24 Sep, 2009
2 commits
-
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
truncate: use new helpers
truncate: new helpers
fs: fix overflow in sys_mount() for in-kernel calls
fs: Make unload_nls() NULL pointer safe
freeze_bdev: grab active reference to frozen superblocks
freeze_bdev: kill bd_mount_sem
exofs: remove BKL from super operations
fs/romfs: correct error-handling code
vfs: seq_file: add helpers for data filling
vfs: remove redundant position check in do_sendfile
vfs: change sb->s_maxbytes to a loff_t
vfs: explicitly cast s_maxbytes in fiemap_check_ranges
libfs: return error code on failed attr set
seq_file: return a negative error code when seq_path_root() fails.
vfs: optimize touch_time() too
vfs: optimization for touch_atime()
vfs: split generic_forget_inode() so that hugetlbfs does not have to copy it
fs/inode.c: add dev-id and inode number for debugging in init_special_inode()
libfs: make simple_read_from_buffer conventional -
Introduce new truncate helpers truncate_pagecache and inode_newsize_ok.
vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and
into mm/truncate.c.Reviewed-by: Christoph Hellwig
Signed-off-by: Nick Piggin
Signed-off-by: Al Viro
16 Sep, 2009
3 commits
-
Truncating metadata pages is not safe right now before
we haven't audited all file systems.To enable truncation only for data address space define
a new address_space callback error_remove_page.This is used for memory_failure.c memory error handling.
This can be then set to truncate_inode_page()
This patch just defines the new operation and adds documentation.
Callers and users come in followon patches.
Signed-off-by: Andi Kleen
-
Add a simple way to invalidate a single page
This is just a refactoring of the truncate.c code.
Originally from Fengguang, modified by Andi Kleen.Signed-off-by: Andi Kleen
-
Extract out truncate_inode_page() out of the truncate path so that
it can be used by memory-failure.c[AK: description, headers, fix typos]
v2: Some white space changes from Fengguang WuSigned-off-by: Andi Kleen
17 Jun, 2009
1 commit
-
Remove __invalidate_mapping_pages atomic variant now that its sole caller
can sleep (fixed in eccb95cee4f0d56faa46ef22fb94dd4a3578d3eb ("vfs: fix
lock inversion in drop_pagecache_sb()")).This fixes softlockups that can occur while in the drop_caches path.
Signed-off-by: Mike Waychison
Cc: Jan Kara
Cc: Wu Fengguang
Cc: Dave Chinner
Cc: Nick Piggin
Acked-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 May, 2009
1 commit
-
mapping->tree_lock can be acquired from interrupt context. Then,
following dead lock can occur.Assume "A" as a page.
CPU0:
lock_page_cgroup(A)
interrupted
-> take mapping->tree_lock.
CPU1:
take mapping->tree_lock
-> lock_page_cgroup(A)This patch tries to fix above deadlock by moving memcg's hook to out of
mapping->tree_lock. charge/uncharge of pagecache/swapcache is protected
by page lock, not tree_lock.After this patch, lock_page_cgroup() is not called under mapping->tree_lock.
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Daisuke Nishimura
Cc: Balbir Singh
Cc: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Apr, 2009
1 commit
-
Recruit a page flag to aid in cache management. The following extra flag is
defined:(1) PG_fscache (PG_private_2)
The marked page is backed by a local cache and is pinning resources in the
cache driver.If PG_fscache is set, then things that checked for PG_private will now also
check for that. This includes things like truncation and page invalidation.
The function page_has_private() had been added to make the checks for both
PG_private and PG_private_2 at the same time.Signed-off-by: David Howells
Acked-by: Steve Dickson
Acked-by: Trond Myklebust
Acked-by: Rik van Riel
Acked-by: Al Viro
Tested-by: Daire Byrne
20 Oct, 2008
1 commit
-
Originally by Nick Piggin
Remove mlocked pages from the LRU using "unevictable infrastructure"
during mmap(), munmap(), mremap() and truncate(). Try to move back to
normal LRU lists on munmap() when last mlocked mapping removed. Remove
PageMlocked() status when page truncated from file.[akpm@linux-foundation.org: cleanup]
[kamezawa.hiroyu@jp.fujitsu.com: fix double unlock_page()]
[kosaki.motohiro@jp.fujitsu.com: split LRU: munlock rework]
[lee.schermerhorn@hp.com: mlock: fix __mlock_vma_pages_range comment block]
[akpm@linux-foundation.org: remove bogus kerneldoc token]
Signed-off-by: Nick Piggin
Signed-off-by: Lee Schermerhorn
Signed-off-by: Rik van Riel
Signed-off-by: KOSAKI Motohiro
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2008
1 commit
-
People can use the real name an an index into MAINTAINERS to find the
current email address.Signed-off-by: Francois Cami
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Sep, 2008
1 commit
-
Dio write returns EIO when try_to_release_page fails because bh is
still referenced.The patch
commit 3f31fddfa26b7594b44ff2b34f9a04ba409e0f91
Author: Mingming Cao
Date: Fri Jul 25 01:46:22 2008 -0700jbd: fix race between free buffer and commit transaction
was merged into 2.6.27-rc1, but I noticed that this patch is not enough
to fix the race.I did fsstress test heavily to 2.6.27-rc1, and found that dio write still
sometimes got EIO through this test.The patch above fixed race between freeing buffer(dio) and committing
transaction(jbd) but I discovered that there is another race, freeing
buffer(dio) and ext3/4_ordered_writepage.: background_writeout()
->write_cache_pages()
->ext3_ordered_writepage()
walk_page_buffers() -> take a bh ref
block_write_full_page() -> unlock_page
: try_to_release_page fails)
walk_page_buffers() ->release a bh refext3_ordered_writepage holds bh ref and does unlock_page remaining
taking a bh ref, so this causes the race and failure of
try_to_release_page.To fix this race, I used the approach of falling back to buffered
writes if try_to_release_page() fails on a page.[akpm@linux-foundation.org: cleanups]
Signed-off-by: Hisashi Hifumi
Cc: Chris Mason
Cc: Jan Kara
Cc: Mingming Cao
Cc: Zach Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Aug, 2008
1 commit
-
Converting page lock to new locking bitops requires a change of page flag
operation naming, so we might as well convert it to something nicer
(!TestSetPageLocked_Lock => trylock_page, SetPageLocked => set_page_locked).This also facilitates lockdeping of page lock.
Signed-off-by: Nick Piggin
Acked-by: KOSAKI Motohiro
Acked-by: Peter Zijlstra
Acked-by: Andrew Morton
Acked-by: Benjamin Herrenschmidt
Signed-off-by: Linus Torvalds
03 Aug, 2008
1 commit
-
Brian Wang reported that a FUSE filesystem exported through NFS could
return I/O errors on read. This was traced to splice_direct_to_actor()
returning a short or zero count when racing with page invalidation.However this is not FUSE or NFSD specific, other filesystems (notably
NFS) also call invalidate_inode_pages2() to purge stale data from the
cache.If this happens while such pages are sitting in a pipe buffer, then
splice(2) from the pipe can return zero, and read(2) from the pipe can
return ENODATA.The zero return is especially bad, since it implies end-of-file or
disconnected pipe/socket, and is documented as such for splice. But
returning an error for read() is also nasty, when in fact there was no
error (data becoming stale is not an error).The same problems can be triggered by "hole punching" with
madvise(MADV_REMOVE).Fix this by not clearing the PG_uptodate flag on truncation and
invalidation.Signed-off-by: Miklos Szeredi
Acked-by: Nick Piggin
Cc: Andrew Morton
Cc: Jens Axboe
Signed-off-by: Linus Torvalds
27 Jul, 2008
1 commit
-
mapping->tree_lock has no read lockers. convert the lock from an rwlock
to a spinlock.Signed-off-by: Nick Piggin
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Hugh Dickins
Cc: "Paul E. McKenney"
Reviewed-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Apr, 2008
1 commit
-
DIO invalidates page cache through invalidate_inode_pages2_range().
invalidate_inode_pages2_range() sets ret=-EIO when
invalidate_complete_page2() fails, but this ret is cleared if
do_launder_page() succeed on a page of next index.In this case, dio is carried out even if invalidate_complete_page2() fails
on some pages.This can cause inconsistency between memory and blocks on HDD because the
page cache still exists.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Hisashi Hifumi
Cc: Badari Pulavarty
Cc: Ken Chen
Cc: Zach Brown
Cc: Nick Piggin
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Cc: Chuck Lever
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Mar, 2008
1 commit
-
Fix docbook problems in kernel-api.tmpl.
These cause the generated docbook to be incorrect.Signed-off-by: Randy Dunlap
Signed-off-by: Linus Torvalds
06 Feb, 2008
3 commits
-
Orphaned page might have fs-private metadata, the page is truncated. As
the page hasn't mapping, page migration refuse to migrate the page. It
appears the page is only freed in page reclaim and if zone watermark is
low, the page is never freed, as a result migration always fail. I thought
we could free the metadata so such page can be freed in migration and make
migration more reliable.[akpm@linux-foundation.org: go direct to try_to_free_buffers()]
Signed-off-by: Shaohua Li
Acked-by: Nick Piggin
Acked-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 pagesAnd 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
Tested-by: Krzysztof Piotr Oledzki
Cc: Jan Kara
Cc: Nick Piggin
Cc: Peter Zijlstra
Cc: Thomas Osterried
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Simplify page cache zeroing of segments of pages through 3 functions
zero_user_segments(page, start1, end1, start2, end2)
Zeros two segments of the page. It takes the position where to
start and end the zeroing which avoids length calculations and
makes code clearer.zero_user_segment(page, start, end)
Same for a single segment.
zero_user(page, start, length)
Length variant for the case where we know the length.
We remove the zero_user_page macro. Issues:
1. Its a macro. Inline functions are preferable.
2. The KM_USER0 macro is only defined for HIGHMEM.
Having to treat this special case everywhere makes the
code needlessly complex. The parameter for zeroing is always
KM_USER0 except in one single case that we open code.Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.Also extract the flushing of the caches to be outside of the kmap.
[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter
Cc: Steven French
Cc: Michael Halcrow
Cc:
Cc: Steven Whitehouse
Cc: Trond Myklebust
Cc: "J. Bruce Fields"
Cc: Anton Altaparmakov
Cc: Mark Fasheh
Cc: David Chinner
Cc: Michael Halcrow
Cc: Steven French
Cc: Steven Whitehouse
Cc: Trond Myklebust
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Feb, 2008
1 commit
-
Fix a typo in the comment for do_invalidatepage().
Signed-off-by: Fengguang Wu
Signed-off-by: Adrian Bunk
17 Oct, 2007
2 commits
-
mm.h doesn't use directly anything from mutex.h and backing-dev.h, so
remove them and add them back to files which need them.Cross-compile tested on many configs and archs.
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Count per BDI reclaimable pages; nr_reclaimable = nr_dirty + nr_unstable.
Signed-off-by: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
2 commits
-
Nonlinear mappings are (AFAIKS) simply a virtual memory concept that encodes
the virtual address -> file offset differently from linear mappings.->populate is a layering violation because the filesystem/pagecache code
should need to know anything about the virtual memory mapping. The hitch here
is that the ->nopage handler didn't pass down enough information (ie. pgoff).
But it is more logical to pass pgoff rather than have the ->nopage function
calculate it itself anyway (because that's a similar layering violation).Having the populate handler install the pte itself is likewise a nasty thing
to be doing.This patch introduces a new fault handler that replaces ->nopage and
->populate and (later) ->nopfn. Most of the old mechanism is still in place
so there is a lot of duplication and nice cleanups that can be removed if
everyone switches over.The rationale for doing this in the first place is that nonlinear mappings are
subject to the pagefault vs invalidate/truncate race too, and it seemed stupid
to duplicate the synchronisation logic rather than just consolidate the two.After this patch, MAP_NONBLOCK no longer sets up ptes for pages present in
pagecache. Seems like a fringe functionality anyway.NOPAGE_REFAULT is removed. This should be implemented with ->fault, and no
users have hit mainline yet.[akpm@linux-foundation.org: cleanup]
[randy.dunlap@oracle.com: doc. fixes for readahead]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Nick Piggin
Signed-off-by: Randy Dunlap
Cc: Mark Fasheh
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 Jul, 2007
1 commit
-
It is a bug to set a page dirty if it is not uptodate unless it has
buffers. If the page has buffers, then the page may be dirty (some buffers
dirty) but not uptodate (some buffers not uptodate). The exception to this
rule is if the set_page_dirty caller is racing with truncate or invalidate.A buffer can not be set dirty if it is not uptodate.
If either of these situations occurs, it indicates there could be some data
loss problem. Some of these warnings could be a harmless one where the
page or buffer is set uptodate immediately after it is dirtied, however we
should fix those up, and enforce this ordering.Bring the order of operations for truncate into line with those of
invalidate. This will prevent a page from being able to go !uptodate while
we're holding the tree_lock, which is probably a good thing anyway.Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jul, 2007
2 commits
-
invalidate_mapping_pages() can sometimes take a long time (millions of pages
to free). Long enough for the softlockup detector to trigger.We used to have a cond_resched() in there but I took it out because the
drop_caches code calls invalidate_mapping_pages() under inode_lock.The patch adds a nasty flag and puts the cond_resched() back.
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix the shrink_list name on some files under mm/ directory.
Signed-off-by: Anderson Briglia
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 May, 2007
1 commit
-
It's very common for file systems to need to zero part or all of a page,
the simplist way is just to use kmap_atomic() and memset(). There's
actually a library function in include/linux/highmem.h that does exactly
that, but it's confusingly named memclear_highpage_flush(), which is
descriptive of *how* it does the work rather than what the *purpose* is.
So this patchset renames the function to zero_user_page(), and calls it
from the various places that currently open code it.This first patch introduces the new function call, and converts all the
core kernel callsites, both the open-coded ones and the old
memclear_highpage_flush() ones. Following this patch is a series of
conversions for each file system individually, per AKPM, and finally a
patch deprecating the old call. The diffstat below shows the entire
patchset.[akpm@linux-foundation.org: fix a few things]
Signed-off-by: Nate Diller
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2007
1 commit
-
Fix invalidate_inode_pages2_range() so that it does not immediately exit
just because a single page in the specified range could not be removed.Signed-off-by: Trond Myklebust
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Feb, 2007
2 commits
-
Convert all calls to invalidate_inode_pages() into open-coded calls to
invalidate_mapping_pages().Leave the invalidate_inode_pages() wrapper in place for now, marked as
deprecated.Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It makes no sense to me to export invalidate_inode_pages() and not
invalidate_mapping_pages() and I actually need invalidate_mapping_pages()
because of its range specification ability...akpm: also remove the export of invalidate_inode_pages() by making it an
inlined wrapper.Signed-off-by: Anton Altaparmakov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jan, 2007
2 commits
-
NFS can handle the case where invalidate_inode_pages2_range() fails, so the
premise behind commit 8258d4a574d3a8c01f0ef68aa26b969398a0e140 is now gone.Remove the WARN_ON_ONCE() which is causing users grief as we can see from
http://bugzilla.kernel.org/show_bug.cgi?id=7826Signed-off-by: Trond Myklebust
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Acked-by: Jens Axboe
Acked-by: Peter Zijlstra
Cc: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jan, 2007
1 commit
-
NFS: Fix race in nfs_release_page()
invalidate_inode_pages2() may find the dirty bit has been set on a page
owing to the fact that the page may still be mapped after it was locked.
Only after the call to unmap_mapping_range() are we sure that the page
can no longer be dirtied.
In order to fix this, NFS has hooked the releasepage() method and tries
to write the page out between the call to unmap_mapping_range() and the
call to remove_mapping(). This, however leads to deadlocks in the page
reclaim code, where the page may be locked without holding a reference
to the inode or dentry.Fix is to add a new address_space_operation, launder_page(), which will
attempt to write out a dirty page without releasing the page lock.Signed-off-by: Trond Myklebust
Also, the bare SetPageDirty() can skew all sort of accounting leading to
other nasties.[akpm@osdl.org: cleanup]
Signed-off-by: Peter Zijlstra
Cc: Trond Myklebust
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Dec, 2006
1 commit
-
Make cancel_dirty_page() act more like all the other dirty and writeback
accounting functions: test for "mapping" being NULL, and do the
NR_FILE_DIRY accounting purely based on mapping_cap_account_dirty()).Also, add it to the exports, so that modular filesystems can use it.
Acked-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Dec, 2006
1 commit
-
Only (un)account for IO and page-dirtying for devices which have real backing
store (ie: not tmpfs or ramdisks).Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Dec, 2006
2 commits
-
truncate presently invalidates the dirty page's buffer_heads then shoots down
the page. But try_to_free_buffers() will now bale out because the page is
dirty.Net effect: the LRU gets filled with dirty pages which have invalidated
buffer_heads attached. They have no ->mapping and hence cannot be cleaned.
The machine leaks memory at an enormous rate.Fix this by cleaning the page before running try_to_free_buffers(), so
try_to_free_buffers() can do its work.Also, remember to do dirty-page-acoounting in cancel_dirty_page() so the
machine won't wedge up trying to write non-existent dirty pages.Probably still wrong, but now less so.
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Cc: Peter Zijlstra
Cc: Hugh Dickins
Cc: Nick Piggin
Cc: Arjan van de Ven
Cc: Andrei Popa
Cc: Andrew Morton
Cc: Dave Kleikamp
Cc: Gordon Farquharson
Cc: Martin Schwidefsky
Cc: Trond Myklebust
Signed-off-by: Linus Torvalds
11 Dec, 2006
1 commit
-
Account for the number of byte writes which this process caused to not happen
after all.Cc: Jay Lan
Cc: Shailabh Nagar
Cc: Balbir Singh
Cc: Chris Sturtivant
Cc: Tony Ernst
Cc: Guillaume Thouvenin
Cc: David Wright
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2006
1 commit
-
If remove_mapping() failed to remove the page from its mapping, don't go and
mark it not uptodate! Makes kernel go dead.(Actually, I don't think the ClearPageUptodate is needed there at all).
Says Nick Piggin:
"Right, it isn't needed because at this point the page is guaranteed
by remove_mapping to have no references (except us) and cannot pick
up any new ones because it is removed from pagecache.We can delete it."
Signed-off-by: Andrew Morton
Acked-by: Nick Piggin
Signed-off-by: Linus Torvalds