From 66cd071a1f839b4834d45aa7dde622151041b1a0 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 9 Apr 2021 19:10:53 +0100 Subject: iov_iter: Remove iov_iter_for_each_range() Remove iov_iter_for_each_range() as it's no longer used with the removal of lustre. Signed-off-by: David Howells Signed-off-by: Al Viro --- include/linux/uio.h | 4 ---- 1 file changed, 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio.h b/include/linux/uio.h index d3ec87706d75..74a401f04bd3 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -294,8 +294,4 @@ ssize_t __import_iovec(int type, const struct iovec __user *uvec, int import_single_range(int type, void __user *buf, size_t len, struct iovec *iov, struct iov_iter *i); -int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, - int (*f)(struct kvec *vec, void *context), - void *context); - #endif -- cgit v1.2.3 From 4b6c132b7da6430cf5dcc96948b04849dea0a32a Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 29 Apr 2021 21:16:56 -0400 Subject: iov_iter: switch ..._full() variants of primitives to use of iov_iter_revert() Use corresponding plain variants, revert on short copy. That's the way it should've been done from the very beginning, except that we didn't have iov_iter_revert() back then... [fixed another braino caught by Qian Cai ] Signed-off-by: Al Viro --- include/linux/uio.h | 32 ++++++++++------ lib/iov_iter.c | 104 ---------------------------------------------------- 2 files changed, 21 insertions(+), 115 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio.h b/include/linux/uio.h index 74a401f04bd3..68079e2f34eb 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -132,9 +132,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); -bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); -bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i); static __always_inline __must_check size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) @@ -157,10 +155,11 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) static __always_inline __must_check bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) { - if (unlikely(!check_copy_size(addr, bytes, false))) - return false; - else - return _copy_from_iter_full(addr, bytes, i); + size_t copied = copy_from_iter(addr, bytes, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; } static __always_inline __must_check @@ -175,10 +174,11 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) static __always_inline __must_check bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) { - if (unlikely(!check_copy_size(addr, bytes, false))) - return false; - else - return _copy_from_iter_full_nocache(addr, bytes, i); + size_t copied = copy_from_iter_nocache(addr, bytes, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; } #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE @@ -278,7 +278,17 @@ struct csum_state { size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i); size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); -bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); + +static __always_inline __must_check +bool csum_and_copy_from_iter_full(void *addr, size_t bytes, + __wsum *csum, struct iov_iter *i) +{ + size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i); + if (likely(copied == bytes)) + return true; + iov_iter_revert(i, copied); + return false; +} size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index bdbe6691457d..ce9f8b9168ea 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -819,35 +819,6 @@ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) } EXPORT_SYMBOL(_copy_from_iter); -bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i) -{ - char *to = addr; - if (unlikely(iov_iter_is_pipe(i))) { - WARN_ON(1); - return false; - } - if (unlikely(i->count < bytes)) - return false; - - if (iter_is_iovec(i)) - might_fault(); - iterate_all_kinds(i, bytes, v, ({ - if (copyin((to += v.iov_len) - v.iov_len, - v.iov_base, v.iov_len)) - return false; - 0;}), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len), - memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len) - ) - - iov_iter_advance(i, bytes); - return true; -} -EXPORT_SYMBOL(_copy_from_iter_full); - size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) { char *to = addr; @@ -907,32 +878,6 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache); #endif -bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i) -{ - char *to = addr; - if (unlikely(iov_iter_is_pipe(i))) { - WARN_ON(1); - return false; - } - if (unlikely(i->count < bytes)) - return false; - iterate_all_kinds(i, bytes, v, ({ - if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len, - v.iov_base, v.iov_len)) - return false; - 0;}), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len), - memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), - memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, - v.bv_offset, v.bv_len) - ) - - iov_iter_advance(i, bytes); - return true; -} -EXPORT_SYMBOL(_copy_from_iter_full_nocache); - static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) { struct page *head; @@ -1740,55 +1685,6 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, } EXPORT_SYMBOL(csum_and_copy_from_iter); -bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, - struct iov_iter *i) -{ - char *to = addr; - __wsum sum, next; - size_t off = 0; - sum = *csum; - if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) { - WARN_ON(1); - return false; - } - if (unlikely(i->count < bytes)) - return false; - iterate_all_kinds(i, bytes, v, ({ - next = csum_and_copy_from_user(v.iov_base, - (to += v.iov_len) - v.iov_len, - v.iov_len); - if (!next) - return false; - sum = csum_block_add(sum, next, off); - off += v.iov_len; - 0; - }), ({ - char *p = kmap_atomic(v.bv_page); - sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, - p + v.bv_offset, v.bv_len, - sum, off); - kunmap_atomic(p); - off += v.bv_len; - }),({ - sum = csum_and_memcpy((to += v.iov_len) - v.iov_len, - v.iov_base, v.iov_len, - sum, off); - off += v.iov_len; - }), ({ - char *p = kmap_atomic(v.bv_page); - sum = csum_and_memcpy((to += v.bv_len) - v.bv_len, - p + v.bv_offset, v.bv_len, - sum, off); - kunmap_atomic(p); - off += v.bv_len; - }) - ) - *csum = sum; - iov_iter_advance(i, bytes); - return true; -} -EXPORT_SYMBOL(csum_and_copy_from_iter_full); - size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, struct iov_iter *i) { -- cgit v1.2.3 From 8cd54c1c848031a87820e58d772166ffdf8c08c0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 22 Apr 2021 14:50:39 -0400 Subject: iov_iter: separate direction from flavour Instead of having them mixed in iter->type, use separate ->iter_type and ->data_source (u8 and bool resp.) And don't bother with (pseudo-) bitmap for the former - microoptimizations from being able to check if the flavour is one of two values are not worth the confusion for optimizer. It can't prove that we never get e.g. ITER_IOVEC | ITER_PIPE, so we end up with extra headache. Signed-off-by: Al Viro --- include/linux/uio.h | 24 +++++++-------- lib/iov_iter.c | 85 ++++++++++++++++++++++++++++++----------------------- 2 files changed, 58 insertions(+), 51 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio.h b/include/linux/uio.h index 68079e2f34eb..ad76eef356b0 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -19,21 +19,17 @@ struct kvec { enum iter_type { /* iter types */ - ITER_IOVEC = 4, - ITER_KVEC = 8, - ITER_BVEC = 16, - ITER_PIPE = 32, - ITER_DISCARD = 64, - ITER_XARRAY = 128, + ITER_IOVEC, + ITER_KVEC, + ITER_BVEC, + ITER_PIPE, + ITER_XARRAY, + ITER_DISCARD, }; struct iov_iter { - /* - * Bit 0 is the read/write bit, set if we're writing. - * Bit 1 is the BVEC_FLAG_NO_REF bit, set if type is a bvec and - * the caller isn't expecting to drop a page reference when done. - */ - unsigned int type; + u8 iter_type; + bool data_source; size_t iov_offset; size_t count; union { @@ -55,7 +51,7 @@ struct iov_iter { static inline enum iter_type iov_iter_type(const struct iov_iter *i) { - return i->type & ~(READ | WRITE); + return i->iter_type; } static inline bool iter_is_iovec(const struct iov_iter *i) @@ -90,7 +86,7 @@ static inline bool iov_iter_is_xarray(const struct iov_iter *i) static inline unsigned char iov_iter_rw(const struct iov_iter *i) { - return i->type & (READ | WRITE); + return i->data_source ? WRITE : READ; } /* diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e6c5834da32d..03c4e677b075 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -489,19 +489,15 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, size_t count) { WARN_ON(direction & ~(READ | WRITE)); - direction &= READ | WRITE; - - /* It will get better. Eventually... */ - if (uaccess_kernel()) { - i->type = ITER_KVEC | direction; - i->kvec = (struct kvec *)iov; - } else { - i->type = ITER_IOVEC | direction; - i->iov = iov; - } - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; + WARN_ON_ONCE(uaccess_kernel()); + *i = (struct iov_iter) { + .iter_type = ITER_IOVEC, + .data_source = direction, + .iov = iov, + .nr_segs = nr_segs, + .iov_offset = 0, + .count = count + }; } EXPORT_SYMBOL(iov_iter_init); @@ -1218,11 +1214,14 @@ void iov_iter_kvec(struct iov_iter *i, unsigned int direction, size_t count) { WARN_ON(direction & ~(READ | WRITE)); - i->type = ITER_KVEC | (direction & (READ | WRITE)); - i->kvec = kvec; - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; + *i = (struct iov_iter){ + .iter_type = ITER_KVEC, + .data_source = direction, + .kvec = kvec, + .nr_segs = nr_segs, + .iov_offset = 0, + .count = count + }; } EXPORT_SYMBOL(iov_iter_kvec); @@ -1231,11 +1230,14 @@ void iov_iter_bvec(struct iov_iter *i, unsigned int direction, size_t count) { WARN_ON(direction & ~(READ | WRITE)); - i->type = ITER_BVEC | (direction & (READ | WRITE)); - i->bvec = bvec; - i->nr_segs = nr_segs; - i->iov_offset = 0; - i->count = count; + *i = (struct iov_iter){ + .iter_type = ITER_BVEC, + .data_source = direction, + .bvec = bvec, + .nr_segs = nr_segs, + .iov_offset = 0, + .count = count + }; } EXPORT_SYMBOL(iov_iter_bvec); @@ -1245,12 +1247,15 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction, { BUG_ON(direction != READ); WARN_ON(pipe_full(pipe->head, pipe->tail, pipe->ring_size)); - i->type = ITER_PIPE | READ; - i->pipe = pipe; - i->head = pipe->head; - i->iov_offset = 0; - i->count = count; - i->start_head = i->head; + *i = (struct iov_iter){ + .iter_type = ITER_PIPE, + .data_source = false, + .pipe = pipe, + .head = pipe->head, + .start_head = pipe->head, + .iov_offset = 0, + .count = count + }; } EXPORT_SYMBOL(iov_iter_pipe); @@ -1271,11 +1276,14 @@ void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray, loff_t start, size_t count) { BUG_ON(direction & ~1); - i->type = ITER_XARRAY | (direction & (READ | WRITE)); - i->xarray = xarray; - i->xarray_start = start; - i->count = count; - i->iov_offset = 0; + *i = (struct iov_iter) { + .iter_type = ITER_XARRAY, + .data_source = direction, + .xarray = xarray, + .xarray_start = start, + .count = count, + .iov_offset = 0 + }; } EXPORT_SYMBOL(iov_iter_xarray); @@ -1291,9 +1299,12 @@ EXPORT_SYMBOL(iov_iter_xarray); void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count) { BUG_ON(direction != READ); - i->type = ITER_DISCARD | READ; - i->count = count; - i->iov_offset = 0; + *i = (struct iov_iter){ + .iter_type = ITER_DISCARD, + .data_source = false, + .count = count, + .iov_offset = 0 + }; } EXPORT_SYMBOL(iov_iter_discard); -- cgit v1.2.3 From 8409a0d261e20180361e7afe6d89847d1bad4ce8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 2 May 2021 11:57:37 -0400 Subject: sanitize iov_iter_fault_in_readable() 1) constify iov_iter argument; we are not advancing it in this primitive. 2) cap the amount requested by the amount of data in iov_iter. All existing callers should've been safe, but the check is really cheap and doing it here makes for easier analysis, as well as more consistent semantics among the primitives. 3) don't bother with iterate_iovec(). Explicit loop is not any harder to follow, and we get rid of standalone iterate_iovec() users - it's only used by iterate_and_advance() and (soon to be gone) iterate_all_kinds(). Signed-off-by: Al Viro --- include/linux/uio.h | 2 +- lib/iov_iter.c | 26 ++++++++++++++++---------- 2 files changed, 17 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uio.h b/include/linux/uio.h index ad76eef356b0..b5cf54859109 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -119,7 +119,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, struct iov_iter *i, unsigned long offset, size_t bytes); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); +int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); size_t iov_iter_single_seg_count(const struct iov_iter *i); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index cd23c79acb94..2b543bea1e0d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -466,19 +466,25 @@ out: * Return 0 on success, or non-zero if the memory could not be accessed (i.e. * because it is an invalid address). */ -int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) +int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes) { - size_t skip = i->iov_offset; - const struct iovec *iov; - int err; - struct iovec v; - if (iter_is_iovec(i)) { - iterate_iovec(i, bytes, v, iov, skip, ({ - err = fault_in_pages_readable(v.iov_base, v.iov_len); + const struct iovec *p; + size_t skip; + + if (bytes > i->count) + bytes = i->count; + for (p = i->iov, skip = i->iov_offset; bytes; p++, skip = 0) { + size_t len = min(bytes, p->iov_len - skip); + int err; + + if (unlikely(!len)) + continue; + err = fault_in_pages_readable(p->iov_base + skip, len); if (unlikely(err)) - return err; - 0;})) + return err; + bytes -= len; + } } return 0; } -- cgit v1.2.3 From f0b65f39ac505e8f1dcdaa165aa7b8c0bd6fd454 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 30 Apr 2021 10:26:41 -0400 Subject: iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the callers do *not* need to do iov_iter_advance() after it. In case when they end up consuming less than they'd been given they need to do iov_iter_revert() on everything they had not consumed. That, however, needs to be done only on slow paths. All in-tree callers converted. And that kills the last user of iterate_all_kinds() Signed-off-by: Al Viro --- Documentation/filesystems/porting.rst | 9 +++++++++ fs/btrfs/file.c | 23 +++++++++++------------ fs/fuse/file.c | 3 +-- fs/iomap/buffered-io.c | 14 +++++++------- fs/ntfs/file.c | 4 +--- include/linux/uio.h | 4 ++-- lib/iov_iter.c | 30 ++++-------------------------- mm/filemap.c | 16 ++++++++-------- 8 files changed, 43 insertions(+), 60 deletions(-) (limited to 'include/linux') diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 0302035781be..43b492d08dec 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -890,3 +890,12 @@ been called or returned with non -EIOCBQUEUED code. mnt_want_write_file() can now only be paired with mnt_drop_write_file(), whereas previously it could be paired with mnt_drop_write() as well. + +--- + +**mandatory** + +iov_iter_copy_from_user_atomic() is gone; use copy_page_from_iter_atomic(). +The difference is copy_page_from_iter_atomic() advances the iterator and +you don't need iov_iter_advance() after it. However, if you decide to use +only a part of obtained data, you should do iov_iter_revert(). diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 864c08d08a35..78cb8f9eaa6b 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -398,7 +398,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, /* * Copy data from userspace to the current page */ - copied = iov_iter_copy_from_user_atomic(page, i, offset, count); + copied = copy_page_from_iter_atomic(page, offset, count, i); /* Flush processor's dcache for this page */ flush_dcache_page(page); @@ -412,20 +412,19 @@ static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, * The rest of the btrfs_file_write code will fall * back to page at a time copies after we return 0. */ - if (!PageUptodate(page) && copied < count) - copied = 0; + if (unlikely(copied < count)) { + if (!PageUptodate(page)) { + iov_iter_revert(i, copied); + copied = 0; + } + if (!copied) + break; + } - iov_iter_advance(i, copied); write_bytes -= copied; total_copied += copied; - - /* Return to btrfs_file_write_iter to fault page */ - if (unlikely(copied == 0)) - break; - - if (copied < PAGE_SIZE - offset) { - offset += copied; - } else { + offset += copied; + if (offset == PAGE_SIZE) { pg++; offset = 0; } diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 44bd301fa4fb..4722fa31a185 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1171,10 +1171,9 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia, if (mapping_writably_mapped(mapping)) flush_dcache_page(page); - tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes); + tmp = copy_page_from_iter_atomic(page, offset, bytes, ii); flush_dcache_page(page); - iov_iter_advance(ii, tmp); if (!tmp) { unlock_page(page); put_page(page); diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 354b41d20e5d..c5ff13e0e7cf 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -785,13 +785,15 @@ again: if (mapping_writably_mapped(inode->i_mapping)) flush_dcache_page(page); - copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); + copied = copy_page_from_iter_atomic(page, offset, bytes, i); status = iomap_write_end(inode, pos, bytes, copied, page, iomap, srcmap); - cond_resched(); + if (unlikely(copied != status)) + iov_iter_revert(i, copied - status); + cond_resched(); if (unlikely(status == 0)) { /* * A short copy made iomap_write_end() reject the @@ -803,11 +805,9 @@ again: bytes = copied; goto again; } - copied = status; - iov_iter_advance(i, copied); - pos += copied; - written += copied; - length -= copied; + pos += status; + written += status; + length -= status; balance_dirty_pages_ratelimited(inode->i_mapping); } while (iov_iter_count(i) && length); diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index 0666d4578137..ab4f3362466d 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1690,9 +1690,7 @@ static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages, len = PAGE_SIZE - ofs; if (len > bytes) len = bytes; - copied = iov_iter_copy_from_user_atomic(*pages, i, ofs, - len); - iov_iter_advance(i, copied); + copied = copy_page_from_iter_atomic(*pages, ofs, len, i); total += copied; bytes -= copied; if (!bytes) diff --git a/include/linux/uio.h b/include/linux/uio.h index b5cf54859109..82c3c3e819e0 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -115,8 +115,8 @@ static inline struct iovec iov_iter_iovec(const struct iov_iter *iter) }; } -size_t iov_iter_copy_from_user_atomic(struct page *page, - struct iov_iter *i, unsigned long offset, size_t bytes); +size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, + size_t bytes, struct iov_iter *i); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); int iov_iter_fault_in_readable(const struct iov_iter *i, size_t bytes); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 72c5bb794e8d..362e8b5a5dc5 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -114,28 +114,6 @@ n = wanted - n; \ } -#define iterate_all_kinds(i, n, v, I, B, K, X) { \ - if (likely(n)) { \ - size_t skip = i->iov_offset; \ - if (likely(iter_is_iovec(i))) { \ - const struct iovec *iov; \ - struct iovec v; \ - iterate_iovec(i, n, v, iov, skip, (I)) \ - } else if (iov_iter_is_bvec(i)) { \ - struct bio_vec v; \ - struct bvec_iter __bi; \ - iterate_bvec(i, n, v, __bi, skip, (B)) \ - } else if (iov_iter_is_kvec(i)) { \ - const struct kvec *kvec; \ - struct kvec v; \ - iterate_kvec(i, n, v, kvec, skip, (K)) \ - } else if (iov_iter_is_xarray(i)) { \ - struct bio_vec v; \ - iterate_xarray(i, n, v, skip, (X)); \ - } \ - } \ -} - #define iterate_and_advance(i, n, v, I, B, K, X) { \ if (unlikely(i->count < n)) \ n = i->count; \ @@ -1009,8 +987,8 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *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) +size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, + struct iov_iter *i) { char *kaddr = kmap_atomic(page), *p = kaddr + offset; if (unlikely(!page_copy_sane(page, offset, bytes))) { @@ -1022,7 +1000,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, WARN_ON(1); return 0; } - iterate_all_kinds(i, bytes, v, + iterate_and_advance(i, bytes, v, copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len), memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page, v.bv_offset, v.bv_len), @@ -1033,7 +1011,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page, kunmap_atomic(kaddr); return bytes; } -EXPORT_SYMBOL(iov_iter_copy_from_user_atomic); +EXPORT_SYMBOL(copy_page_from_iter_atomic); static inline void pipe_truncate(struct iov_iter *i) { diff --git a/mm/filemap.c b/mm/filemap.c index 0be24942bf8e..cf9de790f493 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3661,14 +3661,16 @@ again: if (mapping_writably_mapped(mapping)) flush_dcache_page(page); - copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes); + copied = copy_page_from_iter_atomic(page, offset, bytes, i); flush_dcache_page(page); status = a_ops->write_end(file, mapping, pos, bytes, copied, page, fsdata); - if (unlikely(status < 0)) - break; - + if (unlikely(status != copied)) { + iov_iter_revert(i, copied - max(status, 0L)); + if (unlikely(status < 0)) + break; + } cond_resched(); if (unlikely(status == 0)) { @@ -3682,10 +3684,8 @@ again: bytes = copied; goto again; } - copied = status; - iov_iter_advance(i, copied); - pos += copied; - written += copied; + pos += status; + written += status; balance_dirty_pages_ratelimited(mapping); } while (iov_iter_count(i)); -- cgit v1.2.3