing to itself: how does that come about? Days pass... First guess is this: shmem_delete_inode tests list_empty without taking the global mutex (so the swapping case doesn't slow down the common case); but there's an instant in shmem_unuse_inode's list_move_tail when the list entry may appear empty (a rare case, because it's actually moving the head not the the list member). So there's a danger of leaving the inode on the swaplist when it's freed, then reinitialized to point to itself when reused. Fix that by skipping the list_move_tail when it's a no-op, which happens to plug this. But this same spinning then surfaces on another machine. Ah, I'd never suspected it, but shmem_writepage's swaplist manipulation is unsafe: though we still hold page lock, which would hold off inode deletion if the page were in pagecache, it doesn't hold off once it's in swapcache (free_swap_and_cache doesn't wait on locked pages). Hmm: we could put the the inode on swaplist earlier, but then shmem_unuse_inode could never prune unswapped inodes. Fix this with an igrab before dropping info->lock, as in shmem_unuse_inode; though I am a little uneasy about the iput which has to follow - it works, and I see nothing wrong with it, but it is surprising that shmem inode deletion may now occur below shmem_writepage. Revisit this fix later? And while we're looking at these races: the way shmem_unuse tests swapped without holding info->lock looks unsafe, if we've more than one swap area: a racing shmem_writepage on another page of the same inode could be putting it in swapcache, just as we're deciding to remove the inode from swaplist - there's a danger of going on swap without being listed, so a later swapoff would hang, being unable to locate the entry. Move that test and removal down into shmem_unuse_inode, once info->lock is held. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
Nick has observed that shmem.c still uses GFP_ATOMIC when adding to page cache or swap cache, without any radix tree preload: so tending to deplete emergency reserves of memory. GFP_ATOMIC remains appropriate in shmem_writepage's add_to_swap_cache: it's being called under memory pressure, so must not wait for more memory to become available. But shmem_unuse_inode now has a window in which it can and should preload with GFP_KERNEL, and say GFP_NOWAIT instead of GFP_ATOMIC in its add_to_page_cache. shmem_getpage is not so straightforward: its filepage/swappage integrity relies upon exchanging between caches under spinlock, and it would need a lot of restructuring to place the preloads correctly. Instead, follow its pattern of retrying on races: use GFP_NOWAIT instead of GFP_ATOMIC in add_to_page_cache, and begin each circuit of the repeat loop with a sleeping radix_tree_preload, followed immediately by radix_tree_preload_end - that won't guarantee success in the next add_to_page_cache, but doesn't need to. And we can then remove that bothersome congestion_wait: when needed, it'll automatically get done in the course of the radix_tree_preload. Signed-off-by: NHugh Dickins <hugh@veritas.com> Looks-good-to: Nick Piggin <npiggin@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
There are a couple of reasons (patches follow) why it would be good to open a window for sleep in shmem_unuse_inode, between its search for a matching swap entry, and its handling of the entry found. shmem_unuse_inode must then use igrab to hold the inode against deletion in that window, and its corresponding iput might result in deletion: so it had better unlock_page before the iput, and might as well release the page too. Nor is there any need to hold on to shmem_swaplist_mutex once we know we'll leave the loop. So this unwinding moves from try_to_unuse and shmem_unuse into shmem_unuse_inode, in the case when it finds a match. Let try_to_unuse break on error in the shmem_unuse case, as it does in the unuse_mm case: though at this point in the series, no error to break on. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
shmem_unuse is at present an unbroken search through every swap vector page of every tmpfs file which might be swapped, all under shmem_swaplist_lock. This dates from long ago, when the caller held mmlist_lock over it all too: long gone, but there's never been much pressure for preemptible swapoff. Make it a little more preemptible, replacing shmem_swaplist_lock by shmem_swaplist_mutex, inserting a cond_resched in the main loop, and a cond_resched_lock (on info->lock) at one convenient point in the shmem_unuse_inode loop, where it has no outstanding kmap_atomic. If we're serious about preemptible swapoff, there's much further to go e.g. I'm stupid to let the kmap_atomics of the decreasingly significant HIGHMEM case dictate preemptiblility for other configs. But as in the earlier patch to make swapoff scan ptes preemptibly, my hidden agenda is really towards making memcgroups work, hardly about preemptibility at all. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
tmpfs is expected to limit the memory used (unless mounted with nr_blocks=0 or size=0). But if a stacked filesystem such as unionfs gets pages from a sparse tmpfs file by reading holes, and then writes to them, it can easily exceed any such limit at present. So suppress the SGP_READ "don't allocate page" ZERO_PAGE optimization when reading for the kernel (a KERNEL_DS check, ugh, sorry about that). Indeed, pessimistically mark such pages as dirty, so they cannot get reclaimed and unaccounted by mistake. The venerable shmem_recalc_inode code (originally to account for the reclaim of clean pages) suffices to get the accounting right when swappages are dropped in favour of more uptodate filepages. This also fixes the NULL shmem_swp_entry BUG or oops in shmem_writepage, caused by unionfs writing to a very sparse tmpfs file: to minimize memory allocation in swapout, tmpfs requires the swap vector be allocated upfront, which wasn't always happening in this stacked case. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
tmpfs has long allowed for a fresh filepage to be created in pagecache, just before shmem_getpage gets the chance to match it up with the swappage which already belongs to that offset. But unionfs_writepage now does a find_or_create_page, divorced from shmem_getpage, which leaves conflicting filepage and swappage outstanding indefinitely, when unionfs is over tmpfs. Therefore shmem_writepage (where a page is swizzled from file to swap) must now be on the lookout for existing swap, ready to free it in favour of the more uptodate filepage, instead of BUGging on that clash. And when the add_to_page_cache fails in shmem_unuse_inode, it must defer to an uptodate filepage, otherwise swapoff would hang. Whereas when add_to_page_cache fails in shmem_getpage, it should retry in the same way it already does. Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
move_to_swap_cache and move_from_swap_cache functions (which swizzle a page between tmpfs page cache and swap cache, to avoid page copying) are only used by shmem.c; and our subsequent fix for unionfs needs different treatments in the two instances of move_from_swap_cache. Move them from swap_state.c into their callsites shmem_writepage, shmem_unuse_inode and shmem_getpage, making add_to_swap_cache externally visible. shmem.c likes to say set_page_dirty where swap_state.c liked to say SetPageDirty: respect that diversity, which __set_page_dirty_no_writeback makes moot (and implies we should lose that "shift page from clean_pages to dirty_pages list" comment: it's on neither). Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michael Marineau 提交于
When tmpfs is mounted with a size less than one page, the number of blocks is set to 0 which makes the tmpfs mount unlimited. This can lead to a quick and surprising death if someone typos a tmpfs mount command and writes too much. tmpfs can still be mounted as unlimited if size or nr_blocks is exactly 0, as Documentation/filesystems/tmpfs.txt says. Hugh: do this by rounding size up instead of down in all cases: which slightly expands other odd-sized tmpfs mounts, but in a consistent way. Signed-off-by: NMichael Marineau <mike@marineau.org> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Pavel Emelyanov 提交于
The shmem_sb_info structure has a number of free_inodes. This value is altered in appropriate places under spinlock and with the sbi->max_inodes != 0 check. Consolidate these manipulations into two helpers. This is minus 42 bytes of shmem.o and minus 4 :) lines of code. [akpm@linux-foundation.org: fix error return values] Signed-off-by: NPavel Emelyanov <xemul@openvz.org> Signed-off-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
With the old aops, writing to a tmpfs file had to use its own special method: the generic method would pass in a fresh page to prepare_write when the right page was there in swapcache - which was inefficient to handle, even once we'd concocted the code to handle it. With the new aops, the generic method uses shmem_write_end, which lets shmem_getpage find the right page: so now abandon shmem_file_write in favour of the generic method. Yes, that does do several things that tmpfs hasn't really needed (notably balance_dirty_pages_ratelimited, which ramfs also calls); but more use of common code is preferable. Signed-off-by: NHugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Hugh Dickins 提交于
In the new aops, write_begin is supposed to return the page locked: though I've seen no ill effects, that's been overlooked in the case of shmem_write_begin, and should be fixed. Then shmem_write_end must unlock the page: do so _after_ updating i_size, as we found to be important in other filesystems (though since shmem pages don't go the usual writeback route, they never suffered from that corruption). For shmem_write_begin to return the page locked, we need shmem_getpage to return the page locked in SGP_WRITE case as well as SGP_CACHE case: let's simplify the interface and return it locked even when SGP_READ. Signed-off-by: NHugh Dickins <hugh@veritas.com> Acked-by: NRik van Riel <riel@redhat.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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