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* lockdep: Add helper function for dir vs file i_mutex annotationJosh Boyer2011-08-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Purely in-memory filesystems do not use the inode hash as the dcache tells us if an entry already exists. As a result, they do not call unlock_new_inode, and thus directory inodes do not get put into a different lockdep class for i_sem. We need the different lockdep classes, because the locking order for i_mutex is different for directory inodes and regular inodes. Directory inodes can do "readdir()", which takes i_mutex *before* possibly taking mm->mmap_sem (due to a page fault while copying the directory entry to user space). In contrast, regular inodes can be mmap'ed, which takes mm->mmap_sem before accessing i_mutex. The two cases can never happen for the same inode, so no real deadlock can occur, but without the different lockdep classes, lockdep cannot understand that. As a result, if CONFIG_DEBUG_LOCK_ALLOC is set, this can lead to false positives from lockdep like below: find/645 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<ffffffff81109514>] might_fault+0x5c/0xac but task is already holding lock: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffff81149f34>] vfs_readdir+0x5b/0xb4 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#15){+.+.+.}: [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff814db822>] __mutex_lock_common+0x4c/0x361 [<ffffffff814dbc46>] mutex_lock_nested+0x40/0x45 [<ffffffff811daa87>] hugetlbfs_file_mmap+0x82/0x110 [<ffffffff81111557>] mmap_region+0x258/0x432 [<ffffffff811119dd>] do_mmap_pgoff+0x2ac/0x306 [<ffffffff81111b4f>] sys_mmap_pgoff+0x118/0x16a [<ffffffff8100c858>] sys_mmap+0x22/0x24 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b -> #0 (&mm->mmap_sem){++++++}: [<ffffffff8108a4bc>] __lock_acquire+0xa1a/0xcf7 [<ffffffff8108ac26>] lock_acquire+0xbf/0x103 [<ffffffff81109541>] might_fault+0x89/0xac [<ffffffff81149cff>] filldir+0x6f/0xc7 [<ffffffff811586ea>] dcache_readdir+0x67/0x205 [<ffffffff81149f54>] vfs_readdir+0x7b/0xb4 [<ffffffff8114a073>] sys_getdents+0x7e/0xd1 [<ffffffff814e3ec2>] system_call_fastpath+0x16/0x1b This patch moves the directory vs file lockdep annotation into a helper function that can be called by in-memory filesystems and has hugetlbfs call it. Signed-off-by: Josh Boyer <jwboyer@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge 'akpm' patch seriesLinus Torvalds2011-07-251-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Merge akpm patch series: (122 commits) drivers/connector/cn_proc.c: remove unused local Documentation/SubmitChecklist: add RCU debug config options reiserfs: use hweight_long() reiserfs: use proper little-endian bitops pnpacpi: register disabled resources drivers/rtc/rtc-tegra.c: properly initialize spinlock drivers/rtc/rtc-twl.c: check return value of twl_rtc_write_u8() in twl_rtc_set_time() drivers/rtc: add support for Qualcomm PMIC8xxx RTC drivers/rtc/rtc-s3c.c: support clock gating drivers/rtc/rtc-mpc5121.c: add support for RTC on MPC5200 init: skip calibration delay if previously done misc/eeprom: add eeprom access driver for digsy_mtc board misc/eeprom: add driver for microwire 93xx46 EEPROMs checkpatch.pl: update $logFunctions checkpatch: make utf-8 test --strict checkpatch.pl: add ability to ignore various messages checkpatch: add a "prefer __aligned" check checkpatch: validate signature styles and To: and Cc: lines checkpatch: add __rcu as a sparse modifier checkpatch: suggest using min_t or max_t ... Did this as a merge because of (trivial) conflicts in - Documentation/feature-removal-schedule.txt - arch/xtensa/include/asm/uaccess.h that were just easier to fix up in the merge than in the patch series.
| * fs/hugetlbfs/inode.c: fix pgoff alignment checking on 32-bitBecky Bruce2011-07-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This: vma->vm_pgoff & ~(huge_page_mask(h) >> PAGE_SHIFT) is incorrect on 32-bit. It causes us to & the pgoff with something that looks like this (for a 4m hugepage): 0xfff003ff. The mask should be flipped and *then* shifted, to give you 0x0000_03fff. Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | VFS : mount lock scalability for internal mountsTim Chen2011-07-241-0/+1
|/ | | | | | | | | | | | | | | | | | | For a number of file systems that don't have a mount point (e.g. sockfs and pipefs), they are not marked as long term. Therefore in mntput_no_expire, all locks in vfs_mount lock are taken instead of just local cpu's lock to aggregate reference counts when we release reference to file objects. In fact, only local lock need to have been taken to update ref counts as these file systems are in no danger of going away until we are ready to unregister them. The attached patch marks file systems using kern_mount without mount point as long term. The contentions of vfs_mount lock is now eliminated. Before un-registering such file system, kern_unmount should be called to remove the long term flag and make the mount point ready to be freed. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* mm: don't access vm_flags as 'int'KOSAKI Motohiro2011-05-261-1/+2
| | | | | | | | | | | The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor 'unsigned int'. This patch fixes such misuse. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> [ Changed to use a typedef - we'll extend it to cover more cases later, since there has been discussion about making it a 64-bit type.. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Convert i_mmap_lock to a mutexPeter Zijlstra2011-05-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | Straightforward conversion of i_mmap_lock to a mutex. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: hugetlbfs: change remove_from_page_cacheMinchan Kim2011-03-221-2/+1
| | | | | | | | | | | | | | | | This patch series changes remove_from_page_cache()'s page ref counting rule. Page cache ref count is decreased in delete_from_page_cache(). So we don't need to decrease the page reference in callers. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: William Irwin <wli@holomorphy.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: 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>
* fs: icache RCU free inodesNick Piggin2011-01-071-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* hugetlbfs: lessen the impact of a deprecation warningDave Jones2010-11-121-2/+1
| | | | | | | | | WARN_ONCE is a bit strong for a deprecation warning, given that it spews a huge backtrace. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* convert get_sb_nodev() usersAl Viro2010-10-291-4/+4
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2010-10-261-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits) split invalidate_inodes() fs: skip I_FREEING inodes in writeback_sb_inodes fs: fold invalidate_list into invalidate_inodes fs: do not drop inode_lock in dispose_list fs: inode split IO and LRU lists fs: switch bdev inode bdi's correctly fs: fix buffer invalidation in invalidate_list fsnotify: use dget_parent smbfs: use dget_parent exportfs: use dget_parent fs: use RCU read side protection in d_validate fs: clean up dentry lru modification fs: split __shrink_dcache_sb fs: improve DCACHE_REFERENCED usage fs: use percpu counter for nr_dentry and nr_dentry_unused fs: simplify __d_free fs: take dcache_lock inside __d_path fs: do not assign default i_ino in new_inode fs: introduce a per-cpu last_ino allocator new helper: ihold() ...
| * fs: do not assign default i_ino in new_inodeChristoph Hellwig2010-10-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of always assigning an increasing inode number in new_inode move the call to assign it into those callers that actually need it. For now callers that need it is estimated conservatively, that is the call is added to all filesystems that do not assign an i_ino by themselves. For a few more filesystems we can avoid assigning any inode number given that they aren't user visible, and for others it could be done lazily when an inode number is actually needed, but that's left for later patches. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'hwpoison' of ↵Linus Torvalds2010-10-261-0/+15
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (22 commits) Add _addr_lsb field to ia64 siginfo Fix migration.c compilation on s390 HWPOISON: Remove retry loop for try_to_unmap HWPOISON: Turn addr_valid from bitfield into char HWPOISON: Disable DEBUG by default HWPOISON: Convert pr_debugs to pr_info HWPOISON: Improve comments in memory-failure.c x86: HWPOISON: Report correct address granuality for huge hwpoison faults Encode huge page size for VM_FAULT_HWPOISON errors Fix build error with !CONFIG_MIGRATION hugepage: move is_hugepage_on_freelist inside ifdef to avoid warning Clean up __page_set_anon_rmap HWPOISON, hugetlb: fix unpoison for hugepage HWPOISON, hugetlb: soft offlining for hugepage HWPOSION, hugetlb: recover from free hugepage error when !MF_COUNT_INCREASED hugetlb: move refcounting in hugepage allocation inside hugetlb_lock HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page() hugetlb: hugepage migration core hugetlb: redefine hugepage copy functions hugetlb: add allocate function for hugepage migration ...
| * hugetlb: hugepage migration coreNaoya Horiguchi2010-10-081-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch extends page migration code to support hugepage migration. One of the potential users of this feature is soft offlining which is triggered by memory corrected errors (added by the next patch.) Todo: - there are other users of page migration such as memory policy, memory hotplug and memocy compaction. They are not ready for hugepage support for now. ChangeLog since v4: - define migrate_huge_pages() - remove changes on isolation/putback_lru_page() ChangeLog since v2: - refactor isolate/putback_lru_page() to handle hugepage - add comment about race on unmap_and_move_huge_page() ChangeLog since v1: - divide migration code path for hugepage - define routine checking migration swap entry for hugetlb - replace "goto" with "if/else" in remove_migration_pte() Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* | llseek: automatically add .llseek fopArnd Bergmann2010-10-151-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
* new helper: end_writeback()Al Viro2010-08-091-1/+1
| | | | | | | | | | | Essentially, the minimal variant of ->evict_inode(). It's a trimmed-down clear_inode(), sans any fs callbacks. Once it returns we know that no async writeback will be happening; every ->evict_inode() instance should do that once and do that before doing anything ->write_inode() could interfere with (e.g. freeing the on-disk inode). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch hugetlbfs to ->evict_inode()Al Viro2010-08-091-20/+2
| | | | | | The first spoils - hugetlb can use default ->drop_inode() now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* remove inode_setattrChristoph Hellwig2010-08-091-8/+9
| | | | | | | | | | | | | | | | | | | Replace inode_setattr with opencoded variants of it in all callers. This moves the remaining call to vmtruncate into the filesystem methods where it can be replaced with the proper truncate sequence. In a few cases it was obvious that we would never end up calling vmtruncate so it was left out in the opencoded variant: spufs: explicitly checks for ATTR_SIZE earlier btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above In addition to that ncpfs called inode_setattr with handcrafted iattrs, which allowed to trim down the opencoded variant. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* rename the generic fsync implementationsChristoph Hellwig2010-05-271-1/+1
| | | | | | | | | | | | | | | | We don't name our generic fsync implementations very well currently. The no-op implementation for in-memory filesystems currently is called simple_sync_file which doesn't make too much sense to start with, the the generic one for simple filesystems is called simple_fsync which can lead to some confusion. This patch renames the generic file fsync method to generic_file_fsync to match the other generic_file_* routines it is supposed to be used with, and the no-op implementation to noop_fsync to make it obvious what to expect. In addition add some documentation for both methods. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Untangling ima mess, part 1: alloc_file()Al Viro2009-12-161-2/+0
| | | | | | | | | | There are 2 groups of alloc_file() callers: * ones that are followed by ima_counts_get * ones giving non-regular files So let's pull that ima_counts_get() into alloc_file(); it's a no-op in case of non-regular files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch alloc_file() to passing struct pathAl Viro2009-12-161-7/+8
| | | | | | | ... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2009-09-241-29/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: truncate: use new helpers truncate: new helpers fs: fix overflow in sys_mount() for in-kernel calls fs: Make unload_nls() NULL pointer safe freeze_bdev: grab active reference to frozen superblocks freeze_bdev: kill bd_mount_sem exofs: remove BKL from super operations fs/romfs: correct error-handling code vfs: seq_file: add helpers for data filling vfs: remove redundant position check in do_sendfile vfs: change sb->s_maxbytes to a loff_t vfs: explicitly cast s_maxbytes in fiemap_check_ranges libfs: return error code on failed attr set seq_file: return a negative error code when seq_path_root() fails. vfs: optimize touch_time() too vfs: optimization for touch_atime() vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it fs/inode.c: add dev-id and inode number for debugging in init_special_inode() libfs: make simple_read_from_buffer conventional
| * vfs: split generic_forget_inode() so that hugetlbfs does not have to copy itJan Kara2009-09-241-29/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hugetlbfs needs to do special things instead of truncate_inode_pages(). Currently, it copied generic_forget_inode() except for truncate_inode_pages() call which is asking for trouble (the code there isn't trivial). So create a separate function generic_detach_inode() which does all the list magic done in generic_forget_inode() and call it from hugetlbfs_forget_inode(). Signed-off-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fixFrom: Mel Gorman2009-09-241-9/+3
|/ | | | | | | | | | | | | | | | | | | | Commit 6bfde05bf5c ("hugetlbfs: allow the creation of files suitable for MAP_PRIVATE on the vfs internal mount") altered can_do_hugetlb_shm() to check if a file is being created for shared memory or mmap(). If this returns false, we then unconditionally call user_shm_lock() triggering a warning. This block should never be entered for MAP_HUGETLB. This patch partially reverts the problem and fixes the check. Signed-off-by: Eric B Munson <ebmunson@us.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Adam Litke <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Move magic numbers into magic.hNick Black2009-09-231-3/+1
| | | | | | | | | | | | Move various magic-number definitions into magic.h. Signed-off-by: Nick Black <dank@qemfd.net> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlbfs: allow the creation of files suitable for MAP_PRIVATE on the vfs ↵Eric B Munson2009-09-221-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | internal mount This patchset adds a flag to mmap that allows the user to request that an anonymous mapping be backed with huge pages. This mapping will borrow functionality from the huge page shm code to create a file on the kernel internal mount and use it to approximate an anonymous mapping. The MAP_HUGETLB flag is a modifier to MAP_ANONYMOUS and will not work without both flags being preset. A new flag is necessary because there is no other way to hook into huge pages without creating a file on a hugetlbfs mount which wouldn't be MAP_ANONYMOUS. To userspace, this mapping will behave just like an anonymous mapping because the file is not accessible outside of the kernel. This patchset is meant to simplify the programming model. Presently there is a large chunk of boiler platecode, contained in libhugetlbfs, required to create private, hugepage backed mappings. This patch set would allow use of hugepages without linking to libhugetlbfs or having hugetblfs mounted. Unification of the VM code would provide these same benefits, but it has been resisted each time that it has been suggested for several reasons: it would break PAGE_SIZE assumptions across the kernel, it makes page-table abstractions really expensive, and it does not provide any benefit on architectures that do not support huge pages, incurring fast path penalties without providing any benefit on these architectures. This patch: There are two means of creating mappings backed by huge pages: 1. mmap() a file created on hugetlbfs 2. Use shm which creates a file on an internal mount which essentially maps it MAP_SHARED The internal mount is only used for shared mappings but there is very little that stops it being used for private mappings. This patch extends hugetlbfs_file_setup() to deal with the creation of files that will be mapped MAP_PRIVATE on the internal hugetlbfs mount. This extended API is used in a subsequent patch to implement the MAP_HUGETLB mmap() flag. Signed-off-by: Eric Munson <ebmunson@us.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Adam Litke <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: add name to backing_dev_infoJens Axboe2009-09-111-0/+1
| | | | | | | | This enables us to track who does what and print info. Its main use is catching dirty inodes on the default_backing_dev_info, so we can fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* mm: fix hugetlb bug due to user_shm_unlock callHugh Dickins2009-08-241-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 2.6.30's commit 8a0bdec194c21c8fdef840989d0d7b742bb5d4bc removed user_shm_lock() calls in hugetlb_file_setup() but left the user_shm_unlock call in shm_destroy(). In detail: Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock() is not called in hugetlb_file_setup(). However, user_shm_unlock() is called in any case in shm_destroy() and in the following atomic_dec_and_lock(&up->__count) in free_uid() is executed and if up->__count gets zero, also cleanup_user_struct() is scheduled. Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set. However, the ref counter up->__count gets unexpectedly non-positive and the corresponding structs are freed even though there are live references to them, resulting in a kernel oops after a lots of shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set. Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the time of shm_destroy() may give a different answer from at the time of hugetlb_file_setup(). And fixed newseg()'s no_id error path, which has missed user_shm_unlock() ever since it came in 2.6.9. Reported-by: Stefan Huber <shuber2@gmail.com> Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Tested-by: Stefan Huber <shuber2@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' into nextJames Morris2009-05-221-11/+0
|\ | | | | | | | | | | | | | | | | Conflicts: fs/exec.c Removed IMA changes (the IMA checks are now performed via may_open()). Signed-off-by: James Morris <jmorris@namei.org>
| * Remove implementation of readpage from the hugetlbfs_aopsMel Gorman2009-05-131-11/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The core VM assumes the page size used by the address_space in inode->i_mapping is PAGE_SIZE but hugetlbfs breaks this assumption by inserting pages into the page cache at offsets the core VM considers unexpected. This would not be a problem except that hugetlbfs also provide a ->readpage implementation. As it exists, the core VM can assume the base page size is being used, allocate pages on behalf of the filesystem, insert them into the page cache and call ->readpage to populate them. These pages are the wrong size and at the wrong offset for hugetlbfs causing confusion. This patch deletes the ->readpage implementation for hugetlbfs on the grounds the core VM should not be allocating and populating pages on behalf of hugetlbfs. There should be no existing users of the ->readpage implementation so it should not cause a regression. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | integrity: move ima_counts_getMimi Zohar2009-05-221-0/+2
|/ | | | | | | | | | | | | | | | | Based on discussion on lkml (Andrew Morton and Eric Paris), move ima_counts_get down a layer into shmem/hugetlb__file_setup(). Resolves drm shmem_file_setup() usage case as well. HD comment: I still think you're doing this at the wrong level, but recognize that you probably won't be persuaded until a few more users of alloc_file() emerge, all wanting your ima_counts_get(). Resolving GEM's shmem_file_setup() is an improvement, so I'll say Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* hugetlbfs: return negative error code for bad mount optionAkinobu Mita2009-04-211-2/+1
| | | | | | | | | | | | | | | | | | | | | | | This fixes the following BUG: # mount -o size=MM -t hugetlbfs none /huge hugetlbfs: Bad value 'MM' for mount option 'size=MM' ------------[ cut here ]------------ kernel BUG at fs/super.c:996! Due to BUG_ON(!mnt->mnt_sb); in vfs_kern_mount(). Also, remove unused #include <linux/quotaops.h> Cc: William Irwin <wli@holomorphy.com> Cc: <stable@kernel.org> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: reintroduce and deprecate rlimit based access for SHM_HUGETLBRavikiran G Thirumalai2009-04-011-2/+11
| | | | | | | | | | | | | | Allow non root users with sufficient mlock rlimits to be able to allocate hugetlb backed shm for now. Deprecate this though. This is being deprecated because the mlock based rlimit checks for SHM_HUGETLB is not consistent with mmap based huge page allocations. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: fix SHM_HUGETLB to work with users in hugetlb_shm_groupRavikiran G Thirumalai2009-04-011-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | Fix hugetlb subsystem so that non root users belonging to hugetlb_shm_group can actually allocate hugetlb backed shm. Currently non root users cannot even map one large page using SHM_HUGETLB when they belong to the gid in /proc/sys/vm/hugetlb_shm_group. This is because allocation size is verified against RLIMIT_MEMLOCK resource limit even if the user belongs to hugetlb_shm_group. This patch 1. Fixes hugetlb subsystem so that users with CAP_IPC_LOCK and users belonging to hugetlb_shm_group don't need to be restricted with RLIMIT_MEMLOCK resource limits 2. This patch also disables mlock based rlimit checking (which will be reinstated and marked deprecated in a subsequent patch). Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Do not account for the address space used by hugetlbfs using VM_ACCOUNTMel Gorman2009-02-101-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When overcommit is disabled, the core VM accounts for pages used by anonymous shared, private mappings and special mappings. It keeps track of VMAs that should be accounted for with VM_ACCOUNT and VMAs that never had a reserve with VM_NORESERVE. Overcommit for hugetlbfs is much riskier than overcommit for base pages due to contiguity requirements. It avoids overcommiting on both shared and private mappings using reservation counters that are checked and updated during mmap(). This ensures (within limits) that hugepages exist in the future when faults occurs or it is too easy to applications to be SIGKILLed. As hugetlbfs makes its own reservations of a different unit to the base page size, VM_ACCOUNT should never be set. Even if the units were correct, we would double account for the usage in the core VM and hugetlbfs. VM_NORESERVE may be set because an application can request no reserves be made for hugetlbfs at the risk of getting killed later. With commit fc8744adc870a8d4366908221508bb113d8b72ee, VM_NORESERVE and VM_ACCOUNT are getting unconditionally set for hugetlbfs-backed mappings. This breaks the accounting for both the core VM and hugetlbfs, can trigger an OOM storm when hugepage pools are too small lockups and corrupted counters otherwise are used. This patch brings hugetlbfs more in line with how the core VM treats VM_NORESERVE but prevents VM_ACCOUNT being set. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: unsigned ret cannot be negativeRoel Kluin2009-01-061-4/+8
| | | | | | | | | | | | | | unsigned long ret cannot be negative, but ret can get -EFAULT. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Christoph Lameter <clameter@sgi.com> Cc: Adam Litke <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* zero i_uid/i_gid on inode allocationAl Viro2009-01-051-1/+0
| | | | | | | | | ... and don't bother in callers. Don't bother with zeroing i_blocks, while we are at it - it's already been zeroed. i_mode is not worth the effort; it has no common default value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* CRED: Wrap current->cred and a few other accessorsDavid Howells2008-11-141-2/+3
| | | | | | | | | | Wrap current->cred and a few other accessors to hide their actual implementation. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Separate task security context from task_structDavid Howells2008-11-141-2/+2
| | | | | | | | | | | | | | | | Separate the task security context from task_struct. At this point, the security data is temporarily embedded in the task_struct with two pointers pointing to it. Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in entry.S via asm-offsets. With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* CRED: Wrap task credential accesses in the hugetlbfs filesystemDavid Howells2008-11-141-8/+8
| | | | | | | | | | | | | | | | | Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: William Irwin <wli@holomorphy.com> Signed-off-by: James Morris <jmorris@namei.org>
* vfs: Use const for kernel parser tableSteven Whitehouse2008-10-131-1/+1
| | | | | | | | | | | | | | This is a much better version of a previous patch to make the parser tables constant. Rather than changing the typedef, we put the "const" in all the various places where its required, allowing the __initconst exception for nfsroot which was the cause of the previous trouble. This was posted for review some time ago and I believe its been in -mm since then. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Alexander Viro <aviro@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | 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: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlbfs: per mount huge page sizesAndi Kleen2008-07-241-9/+36
| | | | | | | | | | | | | | | | | | | | | | Add the ability to configure the hugetlb hstate used on a per mount basis. - Add a new pagesize= option to the hugetlbfs mount that allows setting the page size - This option causes the mount code to find the hstate corresponding to the specified size, and sets up a pointer to the hstate in the mount's superblock. - Change the hstate accessors to use this information rather than the global_hstate they were using (requires a slight change in mm/memory.c so we don't NULL deref in the error-unmap path -- see comments). [np: take hstate out of hugetlbfs inode and vma->vm_private_data] Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: modular state for hugetlb page sizeAndi Kleen2008-07-241-22/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | The goal of this patchset is to support multiple hugetlb page sizes. This is achieved by introducing a new struct hstate structure, which encapsulates the important hugetlb state and constants (eg. huge page size, number of huge pages currently allocated, etc). The hstate structure is then passed around the code which requires these fields, they will do the right thing regardless of the exact hstate they are operating on. This patch adds the hstate structure, with a single global instance of it (default_hstate), and does the basic work of converting hugetlb to use the hstate. Future patches will add more hstate structures to allow for different hugetlbfs mounts to have different page sizes. [akpm@linux-foundation.org: coding-style fixes] Acked-by: Adam Litke <agl@us.ibm.com> Acked-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: guarantee that COW faults for a process that called ↵Mel Gorman2008-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mmap(MAP_PRIVATE) on hugetlbfs will succeed After patch 2 in this series, a process that successfully calls mmap() for a MAP_PRIVATE mapping will be guaranteed to successfully fault until a process calls fork(). At that point, the next write fault from the parent could fail due to COW if the child still has a reference. We only reserve pages for the parent but a copy must be made to avoid leaking data from the parent to the child after fork(). Reserves could be taken for both parent and child at fork time to guarantee faults but if the mapping is large it is highly likely we will not have sufficient pages for the reservation, and it is common to fork only to exec() immediatly after. A failure here would be very undesirable. Note that the current behaviour of mainline with MAP_PRIVATE pages is pretty bad. The following situation is allowed to occur today. 1. Process calls mmap(MAP_PRIVATE) 2. Process calls mlock() to fault all pages and makes sure it succeeds 3. Process forks() 4. Process writes to MAP_PRIVATE mapping while child still exists 5. If the COW fails at this point, the process gets SIGKILLed even though it had taken care to ensure the pages existed This patch improves the situation by guaranteeing the reliability of the process that successfully calls mmap(). When the parent performs COW, it will try to satisfy the allocation without using reserves. If that fails the parent will steal the page leaving any children without a page. Faults from the child after that point will result in failure. If the child COW happens first, an attempt will be made to allocate the page without reserves and the child will get SIGKILLed on failure. To summarise the new behaviour: 1. If the original mapper performs COW on a private mapping with multiple references, it will attempt to allocate a hugepage from the pool or the buddy allocator without using the existing reserves. On fail, VMAs mapping the same area are traversed and the page being COW'd is unmapped where found. It will then steal the original page as the last mapper in the normal way. 2. The VMAs the pages were unmapped from are flagged to note that pages with data no longer exist. Future no-page faults on those VMAs will terminate the process as otherwise it would appear that data was corrupted. A warning is printed to the console that this situation occured. 2. If the child performs COW first, it will attempt to satisfy the COW from the pool if there are enough pages or via the buddy allocator if overcommit is allowed and the buddy allocator can satisfy the request. If it fails, the child will be killed. If the pool is large enough, existing applications will not notice that the reserves were a factor. Existing applications depending on the no-reserves been set are unlikely to exist as for much of the history of hugetlbfs, pages were prefaulted at mmap(), allocating the pages at that point or failing the mmap(). [npiggin@suse.de: fix CONFIG_HUGETLB=n build] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hugetlb: reserve huge pages for reliable MAP_PRIVATE hugetlbfs mappings ↵Mel Gorman2008-07-241-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | until fork() This patch reserves huge pages at mmap() time for MAP_PRIVATE mappings in a similar manner to the reservations taken for MAP_SHARED mappings. The reserve count is accounted both globally and on a per-VMA basis for private mappings. This guarantees that a process that successfully calls mmap() will successfully fault all pages in the future unless fork() is called. The characteristics of private mappings of hugetlbfs files behaviour after this patch are; 1. The process calling mmap() is guaranteed to succeed all future faults until it forks(). 2. On fork(), the parent may die due to SIGKILL on writes to the private mapping if enough pages are not available for the COW. For reasonably reliable behaviour in the face of a small huge page pool, children of hugepage-aware processes should not reference the mappings; such as might occur when fork()ing to exec(). 3. On fork(), the child VMAs inherit no reserves. Reads on pages already faulted by the parent will succeed. Successful writes will depend on enough huge pages being free in the pool. 4. Quotas of the hugetlbfs mount are checked at reserve time for the mapper and at fault time otherwise. Before this patch, all reads or writes in the child potentially needs page allocations that can later lead to the death of the parent. This applies to reads and writes of uninstantiated pages as well as COW. After the patch it is only a write to an instantiated page that causes problems. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: bdi: add separate writeback accounting capabilityMiklos Szeredi2008-04-301-1/+1
| | | | | | | | | | | | | | | | | 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: Miklos Szeredi <mszeredi@suse.cz> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mempolicy: use struct mempolicy pointer in shmem_sb_infoLee Schermerhorn2008-04-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Lee 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mempolicy: support optional mode flagsDavid Rientjes2008-04-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: David Rientjes <rientjes@google.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] double iput() on failure exit in hugetlbAl Viro2008-03-191-1/+1
| | | | | | once we'd done d_instantiate(), we should only do dput(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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