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2017-10-12new primitive: iov_iter_for_each_range()Al Viro1-0/+4
For kvec and bvec: feeds segments to given callback as long as it returns 0. For iovec and pipe: fails. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-10-12kill iov_shorten()Al Viro1-2/+0
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-10fix brown paperbag bug in inlined copy_..._iter()Al Viro1-4/+4
"copied nothing" == "return 0", not "return full size". Fixes: aa28de275a24 "iov_iter/hardening: move object size checks to inlined part" Spotted-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-08Merge branch 'uaccess-work.iov_iter' of ↵Linus Torvalds1-10/+64
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull iov_iter hardening from Al Viro: "This is the iov_iter/uaccess/hardening pile. For one thing, it trims the inline part of copy_to_user/copy_from_user to the minimum that *does* need to be inlined - object size checks, basically. For another, it sanitizes the checks for iov_iter primitives. There are 4 groups of checks: access_ok(), might_fault(), object size and KASAN. - access_ok() had been verified by whoever had set the iov_iter up. However, that has happened in a function far away, so proving that there's no path to actual copying bypassing those checks is hard and proving that iov_iter has not been buggered in the meanwhile is also not pleasant. So we want those redone in actual copyin/copyout. - might_fault() is better off consolidated - we know whether it needs to be checked as soon as we enter iov_iter primitive and observe the iov_iter flavour. No need to wait until the copyin/copyout. The call chains are short enough to make sure we won't miss anything - in fact, it's more robust that way, since there are cases where we do e.g. forced fault-in before getting to copyin/copyout. It's not quite what we need to check (in particular, combination of iovec-backed and set_fs(KERNEL_DS) is almost certainly a bug, not a cause to skip checks), but that's for later series. For now let's keep might_fault(). - KASAN checks belong in copyin/copyout - at the same level where other iov_iter flavours would've hit them in memcpy(). - object size checks should apply to *all* iov_iter flavours, not just iovec-backed ones. There are two groups of primitives - one gets the kernel object described as pointer + size (copy_to_iter(), etc.) while another gets it as page + offset + size (copy_page_to_iter(), etc.) For the first group the checks are best done where we actually have a chance to find the object size. In other words, those belong in inline wrappers in uio.h, before calling into iov_iter.c. Same kind as we have for inlined part of copy_to_user(). For the second group there is no object to look at - offset in page is just a number, it bears no type information. So we do them in the common helper called by iov_iter.c primitives of that kind. All it currently does is checking that we are not trying to access outside of the compound page; eventually we might want to add some sanity checks on the page involved. So the things we need in copyin/copyout part of iov_iter.c do not quite match anything in uaccess.h (we want no zeroing, we *do* want access_ok() and KASAN and we want no might_fault() or object size checks done on that level). OTOH, these needs are simple enough to provide a couple of helpers (static in iov_iter.c) doing just what we need..." * 'uaccess-work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: iov_iter: saner checks on copyin/copyout iov_iter: sanity checks for copy to/from page primitives iov_iter/hardening: move object size checks to inlined part copy_{to,from}_user(): consolidate object size checks copy_{from,to}_user(): move kasan checks and might_fault() out-of-line
2017-06-30iov_iter/hardening: move object size checks to inlined partAl Viro1-5/+53
There we actually have useful information about object sizes. Note: this patch has them done for all iov_iter flavours. Right now we do them twice in iovec case, but that'll change very shortly. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-06-09x86, uaccess: introduce copy_from_iter_flushcache for pmem / cache-bypass ↵Dan Williams1-0/+15
operations The pmem driver has a need to transfer data with a persistent memory destination and be able to rely on the fact that the destination writes are not cached. It is sufficient for the writes to be flushed to a cpu-store-buffer (non-temporal / "movnt" in x86 terms), as we expect userspace to call fsync() to ensure data-writes have reached a power-fail-safe zone in the platform. The fsync() triggers a REQ_FUA or REQ_FLUSH to the pmem driver which will turn around and fence previous writes with an "sfence". Implement a __copy_from_user_inatomic_flushcache, memcpy_page_flushcache, and memcpy_flushcache, that guarantee that the destination buffer is not dirty in the cpu cache on completion. The new copy_from_iter_flushcache and sub-routines will be used to replace the "pmem api" (include/linux/pmem.h + arch/x86/include/asm/pmem.h). The availability of copy_from_iter_flushcache() and memcpy_flushcache() are gated by the CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE config symbol, and fallback to copy_from_iter_nocache() and plain memcpy() otherwise. This is meant to satisfy the concern from Linus that if a driver wants to do something beyond the normal nocache semantics it should be something private to that driver [1], and Al's concern that anything uaccess related belongs with the rest of the uaccess code [2]. The first consumer of this interface is a new 'copy_from_iter' dax operation so that pmem can inject cache maintenance operations without imposing this overhead on other dax-capable drivers. [1]: https://lists.01.org/pipermail/linux-nvdimm/2017-January/008364.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2017-April/009942.html Cc: <x86@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-02[iov_iter] new privimitive: iov_iter_revert()Al Viro1-1/+5
opposite to iov_iter_advance(); the caller is responsible for never using it to move back past the initial position. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-16Merge branch 'for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: - more ->d_init() stuff (work.dcache) - pathname resolution cleanups (work.namei) - a few missing iov_iter primitives - copy_from_iter_full() and friends. Either copy the full requested amount, advance the iterator and return true, or fail, return false and do _not_ advance the iterator. Quite a few open-coded callers converted (and became more readable and harder to fuck up that way) (work.iov_iter) - several assorted patches, the big one being logfs removal * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: logfs: remove from tree vfs: fix put_compat_statfs64() does not handle errors namei: fold should_follow_link() with the step into not-followed link namei: pass both WALK_GET and WALK_MORE to should_follow_link() namei: invert WALK_PUT logics namei: shift interpretation of LOOKUP_FOLLOW inside should_follow_link() namei: saner calling conventions for mountpoint_last() namei.c: get rid of user_path_parent() switch getfrag callbacks to ..._full() primitives make skb_add_data,{_nocache}() and skb_copy_to_page_nocache() advance only on success [iov_iter] new primitives - copy_from_iter_full() and friends don't open-code file_inode() ceph: switch to use of ->d_init() ceph: unify dentry_operations instances lustre: switch to use of ->d_init()
2016-12-05[iov_iter] new primitives - copy_from_iter_full() and friendsAl Viro1-0/+3
copy_from_iter_full(), copy_from_iter_full_nocache() and csum_and_copy_from_iter_full() - counterparts of copy_from_iter() et.al., advancing iterator only in case of successful full copy and returning whether it had been successful or not. Convert some obvious users. *NOTE* - do not blindly assume that something is a good candidate for those unless you are sure that not advancing iov_iter in failure case is the right thing in this case. Anything that does short read/short write kind of stuff (or is in a loop, etc.) is unlikely to be a good one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-11-01fs: decouple READ and WRITE from the block layer opsChristoph Hellwig1-1/+1
Move READ and WRITE to kernel.h and don't define them in terms of block layer ops; they are our generic data direction indicators these days and have no more resemblance with the block layer ops. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-10Merge branch 'work.splice_read' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull splice fixups from Al Viro: "A couple of fixups for interaction of pipe-backed iov_iter with O_DIRECT reads + constification of a couple of primitives in uio.h missed by previous rounds. Kudos to davej - his fuzzing has caught those bugs" * 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [btrfs] fix check_direct_IO() for non-iovec iterators constify iov_iter_count() and iter_is_iovec() fix ITER_PIPE interaction with direct_IO
2016-10-10Merge branch 'work.misc' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-10constify iov_iter_count() and iter_is_iovec()Al Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-06new iov_iter flavour: pipe-backedAl Viro1-3/+11
iov_iter variant for passing data into pipe. copy_to_iter() copies data into page(s) it has allocated and stuffs them into the pipe; copy_page_to_iter() stuffs there a reference to the page given to it. Both will try to coalesce if possible. iov_iter_zero() is similar to copy_to_iter(); iov_iter_get_pages() and friends will do as copy_to_iter() would have and return the pages where the data would've been copied. iov_iter_advance() will truncate everything past the spot it has advanced to. New primitive: iov_iter_pipe(), used for initializing those. pipe should be locked all along. Running out of space acts as fault would for iovec-backed ones; in other words, giving it to ->read_iter() may result in short read if the pipe overflows, or -EFAULT if it happens with nothing copied there. In other words, ->read_iter() on those acts pretty much like ->splice_read(). Moreover, all generic_file_splice_read() users, as well as many other ->splice_read() instances can be switched to that scheme - that'll happen in the next commit. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-28get rid of separate multipage fault-in primitivesAl Viro1-1/+0
* the only remaining callers of "short" fault-ins are just as happy with generic variants (both in lib/iov_iter.c); switch them to multipage variants, kill the "short" ones * rename the multipage variants to now available plain ones. * get rid of compat macro defining iov_iter_fault_in_multipage_readable by expanding it in its only user. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-18fix iov_iter_fault_in_readable()Al Viro1-1/+1
... by turning it into what used to be multipages counterpart Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-09fix the copy vs. map logics in blk_rq_map_user_iov()Al Viro1-0/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07iov_iter: constify {csum_and_,}copy_to_iter()Al Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-12new helper: iov_iter_rw()Omar Sandoval1-0/+8
Get either READ or WRITE out of iter->type. Signed-off-by: Omar Sandoval <osandov@osandov.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-12Merge branch 'iov_iter' into for-nextAl Viro1-0/+14
2015-04-12VFS: Add iov_iter_fault_in_multipages_readable()Anton Altaparmakov1-0/+1
simillar to iov_iter_fault_in_readable() but differs in that it is not limited to faulting in the first iovec and instead faults in "bytes" bytes iterating over the iovecs as necessary. Also, instead of only faulting in the first and last page of the range, all pages are faulted in. This function is needed by NTFS when it does multi page file writes. Signed-off-by: Anton Altaparmakov <anton@tuxera.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-30saner iov_iter initialization primitivesAl Viro1-0/+14
iovec-backed iov_iter instances are assumed to satisfy several properties: * no more than UIO_MAXIOV elements in iovec array * total size of all ranges is no more than MAX_RW_COUNT * all ranges pass access_ok(). The problem is, invariants of data structures should be established in the primitives creating those data structures, not in the code using those primitives. And iov_iter_init() violates that principle. For a while we managed to get away with that, but once the use of iov_iter started to spread, it didn't take long for shit to hit the fan - missed check in sys_sendto() had introduced a roothole. We _do_ have primitives for importing and validating iovecs (both native and compat ones) and those primitives are almost always followed by shoving the resulting iovec into iov_iter. Life would be considerably simpler (and safer) if we combined those primitives with initializing iov_iter. That gives us two new primitives - import_iovec() and compat_import_iovec(). Calling conventions: iovec = iov_array; err = import_iovec(direction, uvec, nr_segs, ARRAY_SIZE(iov_array), &iovec, &iter); imports user vector into kernel space (into iov_array if it fits, allocated if it doesn't fit or if iovec was NULL), validates it and sets iter up to refer to it. On success 0 is returned and allocated kernel copy (or NULL if the array had fit into caller-supplied one) is returned via iovec. On failure all allocations are undone and -E... is returned. If the total size of ranges exceeds MAX_RW_COUNT, the excess is silently truncated. compat_import_iovec() expects uvec to be a pointer to user array of compat_iovec; otherwise it's identical to import_iovec(). Finally, import_single_range() sets iov_iter backed by single-element iovec covering a user-supplied range - err = import_single_range(direction, address, size, iovec, &iter); does validation and sets iter up. Again, size in excess of MAX_RW_COUNT gets silently truncated. Next commits will be switching the things up to use of those and reducing the amount of iov_iter_init() instances. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-18new helper: dup_iter()Al Viro1-0/+2
Copy iter and kmemdup the underlying array for the copy. Returns a pointer to result of kmemdup() to be kfree()'d later. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-18Merge branch 'iov_iter' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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()
2015-02-04vhost: vhost_scsi_handle_vq() should just use copy_from_user()Al Viro1-2/+0
it has just verified that it asks no more than the length of the first segment of iovec. And with that the last user of stuff in lib/iovec.c is gone. RIP. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Nicholas A. Bellinger <nab@linux-iscsi.org> Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-04vhost: don't bother copying iovecs in handle_rx(), kill memcpy_toiovecend()Al Viro1-3/+0
Cc: Michael S. Tsirkin <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-04vhost: switch vhost get_indirect() to iov_iter, kill memcpy_fromiovec()Al Viro1-1/+0
Cc: Michael S. Tsirkin <mst@redhat.com> Cc: kvm@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-29new helper: iov_iter_bvec()Al Viro1-1/+3
similar to iov_iter_kvec(), for ITER_BVEC ones Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-17new helper: iter_is_iovec()Al Viro1-0/+5
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10bury memcpy_toiovec()Al Viro1-1/+0
no users left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09copy_from_iter_nocache()Al Viro1-0/+1
BTW, do we want memcpy_nocache()? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09new helper: iov_iter_kvec()Al Viro1-0/+2
initialization of kvec-backed iov_iter Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09csum_and_copy_..._iter()Al Viro1-0/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-09iov_iter.c: handle ITER_KVEC directlyAl Viro1-0/+1
... without bothering with copy_..._user() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09Add copy_to_iter(), copy_from_iter() and iov_iter_zero()Matthew Wilcox1-0/+3
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>
2014-09-27fuse: honour max_read and max_write in direct_io modeMiklos Szeredi1-1/+1
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: c9c37e2e6378 ("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>
2014-08-07switch iov_iter_get_pages() to passing maximal number of pagesAl Viro1-1/+1
... instead of maximal size. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pendingLinus Torvalds1-1/+4
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
2014-06-27iovec: move memcpy_from/toiovecend to lib/iovec.cMichael S. Tsirkin1-1/+4
ERROR: "memcpy_fromiovecend" [drivers/vhost/vhost_scsi.ko] undefined! commit 9f977ef7b671f6169eca78bf40f230fe84b7c7e5 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>
2014-06-27Fix 32-bit regression in block device read(2)Al Viro1-1/+13
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>
2014-05-07bio_vec-backed iov_iterAl Viro1-2/+12
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>
2014-05-07lustre: get rid of messing with iovecsAl Viro1-0/+9
* 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>
2014-05-07new helper: copy_page_from_iter()Al Viro1-0/+2
parallel to copy_page_to_iter(). pipe_write() switched to it (and became ->write_iter()). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-07iov_iter_truncate()Al Viro1-0/+6
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>
2014-05-07new helper: iov_iter_get_pages_alloc()Al Viro1-0/+2
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>
2014-05-07new helper: iov_iter_npages()Al Viro1-0/+1
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>
2014-05-07new helper: iov_iter_get_pages()Al Viro1-0/+2
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>
2014-05-07start adding the tag to iov_iterAl Viro1-12/+3
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>
2014-05-07new primitive: iov_iter_alignment()Al Viro1-0/+2
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>
2014-05-07kill iov_iter_copy_from_user()Al Viro1-2/+0
all callers can use copy_page_from_iter() and it actually simplifies them. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>