Beginning to introduce those. Just the callers for now, and it's
clumsier than it'll eventually become; once we finish converting
aio_read and aio_write instances, the things will get nicer.
For now, these guys are in parallel to ->aio_read() and ->aio_write();
they take iocb and iov_iter, with everything in iov_iter already
validated. File offset is passed in iocb->ki_pos, iov/nr_segs -
in iov_iter.
Main concerns in that series are stack footprint and ability to
split the damn thing cleanly.
[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Since we are about to introduce new methods (read_iter/write_iter), the
tests in a bunch of places would have to grow inconveniently. Check
once (at open() time) and store results in ->f_mode as FMODE_CAN_READ
and FMODE_CAN_WRITE resp. It might end up being a temporary measure -
once everything switches from ->aio_{read,write} to ->{read,write}_iter
it might make sense to return to open-coded checks. We'll see...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pos is redundant (it's iocb->ki_pos), and iov/nr_segs/count are taken
care of by lifting iov_iter into the caller.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.
Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
same as iov_iter_get_pages(), except that pages array is allocated
(kmalloc if possible, vmalloc if that fails) and left for caller to
free. Lustre and NFS ->direct_IO() switched to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
counts the pages covered by iov_iter, up to given limit.
do_block_direct_io() and fuse_iter_npages() switched to
it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
iov_iter_get_pages(iter, pages, maxsize, &start) grabs references pinning
the pages of up to maxsize of (contiguous) data from iter. Returns the
amount of memory grabbed or -error. In case of success, the requested
area begins at offset start in pages[0] and runs through pages[1], etc.
Less than requested amount might be returned - either because the contiguous
area in the beginning of iterator is smaller than requested, or because
the kernel failed to pin that many pages.
direct-io.c switched to using iov_iter_get_pages()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For now, just use the same thing we pass to ->direct_IO() - it's all
iovec-based at the moment. Pass it explicitly to iov_iter_init() and
account for kvec vs. iovec in there, by the same kludge NFS ->direct_IO()
uses.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
iov_iter-using variant of generic_file_aio_read(). Some callers
converted. Note that it's still not quite there for use as ->read_iter() -
we depend on having zero iter->iov_offset in O_DIRECT case. Fortunately,
that's true for all converted callers (and for generic_file_aio_read() itself).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
returns the value aligned as badly as the worst remaining segment
in iov_iter is. Use instead of open-coded equivalents.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
the thing is, we want to advance what's given to ->direct_IO() as we
are forming the request; however, the callers care about the amount
of data actually transferred, not the amount we tried to transfer.
It's more convenient to allow ->direct_IO() instances do use
iov_iter_advance() on the copy of iov_iter, leaving the actual
advancing of the original to caller.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
all callers of ->aio_read() and ->aio_write() have iov/nr_segs already
checked - generic_segment_checks() done after that is just an odd way
to spell iov_length().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Merge misc fixes from Andrew Morton:
"13 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
agp: info leak in agpioc_info_wrap()
fs/affs/super.c: bugfix / double free
fanotify: fix -EOVERFLOW with large files on 64-bit
slub: use sysfs'es release mechanism for kmem_cache
revert "mm: vmscan: do not swap anon pages just because free+file is low"
autofs: fix lockref lookup
mm: filemap: update find_get_pages_tag() to deal with shadow entries
mm/compaction: make isolate_freepages start at pageblock boundary
MAINTAINERS: zswap/zbud: change maintainer email address
mm/page-writeback.c: fix divide by zero in pos_ratio_polynom
hugetlb: ensure hugepage access is denied if hugepages are not supported
slub: fix memcg_propagate_slab_attrs
drivers/rtc/rtc-pcf8523.c: fix month definition
On 64 bit systems the agp_info struct has a 4 byte hole between
->agp_mode and ->aper_base. We need to clear it to avoid disclosing
stack information to userspace.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 842a859db2 ("affs: use ->kill_sb() to simplify ->put_super()
and failure exits of ->mount()") adds .kill_sb which frees sbi but
doesn't remove sbi free in case of parse_options error causing double
free+random crash.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org> [3.14.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On 64-bit systems, O_LARGEFILE is automatically added to flags inside
the open() syscall (also openat(), blkdev_open(), etc). Userspace
therefore defines O_LARGEFILE to be 0 - you can use it, but it's a
no-op. Everything should be O_LARGEFILE by default.
But: when fanotify does create_fd() it uses dentry_open(), which skips
all that. And userspace can't set O_LARGEFILE in fanotify_init()
because it's defined to 0. So if fanotify gets an event regarding a
large file, the read() will just fail with -EOVERFLOW.
This patch adds O_LARGEFILE to fanotify_init()'s event_f_flags on 64-bit
systems, using the same test as open()/openat()/etc.
Addresses https://bugzilla.redhat.com/show_bug.cgi?id=696821
Signed-off-by: Will Woods <wwoods@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 0bf1457f0c ("mm: vmscan: do not swap anon pages
just because free+file is low") because it introduced a regression in
mostly-anonymous workloads, where reclaim would become ineffective and
trap every allocating task in direct reclaim.
The problem is that there is a runaway feedback loop in the scan balance
between file and anon, where the balance tips heavily towards a tiny
thrashing file LRU and anonymous pages are no longer being looked at.
The commit in question removed the safe guard that would detect such
situations and respond with forced anonymous reclaim.
This commit was part of a series to fix premature swapping in loads with
relatively little cache, and while it made a small difference, the cure
is obviously worse than the disease. Revert it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org> [3.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
autofs needs to be able to see private data dentry flags for its dentrys
that are being created but not yet hashed and for its dentrys that have
been rmdir()ed but not yet freed. It needs to do this so it can block
processes in these states until a status has been returned to indicate
the given operation is complete.
It does this by keeping two lists, active and expring, of dentrys in
this state and uses ->d_release() to keep them stable while it checks
the reference count to determine if they should be used.
But with the recent lockref changes dentrys being freed sometimes don't
transition to a reference count of 0 before being freed so autofs can
occassionally use a dentry that is invalid which can lead to a panic.
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Jones reports the following crash when find_get_pages_tag() runs
into an exceptional entry:
kernel BUG at mm/filemap.c:1347!
RIP: find_get_pages_tag+0x1cb/0x220
Call Trace:
find_get_pages_tag+0x36/0x220
pagevec_lookup_tag+0x21/0x30
filemap_fdatawait_range+0xbe/0x1e0
filemap_fdatawait+0x27/0x30
sync_inodes_sb+0x204/0x2a0
sync_inodes_one_sb+0x19/0x20
iterate_supers+0xb2/0x110
sys_sync+0x44/0xb0
ia32_do_call+0x13/0x13
1343 /*
1344 * This function is never used on a shmem/tmpfs
1345 * mapping, so a swap entry won't be found here.
1346 */
1347 BUG();
After commit 0cd6144aad ("mm + fs: prepare for non-page entries in
page cache radix trees") this comment and BUG() are out of date because
exceptional entries can now appear in all mappings - as shadows of
recently evicted pages.
However, as Hugh Dickins notes,
"it is truly surprising for a PAGECACHE_TAG_WRITEBACK (and probably
any other PAGECACHE_TAG_*) to appear on an exceptional entry.
I expect it comes down to an occasional race in RCU lookup of the
radix_tree: lacking absolute synchronization, we might sometimes
catch an exceptional entry, with the tag which really belongs with
the unexceptional entry which was there an instant before."
And indeed, not only is the tree walk lockless, the tags are also read
in chunks, one radix tree node at a time. There is plenty of time for
page reclaim to swoop in and replace a page that was already looked up
as tagged with a shadow entry.
Remove the BUG() and update the comment. While reviewing all other
lookup sites for whether they properly deal with shadow entries of
evicted pages, update all the comments and fix memcg file charge moving
to not miss shmem/tmpfs swapcache pages.
Fixes: 0cd6144aad ("mm + fs: prepare for non-page entries in page cache radix trees")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compaction freepage scanner implementation in isolate_freepages()
starts by taking the current cc->free_pfn value as the first pfn. In a
for loop, it scans from this first pfn to the end of the pageblock, and
then subtracts pageblock_nr_pages from the first pfn to obtain the first
pfn for the next for loop iteration.
This means that when cc->free_pfn starts at offset X rather than being
aligned on pageblock boundary, the scanner will start at offset X in all
scanned pageblock, ignoring potentially many free pages. Currently this
can happen when
a) zone's end pfn is not pageblock aligned, or
b) through zone->compact_cached_free_pfn with CONFIG_HOLES_IN_ZONE
enabled and a hole spanning the beginning of a pageblock
This patch fixes the problem by aligning the initial pfn in
isolate_freepages() to pageblock boundary. This also permits replacing
the end-of-pageblock alignment within the for loop with a simple
pageblock_nr_pages increment.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Heesub Shin <heesub.shin@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Dongjun Shin <d.j.shin@samsung.com>
Cc: Sunghwan Yun <sunghwan.yun@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sjenning@linux.vnet.ibm.com is no longer a viable entity.
Signed-off-by: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is possible for "limit - setpoint + 1" to equal zero, after getting
truncated to a 32 bit variable, and resulting in a divide by zero error.
Using the fully 64 bit divide functions avoids this problem. It also
will cause pos_ratio_polynom() to return the correct value when
(setpoint - limit) exceeds 2^32.
Also uninline pos_ratio_polynom, at Andrew's request.
Signed-off-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, I am seeing the following when I `mount -t hugetlbfs /none
/dev/hugetlbfs`, and then simply do a `ls /dev/hugetlbfs`. I think it's
related to the fact that hugetlbfs is properly not correctly setting
itself up in this state?:
Unable to handle kernel paging request for data at address 0x00000031
Faulting instruction address: 0xc000000000245710
Oops: Kernel access of bad area, sig: 11 [#1]
SMP NR_CPUS=2048 NUMA pSeries
....
In KVM guests on Power, in a guest not backed by hugepages, we see the
following:
AnonHugePages: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 64 kB
HPAGE_SHIFT == 0 in this configuration, which indicates that hugepages
are not supported at boot-time, but this is only checked in
hugetlb_init(). Extract the check to a helper function, and use it in a
few relevant places.
This does make hugetlbfs not supported (not registered at all) in this
environment. I believe this is fine, as there are no valid hugepages
and that won't change at runtime.
[akpm@linux-foundation.org: use pr_info(), per Mel]
[akpm@linux-foundation.org: fix build when HPAGE_SHIFT is undefined]
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After creating a cache for a memcg we should initialize its sysfs attrs
with the values from its parent. That's what memcg_propagate_slab_attrs
is for. Currently it's broken - we clearly muddled root-vs-memcg caches
there. Let's fix it up.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PCF8523 uses 1-12 to represent month according to datasheet.
link: www.nxp.com/documents/data_sheet/PCF8523.pdf.
Signed-off-by: Chris Cui <chris.wei.cui@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs fixes from Al Viro:
"dcache fixes + kvfree() (uninlined, exported by mm/util.c) + posix_acl
bugfix from hch"
The dcache fixes are for a subtle LRU list corruption bug reported by
Miklos Szeredi, where people inside IBM saw list corruptions with the
LTP/host01 test.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
nick kvfree() from apparmor
posix_acl: handle NULL ACL in posix_acl_equiv_mode
dcache: don't need rcu in shrink_dentry_list()
more graceful recovery in umount_collect()
don't remove from shrink list in select_collect()
dentry_kill(): don't try to remove from shrink list
expand the call of dentry_lru_del() in dentry_kill()
new helper: dentry_free()
fold try_prune_one_dentry()
fold d_kill() and d_free()
fix races between __d_instantiate() and checks of dentry flags
Various filesystems don't bother checking for a NULL ACL in
posix_acl_equiv_mode, and thus can dereference a NULL pointer when it
gets passed one. This usually happens from the NFS server, as the ACL tools
never pass a NULL ACL, but instead of one representing the mode bits.
Instead of adding boilerplat to all filesystems put this check into one place,
which will allow us to remove the check from other filesystems as well later
on.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ben Greear <greearb@candelatech.com>
Reported-by: Marco Munderloh <munderl@tnt.uni-hannover.de>,
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull fuse fixes from Miklos Szeredi:
"This adds ctime update in the new cached writeback mode and also
fixes/simplifies the mtime update handling. Support for rename flags
(aka renameat2) is also added to the userspace API"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: add renameat2 support
fuse: clear MS_I_VERSION
fuse: clear FUSE_I_CTIME_DIRTY flag on setattr
fuse: trust kernel i_ctime only
fuse: remove .update_time
fuse: allow ctime flushing to userspace
fuse: fuse: add time_gran to INIT_OUT
fuse: add .write_inode
fuse: clean up fsync
fuse: fuse: fallocate: use file_update_time()
fuse: update mtime on open(O_TRUNC) in atomic_o_trunc mode
fuse: update mtime on truncate(2)
fuse: do not use uninitialized i_mode
fuse: fix mtime update error in fsync
fuse: check fallocate mode
fuse: add __exit to fuse_ctl_cleanup
Pull sparc fixes from David Miller:
"I've been auditing the THP support on sparc64 and found several bugs,
hopefully most of which are fixed completely here.
Also an RT kernel locking fix from Kirill Tkhai"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc64: Give more detailed information in {pgd,pmd}_ERROR() and kill pte_ERROR().
sparc64: Add basic validations to {pud,pmd}_bad().
sparc64: Use 'ILOG2_4MB' instead of constant '22'.
sparc64: Fix range check in kern_addr_valid().
sparc64: Fix top-level fault handling bugs.
sparc64: Handle 32-bit tasks properly in compute_effective_address().
sparc64: Don't use _PAGE_PRESENT in pte_modify() mask.
sparc64: Fix hex values in comment above pte_modify().
sparc64: Fix bugs in get_user_pages_fast() wrt. THP.
sparc64: Fix huge PMD invalidation.
sparc64: Fix executable bit testing in set_pmd_at() paths.
sparc64: Normalize NMI watchdog logging and behavior.
sparc64: Make itc_sync_lock raw
sparc64: Fix argument sign extension for compat_sys_futex().
If freelist_idx_t is a byte, SLAB_OBJ_MAX_NUM should be 255 not 256, and
likewise if freelist_idx_t is a short, then it should be 65535 not
65536.
This was leading to all kinds of random crashes on sparc64 where
PAGE_SIZE is 8192. One problem shown was that if spinlock debugging was
enabled, we'd get deadlocks in copy_pte_range() or do_wp_page() with the
same cpu already holding a lock it shouldn't hold, or the lock belonging
to a completely unrelated process.
Fixes: a41adfaa23 ("slab: introduce byte sized index for the freelist of a slab")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a41adfaa23 ("slab: introduce byte sized index for the freelist
of a slab") changes the size of freelist index and also changes
prototype of accessor function to freelist index. And there was a
mistake.
The mistake is that although it changes the size of freelist index
correctly, it changes the size of the index of freelist index
incorrectly. With patch, freelist index can be 1 byte or 2 bytes, that
means that num of object on on a slab can be more than 255. So we need
more than 1 byte for the index to find the index of free object on
freelist. But, above patch makes this index type 1 byte, so slab which
have more than 255 objects cannot work properly and in consequence of
it, the system cannot boot.
This issue was reported by Steven King on m68knommu which would use
2 bytes freelist index:
https://lkml.org/lkml/2014/4/16/433
To fix is easy. To change the type of the index of freelist index on
accessor functions is enough to fix this bug. Although 2 bytes is
enough, I use 4 bytes since it have no bad effect and make things more
easier. This fix was suggested and tested by Steven in his original
report.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reported-and-acked-by: Steven King <sfking@fdwdc.com>
Acked-by: Christoph Lameter <cl@linux.com>
Tested-by: James Hogan <james.hogan@imgtec.com>
Tested-by: David Miller <davem@davemloft.net>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
