- 24 Feb, 2011 2 commits
-
-
NeilBrown authored
There are two cases when we call flush_disk. In one, the device has disappeared (check_disk_change) so any data will hold becomes irrelevant. In the oter, the device has changed size (check_disk_size_change) so data we hold may be irrelevant. In both cases it makes sense to discard any 'clean' buffers, so they will be read back from the device if needed. In the former case it makes sense to discard 'dirty' buffers as there will never be anywhere safe to write the data. In the second case it *does*not* make sense to discard dirty buffers as that will lead to file system corruption when you simply enlarge the containing devices. flush_disk calls __invalidate_devices. __invalidate_device calls both invalidate_inodes and invalidate_bdev. invalidate_inodes *does* discard I_DIRTY inodes and this does lead to fs corruption. invalidate_bev *does*not* discard dirty pages, but I don't really care about that at present. So this patch adds a flag to __invalidate_device (calling it __invalidate_device2) to indicate whether dirty buffers should be killed, and this is passed to invalidate_inodes which can choose to skip dirty inodes. flusk_disk then passes true from check_disk_change and false from check_disk_size_change. dm avoids tripping over this problem by calling i_size_write directly rathher than using check_disk_size_change. md does use check_disk_size_change and so is affected. This regression was introduced by commit 608aeef1 which causes check_disk_size_change to call flush_disk, so it is suitable for any kernel since 2.6.27. Cc: stable@kernel.org Acked-by:
Jeff Moyer <jmoyer@redhat.com> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by:
NeilBrown <neilb@suse.de>
-
Miklos Szeredi authored
Michael Leun reported that running parallel opens on a fuse filesystem can trigger a "kernel BUG at mm/truncate.c:475" Gurudas Pai reported the same bug on NFS. The reason is, unmap_mapping_range() is not prepared for more than one concurrent invocation per inode. For example: thread1: going through a big range, stops in the middle of a vma and stores the restart address in vm_truncate_count. thread2: comes in with a small (e.g. single page) unmap request on the same vma, somewhere before restart_address, finds that the vma was already unmapped up to the restart address and happily returns without doing anything. Another scenario would be two big unmap requests, both having to restart the unmapping and each one setting vm_truncate_count to its own value. This could go on forever without any of them being able to finish. Truncate and hole punching already serialize with i_mutex. Other callers of unmap_mapping_range() do not, and it's difficult to get i_mutex protection for all callers. In particular ->d_revalidate(), which calls invalidate_inode_pages2_range() in fuse, may be called with or without i_mutex. This patch adds a new mutex to 'struct address_space' to prevent running multiple concurrent unmap_mapping_range() on the same mapping. [ We'll hopefully get rid of all this with the upcoming mm preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex lockbreak" patch in particular. But that is for 2.6.39 ] Signed-off-by:Miklos Szeredi <mszeredi@suse.cz> Reported-by:
Michael Leun <lkml20101129@newton.leun.net> Reported-by:
Gurudas Pai <gurudas.pai@oracle.com> Tested-by:
Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
- 07 Jan, 2011 4 commits
-
-
Nick Piggin authored
Pseudo filesystems that don't put inode on RCU list or reachable by rcu-walk dentries do not need to RCU free their inodes. Signed-off-by:Nick Piggin <npiggin@kernel.dk>
-
Nick Piggin authored
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 authored
percpu_counter library generates quite nasty code, so unless you need to dynamically allocate counters or take fast approximate value, a simple per cpu set of counters is much better. The percpu_counter can never be made to work as well, because it has an indirection from pointer to percpu memory, and it can't use direct this_cpu_inc interfaces because it doesn't use static PER_CPU data, so code will always be worse. In the fastpath, it is the difference between this: incl %gs:nr_dentry # nr_dentry and this: movl percpu_counter_batch(%rip), %edx # percpu_counter_batch, movl $1, %esi #, movq $nr_dentry, %rdi #, call __percpu_counter_add # (plus I clobber registers) __percpu_counter_add: pushq %rbp # movq %rsp, %rbp #, subq $32, %rsp #, movq %rbx, -24(%rbp) #, movq %r12, -16(%rbp) #, movq %r13, -8(%rbp) #, movq %rdi, %rbx # fbc, fbc #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP incl -8124(%rax) # <variable>.preempt_count movq 32(%rdi), %r12 # <variable>.counters, tcp_ptr__ #APP # 78 "lib/percpu_counter.c" 1 add %gs:this_cpu_off, %r12 # this_cpu_off, tcp_ptr__ # 0 "" 2 #NO_APP movslq (%r12),%r13 #* tcp_ptr__, tmp73 movslq %edx,%rax # batch, batch addq %rsi, %r13 # amount, count cmpq %rax, %r13 # batch, count jge .L27 #, negl %edx # tmp76 movslq %edx,%rdx # tmp76, tmp77 cmpq %rdx, %r13 # tmp77, count jg .L28 #, .L27: movq %rbx, %rdi # fbc, call _raw_spin_lock # addq %r13, 8(%rbx) # count, <variable>.count movq %rbx, %rdi # fbc, movl $0, (%r12) #,* tcp_ptr__ call _raw_spin_unlock # .L29: #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP decl -8124(%rax) # <variable>.preempt_count movq -8136(%rax), %rax #, D.14625 testb $8, %al #, D.14625 jne .L32 #, .L31: movq -24(%rbp), %rbx #, movq -16(%rbp), %r12 #, movq -8(%rbp), %r13 #, leave ret .p2align 4,,10 .p2align 3 .L28: movl %r13d, (%r12) # count,* jmp .L29 # .L32: call preempt_schedule # .p2align 4,,6 jmp .L31 # .size __percpu_counter_add, .-__percpu_counter_add .p2align 4,,15 Signed-off-by: -
Nick Piggin authored
The nr_unused counters count the number of objects on an LRU, and as such they are synchronized with LRU object insertion and removal and scanning, and protected under the LRU lock. Making it per-cpu does not actually get any concurrency improvements because of this lock, and summing the counter is much slower, and incrementing/decrementing it costs more code size and is slower too. These counters should stay per-LRU, which currently means global. Signed-off-by:
-
- 26 Oct, 2010 19 commits
-
-
Eric Paris authored
IMA currently allocated an inode integrity structure for every inode in core. This stucture is about 120 bytes long. Most files however (especially on a system which doesn't make use of IMA) will never need any of this space. The problem is that if IMA is enabled we need to know information about the number of readers and the number of writers for every inode on the box. At the moment we collect that information in the per inode iint structure and waste the rest of the space. This patch moves those counters into the struct inode so we can eventually stop allocating an IMA integrity structure except when absolutely needed. This patch does the minimum needed to move the location of the data. Further cleanups, especially the location of counter updates, may still be possible. Signed-off-by:
Eric Paris <eparis@redhat.com> Acked-by:
Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by:
-
Al Viro authored
Pull removal of fsnotify marks into generic_shutdown_super(). Split umount-time work into a new function - evict_inodes(). Make sure that invalidate_inodes() will be able to cope with I_FREEING once we change locking in iput(). Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
-
Christoph Hellwig authored
Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
-
Christoph Hellwig authored
Despite the comment above it we can not safely drop the lock here. invalidate_list is called from many other places that just umount. Also switch to proper list macros now that we never drop the lock. Signed-off-by:
-
Nick Piggin authored
The use of the same inode list structure (inode->i_list) for two different list constructs with different lifecycles and purposes makes it impossible to separate the locking of the different operations. Therefore, to enable the separation of the locking of the writeback and reclaim lists, split the inode->i_list into two separate lists dedicated to their specific tracking functions. Signed-off-by:
Nick Piggin <npiggin@suse.de> Signed-off-by:
Dave Chinner <dchinner@redhat.com> Reviewed-by:
-
Christoph Hellwig authored
We must not call invalidate_inode_buffers in invalidate_list unless the inode can be reclaimed. If we remove the buffer association of a busy inode fsync won't find the buffers anymore. As invalidate_inode_buffers is called from various others sources than umount this actually does matter in practice. While at it change the loop to a more natural form and remove the WARN_ON for I_NEW, wich we already tested a few lines above. Signed-off-by:
-
Christoph Hellwig authored
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:
-
Eric Dumazet authored
new_inode() dirties a contended cache line to get increasing inode numbers. This limits performance on workloads that cause significant parallel inode allocation. Solve this problem by using a per_cpu variable fed by the shared last_ino in batches of 1024 allocations. This reduces contention on the shared last_ino, and give same spreading ino numbers than before (i.e. same wraparound after 2^32 allocations). Signed-off-by:
Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by:
-
Al Viro authored
Clones an existing reference to inode; caller must already hold one. Signed-off-by: -
Christoph Hellwig authored
Split up inode_add_to_list/__inode_add_to_list. Locking for the two lists will be split soon so these helpers really don't buy us much anymore. The __ prefixes for the sb list helpers will go away soon, but until inode_lock is gone we'll need them to distinguish between the locked and unlocked variants. Signed-off-by:
-
Christoph Hellwig authored
Now that iunique is not abusing find_inode anymore we can move the i_ref increment back to where it belongs. Signed-off-by:
-
Christoph Hellwig authored
Stop abusing find_inode_fast for iunique and opencode the inode hash walk. Introduce a new iunique_lock to protect the iunique counters once inode_lock is removed. Based on a patch originally from Nick Piggin. Signed-off-by:
-
Dave Chinner authored
Before replacing the inode hash locking with a more scalable mechanism, factor the removal of the inode from the hashes rather than open coding it in several places. Based on a patch originally from Nick Piggin. Signed-off-by:
-
Nick Piggin authored
Convert the inode LRU to use lazy updates to reduce lock and cacheline traffic. We avoid moving inodes around in the LRU list during iget/iput operations so these frequent operations don't need to access the LRUs. Instead, we defer the refcount checks to reclaim-time and use a per-inode state flag, I_REFERENCED, to tell reclaim that iget has touched the inode in the past. This means that only reclaim should be touching the LRU with any frequency, hence significantly reducing lock acquisitions and the amount contention on LRU updates. This also removes the inode_in_use list, which means we now only have one list for tracking the inode LRU status. This makes it much simpler to split out the LRU list operations under it's own lock. Signed-off-by:
-
Dave Chinner authored
The number of inodes allocated does not need to be tied to the addition or removal of an inode to/from a list. If we are not tied to a list lock, we could update the counters when inodes are initialised or destroyed, but to do that we need to convert the counters to be per-cpu (i.e. independent of a lock). This means that we have the freedom to change the list/locking implementation without needing to care about the counters. Based on a patch originally from Eric Dumazet. [AV: cleaned up a bit, fixed build breakage on weird configs Signed-off-by:
-
Al Viro authored
note: for race-free uses you inode_lock held Signed-off-by: -
Al Viro authored
Signed-off-by: -
Namhyung Kim authored
Since inode->i_mode shares its bits for S_IFMT, S_ISDIR should be used to distinguish whether it is a dir or not. Signed-off-by:
Namhyung Kim <namhyung@gmail.com> Signed-off-by:
-
Christoph Hellwig authored
Hugetlbfs used to need it, but after the destroy_inode and evict_inode changes it's not required anymore. Signed-off-by:
-
- 09 Aug, 2010 12 commits
-
-
Al Viro authored
Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
... and let iput_final() do the actual eviction or retention Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
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 authored
All call chains to clear_inode() pass through evict_inode() and clear_inode() should be called by evict_inode() exactly once. So we can pull i_bdev/i_cdev detaching up to evict_inode() itself. Signed-off-by: -
Al Viro authored
Signed-off-by: -
Al Viro authored
Hybrid of ->clear_inode() and ->delete_inode(); if present, does all fs work to be done when in-core inode is about to be gone, for whatever reason. Signed-off-by: -
Al Viro authored
For now, just a straightforward merge Signed-off-by: -
Al Viro authored
add I_CLEAR instead of replacing I_FREEING with it. I_CLEAR is equivalent to I_FREEING for almost all code looking at either; it's there to keep track of having called clear_inode() exactly once per inode lifetime, at some point after having set I_FREEING. I_CLEAR and I_FREEING never get set at the same time with the current code, so we can switch to setting i_flags to I_FREEING | I_CLEAR instead of I_CLEAR without loss of information. As the result of such change, checks become simpler and the amount of code that needs to know about I_CLEAR shrinks a lot. Signed-off-by:
-
- 28 Jul, 2010 2 commits
-
-
Eric Paris authored
The name is long and it serves no real purpose. So rename fsnotify_mark_entry to just fsnotify_mark. Signed-off-by: -
Eric Paris authored
nothing uses inotify in the kernel, drop it! Signed-off-by:
-
- 19 Jul, 2010 1 commit
-
-
Dave Chinner authored
The current shrinker implementation requires the registered callback to have global state to work from. This makes it difficult to shrink caches that are not global (e.g. per-filesystem caches). Pass the shrinker structure to the callback so that users can embed the shrinker structure in the context the shrinker needs to operate on and get back to it in the callback via container_of(). Signed-off-by:
-
