Pull iov_iter updates from Al Viro:
"More iov_iter work - missing counterpart of iov_iter_init() for
bvec-backed ones and vfs_read_iter()/vfs_write_iter() - wrappers for
sync calls of ->read_iter()/->write_iter()"
* 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: add vfs_iter_{read,write} helpers
new helper: iov_iter_bvec()
For DAX, we want to be able to copy between iovecs and kernel addresses
that don't necessarily have a struct page. This is a fairly simple
rearrangement for bvec iters to kmap the pages outside and pass them in,
but for user iovecs it gets more complicated because we might try various
different ways to kmap the memory. Duplicating the existing logic works
out best in this case.
We need to be able to write zeroes to an iovec for reads from unwritten
ranges in a file. This is performed by the new iov_iter_zero() function,
again patterned after the existing code that handles iovec iterators.
[AV: and export the buggers...]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The third argument of fuse_get_user_pages() "nbytesp" refers to the number of
bytes a caller asked to pack into fuse request. This value may be lesser
than capacity of fuse request or iov_iter. So fuse_get_user_pages() must
ensure that *nbytesp won't grow.
Now, when helper iov_iter_get_pages() performs all hard work of extracting
pages from iov_iter, it can be done by passing properly calculated
"maxsize" to the helper.
The other caller of iov_iter_get_pages() (dio_refill_pages()) doesn't need
this capability, so pass LONG_MAX as the maxsize argument here.
Fixes: c9c37e2e63 ("fuse: switch to iov_iter_get_pages()")
Reported-by: Werner Baumann <werner.baumann@onlinehome.de>
Tested-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull SCSI target fixes from Nicholas Bellinger:
"Mostly minor fixes this time around. The highlights include:
- iscsi-target CHAP authentication fixes to enforce explicit key
values (Tejas Vaykole + rahul.rane)
- fix a long-standing OOPs in target-core when a alua configfs
attribute is accessed after port symlink has been removed.
(Sebastian Herbszt)
- fix a v3.10.y iscsi-target regression causing the login reject
status class/detail to be ignored (Christoph Vu-Brugier)
- fix a v3.10.y iscsi-target regression to avoid rejecting an
existing ITT during Data-Out when data-direction is wrong (Santosh
Kulkarni + Arshad Hussain)
- fix a iscsi-target related shutdown deadlock on UP kernels (Mikulas
Patocka)
- fix a v3.16-rc1 build issue with vhost-scsi + !CONFIG_NET (MST)"
* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
iscsi-target: fix iscsit_del_np deadlock on unload
iovec: move memcpy_from/toiovecend to lib/iovec.c
iscsi-target: Avoid rejecting incorrect ITT for Data-Out
tcm_loop: Fix memory leak in tcm_loop_submission_work error path
iscsi-target: Explicily clear login response PDU in exception path
target: Fix left-over se_lun->lun_sep pointer OOPs
iscsi-target; Enforce 1024 byte maximum for CHAP_C key value
iscsi-target: Convert chap_server_compute_md5 to use kstrtoul
ERROR: "memcpy_fromiovecend" [drivers/vhost/vhost_scsi.ko] undefined!
commit 9f977ef7b6
vhost-scsi: Include prot_bytes into expected data transfer length
in target-pending makes drivers/vhost/scsi.c call memcpy_fromiovecend().
This function is not available when CONFIG_NET is not enabled.
socket.h already includes uio.h, so no callers need updating.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
blkdev_read_iter() wants to cap the iov_iter by the amount of data
remaining to the end of device. That's what iov_iter_truncate() is for
(trim iter->count if it's above the given limit). So far, so good, but
the argument of iov_iter_truncate() is size_t, so on 32bit boxen (in
case of a large device) we end up with that upper limit truncated down
to 32 bits *before* comparing it with iter->count.
Easily fixed by making iov_iter_truncate() take 64bit argument - it does
the right thing after such change (we only reach the assignment in there
when the current value of iter->count is greater than the limit, i.e.
for anything that would get truncated we don't reach the assignment at
all) and that argument is not the new value of iter->count - it's an
upper limit for such.
The overhead of passing u64 is not an issue - the thing is inlined, so
callers passing size_t won't pay any penalty.
Reported-and-tested-by: Theodore Tso <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Tested-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
New variant of iov_iter - ITER_BVEC in iter->type, backed with
bio_vec array instead of iovec one. Primitives taught to deal
with such beasts, __swap_write() switched to using that kind
of iov_iter.
Note that bio_vec is just a <page, offset, length> triple - there's
nothing block-specific about it. I've left the definition where it
was, but took it from under ifdef CONFIG_BLOCK.
Next target: ->splice_write()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* switch to ->read_iter/->write_iter
* keep a pointer to iov_iter instead of iov/nr_segs
* do not modify iovecs; use iov_iter_truncate()/iov_iter_advance() and
a new primitive - iov_iter_reexpand() (expand previously truncated
iterator) istead.
* (racy) check for lustre VMAs intersecting with iovecs kept for now as
for_each_iov() loop.
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>
