2005-04-16 22:20:36 +00:00
|
|
|
/*
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|
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|
* mm/truncate.c - code for taking down pages from address_spaces
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*
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|
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* Copyright (C) 2002, Linus Torvalds
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|
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*
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2008-10-16 05:01:59 +00:00
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* 10Sep2002 Andrew Morton
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2005-04-16 22:20:36 +00:00
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* Initial version.
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*/
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#include <linux/kernel.h>
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2007-10-17 06:29:23 +00:00
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#include <linux/backing-dev.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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 <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
|
|
|
#include <linux/gfp.h>
|
2005-04-16 22:20:36 +00:00
|
|
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#include <linux/mm.h>
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2006-09-27 08:50:02 +00:00
|
|
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#include <linux/swap.h>
|
2011-10-16 06:01:52 +00:00
|
|
|
#include <linux/export.h>
|
2005-04-16 22:20:36 +00:00
|
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|
#include <linux/pagemap.h>
|
2007-05-09 09:35:07 +00:00
|
|
|
#include <linux/highmem.h>
|
2005-04-16 22:20:36 +00:00
|
|
|
#include <linux/pagevec.h>
|
2006-12-10 10:19:31 +00:00
|
|
|
#include <linux/task_io_accounting_ops.h>
|
2005-04-16 22:20:36 +00:00
|
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|
#include <linux/buffer_head.h> /* grr. try_to_release_page,
|
2005-10-30 23:00:16 +00:00
|
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|
do_invalidatepage */
|
2011-05-26 16:01:43 +00:00
|
|
|
#include <linux/cleancache.h>
|
2008-10-19 03:26:50 +00:00
|
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|
#include "internal.h"
|
2005-04-16 22:20:36 +00:00
|
|
|
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2006-08-29 18:05:54 +00:00
|
|
|
/**
|
2008-02-03 16:04:10 +00:00
|
|
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* do_invalidatepage - invalidate part or all of a page
|
2006-08-29 18:05:54 +00:00
|
|
|
* @page: the page which is affected
|
|
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|
* @offset: the index of the truncation point
|
|
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*
|
|
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|
* do_invalidatepage() is called when all or part of the page has become
|
|
|
|
* invalidated by a truncate operation.
|
|
|
|
*
|
|
|
|
* do_invalidatepage() does not have to release all buffers, but it must
|
|
|
|
* ensure that no dirty buffer is left outside @offset and that no I/O
|
|
|
|
* is underway against any of the blocks which are outside the truncation
|
|
|
|
* point. Because the caller is about to free (and possibly reuse) those
|
|
|
|
* blocks on-disk.
|
|
|
|
*/
|
|
|
|
void do_invalidatepage(struct page *page, unsigned long offset)
|
|
|
|
{
|
|
|
|
void (*invalidatepage)(struct page *, unsigned long);
|
|
|
|
invalidatepage = page->mapping->a_ops->invalidatepage;
|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 18:45:40 +00:00
|
|
|
#ifdef CONFIG_BLOCK
|
2006-08-29 18:05:54 +00:00
|
|
|
if (!invalidatepage)
|
|
|
|
invalidatepage = block_invalidatepage;
|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 18:45:40 +00:00
|
|
|
#endif
|
2006-08-29 18:05:54 +00:00
|
|
|
if (invalidatepage)
|
|
|
|
(*invalidatepage)(page, offset);
|
|
|
|
}
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
static inline void truncate_partial_page(struct page *page, unsigned partial)
|
|
|
|
{
|
2008-02-05 06:28:29 +00:00
|
|
|
zero_user_segment(page, partial, PAGE_CACHE_SIZE);
|
2011-05-26 16:01:43 +00:00
|
|
|
cleancache_flush_page(page->mapping, page);
|
2009-04-03 15:42:36 +00:00
|
|
|
if (page_has_private(page))
|
2005-04-16 22:20:36 +00:00
|
|
|
do_invalidatepage(page, partial);
|
|
|
|
}
|
|
|
|
|
Resurrect 'try_to_free_buffers()' VM hackery
It's not pretty, but it appears that ext3 with data=journal will clean
pages without ever actually telling the VM that they are clean. This,
in turn, will result in the VM (and balance_dirty_pages() in particular)
to never realize that the pages got cleaned, and wait forever for an
event that already happened.
Technically, this seems to be a problem with ext3 itself, but it used to
be hidden by 'try_to_free_buffers()' noticing this situation on its own,
and just working around the filesystem problem.
This commit re-instates that hack, in order to avoid a regression for
the 2.6.20 release. This fixes bugzilla 7844:
http://bugzilla.kernel.org/show_bug.cgi?id=7844
Peter Zijlstra points out that we should probably retain the debugging
code that this removes from cancel_dirty_page(), and I agree, but for
the imminent release we might as well just silence the warning too
(since it's not a new bug: anything that triggers that warning has been
around forever).
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26 20:47:06 +00:00
|
|
|
/*
|
|
|
|
* This cancels just the dirty bit on the kernel page itself, it
|
|
|
|
* does NOT actually remove dirty bits on any mmap's that may be
|
|
|
|
* around. It also leaves the page tagged dirty, so any sync
|
|
|
|
* activity will still find it on the dirty lists, and in particular,
|
|
|
|
* clear_page_dirty_for_io() will still look at the dirty bits in
|
|
|
|
* the VM.
|
|
|
|
*
|
|
|
|
* Doing this should *normally* only ever be done when a page
|
|
|
|
* is truncated, and is not actually mapped anywhere at all. However,
|
|
|
|
* fs/buffer.c does this when it notices that somebody has cleaned
|
|
|
|
* out all the buffers on a page without actually doing it through
|
|
|
|
* the VM. Can you say "ext3 is horribly ugly"? Tought you could.
|
|
|
|
*/
|
VM: Remove "clear_page_dirty()" and "test_clear_page_dirty()" functions
They were horribly easy to mis-use because of their tempting naming, and
they also did way more than any users of them generally wanted them to
do.
A dirty page can become clean under two circumstances:
(a) when we write it out. We have "clear_page_dirty_for_io()" for
this, and that function remains unchanged.
In the "for IO" case it is not sufficient to just clear the dirty
bit, you also have to mark the page as being under writeback etc.
(b) when we actually remove a page due to it becoming inaccessible to
users, notably because it was truncate()'d away or the file (or
metadata) no longer exists, and we thus want to cancel any
outstanding dirty state.
For the (b) case, we now introduce "cancel_dirty_page()", which only
touches the page state itself, and verifies that the page is not mapped
(since cancelling writes on a mapped page would be actively wrong as it
is still accessible to users).
Some filesystems need to be fixed up for this: CIFS, FUSE, JFS,
ReiserFS, XFS all use the old confusing functions, and will be fixed
separately in subsequent commits (with some of them just removing the
offending logic, and others using clear_page_dirty_for_io()).
This was confirmed by Martin Michlmayr to fix the apt database
corruption on ARM.
Cc: Martin Michlmayr <tbm@cyrius.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Andrei Popa <andrei.popa@i-neo.ro>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Gordon Farquharson <gordonfarquharson@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-20 21:46:42 +00:00
|
|
|
void cancel_dirty_page(struct page *page, unsigned int account_size)
|
|
|
|
{
|
2006-12-23 17:25:04 +00:00
|
|
|
if (TestClearPageDirty(page)) {
|
|
|
|
struct address_space *mapping = page->mapping;
|
|
|
|
if (mapping && mapping_cap_account_dirty(mapping)) {
|
|
|
|
dec_zone_page_state(page, NR_FILE_DIRTY);
|
2007-10-17 06:25:47 +00:00
|
|
|
dec_bdi_stat(mapping->backing_dev_info,
|
|
|
|
BDI_RECLAIMABLE);
|
2006-12-23 17:25:04 +00:00
|
|
|
if (account_size)
|
|
|
|
task_io_account_cancelled_write(account_size);
|
|
|
|
}
|
2006-12-21 19:00:33 +00:00
|
|
|
}
|
VM: Remove "clear_page_dirty()" and "test_clear_page_dirty()" functions
They were horribly easy to mis-use because of their tempting naming, and
they also did way more than any users of them generally wanted them to
do.
A dirty page can become clean under two circumstances:
(a) when we write it out. We have "clear_page_dirty_for_io()" for
this, and that function remains unchanged.
In the "for IO" case it is not sufficient to just clear the dirty
bit, you also have to mark the page as being under writeback etc.
(b) when we actually remove a page due to it becoming inaccessible to
users, notably because it was truncate()'d away or the file (or
metadata) no longer exists, and we thus want to cancel any
outstanding dirty state.
For the (b) case, we now introduce "cancel_dirty_page()", which only
touches the page state itself, and verifies that the page is not mapped
(since cancelling writes on a mapped page would be actively wrong as it
is still accessible to users).
Some filesystems need to be fixed up for this: CIFS, FUSE, JFS,
ReiserFS, XFS all use the old confusing functions, and will be fixed
separately in subsequent commits (with some of them just removing the
offending logic, and others using clear_page_dirty_for_io()).
This was confirmed by Martin Michlmayr to fix the apt database
corruption on ARM.
Cc: Martin Michlmayr <tbm@cyrius.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Andrei Popa <andrei.popa@i-neo.ro>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Gordon Farquharson <gordonfarquharson@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-20 21:46:42 +00:00
|
|
|
}
|
2006-12-23 17:25:04 +00:00
|
|
|
EXPORT_SYMBOL(cancel_dirty_page);
|
VM: Remove "clear_page_dirty()" and "test_clear_page_dirty()" functions
They were horribly easy to mis-use because of their tempting naming, and
they also did way more than any users of them generally wanted them to
do.
A dirty page can become clean under two circumstances:
(a) when we write it out. We have "clear_page_dirty_for_io()" for
this, and that function remains unchanged.
In the "for IO" case it is not sufficient to just clear the dirty
bit, you also have to mark the page as being under writeback etc.
(b) when we actually remove a page due to it becoming inaccessible to
users, notably because it was truncate()'d away or the file (or
metadata) no longer exists, and we thus want to cancel any
outstanding dirty state.
For the (b) case, we now introduce "cancel_dirty_page()", which only
touches the page state itself, and verifies that the page is not mapped
(since cancelling writes on a mapped page would be actively wrong as it
is still accessible to users).
Some filesystems need to be fixed up for this: CIFS, FUSE, JFS,
ReiserFS, XFS all use the old confusing functions, and will be fixed
separately in subsequent commits (with some of them just removing the
offending logic, and others using clear_page_dirty_for_io()).
This was confirmed by Martin Michlmayr to fix the apt database
corruption on ARM.
Cc: Martin Michlmayr <tbm@cyrius.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Andrei Popa <andrei.popa@i-neo.ro>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Gordon Farquharson <gordonfarquharson@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-20 21:46:42 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/*
|
|
|
|
* If truncate cannot remove the fs-private metadata from the page, the page
|
2008-02-05 06:29:33 +00:00
|
|
|
* becomes orphaned. It will be left on the LRU and may even be mapped into
|
2007-07-19 08:46:59 +00:00
|
|
|
* user pagetables if we're racing with filemap_fault().
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* We need to bale out if page->mapping is no longer equal to the original
|
|
|
|
* mapping. This happens a) when the VM reclaimed the page while we waited on
|
2007-02-10 09:45:39 +00:00
|
|
|
* its lock, b) when a concurrent invalidate_mapping_pages got there first and
|
2005-04-16 22:20:36 +00:00
|
|
|
* c) when tmpfs swizzles a page between a tmpfs inode and swapper_space.
|
|
|
|
*/
|
2009-09-16 09:50:12 +00:00
|
|
|
static int
|
2005-04-16 22:20:36 +00:00
|
|
|
truncate_complete_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (page->mapping != mapping)
|
2009-09-16 09:50:12 +00:00
|
|
|
return -EIO;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2009-04-03 15:42:36 +00:00
|
|
|
if (page_has_private(page))
|
2005-04-16 22:20:36 +00:00
|
|
|
do_invalidatepage(page, 0);
|
|
|
|
|
Fix dirty page accounting leak with ext3 data=journal
In 46d2277c796f9f4937bfa668c40b2e3f43e93dd0 ("Clean up and make
try_to_free_buffers() not race with dirty pages"), try_to_free_buffers
was changed to bail out if the page was dirty.
That in turn caused truncate_complete_page to leak massive amounts of
memory, because the dirty bit was only cleared after the call to
try_to_free_buffers.
So the call to cancel_dirty_page was moved up to have the dirty bit
cleared early in 3e67c0987d7567ad666641164a153dca9a43b11d ("truncate:
clear page dirtiness before running try_to_free_buffers()").
The problem with that fix is, that the page can be redirtied after
cancel_dirty_page was called, eg. like this:
truncate_complete_page()
cancel_dirty_page() // PG_dirty cleared, decr. dirty pages
do_invalidatepage()
ext3_invalidatepage()
journal_invalidatepage()
journal_unmap_buffer()
__dispose_buffer()
__journal_unfile_buffer()
__journal_temp_unlink_buffer()
mark_buffer_dirty(); // PG_dirty set, incr. dirty pages
And then we end up with dirty pages being wrongly accounted.
As a result, in ecdfc9787fe527491baefc22dce8b2dbd5b2908d ("Resurrect
'try_to_free_buffers()' VM hackery") the changes to try_to_free_buffers
were reverted, so the original reason for the massive memory leak is
gone, and we can also revert the move of the call to cancel_dirty_page
from truncate_complete_page and get the accounting right again.
I'm not sure if it matters, but opposed to the final check in
__remove_from_page_cache, this one also cares about the task io
accounting, so maybe we want to use this instead, although it's not
quite the clean fix either.
Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Cc: Jan Kara <jack@ucw.cz>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Osterried <osterried@jesse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 06:29:28 +00:00
|
|
|
cancel_dirty_page(page, PAGE_CACHE_SIZE);
|
|
|
|
|
2008-10-19 03:26:50 +00:00
|
|
|
clear_page_mlock(page);
|
2005-04-16 22:20:36 +00:00
|
|
|
ClearPageMappedToDisk(page);
|
2011-03-22 23:32:41 +00:00
|
|
|
delete_from_page_cache(page);
|
2009-09-16 09:50:12 +00:00
|
|
|
return 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2007-02-10 09:45:39 +00:00
|
|
|
* This is for invalidate_mapping_pages(). That function can be called at
|
2005-04-16 22:20:36 +00:00
|
|
|
* any time, and is not supposed to throw away dirty pages. But pages can
|
2006-09-27 08:50:02 +00:00
|
|
|
* be marked dirty at any time too, so use remove_mapping which safely
|
|
|
|
* discards clean, unused pages.
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* Returns non-zero if the page was successfully invalidated.
|
|
|
|
*/
|
|
|
|
static int
|
|
|
|
invalidate_complete_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
2006-09-27 08:50:02 +00:00
|
|
|
int ret;
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
if (page->mapping != mapping)
|
|
|
|
return 0;
|
|
|
|
|
2009-04-03 15:42:36 +00:00
|
|
|
if (page_has_private(page) && !try_to_release_page(page, 0))
|
2005-04-16 22:20:36 +00:00
|
|
|
return 0;
|
|
|
|
|
2008-10-19 03:26:50 +00:00
|
|
|
clear_page_mlock(page);
|
2006-09-27 08:50:02 +00:00
|
|
|
ret = remove_mapping(mapping, page);
|
|
|
|
|
|
|
|
return ret;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
2009-09-16 09:50:12 +00:00
|
|
|
int truncate_inode_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (page_mapped(page)) {
|
|
|
|
unmap_mapping_range(mapping,
|
|
|
|
(loff_t)page->index << PAGE_CACHE_SHIFT,
|
|
|
|
PAGE_CACHE_SIZE, 0);
|
|
|
|
}
|
|
|
|
return truncate_complete_page(mapping, page);
|
|
|
|
}
|
|
|
|
|
2009-09-16 09:50:13 +00:00
|
|
|
/*
|
|
|
|
* Used to get rid of pages on hardware memory corruption.
|
|
|
|
*/
|
|
|
|
int generic_error_remove_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (!mapping)
|
|
|
|
return -EINVAL;
|
|
|
|
/*
|
|
|
|
* Only punch for normal data pages for now.
|
|
|
|
* Handling other types like directories would need more auditing.
|
|
|
|
*/
|
|
|
|
if (!S_ISREG(mapping->host->i_mode))
|
|
|
|
return -EIO;
|
|
|
|
return truncate_inode_page(mapping, page);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(generic_error_remove_page);
|
|
|
|
|
2009-09-16 09:50:13 +00:00
|
|
|
/*
|
|
|
|
* Safely invalidate one page from its pagecache mapping.
|
|
|
|
* It only drops clean, unused pages. The page must be locked.
|
|
|
|
*
|
|
|
|
* Returns 1 if the page is successfully invalidated, otherwise 0.
|
|
|
|
*/
|
|
|
|
int invalidate_inode_page(struct page *page)
|
|
|
|
{
|
|
|
|
struct address_space *mapping = page_mapping(page);
|
|
|
|
if (!mapping)
|
|
|
|
return 0;
|
|
|
|
if (PageDirty(page) || PageWriteback(page))
|
|
|
|
return 0;
|
|
|
|
if (page_mapped(page))
|
|
|
|
return 0;
|
|
|
|
return invalidate_complete_page(mapping, page);
|
|
|
|
}
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/**
|
2012-02-21 02:57:20 +00:00
|
|
|
* truncate_inode_pages_range - truncate range of pages specified by start & end byte offsets
|
2005-04-16 22:20:36 +00:00
|
|
|
* @mapping: mapping to truncate
|
|
|
|
* @lstart: offset from which to truncate
|
2006-01-06 08:10:36 +00:00
|
|
|
* @lend: offset to which to truncate
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
2006-01-06 08:10:36 +00:00
|
|
|
* Truncate the page cache, removing the pages that are between
|
|
|
|
* specified offsets (and zeroing out partial page
|
|
|
|
* (if lstart is not page aligned)).
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* Truncate takes two passes - the first pass is nonblocking. It will not
|
|
|
|
* block on page locks and it will not block on writeback. The second pass
|
|
|
|
* will wait. This is to prevent as much IO as possible in the affected region.
|
|
|
|
* The first pass will remove most pages, so the search cost of the second pass
|
|
|
|
* is low.
|
|
|
|
*
|
|
|
|
* We pass down the cache-hot hint to the page freeing code. Even if the
|
|
|
|
* mapping is large, it is probably the case that the final pages are the most
|
|
|
|
* recently touched, and freeing happens in ascending file offset order.
|
|
|
|
*/
|
2006-01-06 08:10:36 +00:00
|
|
|
void truncate_inode_pages_range(struct address_space *mapping,
|
|
|
|
loff_t lstart, loff_t lend)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
const pgoff_t start = (lstart + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
|
|
|
|
const unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
|
|
|
|
struct pagevec pvec;
|
2011-07-26 00:12:25 +00:00
|
|
|
pgoff_t index;
|
|
|
|
pgoff_t end;
|
2005-04-16 22:20:36 +00:00
|
|
|
int i;
|
|
|
|
|
2011-05-26 16:01:43 +00:00
|
|
|
cleancache_flush_inode(mapping);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (mapping->nrpages == 0)
|
|
|
|
return;
|
|
|
|
|
2006-01-06 08:10:36 +00:00
|
|
|
BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
|
|
|
|
end = (lend >> PAGE_CACHE_SHIFT);
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
pagevec_init(&pvec, 0);
|
2011-07-26 00:12:25 +00:00
|
|
|
index = start;
|
|
|
|
while (index <= end && pagevec_lookup(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
|
2011-02-25 22:44:29 +00:00
|
|
|
mem_cgroup_uncharge_start();
|
2005-04-16 22:20:36 +00:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
|
|
|
|
2011-07-26 00:12:25 +00:00
|
|
|
/* We rely upon deletion not changing page->index */
|
|
|
|
index = page->index;
|
|
|
|
if (index > end)
|
2006-01-06 08:10:36 +00:00
|
|
|
break;
|
|
|
|
|
2008-08-02 10:01:03 +00:00
|
|
|
if (!trylock_page(page))
|
2005-04-16 22:20:36 +00:00
|
|
|
continue;
|
2011-07-26 00:12:25 +00:00
|
|
|
WARN_ON(page->index != index);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (PageWriteback(page)) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
}
|
2009-09-16 09:50:12 +00:00
|
|
|
truncate_inode_page(mapping, page);
|
2005-04-16 22:20:36 +00:00
|
|
|
unlock_page(page);
|
|
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
2011-02-25 22:44:29 +00:00
|
|
|
mem_cgroup_uncharge_end();
|
2005-04-16 22:20:36 +00:00
|
|
|
cond_resched();
|
2011-07-26 00:12:25 +00:00
|
|
|
index++;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
if (partial) {
|
|
|
|
struct page *page = find_lock_page(mapping, start - 1);
|
|
|
|
if (page) {
|
|
|
|
wait_on_page_writeback(page);
|
|
|
|
truncate_partial_page(page, partial);
|
|
|
|
unlock_page(page);
|
|
|
|
page_cache_release(page);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2011-07-26 00:12:25 +00:00
|
|
|
index = start;
|
2005-04-16 22:20:36 +00:00
|
|
|
for ( ; ; ) {
|
|
|
|
cond_resched();
|
2011-07-26 00:12:25 +00:00
|
|
|
if (!pagevec_lookup(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
|
|
|
|
if (index == start)
|
2005-04-16 22:20:36 +00:00
|
|
|
break;
|
2011-07-26 00:12:25 +00:00
|
|
|
index = start;
|
2005-04-16 22:20:36 +00:00
|
|
|
continue;
|
|
|
|
}
|
2011-07-26 00:12:25 +00:00
|
|
|
if (index == start && pvec.pages[0]->index > end) {
|
2006-01-06 08:10:36 +00:00
|
|
|
pagevec_release(&pvec);
|
|
|
|
break;
|
|
|
|
}
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_start();
|
2005-04-16 22:20:36 +00:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
|
|
|
|
2011-07-26 00:12:25 +00:00
|
|
|
/* We rely upon deletion not changing page->index */
|
|
|
|
index = page->index;
|
|
|
|
if (index > end)
|
2006-01-06 08:10:36 +00:00
|
|
|
break;
|
2011-07-26 00:12:25 +00:00
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
lock_page(page);
|
2011-07-26 00:12:25 +00:00
|
|
|
WARN_ON(page->index != index);
|
2005-04-16 22:20:36 +00:00
|
|
|
wait_on_page_writeback(page);
|
2009-09-16 09:50:12 +00:00
|
|
|
truncate_inode_page(mapping, page);
|
2005-04-16 22:20:36 +00:00
|
|
|
unlock_page(page);
|
|
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_end();
|
2011-07-26 00:12:25 +00:00
|
|
|
index++;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2011-05-26 16:01:43 +00:00
|
|
|
cleancache_flush_inode(mapping);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2006-01-06 08:10:36 +00:00
|
|
|
EXPORT_SYMBOL(truncate_inode_pages_range);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2006-01-06 08:10:36 +00:00
|
|
|
/**
|
|
|
|
* truncate_inode_pages - truncate *all* the pages from an offset
|
|
|
|
* @mapping: mapping to truncate
|
|
|
|
* @lstart: offset from which to truncate
|
|
|
|
*
|
2006-01-09 23:59:24 +00:00
|
|
|
* Called under (and serialised by) inode->i_mutex.
|
2011-06-27 23:18:10 +00:00
|
|
|
*
|
|
|
|
* Note: When this function returns, there can be a page in the process of
|
|
|
|
* deletion (inside __delete_from_page_cache()) in the specified range. Thus
|
|
|
|
* mapping->nrpages can be non-zero when this function returns even after
|
|
|
|
* truncation of the whole mapping.
|
2006-01-06 08:10:36 +00:00
|
|
|
*/
|
|
|
|
void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
|
|
|
|
{
|
|
|
|
truncate_inode_pages_range(mapping, lstart, (loff_t)-1);
|
|
|
|
}
|
2005-04-16 22:20:36 +00:00
|
|
|
EXPORT_SYMBOL(truncate_inode_pages);
|
|
|
|
|
2009-06-16 22:32:59 +00:00
|
|
|
/**
|
|
|
|
* invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
|
|
|
|
* @mapping: the address_space which holds the pages to invalidate
|
|
|
|
* @start: the offset 'from' which to invalidate
|
|
|
|
* @end: the offset 'to' which to invalidate (inclusive)
|
|
|
|
*
|
|
|
|
* This function only removes the unlocked pages, if you want to
|
|
|
|
* remove all the pages of one inode, you must call truncate_inode_pages.
|
|
|
|
*
|
|
|
|
* invalidate_mapping_pages() will not block on IO activity. It will not
|
|
|
|
* invalidate pages which are dirty, locked, under writeback or mapped into
|
|
|
|
* pagetables.
|
|
|
|
*/
|
|
|
|
unsigned long invalidate_mapping_pages(struct address_space *mapping,
|
2011-03-22 23:32:52 +00:00
|
|
|
pgoff_t start, pgoff_t end)
|
2005-04-16 22:20:36 +00:00
|
|
|
{
|
|
|
|
struct pagevec pvec;
|
2011-07-26 00:12:25 +00:00
|
|
|
pgoff_t index = start;
|
2011-03-22 23:32:52 +00:00
|
|
|
unsigned long ret;
|
|
|
|
unsigned long count = 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
int i;
|
|
|
|
|
2011-08-03 23:21:27 +00:00
|
|
|
/*
|
|
|
|
* Note: this function may get called on a shmem/tmpfs mapping:
|
|
|
|
* pagevec_lookup() might then return 0 prematurely (because it
|
|
|
|
* got a gangful of swap entries); but it's hardly worth worrying
|
|
|
|
* about - it can rarely have anything to free from such a mapping
|
|
|
|
* (most pages are dirty), and already skips over any difficulties.
|
|
|
|
*/
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
pagevec_init(&pvec, 0);
|
2011-07-26 00:12:25 +00:00
|
|
|
while (index <= end && pagevec_lookup(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_start();
|
2005-04-16 22:20:36 +00:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
|
|
|
struct page *page = pvec.pages[i];
|
2006-06-23 09:05:48 +00:00
|
|
|
|
2011-07-26 00:12:25 +00:00
|
|
|
/* We rely upon deletion not changing page->index */
|
2006-06-23 09:05:48 +00:00
|
|
|
index = page->index;
|
2011-07-26 00:12:25 +00:00
|
|
|
if (index > end)
|
|
|
|
break;
|
2006-06-23 09:05:48 +00:00
|
|
|
|
2011-07-26 00:12:25 +00:00
|
|
|
if (!trylock_page(page))
|
|
|
|
continue;
|
|
|
|
WARN_ON(page->index != index);
|
2011-03-22 23:32:52 +00:00
|
|
|
ret = invalidate_inode_page(page);
|
2005-04-16 22:20:36 +00:00
|
|
|
unlock_page(page);
|
2011-03-22 23:32:52 +00:00
|
|
|
/*
|
|
|
|
* Invalidation is a hint that the page is no longer
|
|
|
|
* of interest and try to speed up its reclaim.
|
|
|
|
*/
|
|
|
|
if (!ret)
|
|
|
|
deactivate_page(page);
|
|
|
|
count += ret;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_end();
|
2009-06-16 22:32:59 +00:00
|
|
|
cond_resched();
|
2011-07-26 00:12:25 +00:00
|
|
|
index++;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2011-03-22 23:32:52 +00:00
|
|
|
return count;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2007-02-10 09:45:38 +00:00
|
|
|
EXPORT_SYMBOL(invalidate_mapping_pages);
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2006-10-01 06:29:29 +00:00
|
|
|
/*
|
|
|
|
* This is like invalidate_complete_page(), except it ignores the page's
|
|
|
|
* refcount. We do this because invalidate_inode_pages2() needs stronger
|
|
|
|
* invalidation guarantees, and cannot afford to leave pages behind because
|
2007-07-16 06:38:09 +00:00
|
|
|
* shrink_page_list() has a temp ref on them, or because they're transiently
|
|
|
|
* sitting in the lru_cache_add() pagevecs.
|
2006-10-01 06:29:29 +00:00
|
|
|
*/
|
|
|
|
static int
|
|
|
|
invalidate_complete_page2(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (page->mapping != mapping)
|
|
|
|
return 0;
|
|
|
|
|
2009-04-03 15:42:36 +00:00
|
|
|
if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
|
2006-10-01 06:29:29 +00:00
|
|
|
return 0;
|
|
|
|
|
2008-07-26 02:45:32 +00:00
|
|
|
spin_lock_irq(&mapping->tree_lock);
|
2006-10-01 06:29:29 +00:00
|
|
|
if (PageDirty(page))
|
|
|
|
goto failed;
|
|
|
|
|
2008-10-19 03:26:50 +00:00
|
|
|
clear_page_mlock(page);
|
2009-04-03 15:42:36 +00:00
|
|
|
BUG_ON(page_has_private(page));
|
2011-03-22 23:32:44 +00:00
|
|
|
__delete_from_page_cache(page);
|
2008-07-26 02:45:32 +00:00
|
|
|
spin_unlock_irq(&mapping->tree_lock);
|
2009-05-28 21:34:28 +00:00
|
|
|
mem_cgroup_uncharge_cache_page(page);
|
2010-12-01 18:35:19 +00:00
|
|
|
|
|
|
|
if (mapping->a_ops->freepage)
|
|
|
|
mapping->a_ops->freepage(page);
|
|
|
|
|
2006-10-01 06:29:29 +00:00
|
|
|
page_cache_release(page); /* pagecache ref */
|
|
|
|
return 1;
|
|
|
|
failed:
|
2008-07-26 02:45:32 +00:00
|
|
|
spin_unlock_irq(&mapping->tree_lock);
|
2006-10-01 06:29:29 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2007-01-11 07:15:39 +00:00
|
|
|
static int do_launder_page(struct address_space *mapping, struct page *page)
|
|
|
|
{
|
|
|
|
if (!PageDirty(page))
|
|
|
|
return 0;
|
|
|
|
if (page->mapping != mapping || mapping->a_ops->launder_page == NULL)
|
|
|
|
return 0;
|
|
|
|
return mapping->a_ops->launder_page(page);
|
|
|
|
}
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/**
|
|
|
|
* invalidate_inode_pages2_range - remove range of pages from an address_space
|
2005-05-01 15:59:26 +00:00
|
|
|
* @mapping: the address_space
|
2005-04-16 22:20:36 +00:00
|
|
|
* @start: the page offset 'from' which to invalidate
|
|
|
|
* @end: the page offset 'to' which to invalidate (inclusive)
|
|
|
|
*
|
|
|
|
* Any pages which are found to be mapped into pagetables are unmapped prior to
|
|
|
|
* invalidation.
|
|
|
|
*
|
2008-09-02 21:35:40 +00:00
|
|
|
* Returns -EBUSY if any pages could not be invalidated.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
|
|
|
int invalidate_inode_pages2_range(struct address_space *mapping,
|
|
|
|
pgoff_t start, pgoff_t end)
|
|
|
|
{
|
|
|
|
struct pagevec pvec;
|
2011-07-26 00:12:25 +00:00
|
|
|
pgoff_t index;
|
2005-04-16 22:20:36 +00:00
|
|
|
int i;
|
|
|
|
int ret = 0;
|
2008-04-28 09:12:08 +00:00
|
|
|
int ret2 = 0;
|
2005-04-16 22:20:36 +00:00
|
|
|
int did_range_unmap = 0;
|
|
|
|
|
2011-05-26 16:01:43 +00:00
|
|
|
cleancache_flush_inode(mapping);
|
2005-04-16 22:20:36 +00:00
|
|
|
pagevec_init(&pvec, 0);
|
2011-07-26 00:12:25 +00:00
|
|
|
index = start;
|
|
|
|
while (index <= end && pagevec_lookup(&pvec, mapping, index,
|
|
|
|
min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1)) {
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_start();
|
2007-03-01 04:13:55 +00:00
|
|
|
for (i = 0; i < pagevec_count(&pvec); i++) {
|
2005-04-16 22:20:36 +00:00
|
|
|
struct page *page = pvec.pages[i];
|
2011-07-26 00:12:25 +00:00
|
|
|
|
|
|
|
/* We rely upon deletion not changing page->index */
|
|
|
|
index = page->index;
|
|
|
|
if (index > end)
|
|
|
|
break;
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
lock_page(page);
|
2011-07-26 00:12:25 +00:00
|
|
|
WARN_ON(page->index != index);
|
2005-04-16 22:20:36 +00:00
|
|
|
if (page->mapping != mapping) {
|
|
|
|
unlock_page(page);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
wait_on_page_writeback(page);
|
mm: fix fault vs invalidate race for linear mappings
Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.
The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.
The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.
Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).
Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.
Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.
This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).
This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 08:46:57 +00:00
|
|
|
if (page_mapped(page)) {
|
2005-04-16 22:20:36 +00:00
|
|
|
if (!did_range_unmap) {
|
|
|
|
/*
|
|
|
|
* Zap the rest of the file in one hit.
|
|
|
|
*/
|
|
|
|
unmap_mapping_range(mapping,
|
2011-07-26 00:12:25 +00:00
|
|
|
(loff_t)index << PAGE_CACHE_SHIFT,
|
|
|
|
(loff_t)(1 + end - index)
|
|
|
|
<< PAGE_CACHE_SHIFT,
|
2005-04-16 22:20:36 +00:00
|
|
|
0);
|
|
|
|
did_range_unmap = 1;
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Just zap this page
|
|
|
|
*/
|
|
|
|
unmap_mapping_range(mapping,
|
2011-07-26 00:12:25 +00:00
|
|
|
(loff_t)index << PAGE_CACHE_SHIFT,
|
|
|
|
PAGE_CACHE_SIZE, 0);
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
|
|
|
}
|
mm: fix fault vs invalidate race for linear mappings
Fix the race between invalidate_inode_pages and do_no_page.
Andrea Arcangeli identified a subtle race between invalidation of pages from
pagecache with userspace mappings, and do_no_page.
The issue is that invalidation has to shoot down all mappings to the page,
before it can be discarded from the pagecache. Between shooting down ptes to
a particular page, and actually dropping the struct page from the pagecache,
do_no_page from any process might fault on that page and establish a new
mapping to the page just before it gets discarded from the pagecache.
The most common case where such invalidation is used is in file truncation.
This case was catered for by doing a sort of open-coded seqlock between the
file's i_size, and its truncate_count.
Truncation will decrease i_size, then increment truncate_count before
unmapping userspace pages; do_no_page will read truncate_count, then find the
page if it is within i_size, and then check truncate_count under the page
table lock and back out and retry if it had subsequently been changed (ptl
will serialise against unmapping, and ensure a potentially updated
truncate_count is actually visible).
Complexity and documentation issues aside, the locking protocol fails in the
case where we would like to invalidate pagecache inside i_size. do_no_page
can come in anytime and filemap_nopage is not aware of the invalidation in
progress (as it is when it is outside i_size). The end result is that
dangling (->mapping == NULL) pages that appear to be from a particular file
may be mapped into userspace with nonsense data. Valid mappings to the same
place will see a different page.
Andrea implemented two working fixes, one using a real seqlock, another using
a page->flags bit. He also proposed using the page lock in do_no_page, but
that was initially considered too heavyweight. However, it is not a global or
per-file lock, and the page cacheline is modified in do_no_page to increment
_count and _mapcount anyway, so a further modification should not be a large
performance hit. Scalability is not an issue.
This patch implements this latter approach. ->nopage implementations return
with the page locked if it is possible for their underlying file to be
invalidated (in that case, they must set a special vm_flags bit to indicate
so). do_no_page only unlocks the page after setting up the mapping
completely. invalidation is excluded because it holds the page lock during
invalidation of each page (and ensures that the page is not mapped while
holding the lock).
This also allows significant simplifications in do_no_page, because we have
the page locked in the right place in the pagecache from the start.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 08:46:57 +00:00
|
|
|
BUG_ON(page_mapped(page));
|
2008-04-28 09:12:08 +00:00
|
|
|
ret2 = do_launder_page(mapping, page);
|
|
|
|
if (ret2 == 0) {
|
|
|
|
if (!invalidate_complete_page2(mapping, page))
|
2008-09-02 21:35:40 +00:00
|
|
|
ret2 = -EBUSY;
|
2008-04-28 09:12:08 +00:00
|
|
|
}
|
|
|
|
if (ret2 < 0)
|
|
|
|
ret = ret2;
|
2005-04-16 22:20:36 +00:00
|
|
|
unlock_page(page);
|
|
|
|
}
|
|
|
|
pagevec_release(&pvec);
|
2009-12-16 00:47:03 +00:00
|
|
|
mem_cgroup_uncharge_end();
|
2005-04-16 22:20:36 +00:00
|
|
|
cond_resched();
|
2011-07-26 00:12:25 +00:00
|
|
|
index++;
|
2005-04-16 22:20:36 +00:00
|
|
|
}
|
2011-05-26 16:01:43 +00:00
|
|
|
cleancache_flush_inode(mapping);
|
2005-04-16 22:20:36 +00:00
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(invalidate_inode_pages2_range);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* invalidate_inode_pages2 - remove all pages from an address_space
|
2005-05-01 15:59:26 +00:00
|
|
|
* @mapping: the address_space
|
2005-04-16 22:20:36 +00:00
|
|
|
*
|
|
|
|
* Any pages which are found to be mapped into pagetables are unmapped prior to
|
|
|
|
* invalidation.
|
|
|
|
*
|
2009-10-19 06:48:13 +00:00
|
|
|
* Returns -EBUSY if any pages could not be invalidated.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
|
|
|
int invalidate_inode_pages2(struct address_space *mapping)
|
|
|
|
{
|
|
|
|
return invalidate_inode_pages2_range(mapping, 0, -1);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
|
2009-08-20 16:35:05 +00:00
|
|
|
|
|
|
|
/**
|
|
|
|
* truncate_pagecache - unmap and remove pagecache that has been truncated
|
|
|
|
* @inode: inode
|
2011-07-26 00:12:24 +00:00
|
|
|
* @oldsize: old file size
|
|
|
|
* @newsize: new file size
|
2009-08-20 16:35:05 +00:00
|
|
|
*
|
|
|
|
* inode's new i_size must already be written before truncate_pagecache
|
|
|
|
* is called.
|
|
|
|
*
|
|
|
|
* This function should typically be called before the filesystem
|
|
|
|
* releases resources associated with the freed range (eg. deallocates
|
|
|
|
* blocks). This way, pagecache will always stay logically coherent
|
|
|
|
* with on-disk format, and the filesystem would not have to deal with
|
|
|
|
* situations such as writepage being called for a page that has already
|
|
|
|
* had its underlying blocks deallocated.
|
|
|
|
*/
|
2011-07-26 00:12:24 +00:00
|
|
|
void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize)
|
2009-08-20 16:35:05 +00:00
|
|
|
{
|
2010-01-13 12:14:09 +00:00
|
|
|
struct address_space *mapping = inode->i_mapping;
|
2011-07-26 00:12:24 +00:00
|
|
|
loff_t holebegin = round_up(newsize, PAGE_SIZE);
|
2010-01-13 12:14:09 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* unmap_mapping_range is called twice, first simply for
|
|
|
|
* efficiency so that truncate_inode_pages does fewer
|
|
|
|
* single-page unmaps. However after this first call, and
|
|
|
|
* before truncate_inode_pages finishes, it is possible for
|
|
|
|
* private pages to be COWed, which remain after
|
|
|
|
* truncate_inode_pages finishes, hence the second
|
|
|
|
* unmap_mapping_range call must be made for correctness.
|
|
|
|
*/
|
2011-07-26 00:12:24 +00:00
|
|
|
unmap_mapping_range(mapping, holebegin, 0, 1);
|
|
|
|
truncate_inode_pages(mapping, newsize);
|
|
|
|
unmap_mapping_range(mapping, holebegin, 0, 1);
|
2009-08-20 16:35:05 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_pagecache);
|
|
|
|
|
2010-06-04 09:30:04 +00:00
|
|
|
/**
|
|
|
|
* truncate_setsize - update inode and pagecache for a new file size
|
|
|
|
* @inode: inode
|
|
|
|
* @newsize: new file size
|
|
|
|
*
|
2011-01-20 22:44:26 +00:00
|
|
|
* truncate_setsize updates i_size and performs pagecache truncation (if
|
|
|
|
* necessary) to @newsize. It will be typically be called from the filesystem's
|
|
|
|
* setattr function when ATTR_SIZE is passed in.
|
2010-06-04 09:30:04 +00:00
|
|
|
*
|
2011-01-20 22:44:26 +00:00
|
|
|
* Must be called with inode_mutex held and before all filesystem specific
|
|
|
|
* block truncation has been performed.
|
2010-06-04 09:30:04 +00:00
|
|
|
*/
|
|
|
|
void truncate_setsize(struct inode *inode, loff_t newsize)
|
|
|
|
{
|
|
|
|
loff_t oldsize;
|
|
|
|
|
|
|
|
oldsize = inode->i_size;
|
|
|
|
i_size_write(inode, newsize);
|
|
|
|
|
|
|
|
truncate_pagecache(inode, oldsize, newsize);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(truncate_setsize);
|
|
|
|
|
2009-08-20 16:35:05 +00:00
|
|
|
/**
|
|
|
|
* vmtruncate - unmap mappings "freed" by truncate() syscall
|
|
|
|
* @inode: inode of the file used
|
2011-07-26 00:12:24 +00:00
|
|
|
* @newsize: file offset to start truncating
|
2009-08-20 16:35:05 +00:00
|
|
|
*
|
2010-06-04 09:30:04 +00:00
|
|
|
* This function is deprecated and truncate_setsize or truncate_pagecache
|
|
|
|
* should be used instead, together with filesystem specific block truncation.
|
2009-08-20 16:35:05 +00:00
|
|
|
*/
|
2011-07-26 00:12:24 +00:00
|
|
|
int vmtruncate(struct inode *inode, loff_t newsize)
|
2009-08-20 16:35:05 +00:00
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2011-07-26 00:12:24 +00:00
|
|
|
error = inode_newsize_ok(inode, newsize);
|
2009-08-20 16:35:05 +00:00
|
|
|
if (error)
|
|
|
|
return error;
|
fs: introduce new truncate sequence
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 <hch@lst.de>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-26 15:05:33 +00:00
|
|
|
|
2011-07-26 00:12:24 +00:00
|
|
|
truncate_setsize(inode, newsize);
|
2009-08-20 16:35:05 +00:00
|
|
|
if (inode->i_op->truncate)
|
|
|
|
inode->i_op->truncate(inode);
|
2010-06-04 09:30:04 +00:00
|
|
|
return 0;
|
2009-08-20 16:35:05 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(vmtruncate);
|
2011-06-27 23:18:01 +00:00
|
|
|
|
2011-07-26 00:12:24 +00:00
|
|
|
int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend)
|
2011-06-27 23:18:01 +00:00
|
|
|
{
|
|
|
|
struct address_space *mapping = inode->i_mapping;
|
2011-07-26 00:12:24 +00:00
|
|
|
loff_t holebegin = round_up(lstart, PAGE_SIZE);
|
|
|
|
loff_t holelen = 1 + lend - holebegin;
|
2011-06-27 23:18:01 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* If the underlying filesystem is not going to provide
|
|
|
|
* a way to truncate a range of blocks (punch a hole) -
|
|
|
|
* we should return failure right now.
|
|
|
|
*/
|
|
|
|
if (!inode->i_op->truncate_range)
|
|
|
|
return -ENOSYS;
|
|
|
|
|
|
|
|
mutex_lock(&inode->i_mutex);
|
2011-06-24 18:29:43 +00:00
|
|
|
inode_dio_wait(inode);
|
2011-07-26 00:12:24 +00:00
|
|
|
unmap_mapping_range(mapping, holebegin, holelen, 1);
|
|
|
|
inode->i_op->truncate_range(inode, lstart, lend);
|
tmpfs: take control of its truncate_range
2.6.35's new truncate convention gave tmpfs the opportunity to control
its file truncation, no longer enforced from outside by vmtruncate().
We shall want to build upon that, to handle pagecache and swap together.
Slightly redefine the ->truncate_range interface: let it now be called
between the unmap_mapping_range()s, with the filesystem responsible for
doing the truncate_inode_pages_range() from it - just as the filesystem
is nowadays responsible for doing that from its ->setattr.
Let's rename shmem_notify_change() to shmem_setattr(). Instead of
calling the generic truncate_setsize(), bring that code in so we can
call shmem_truncate_range() - which will later be updated to perform its
own variant of truncate_inode_pages_range().
Remove the punch_hole unmap_mapping_range() from shmem_truncate_range():
now that the COW's unmap_mapping_range() comes after ->truncate_range,
there is no need to call it a third time.
Export shmem_truncate_range() and add it to the list in shmem_fs.h, so
that i915_gem_object_truncate() can call it explicitly in future; get
this patch in first, then update drm/i915 once this is available (until
then, i915 will just be doing the truncate_inode_pages() twice).
Though introduced five years ago, no other filesystem is implementing
->truncate_range, and its only other user is madvise(,,MADV_REMOVE): we
expect to convert it to fallocate(,FALLOC_FL_PUNCH_HOLE,,) shortly,
whereupon ->truncate_range can be removed from inode_operations -
shmem_truncate_range() will help i915 across that transition too.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 23:18:03 +00:00
|
|
|
/* unmap again to remove racily COWed private pages */
|
2011-07-26 00:12:24 +00:00
|
|
|
unmap_mapping_range(mapping, holebegin, holelen, 1);
|
2011-06-27 23:18:01 +00:00
|
|
|
mutex_unlock(&inode->i_mutex);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|