linux/mm/truncate.c, branch v2.6.39-rc2

mm: deactivate invalidated pages

2011-03-23T00:44:03Z

Recently, there are reported problem about thrashing. (http://marc.info/?l=rsync&m=128885034930933&w=2) It happens by backup workloads(ex, nightly rsync). That's because the workload makes just use-once pages and touches pages twice. It promotes the page into active list so that it results in working set page eviction. Some app developer want to support POSIX_FADV_NOREUSE. But other OSes don't support it, either. (http://marc.info/?l=linux-mm&m=128928979512086&w=2) By other approach, app developers use POSIX_FADV_DONTNEED. But it has a problem. If kernel meets page is writing during invalidate_mapping_pages, it can't work. It makes for application programmer to use it since they always have to sync data before calling fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could be discardable. At last, they can't use deferred write of kernel so that they could see performance loss. (http://insights.oetiker.ch/linux/fadvise.html) In fact, invalidation is very big hint to reclaimer. It means we don't use the page any more. So let's move the writing page into inactive list's head if we can't truncate it right now. Why I move page to head of lru on this patch, Dirty/Writeback page would be flushed sooner or later. It can prevent writeout of pageout which is less effective than flusher's writeout. Originally, I reused lru_demote of Peter with some change so added his Signed-off-by. Signed-off-by: Minchan Kim Reported-by: Ben Gamari Signed-off-by: Peter Zijlstra Acked-by: Rik van Riel Acked-by: Mel Gorman Reviewed-by: KOSAKI Motohiro Cc: Wu Fengguang Acked-by: Johannes Weiner Cc: Nick Piggin Cc: Andrea Arcangeli Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: change __remove_from_page_cache()

2011-03-23T00:44:02Z

Now we renamed remove_from_page_cache with delete_from_page_cache. As consistency of __remove_from_swap_cache and remove_from_swap_cache, we change internal page cache handling function name, too. Signed-off-by: Minchan Kim Cc: Christoph Hellwig Acked-by: Hugh Dickins Acked-by: Mel Gorman Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: Johannes Weiner Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: truncate: change remove_from_page_cache

2011-03-23T00:44:02Z

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 Cc: Dan Magenheimer Cc: Andi Kleen Cc: Nick Piggin Cc: Al Viro Acked-by: Hugh Dickins Acked-by: Mel Gorman Reviewed-by: KAMEZAWA Hiroyuki Reviewed-by: Johannes Weiner Reviewed-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memcg: more mem_cgroup_uncharge() batching

2011-02-25T23:07:37Z

It seems odd that truncate_inode_pages_range(), called not only when truncating but also when evicting inodes, has mem_cgroup_uncharge_start and _end() batching in its second loop to clear up a few leftovers, but not in its first loop that does almost all the work: add them there too. Signed-off-by: Hugh Dickins Acked-by: KAMEZAWA Hiroyuki Acked-by: Balbir Singh Acked-by: Daisuke Nishimura Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: fix truncate_setsize() comment

2011-01-21T01:02:06Z

Contrary to what the comment says, truncate_setsize() should be called *before* filesystem truncated blocks. Signed-off-by: Jan Kara Cc: Christoph Hellwig Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Call the filesystem back whenever a page is removed from the page cache

2010-12-02T14:55:21Z

NFS needs to be able to release objects that are stored in the page cache once the page itself is no longer visible from the page cache. This patch adds a callback to the address space operations that allows filesystems to perform page cleanups once the page has been removed from the page cache. Original patch by: Linus Torvalds [trondmy: cover the cases of invalidate_inode_pages2() and truncate_inode_pages()] Signed-off-by: Trond Myklebust

check ATTR_SIZE contraints in inode_change_ok

2010-08-09T20:47:39Z

Make sure we check the truncate constraints early on in ->setattr by adding those checks to inode_change_ok. Also clean up and document inode_change_ok to make this obvious. As a fallout we don't have to call inode_newsize_ok from simple_setsize and simplify it down to a truncate_setsize which doesn't return an error. This simplifies a lot of setattr implementations and means we use truncate_setsize almost everywhere. Get rid of fat_setsize now that it's trivial and mark ext2_setsize static to make the calling convention obvious. Keep the inode_newsize_ok in vmtruncate for now as all callers need an audit for its removal anyway. Note: setattr code in ecryptfs doesn't call inode_change_ok at all and needs a deeper audit, but that is left for later. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

fs: introduce new truncate sequence

2010-05-28T02:15:33Z

Introduce a new truncate calling sequence into fs/mm subsystems. Rather than setattr > vmtruncate > truncate, have filesystems call their truncate sequence from ->setattr if filesystem specific operations are required. vmtruncate is deprecated, and truncate_pagecache and inode_newsize_ok helpers introduced previously should be used. simple_setattr is introduced for simple in-ram filesystems to implement the new truncate sequence. Eventually all filesystems should be converted to implement a setattr, and the default code in notify_change should go away. simple_setsize is also introduced to perform just the ATTR_SIZE portion of simple_setattr (ie. changing i_size and trimming pagecache). To implement the new truncate sequence: - filesystem specific manipulations (eg freeing blocks) must be done in the setattr method rather than ->truncate. - vmtruncate can not be used by core code to trim blocks past i_size in the event of write failure after allocation, so this must be performed in the fs code. - convert usage of helpers block_write_begin, nobh_write_begin, cont_write_begin, and *blockdev_direct_IO* to use _newtrunc postfixed variants. These avoid calling vmtruncate to trim blocks (see previous). - inode_setattr should not be used. generic_setattr is a new function to be used to copy simple attributes into the generic inode. - make use of the better opportunity to handle errors with the new sequence. Big problem with the previous calling sequence: the filesystem is not called until i_size has already changed. This means it is not allowed to fail the call, and also it does not know what the previous i_size was. Also, generic code calling vmtruncate to truncate allocated blocks in case of error had no good way to return a meaningful error (or, for example, atomically handle block deallocation). Cc: Christoph Hellwig Acked-by: Jan Kara Signed-off-by: Nick Piggin Signed-off-by: Al Viro

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32Z

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

vfs: Fix vmtruncate() regression

2010-01-14T00:09:33Z

If __block_prepare_write() was failed in block_write_begin(), the allocated blocks can be outside of ->i_size. But new truncate_pagecache() in vmtuncate() does nothing if new < old. It means the above usage is not working anymore. So, this patch fixes it by removing "new < old" check. It would need more cleanup/change. But, now -rc and truncate working is in progress, so, this tried to fix it minimum change. Acked-by: Nick Piggin Signed-off-by: OGAWA Hirofumi Signed-off-by: Linus Torvalds