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2009-09-25cifs: fix locking and list handling code in cifs_open and its helperJeff Layton
The patch to remove cifs_init_private introduced a locking imbalance. It didn't remove the leftover list addition code and the unlocking in that function. cifs_new_fileinfo does the list addition now, so there should be no need to do it outside of that function. pCifsInode will never be NULL, so we don't need to check for that. This patch also gets rid of the ugly locking and unlocking across function calls. Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: Steve French <sfrench@us.ibm.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-25Merge branch 'writeback' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'writeback' of git://git.kernel.dk/linux-2.6-block: writeback: writeback_inodes_sb() should use bdi_start_writeback() writeback: don't delay inodes redirtied by a fast dirtier writeback: make the super_block pinning more efficient writeback: don't resort for a single super_block in move_expired_inodes() writeback: move inodes from one super_block together writeback: get rid to incorrect references to pdflush in comments writeback: improve readability of the wb_writeback() continue/break logic writeback: cleanup writeback_single_inode() writeback: kupdate writeback shall not stop when more io is possible writeback: stop background writeback when below background threshold writeback: balance_dirty_pages() shall write more than dirtied pages fs: Fix busyloop in wb_writeback()
2009-09-25writeback: writeback_inodes_sb() should use bdi_start_writeback()Jens Axboe
Pointless to iterate other devices looking for a super, when we have a bdi mapping. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: don't delay inodes redirtied by a fast dirtierWu Fengguang
Debug traces show that in per-bdi writeback, the inode under writeback almost always get redirtied by a busy dirtier. We used to call redirty_tail() in this case, which could delay inode for up to 30s. This is unacceptable because it now happens so frequently for plain cp/dd, that the accumulated delays could make writeback of big files very slow. So let's distinguish between data redirty and metadata only redirty. The first one is caused by a busy dirtier, while the latter one could happen in XFS, NFS, etc. when they are doing delalloc or updating isize. The inode being busy dirtied will now be requeued for next io, while the inode being redirtied by fs will continue to be delayed to avoid repeated IO. CC: Jan Kara <jack@suse.cz> CC: Theodore Ts'o <tytso@mit.edu> CC: Dave Chinner <david@fromorbit.com> CC: Chris Mason <chris.mason@oracle.com> CC: Christoph Hellwig <hch@infradead.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: make the super_block pinning more efficientJens Axboe
Currently we pin the inode->i_sb for every single inode. This increases cache traffic on sb->s_umount sem. Lets instead cache the inode sb pin state and keep the super_block pinned for as long as keep writing out inodes from the same super_block. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: don't resort for a single super_block in move_expired_inodes()Jens Axboe
If we only moved inodes from a single super_block to the temporary list, there's no point in doing a resort for multiple super_blocks. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: move inodes from one super_block togetherShaohua Li
__mark_inode_dirty adds inode to wb dirty list in random order. If a disk has several partitions, writeback might keep spindle moving between partitions. To reduce the move, better write big chunk of one partition and then move to another. Inodes from one fs usually are in one partion, so idealy move indoes from one fs together should reduce spindle move. This patch tries to address this. Before per-bdi writeback is added, the behavior is write indoes from one fs first and then another, so the patch restores previous behavior. The loop in the patch is a bit ugly, should we add a dirty list for each superblock in bdi_writeback? Test in a two partition disk with attached fio script shows about 3% ~ 6% improvement. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: get rid to incorrect references to pdflush in commentsJens Axboe
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: improve readability of the wb_writeback() continue/break logicJens Axboe
And throw some comments in there, too. Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: cleanup writeback_single_inode()Wu Fengguang
Make the if-else straight in writeback_single_inode(). No behavior change. Cc: Jan Kara <jack@suse.cz> Cc: Michael Rubin <mrubin@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: kupdate writeback shall not stop when more io is possibleWu Fengguang
Fix the kupdate case, which disregards wbc.more_io and stop writeback prematurely even when there are more inodes to be synced. wbc.more_io should always be respected. Also remove the pages_skipped check. It will set when some page(s) of some inode(s) cannot be written for now. Such inodes will be delayed for a while. This variable has nothing to do with whether there are other writeable inodes. CC: Jan Kara <jack@suse.cz> CC: Dave Chinner <david@fromorbit.com> CC: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25writeback: stop background writeback when below background thresholdWu Fengguang
Treat bdi_start_writeback(0) as a special request to do background write, and stop such work when we are below the background dirty threshold. Also simplify the (nr_pages <= 0) checks. Since we already pass in nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't need to worry about it being decreased to zero. Reported-by: Richard Kennedy <richard@rsk.demon.co.uk> CC: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25fs: Fix busyloop in wb_writeback()Jan Kara
If all inodes are under writeback (e.g. in case when there's only one inode with dirty pages), wb_writeback() with WB_SYNC_NONE work basically degrades to busylooping until I_SYNC flags of the inode is cleared. Fix the problem by waiting on I_SYNC flags of an inode on b_more_io list in case we failed to write anything. Tested-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-09-25[CIFS] Remove build warningSteve French
Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-25cifs: fix problems with last two commitsJeff Layton
Fix problems with commits: 086f68bd97126618ecb2dcff5f766f3a21722df7 3bc303c254335dbd7c7012cc1760b12f1d5514d3 Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-25[CIFS] Fix build break when keys support turned offSteve French
Acked-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-24procfs: disable per-task stack usage on NOMMUAndrew Morton
It needs walk_page_range(). Reported-by: Michal Simek <monstr@monstr.eu> Tested-by: Michal Simek <monstr@monstr.eu> Cc: Stefani Seibold <stefani@seibold.net> Cc: David Howells <dhowells@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6: eCryptfs: Prevent lower dentry from going negative during unlink eCryptfs: Propagate vfs_read and vfs_write return codes eCryptfs: Validate global auth tok keys eCryptfs: Filename encryption only supports password auth tokens eCryptfs: Check for O_RDONLY lower inodes when opening lower files eCryptfs: Handle unrecognized tag 3 cipher codes ecryptfs: improved dependency checking and reporting eCryptfs: Fix lockdep-reported AB-BA mutex issue ecryptfs: Remove unneeded locking that triggers lockdep false positives
2009-09-24cifs: eliminate cifs_init_privateJeff Layton
...it does the same thing as cifs_fill_fileinfo, but doesn't handle the flist ordering correctly. Also rename cifs_fill_fileinfo to a more descriptive name and have it take an open flags arg instead of just a write_only flag. That makes the logic in the callers a little simpler. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-24nfs[23] tcp breakage in mount with binary optionsAl Viro
We forget to set nfs_server.protocol in tcp case when old-style binary options are passed to mount. The thing remains zero and never validated afterwards. As the result, we hit BUG in fs/nfs/client.c:588. Breakage has been introduced in NFS: Add nfs_alloc_parsed_mount_data merged yesterday... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2009-09-24cifs: convert oplock breaks to use slow_work facility (try #4)Jeff Layton
This is the fourth respin of the patch to convert oplock breaks to use the slow_work facility. A customer of ours was testing a backport of one of the earlier patchsets, and hit a "Busy inodes after umount..." problem. An oplock break job had raced with a umount, and the superblock got torn down and its memory reused. When the oplock break job tried to dereference the inode->i_sb, the kernel oopsed. This patchset has the oplock break job hold an inode and vfsmount reference until the oplock break completes. With this, there should be no need to take a tcon reference (the vfsmount implicitly holds one already). Currently, when an oplock break comes in there's a chance that the oplock break job won't occur if the allocation of the oplock_q_entry fails. There are also some rather nasty races in the allocation and handling these structs. Rather than allocating oplock queue entries when an oplock break comes in, add a few extra fields to the cifsFileInfo struct. Get rid of the dedicated cifs_oplock_thread as well and queue the oplock break job to the slow_work thread pool. This approach also has the advantage that the oplock break jobs can potentially run in parallel rather than be serialized like they are today. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-09-24Merge branch 'cputime' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds
* 'cputime' of git://git390.marist.edu/pub/scm/linux-2.6: [PATCH] Fix idle time field in /proc/uptime
2009-09-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (42 commits) Btrfs: hash the btree inode during fill_super Btrfs: relocate file extents in clusters Btrfs: don't rename file into dummy directory Btrfs: check size of inode backref before adding hardlink Btrfs: fix releasepage to avoid unlocking extents we haven't locked Btrfs: Fix test_range_bit for whole file extents Btrfs: fix errors handling cached state in set/clear_extent_bit Btrfs: fix early enospc during balancing Btrfs: deal with NULL space info Btrfs: account for space used by the super mirrors Btrfs: fix extent entry threshold calculation Btrfs: remove dead code Btrfs: fix bitmap size tracking Btrfs: don't keep retrying a block group if we fail to allocate a cluster Btrfs: make balance code choose more wisely when relocating Btrfs: fix arithmetic error in clone ioctl Btrfs: add snapshot/subvolume destroy ioctl Btrfs: change how subvolumes are organized Btrfs: do not reuse objectid of deleted snapshot/subvol Btrfs: speed up snapshot dropping ...
2009-09-24Merge branch 'for-linus' of ↵Linus Torvalds
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
2009-09-24Merge branch 'hwpoison' of ↵Linus Torvalds
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: (21 commits) HWPOISON: Enable error_remove_page on btrfs HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs HWPOISON: Add madvise() based injector for hardware poisoned pages v4 HWPOISON: Enable error_remove_page for NFS HWPOISON: Enable .remove_error_page for migration aware file systems HWPOISON: The high level memory error handler in the VM v7 HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process HWPOISON: shmem: call set_page_dirty() with locked page HWPOISON: Define a new error_remove_page address space op for async truncation HWPOISON: Add invalidate_inode_page HWPOISON: Refactor truncate to allow direct truncating of page v2 HWPOISON: check and isolate corrupted free pages v2 HWPOISON: Handle hardware poisoned pages in try_to_unmap HWPOISON: Use bitmask/action code for try_to_unmap behaviour HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2 HWPOISON: Add poison check to page fault handling HWPOISON: Add basic support for poisoned pages in fault handler v3 HWPOISON: Add new SIGBUS error codes for hardware poison signals HWPOISON: Add support for poison swap entries v2 HWPOISON: Export some rmap vma locking to outside world ...
2009-09-24task_struct cleanup: move binfmt field to mm_structHiroshi Shimamoto
Because the binfmt is not different between threads in the same process, it can be moved from task_struct to mm_struct. And binfmt moudle is handled per mm_struct instead of task_struct. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24fs/romfs: correct error-handling codeJulia Lawall
romfs_iget returns an ERR_PTR value in an error case instead of NULL. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @match exists@ expression x, E; statement S1, S2; @@ x = romfs_iget(...) ... when != x = E ( * if (x == NULL || ...) S1 else S2 | * if (x == NULL && ...) S1 else S2 ) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24adfs: remove redundant test on unsignedRoel Kluin
unsigned block cannot be less than 0. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan
It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24fs/char_dev.c: remove useless loopRenzo Davoli
There are two useless lines in fs/char_dev.c. In register_chrdev there is a loop to change all '/' into '!' in the kernel object name. This code is useless as the same substitution is in kobject_set_name_vargs in lib/kobject.c: 228 /* ewww... some of these buggers have '/' in the name ... */ 229 while ((s = strchr(kobj->name, '/'))) 230 s[0] = '!'; kobject_set_name_vargs is called by kobject_set_name. kobject_set_name is called just above the useless loop. [hidave.darkstar@gmail.com: fix warning, remove the unused char *s] Signed-off-by: Renzo Davoli <renzo@cs.unibo.it> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24flat: use IS_ERR_VALUE() helper macroMike Frysinger
There is a common macro now for testing mixed pointer/errno values, so use that rather than handling the casts ourself. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David McCullough <david_mccullough@securecomputing.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Cc: David Howells <dhowells@redhat.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24fdpic: ignore the loader's PT_GNU_STACK when calculating the stack sizeDavid Howells
Ignore the loader's PT_GNU_STACK when calculating the stack size, and only consider the executable's PT_GNU_STACK, assuming the executable has one. Currently the behaviour is to take the largest stack size and use that, but that means you can't reduce the stack size in the executable. The loader's stack size should probably only be used when executing the loader directly. WARNING: This patch is slightly dangerous - it may render a system inoperable if the loader's stack size is larger than that of important executables, and the system relies unknowingly on this increasing the size of the stack. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24elf: clean up fill_note_info()Amerigo Wang
Introduce a helper function elf_note_info_init() to help fill_note_info() to do initializations, also fix the potential memory leaks. [akpm@linux-foundation.org: remove NUM_NOTES] Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24fcntl: add F_[SG]ETOWN_EXPeter Zijlstra
In order to direct the SIGIO signal to a particular thread of a multi-threaded application we cannot, like suggested by the manpage, put a TID into the regular fcntl(F_SETOWN) call. It will still be send to the whole process of which that thread is part. Since people do want to properly direct SIGIO we introduce F_SETOWN_EX. The need to direct SIGIO comes from self-monitoring profiling such as with perf-counters. Perf-counters uses SIGIO to notify that new sample data is available. If the signal is delivered to the same task that generated the new sample it can augment that data by inspecting the task's user-space state right after it returns from the kernel. This is esp. convenient for interpreted or virtual machine driven environments. Both F_SETOWN_EX and F_GETOWN_EX take a pointer to a struct f_owner_ex as argument: struct f_owner_ex { int type; pid_t pid; }; Where type is one of F_OWNER_TID, F_OWNER_PID or F_OWNER_GID. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Tested-by: stephane eranian <eranian@googlemail.com> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Roland McGrath <roland@redhat.com> 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: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24signals: send_sigio: use do_send_sig_info() to avoid check_kill_permission()Oleg Nesterov
group_send_sig_info()->check_kill_permission() assumes that current is the sender and uses current_cred(). This is not true in send_sigio_to_task() case. From the security pov the sender is not current, but the task which did fcntl(F_SETOWN), that is why we have sigio_perm() which uses the right creds to check. Fortunately, send_sigio() always sends either SEND_SIG_PRIV or SI_FROMKERNEL() signal, so check_kill_permission() does nothing. But still it would be tidier to avoid this bogus security check and save a couple of cycles. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stephane eranian <eranian@googlemail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24exec: fix set_binfmt() vs sys_delete_module() raceOleg Nesterov
sys_delete_module() can set MODULE_STATE_GOING after search_binary_handler() does try_module_get(). In this case set_binfmt()->try_module_get() fails but since none of the callers check the returned error, the task will run with the wrong old ->binfmt. The proper fix should change all ->load_binary() methods, but we can rely on fact that the caller must hold a reference to binfmt->module and use __module_get() which never fails. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24exec: allow do_coredump() to wait for user space pipe readers to completeNeil Horman
Allow core_pattern pipes to wait for user space to complete One of the things that user space processes like to do is look at metadata for a crashing process in their /proc/<pid> directory. this is racy however, since do_coredump in the kernel doesn't wait for the user space process to complete before it reaps the crashing process. This patch corrects that. Allowing the kernel to wait for the user space process to complete before cleaning up the crashing process. This is a bit tricky to do for a few reasons: 1) The user space process isn't our child, so we can't sys_wait4 on it 2) We need to close the pipe before waiting for the user process to complete, since the user process may rely on an EOF condition I've discussed several solutions with Oleg Nesterov off-list about this, and this is the one we've come up with. We add ourselves as a pipe reader (to prevent premature cleanup of the pipe_inode_info), and remove ourselves as a writer (to provide an EOF condition to the writer in user space), then we iterate until the user space process exits (which we detect by pipe->readers == 1, hence the > 1 check in the loop). When we exit the loop, we restore the proper reader/writer values, then we return and let filp_close in do_coredump clean up the pipe data properly. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Earl Chew <earl_chew@agilent.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24exec: let do_coredump() limit the number of concurrent dumps to pipesNeil Horman
Introduce core pipe limiting sysctl. Since we can dump cores to pipe, rather than directly to the filesystem, we create a condition in which a user can create a very high load on the system simply by running bad applications. If the pipe reader specified in core_pattern is poorly written, we can have lots of ourstandig resources and processes in the system. This sysctl introduces an ability to limit that resource consumption. core_pipe_limit defines how many in-flight dumps may be run in parallel, dumps beyond this value are skipped and a note is made in the kernel log. A special value of 0 in core_pipe_limit denotes unlimited core dumps may be handled (this is the default value). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Earl Chew <earl_chew@agilent.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24exec: make do_coredump() more resilient to recursive crashesNeil Horman
Change how we detect recursive dumps. Currently we have a mechanism by which we try to compare pathnames of the crashing process to the core_pattern path. This is broken for a dozen reasons, and just doesn't work in any sort of robust way. I'm replacing it with the use of a 0 RLIMIT_CORE value. Since helper apps set RLIMIT_CORE to zero, we don't write out core files for any process with that particular limit set. It the core_pattern is a pipe, any non-zero limit is translated to RLIM_INFINITY. This allows complete dumps to be captured, but prevents infinite recursion in the event that the core_pattern process itself crashes. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Earl Chew <earl_chew@agilent.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Andi Kleen <andi@firstfloor.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24hugetlbfs: do not call user_shm_lock() for MAP_HUGETLB fixFrom: Mel Gorman
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>
2009-09-24Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus Conflicts: fs/btrfs/super.c
2009-09-24Btrfs: hash the btree inode during fill_superYan Zheng
The snapshot deletion patches dropped this line, but the inode needs to be hashed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24Btrfs: relocate file extents in clustersYan, Zheng
The extent relocation code copy file extents one by one when relocating data block group. This is inefficient if file extents are small. This patch makes the relocation code copy file extents in clusters. So we can can make better use of read-ahead. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24Btrfs: don't rename file into dummy directoryYan, Zheng
A recent change enforces only one access point to each subvolume. The first directory entry (the one added when the subvolume/snapshot was created) is treated as valid access point, all other subvolume links are linked to dummy empty directories. The dummy directories are temporary inodes that only in memory, so we can not rename file into them. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24Btrfs: check size of inode backref before adding hardlinkYan, Zheng
For every hardlink in btrfs, there is a corresponding inode back reference. All inode back references for hardlinks in a given directory are stored in single b-tree item. The size of b-tree item is limited by the size of b-tree leaf, so we can only create limited number of hardlinks to a given file in a directory. The original code lacks of the check, it oops if the number of hardlinks goes over the limit. This patch fixes the issue by adding check to btrfs_link and btrfs_rename. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24truncate: use new helpersnpiggin@suse.de
Update some fs code to make use of new helper functions introduced in the previous patch. Should be no significant change in behaviour (except CIFS now calls send_sig under i_lock, via inode_newsize_ok). Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Miklos Szeredi <miklos@szeredi.hu> Cc: linux-nfs@vger.kernel.org Cc: Trond.Myklebust@netapp.com Cc: linux-cifs-client@lists.samba.org Cc: sfrench@samba.org Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24truncate: new helpersnpiggin@suse.de
Introduce new truncate helpers truncate_pagecache and inode_newsize_ok. vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and into mm/truncate.c. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24fs: fix overflow in sys_mount() for in-kernel callsVegard Nossum
sys_mount() reads/copies a whole page for its "type" parameter. When do_mount_root() passes a kernel address that points to an object which is smaller than a whole page, copy_mount_options() will happily go past this memory object, possibly dereferencing "wild" pointers that could be in any state (hence the kmemcheck warning, which shows that parts of the next page are not even allocated). (The likelihood of something going wrong here is pretty low -- first of all this only applies to kernel calls to sys_mount(), which are mostly found in the boot code. Secondly, I guess if the page was not mapped, exact_copy_from_user() _would_ in fact handle it correctly because of its access_ok(), etc. checks.) But it is much nicer to avoid the dubious reads altogether, by stopping as soon as we find a NUL byte. Is there a good reason why we can't do something like this, using the already existing strndup_from_user()? [akpm@linux-foundation.org: make copy_mount_string() static] [AV: fix compat mount breakage, which involves undoing akpm's change above] Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: al <al@dizzy.pdmi.ras.ru>
2009-09-24fs: Make unload_nls() NULL pointer safeThomas Gleixner
Most call sites of unload_nls() do: if (nls) unload_nls(nls); Check the pointer inside unload_nls() like we do in kfree() and simplify the call sites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Steve French <sfrench@us.ibm.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Petr Vandrovec <vandrove@vc.cvut.cz> Cc: Anton Altaparmakov <aia21@cantab.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24freeze_bdev: grab active reference to frozen superblocksChristoph Hellwig
Currently we held s_umount while a filesystem is frozen, despite that we might return to userspace and unlock it from a different process. Instead grab an active reference to keep the file system busy and add an explicit check for frozen filesystems in remount and reject the remount instead of blocking on s_umount. Add a new get_active_super helper to super.c for use by freeze_bdev that grabs an active reference to a superblock from a given block device. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>