unfortunately, Ted's changes to ext4_file_write() are *still* an
incomplete fix - playing with rlimits can let you smuggle an
unaligned request past the checks. So there almost certainly
will be more merge PITA around that place...
[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
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
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>
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>
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>
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
Al Viro
Linus Torvalds
Fabian Frederick
Will Woods
Ian Kent
Nishanth Aravamudan