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* generic block based fiemap implementationJosef Bacik2008-10-03
| | | | | | | | | | | | | | | | | | Any block based fs (this patch includes ext3) just has to declare its own fiemap() function and then call this generic function with its own get_block_t. This works well for block based filesystems that will map multiple contiguous blocks at one time, but will work for filesystems that only map one block at a time, you will just end up with an "extent" for each block. One gotcha is this will not play nicely where there is hole+data after the EOF. This function will assume its hit the end of the data as soon as it hits a hole after the EOF, so if there is any data past that it will not pick that up. AFAIK no block based fs does this anyway, but its in the comments of the function anyway just in case. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: linux-fsdevel@vger.kernel.org
* ocfs2: fiemap supportMark Fasheh2008-10-03
| | | | | | | | | | | | | | Plug ocfs2 into ->fiemap. Some portions of ocfs2_get_clusters() had to be refactored so that the extent cache can be skipped in favor of going directly to the on-disk records. This makes it easier for us to determine which extent is the last one in the btree. Also, I'm not sure we want to be caching fiemap lookups anyway as they're not directly related to data read/write. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: ocfs2-devel@oss.oracle.com Cc: linux-fsdevel@vger.kernel.org
* vfs: vfs-level fiemap interfaceMark Fasheh2008-10-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basic vfs-level fiemap infrastructure, which sets up a new ->fiemap inode operation. Userspace can get extent information on a file via fiemap ioctl. As input, the fiemap ioctl takes a struct fiemap which includes an array of struct fiemap_extent (fm_extents). Size of the extent array is passed as fm_extent_count and number of extents returned will be written into fm_mapped_extents. Offset and length fields on the fiemap structure (fm_start, fm_length) describe a logical range which will be searched for extents. All extents returned will at least partially contain this range. The actual extent offsets and ranges returned will be unmodified from their offset and range on-disk. The fiemap ioctl returns '0' on success. On error, -1 is returned and errno is set. If errno is equal to EBADR, then fm_flags will contain those flags which were passed in which the kernel did not understand. On all other errors, the contents of fm_extents is undefined. As fiemap evolved, there have been many authors of the vfs patch. As far as I can tell, the list includes: Kalpak Shah <kalpak.shah@sun.com> Andreas Dilger <adilger@sun.com> Eric Sandeen <sandeen@redhat.com> Mark Fasheh <mfasheh@suse.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: linux-api@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org
* ext4: fix xattr deadlockKalpak Shah2008-10-08
| | | | | | | | | | | | | ext4_xattr_set_handle() eventually ends up calling ext4_mark_inode_dirty() which tries to expand the inode by shifting the EAs. This leads to the xattr_sem being downed again and leading to a deadlock. This patch makes sure that if ext4_xattr_set_handle() is in the call-chain, ext4_mark_inode_dirty() will not expand the inode. Signed-off-by: Kalpak Shah <kalpak.shah@sun.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* jbd2: Fix buffer head leak when writing the commit blockTheodore Ts'o2008-10-06
| | | | | | | | | Also make sure the buffer heads are marked clean before submitting bh for writing. The previous code was marking the buffer head dirty, which would have forced an unneeded write (and seek) to the journal for no good reason. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add debugging markers that can be used by systemtapTheodore Ts'o2008-10-05
| | | | | | | This debugging markers are designed to debug problems such as the random filesystem latency problems reported by Arjan. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* jbd2: abort instead of waiting for nonexistent transactionDuane Griffin2008-10-08
| | | | | | | | | | | | | | | | | | | | The __jbd2_log_wait_for_space function sits in a loop checkpointing transactions until there is sufficient space free in the journal. However, if there are no transactions to be processed (e.g. because the free space calculation is wrong due to a corrupted filesystem) it will never progress. Check for space being required when no transactions are outstanding and abort the journal instead of endlessly looping. This patch fixes the bug reported by Sami Liedes at: http://bugzilla.kernel.org/show_bug.cgi?id=10976 Signed-off-by: Duane Griffin <duaneg@dghda.com> Cc: Sami Liedes <sliedes@cc.hut.fi> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: fix initialization of UNINIT bitmap blocksFrederic Bohe2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | This fixes a bug which caused on-line resizing of filesystems with a 1k blocksize to fail. The root cause of this bug was the fact that if an uninitalized bitmap block gets read in by userspace (which e2fsprogs does try to avoid, but can happen when the blocksize is less than the pagesize and an adjacent blocks is read into memory) ext4_read_block_bitmap() was erroneously depending on the buffer uptodate flag to decide whether it needed to initialize the bitmap block in memory --- i.e., to set the standard set of blocks in use by a block group (superblock, bitmaps, inode table, etc.). Essentially, ext4_read_block_bitmap() assumed it was the only routine that might try to read a block containing a block bitmap, which is simply not true. To fix this, ext4_read_block_bitmap() and ext4_read_inode_bitmap() must always initialize uninitialized bitmap blocks. Once a block or inode is allocated out of that bitmap, it will be marked as initialized in the block group descriptor, so in general this won't result any extra unnecessary work. Signed-off-by: Frederic Bohe <frederic.bohe@bull.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Remove old legacy block allocatorTheodore Ts'o2008-10-10
| | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Use readahead when reading an inode from the inode tableTheodore Ts'o2008-10-09
| | | | | | | | | | | | With modern hard drives, reading 64k takes roughly the same time as reading a 4k block. So request readahead for adjacent inode table blocks to reduce the time it takes when iterating over directories (especially when doing this in htree sort order) in a cold cache case. With this patch, the time it takes to run "git status" on a kernel tree after flushing the caches via "echo 3 > /proc/sys/vm/drop_caches" is reduced by 21%. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Combine proc file handling into a single set of functionsTheodore Ts'o2008-09-23
| | | | | | | | | Previously mballoc created a separate set of functions for each proc file. This combines the tunables into a single set of functions which gets used for all of the per-superblock proc files, saving approximately 2k of compiled object code. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: move /proc setup and teardown out of mballoc.cTheodore Ts'o2008-09-23
| | | | | | | ...and into the core setup/teardown code in fs/ext4/super.c so that other parts of ext4 can define tuning parameters. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Don't use 'struct dentry' for internal lookupsTheodore Ts'o2008-09-22
| | | | | | | | | | | | This is a port of a patch from Linus which fixes a 200+ byte stack usage problem in ext4_get_parent(). It's more efficient to pass down only the actual parts of the dentry that matter: the parent inode and the name, instead of allocating a struct dentry on the stack. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4/jbd2: Avoid WARN() messages when failing to write to the superblockTheodore Ts'o2008-10-06
| | | | | | This fixes some very common warnings reported by kerneloops.org Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: use percpu data structures for lg_prealloc_listEric Sandeen2008-09-13
| | | | | | | | | | lg_prealloc_list seems to cry out for a per-cpu data structure; on a large smp system I think this should be better. I've lightly tested this change on a 4-cpu system. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Renumber EXT4_IOC_MIGRATETheodore Ts'o2008-09-13
| | | | | | | | | | | | Pick an ioctl number for EXT4_IOC_MIGRATE that won't conflict with other ext4 ioctl's. Since there haven't been any major userspace users of this ioctl, we can afford to change this now, to avoid potential problems later. Also, reorder the ioctl numbers in ext4.h to avoid this sort of mistake in the future. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: hook the ext3 migration interface to the EXT4_IOC_SETFLAGS ioctlAneesh Kumar K.V2008-10-08
| | | | | | | | | | This patch hooks the ext3 to ext4 migrate interface to EXT4_IOC_SETFLAGS ioctl. The userspace interface is via chattr +e. We only allow setting extent flags. Clearing extent flag (migrating from ext4 to ext3) is not supported. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: elevate write count for migrate ioctlAneesh Kumar K.V2008-09-13
| | | | | | | | The migrate ioctl writes to the filsystem, so we need to elevate the write count. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add missing unlock in ext4_check_descriptors() on error pathLi Zefan2008-09-08
| | | | | | | | | If there group descriptors are corrupted we need unlock the block group lock before returning from the function; else we will oops when freeing a spinlock which is still being held. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* jbd2: clean up how the journal device name is printedTheodore Ts'o2008-09-16
| | | | | | | | | | | | | Calculate the journal device name once and stash it away in the journal_s structure. This avoids needing to call bdevname() everywhere and reduces stack usage by not needing to allocate an on-stack buffer. In addition, we eliminate the '/' that can appear in device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that can cause problems when creating proc directory names, and include the inode number to support ocfs2 which creates multiple journals with different inode numbers. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: fix #11321: create /proc/ext4/*/stats more carefullyAlexey Dobriyan2008-09-14
| | | | | | | | | | | | | | | | | | ext4 creates per-suberblock directory in /proc/ext4/ . Name used as basis is taken from bdevname, which, surprise, can contain slash. However, proc while allowing to use proc_create("a/b", parent) form of PDE creation, assumes that parent/a was already created. bdevname in question is 'cciss/c0d0p9', directory is not created and all this stuff goes directly into /proc (which is real bug). Warning comes when _second_ partition is mounted. http://bugzilla.kernel.org/show_bug.cgi?id=11321 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* Update flex_bg free blocks and free inodes counters when resizing.Frederic Bohe2008-09-08
| | | | | | | | This fixes a bug which prevented the newly created inodes after a resize from being used on filesystems with flex_bg. Signed-off-by: Frederic Bohe <frederic.bohe@bull.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Avoid printk floods in the face of directory corruptionEric Sandeen2008-10-09
| | | | | | | | | | | | | | | | | | Note: some people thinks this represents a security bug, since it might make the system go away while it is printing a large number of console messages, especially if a serial console is involved. Hence, it has been assigned CVE-2008-3528, but it requires that the attacker either has physical access to your machine to insert a USB disk with a corrupted filesystem image (at which point why not just hit the power button), or is otherwise able to convince the system administrator to mount an arbitrary filesystem image (at which point why not just include a setuid shell or world-writable hard disk device file or some such). Me, I think they're just being silly. --tytso Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: linux-ext4@vger.kernel.org Cc: Eugene Teo <eugeneteo@kernel.sg>
* ext4: Properly update i_disksize.Aneesh Kumar K.V2008-09-13
| | | | | | | | | | | | | | | | With delayed allocation we use i_data_sem to update i_disksize. We need to update i_disksize only if the new size specified is greater than the current value and we need to make sure we don't race with other i_disksize update. With delayed allocation we will switch to the write_begin function for non-delayed allocation if we are low on free blocks. This means the write_begin function for non-delayed allocation also needs to use the same locking. We also need to check and update i_disksize even if the new size is less that inode.i_size because of delayed allocation. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: truncate block allocated on a failed ext4_write_beginAneesh Kumar K.V2008-09-13
| | | | | | | | | | For blocksize < pagesize we need to remove blocks that got allocated in block_write_begin() if we fail with ENOSPC for later blocks. block_write_begin() internally does this if it allocated pages locally. This makes sure we don't have blocks outside inode.i_size during ENOSPC. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Retry block allocation if we have free blocks leftAneesh Kumar K.V2008-09-08
| | | | | | | | | | | | When we truncate files, the meta-data blocks released are not reused untill we commit the truncate transaction. That means delayed get_block request will return ENOSPC even if we have free blocks left. Force a journal commit and retry block allocation if we get ENOSPC with free blocks left. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Don't add the inode to journal handle until after the block is allocatedAneesh Kumar K.V2008-09-08
| | | | | | | | | | Make sure we don't add the inode to the journal handle until after the block allocation, so that a journal commit will not include the inode in case of block allocation failure. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Fix ext4 nomballoc allocator for ENOSPCAneesh Kumar K.V2008-09-08
| | | | | | | | | | | | | | | | | | | | We run into ENOSPC error on nonmballoc ext4, even when there is free blocks on the filesystem. The patch includes two changes: a) Set reservation to NULL if we trying to allocate near group_target_block from the goal group if the free block in the group is less than windows. This should give us a better chance to allocate near group_target_block. This also ensures that if we are not allocating near group_target_block then we don't trun off reservation. This should enable us to allocate with reservation from other groups that have large free blocks count. b) we don't need to check the window size if the block reservation is off. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Signed arithmetic fixAneesh Kumar K.V2008-10-08
| | | | | | | | | | This patch converts some usage of ext4_fsblk_t to s64. This is needed so that some of the sign conversion works as expected in if loops. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Switch to non delalloc mode when we are low on free blocks count.Aneesh Kumar K.V2008-10-08
| | | | | | | | | | | | | | The delayed allocation code allocates blocks during writepages(), which can not handle block allocation failures. To deal with this, we switch away from delayed allocation mode when we are running low on free blocks. This also allows us to avoid needing to reserve a large number of meta-data blocks in case all of the requested blocks are discontiguous. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add percpu dirty block accounting.Aneesh Kumar K.V2008-10-10
| | | | | | | | | | | | This patch adds dirty block accounting using percpu_counters. Delayed allocation block reservation is now done by updating dirty block counter. In a later patch we switch to non delalloc mode if the filesystem free blocks is greater than 150% of total filesystem dirty blocks Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao<cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Retry block reservationAneesh Kumar K.V2008-09-08
| | | | | | | | | | | | | During block reservation if we don't have enough blocks left, retry block reservation with smaller block counts. This makes sure we try fallocate and DIO with smaller request size and don't fail early. The delayed allocation reservation cannot try with smaller block count. So retry block reservation to handle temporary disk full conditions. Also print free blocks details if we fail block allocation during writepages. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Make sure all the block allocation paths reserve blocksAneesh Kumar K.V2008-10-09
| | | | | | | | | | | | | | | | With delayed allocation we need to make sure block are reserved before we attempt to allocate them. Otherwise we get block allocation failure (ENOSPC) during writepages which cannot be handled. This would mean silent data loss (We do a printk stating data will be lost). This patch updates the DIO and fallocate code path to do block reservation before block allocation. This is needed to make sure parallel DIO and fallocate request doesn't take block out of delayed reserve space. When free blocks count go below a threshold we switch to a slow patch which looks at other CPU's accumulated percpu counter values. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: invalidate pages if delalloc block allocation fails.Aneesh Kumar K.V2008-08-19
| | | | | | | | | We are a bit agressive in invalidating all the pages. But it is ok because we really don't know why the block allocation failed and it is better to come of the writeback path so that user can look for more info. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
* ext4: Fix whitespace checkpatch warnings/errorsTheodore Ts'o2008-09-08
| | | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Fix long long checkpatch warningsTheodore Ts'o2008-09-08
| | | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add printk priority levels to clean up checkpatch warningsTheodore Ts'o2008-09-08
| | | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* percpu counter: clean up percpu_counter_sum_and_set()Mingming Cao2008-10-09
| | | | | | | | | | | | | | | | percpu_counter_sum_and_set() and percpu_counter_sum() is the same except the former updates the global counter after accounting. Since we are taking the fbc->lock to calculate the precise value of the counter in percpu_counter_sum() anyway, it should simply set fbc->count too, as the percpu_counter_sum_and_set() does. This patch merges these two interfaces into one. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* Don't allow splice() to files opened with O_APPENDLinus Torvalds2008-10-09
| | | | | | | | | | | | | | | | | | | | | This is debatable, but while we're debating it, let's disallow the combination of splice and an O_APPEND destination. It's not entirely clear what the semantics of O_APPEND should be, and POSIX apparently expects pwrite() to ignore O_APPEND, for example. So we could make up any semantics we want, including the old ones. But Miklos convinced me that we should at least give it some thought, and that accepting writes at arbitrary offsets is wrong at least for IS_APPEND() files (which always have O_APPEND set, even if the reverse isn't true: you can obviously have O_APPEND set on a regular file). So disallow O_APPEND entirely for now. I doubt anybody cares, and this way we have one less gray area to worry about. Reported-and-argued-for-by: Miklos Szeredi <miklos@szeredi.hu> Acked-by: Jens Axboe <ens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: tiny-shmem nommu fixNick Piggin2008-10-02
| | | | | | | | | | | | | | | | | | | | The previous patch db203d53d474aa068984e409d807628f5841da1b ("mm: tiny-shmem fix lock ordering: mmap_sem vs i_mutex") to fix the lock ordering in tiny-shmem breaks shared anonymous and IPC memory on NOMMU architectures because it was using the expanding truncate to signal ramfs to allocate a physically contiguous RAM backing the inode (otherwise it is unusable for "memory mapping" it to userspace). However do_truncate is what caused the lock ordering error, due to it taking i_mutex. In this case, we can actually just call ramfs directly to allocate memory for the mapping, rather than go via truncate. Acked-by: David Howells <dhowells@redhat.com> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* inotify: fix lock ordering wrt do_page_fault's mmap_semNick Piggin2008-10-02
| | | | | | | | | | | | | Fix inotify lock order reversal with mmap_sem due to holding locks over copy_to_user. Signed-off-by: Nick Piggin <npiggin@suse.de> Reported-by: "Daniel J Blueman" <daniel.blueman@gmail.com> Tested-by: "Daniel J Blueman" <daniel.blueman@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> 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>
* mm owner: fix race between swapoff and exitBalbir Singh2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a race between mm->owner assignment and swapoff, more easily seen when task slab poisoning is turned on. The condition occurs when try_to_unuse() runs in parallel with an exiting task. A similar race can occur with callers of get_task_mm(), such as /proc/<pid>/<mmstats> or ptrace or page migration. CPU0 CPU1 try_to_unuse looks at mm = task0->mm increments mm->mm_users task 0 exits mm->owner needs to be updated, but no new owner is found (mm_users > 1, but no other task has task->mm = task0->mm) mm_update_next_owner() leaves mmput(mm) decrements mm->mm_users task0 freed dereferencing mm->owner fails The fix is to notify the subsystem via mm_owner_changed callback(), if no new owner is found, by specifying the new task as NULL. Jiri Slaby: mm->owner was set to NULL prior to calling cgroup_mm_owner_callbacks(), but must be set after that, so as not to pass NULL as old owner causing oops. Daisuke Nishimura: mm_update_next_owner() may set mm->owner to NULL, but mem_cgroup_from_task() and its callers need to take account of this situation to avoid oops. Hugh Dickins: Lockdep warning and hang below exec_mmap() when testing these patches. exit_mm() up_reads mmap_sem before calling mm_update_next_owner(), so exec_mmap() now needs to do the same. And with that repositioning, there's now no point in mm_need_new_owner() allowing for NULL mm. Reported-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix NULL pointer dereference in proc_sys_compareLinus Torvalds2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VFS interface for the 'd_compare()' is a bit special (read: 'odd'), because it really just essentially replaces a memcmp(). The filesystem is supposed to just compare the two names with whatever case-independent or other function. And when I say 'is supposed to', I obviously mean that 'procfs does odd things, and actually looks at the dentry that we don't even pass down, rather than just the name'. Which results in problems, because we actually call d_compare before we have even verified that the dentry is still hashed at all. And that causes a problm since the inode that procfs looks at may have been free'd and the d_inode pointer is NULL. procfs just assumes that all dentries are positive, since procfs itself never generates a negative one. But memory pressure will still result in the dentry getting torn down, and as it is removed by RCU, it still remains visible on some lists - and to d_compare. If the filesystem just did a name comparison, we wouldn't care. And we could just fix procfs to know about negative dentries too. But rather than have the low-level filesystems know about internal VFS details, just move the check for a unhashed dentry up a bit, so that we will only call d_compare on dentries that are still active. The actual oops this caused didn't look like a NULL pointer dereference because procfs did a 'container_of(inode, struct proc_inode, vfs_inode)' to get at its internal proc_inode information from the inode pointer, and accessed a field below the inode. So the oops would look something like BUG: unable to handle kernel paging request at fffffffffffffff0 IP: [<ffffffff802bc6c6>] proc_sys_compare+0x36/0x50 and was seen on both x86-64 (Alexey Dobriyan and Hugh Dickins) and ppc64 (Hugh Dickins). Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Hugh Dickins <hugh@veritas.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-of-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://oss.sgi.com:8090/xfs/linux-2.6Linus Torvalds2008-09-26
|\ | | | | | | | | | | * git://oss.sgi.com:8090/xfs/linux-2.6: [XFS] Remove xfs_iext_irec_compact_full() [XFS] Fix extent list corruption in xfs_iext_irec_compact_full().
| * [XFS] Remove xfs_iext_irec_compact_full()Lachlan McIlroy2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yet another bug was found in xfs_iext_irec_compact_full() and while the source of the bug was found it wasn't an easy task to track it down because the conditions are very difficult to reproduce. A HUGE thank-you goes to Russell Cattelan and Eric Sandeen for their significant effort in tracking down the source of this corruption. xfs_iext_irec_compact_full() and xfs_iext_irec_compact_pages() are almost identical - they both compact indirect extent lists by moving extents from subsequent buffers into earlier ones. xfs_iext_irec_compact_pages() only moves extents if all of the extents in the next buffer will fit into the empty space in the buffer before it. xfs_iext_irec_compact_full() will go a step further and move part of the next buffer if all the extents wont fit. It will then shift the remaining extents in the next buffer up to the start of the buffer. The bug here was that we did not update er_extoff and this caused extent list corruption. It does not appear that this extra functionality gains us much. Calling xfs_iext_irec_compact_pages() instead will do a good enough job at compacting the indirect list and will be quicker too. For the case in xfs_iext_indirect_to_direct() the total number of extents in the indirect list will fit into one buffer so we will never need the extra functionality of xfs_iext_irec_compact_full() there. Also xfs_iext_irec_compact_pages() doesn't need to do a memmove() (the buffers will never overlap) so we don't want the performance hit that can incur. SGI-PV: 987159 SGI-Modid: xfs-linux-melb:xfs-kern:32166a Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
| * [XFS] Fix extent list corruption in xfs_iext_irec_compact_full().Lachlan McIlroy2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If we don't move all the records from the next buffer into the current buffer then we need to update the er_extoff field of the next buffer as we shift the remaining records to the start of the buffer. SGI-PV: 987159 SGI-Modid: xfs-linux-melb:xfs-kern:32165a Signed-off-by: Lachlan McIlroy <lachlan@sgi.com> Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Russell Cattelan <cattelan@thebarn.com>
* | Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubifs-2.6Linus Torvalds2008-09-26
|\ \ | |/ |/| | | | | | | | | | | * 'linux-next' of git://git.infradead.org/~dedekind/ubifs-2.6: UBIFS: fix printk format warnings UBIFS: remove incorrect assert UBIFS: TNC / GC race fixes UBIFS: create the name of the background thread in every case
| * UBIFS: fix printk format warningsAlexander Beregalov2008-09-18
| | | | | | | | | | | | | | | | | | | | | | fs/ubifs/dir.c:428: warning: format '%llu' expects type 'long long unsigned int', but argument 5 has type 'long unsigned int' fs/ubifs/debug.c:541: warning: format '%llu' expects type 'long long unsigned int', but argument 2 has type 'long unsigned int' Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * UBIFS: remove incorrect assertAdrian Hunter2008-09-17
| | | | | | | | | | | | | | | | | | The assert was not valid because one of the variables 'taken_empty_lebs' has transient values out of sync with the other variables. Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * UBIFS: TNC / GC race fixesAdrian Hunter2008-09-17
| | | | | | | | | | | | | | | | | | - update GC sequence number if any nodes may have been moved even if GC did not finish the LEB - don't ignore error return when reading Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>