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authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-13 11:28:42 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-13 11:28:42 +0200
commit77c688ac87183537ed0fb84ec2cb8fa8ec97c458 (patch)
treed18e117e05c0d71463823536165ddd9ad75b6bc5 /mm
parent5e40d331bd72447197f26525f21711c4a265b6a6 (diff)
parenta457606a6f81cfddfc9da1ef2a8bf2c65a8eb35e (diff)
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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...
Diffstat (limited to 'mm')
-rw-r--r--mm/iov_iter.c240
1 files changed, 226 insertions, 14 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 9a09f2034fcc..eafcf60f6b83 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -4,6 +4,96 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
+static size_t copy_to_iter_iovec(void *from, size_t bytes, struct iov_iter *i)
+{
+ size_t skip, copy, left, wanted;
+ const struct iovec *iov;
+ char __user *buf;
+
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ wanted = bytes;
+ iov = i->iov;
+ skip = i->iov_offset;
+ buf = iov->iov_base + skip;
+ copy = min(bytes, iov->iov_len - skip);
+
+ left = __copy_to_user(buf, from, copy);
+ copy -= left;
+ skip += copy;
+ from += copy;
+ bytes -= copy;
+ while (unlikely(!left && bytes)) {
+ iov++;
+ buf = iov->iov_base;
+ copy = min(bytes, iov->iov_len);
+ left = __copy_to_user(buf, from, copy);
+ copy -= left;
+ skip = copy;
+ from += copy;
+ bytes -= copy;
+ }
+
+ if (skip == iov->iov_len) {
+ iov++;
+ skip = 0;
+ }
+ i->count -= wanted - bytes;
+ i->nr_segs -= iov - i->iov;
+ i->iov = iov;
+ i->iov_offset = skip;
+ return wanted - bytes;
+}
+
+static size_t copy_from_iter_iovec(void *to, size_t bytes, struct iov_iter *i)
+{
+ size_t skip, copy, left, wanted;
+ const struct iovec *iov;
+ char __user *buf;
+
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ wanted = bytes;
+ iov = i->iov;
+ skip = i->iov_offset;
+ buf = iov->iov_base + skip;
+ copy = min(bytes, iov->iov_len - skip);
+
+ left = __copy_from_user(to, buf, copy);
+ copy -= left;
+ skip += copy;
+ to += copy;
+ bytes -= copy;
+ while (unlikely(!left && bytes)) {
+ iov++;
+ buf = iov->iov_base;
+ copy = min(bytes, iov->iov_len);
+ left = __copy_from_user(to, buf, copy);
+ copy -= left;
+ skip = copy;
+ to += copy;
+ bytes -= copy;
+ }
+
+ if (skip == iov->iov_len) {
+ iov++;
+ skip = 0;
+ }
+ i->count -= wanted - bytes;
+ i->nr_segs -= iov - i->iov;
+ i->iov = iov;
+ i->iov_offset = skip;
+ return wanted - bytes;
+}
+
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -166,6 +256,50 @@ done:
return wanted - bytes;
}
+static size_t zero_iovec(size_t bytes, struct iov_iter *i)
+{
+ size_t skip, copy, left, wanted;
+ const struct iovec *iov;
+ char __user *buf;
+
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ wanted = bytes;
+ iov = i->iov;
+ skip = i->iov_offset;
+ buf = iov->iov_base + skip;
+ copy = min(bytes, iov->iov_len - skip);
+
+ left = __clear_user(buf, copy);
+ copy -= left;
+ skip += copy;
+ bytes -= copy;
+
+ while (unlikely(!left && bytes)) {
+ iov++;
+ buf = iov->iov_base;
+ copy = min(bytes, iov->iov_len);
+ left = __clear_user(buf, copy);
+ copy -= left;
+ skip = copy;
+ bytes -= copy;
+ }
+
+ if (skip == iov->iov_len) {
+ iov++;
+ skip = 0;
+ }
+ i->count -= wanted - bytes;
+ i->nr_segs -= iov - i->iov;
+ i->iov = iov;
+ i->iov_offset = skip;
+ return wanted - bytes;
+}
+
static size_t __iovec_copy_from_user_inatomic(char *vaddr,
const struct iovec *iov, size_t base, size_t bytes)
{
@@ -414,12 +548,17 @@ static void memcpy_to_page(struct page *page, size_t offset, char *from, size_t
kunmap_atomic(to);
}
-static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, size_t bytes,
- struct iov_iter *i)
+static void memzero_page(struct page *page, size_t offset, size_t len)
+{
+ char *addr = kmap_atomic(page);
+ memset(addr + offset, 0, len);
+ kunmap_atomic(addr);
+}
+
+static size_t copy_to_iter_bvec(void *from, size_t bytes, struct iov_iter *i)
{
size_t skip, copy, wanted;
const struct bio_vec *bvec;
- void *kaddr, *from;
if (unlikely(bytes > i->count))
bytes = i->count;
@@ -432,8 +571,6 @@ static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, size_t by
skip = i->iov_offset;
copy = min_t(size_t, bytes, bvec->bv_len - skip);
- kaddr = kmap_atomic(page);
- from = kaddr + offset;
memcpy_to_page(bvec->bv_page, skip + bvec->bv_offset, from, copy);
skip += copy;
from += copy;
@@ -446,7 +583,6 @@ static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, size_t by
from += copy;
bytes -= copy;
}
- kunmap_atomic(kaddr);
if (skip == bvec->bv_len) {
bvec++;
skip = 0;
@@ -458,12 +594,10 @@ static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, size_t by
return wanted - bytes;
}
-static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, size_t bytes,
- struct iov_iter *i)
+static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i)
{
size_t skip, copy, wanted;
const struct bio_vec *bvec;
- void *kaddr, *to;
if (unlikely(bytes > i->count))
bytes = i->count;
@@ -475,10 +609,6 @@ static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, size_t
bvec = i->bvec;
skip = i->iov_offset;
- kaddr = kmap_atomic(page);
-
- to = kaddr + offset;
-
copy = min(bytes, bvec->bv_len - skip);
memcpy_from_page(to, bvec->bv_page, bvec->bv_offset + skip, copy);
@@ -495,7 +625,6 @@ static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, size_t
to += copy;
bytes -= copy;
}
- kunmap_atomic(kaddr);
if (skip == bvec->bv_len) {
bvec++;
skip = 0;
@@ -507,6 +636,61 @@ static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, size_t
return wanted;
}
+static size_t copy_page_to_iter_bvec(struct page *page, size_t offset,
+ size_t bytes, struct iov_iter *i)
+{
+ void *kaddr = kmap_atomic(page);
+ size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i);
+ kunmap_atomic(kaddr);
+ return wanted;
+}
+
+static size_t copy_page_from_iter_bvec(struct page *page, size_t offset,
+ size_t bytes, struct iov_iter *i)
+{
+ void *kaddr = kmap_atomic(page);
+ size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i);
+ kunmap_atomic(kaddr);
+ return wanted;
+}
+
+static size_t zero_bvec(size_t bytes, struct iov_iter *i)
+{
+ size_t skip, copy, wanted;
+ const struct bio_vec *bvec;
+
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ wanted = bytes;
+ bvec = i->bvec;
+ skip = i->iov_offset;
+ copy = min_t(size_t, bytes, bvec->bv_len - skip);
+
+ memzero_page(bvec->bv_page, skip + bvec->bv_offset, copy);
+ skip += copy;
+ bytes -= copy;
+ while (bytes) {
+ bvec++;
+ copy = min(bytes, (size_t)bvec->bv_len);
+ memzero_page(bvec->bv_page, bvec->bv_offset, copy);
+ skip = copy;
+ bytes -= copy;
+ }
+ if (skip == bvec->bv_len) {
+ bvec++;
+ skip = 0;
+ }
+ i->count -= wanted - bytes;
+ i->nr_segs -= bvec - i->bvec;
+ i->bvec = bvec;
+ i->iov_offset = skip;
+ return wanted - bytes;
+}
+
static size_t copy_from_user_bvec(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes)
{
@@ -672,6 +856,34 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
}
EXPORT_SYMBOL(copy_page_from_iter);
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+ if (i->type & ITER_BVEC)
+ return copy_to_iter_bvec(addr, bytes, i);
+ else
+ return copy_to_iter_iovec(addr, bytes, i);
+}
+EXPORT_SYMBOL(copy_to_iter);
+
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+ if (i->type & ITER_BVEC)
+ return copy_from_iter_bvec(addr, bytes, i);
+ else
+ return copy_from_iter_iovec(addr, bytes, i);
+}
+EXPORT_SYMBOL(copy_from_iter);
+
+size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
+{
+ if (i->type & ITER_BVEC) {
+ return zero_bvec(bytes, i);
+ } else {
+ return zero_iovec(bytes, i);
+ }
+}
+EXPORT_SYMBOL(iov_iter_zero);
+
size_t iov_iter_copy_from_user_atomic(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes)
{