path: root/lib
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-17 12:08:18 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-17 12:08:18 -0800
commit16382e17c0ff583df2d5eed56ca7c771d637e9d1 (patch)
tree568c5a69b55d08cda20b8e1367df3135dbafeeb6 /lib
parent93f30c73ecd0281cf3685ef0e4e384980a176176 (diff)
parentcfe057f7db1ff026c8db75469a3f9ba9736e1975 (diff)
Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro: - bio_{map,copy}_user_iov() series; those are cleanups - fixes from the same pile went into mainline (and stable) in late September. - fs/iomap.c iov_iter-related fixes - new primitive - iov_iter_for_each_range(), which applies a function to kernel-mapped segments of an iov_iter. Usable for kvec and bvec ones, the latter does kmap()/kunmap() around the callback. _Not_ usable for iovec- or pipe-backed iov_iter; the latter is not hard to fix if the need ever appears, the former is by design. Another related primitive will have to wait for the next cycle - it passes page + offset + size instead of pointer + size, and that one will be usable for everything _except_ kvec. Unfortunately, that one didn't get exposure in -next yet, so... - a bit more lustre iov_iter work, including a use case for iov_iter_for_each_range() (checksum calculation) - vhost/scsi leak fix in failure exit - misc cleanups and detritectomy... * 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits) iomap_dio_actor(): fix iov_iter bugs switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range() lustre: switch struct ksock_conn to iov_iter vhost/scsi: switch to iov_iter_get_pages() fix a page leak in vhost_scsi_iov_to_sgl() error recovery new primitive: iov_iter_for_each_range() lnet_return_rx_credits_locked: don't abuse list_entry xen: don't open-code iov_iter_kvec() orangefs: remove detritus from struct orangefs_kiocb_s kill iov_shorten() bio_alloc_map_data(): do bmd->iter setup right there bio_copy_user_iov(): saner bio size calculation bio_map_user_iov(): get rid of copying iov_iter bio_copy_from_iter(): get rid of copying iov_iter move more stuff down into bio_copy_user_iov() blk_rq_map_user_iov(): move iov_iter_advance() down bio_map_user_iov(): get rid of the iov_for_each() bio_map_user_iov(): move alignment check into the main loop don't rely upon subsequent bio_add_pc_page() calls failing ... and with iov_iter_get_pages_alloc() it becomes even simpler ...
Diffstat (limited to 'lib')
1 files changed, 22 insertions, 0 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1c1c06ddc20a..970212670b6a 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1446,3 +1446,25 @@ int import_single_range(int rw, void __user *buf, size_t len,
return 0;
+int iov_iter_for_each_range(struct iov_iter *i, size_t bytes,
+ int (*f)(struct kvec *vec, void *context),
+ void *context)
+ struct kvec w;
+ int err = -EINVAL;
+ if (!bytes)
+ return 0;
+ iterate_all_kinds(i, bytes, v, -EINVAL, ({
+ w.iov_base = kmap(v.bv_page) + v.bv_offset;
+ w.iov_len = v.bv_len;
+ err = f(&w, context);
+ kunmap(v.bv_page);
+ err;}), ({
+ w = v;
+ err = f(&w, context);})
+ )
+ return err;

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