diff options
| -rw-r--r-- | fs/direct-io.c | 9 | ||||
| -rw-r--r-- | fs/fuse/file.c | 16 | ||||
| -rw-r--r-- | include/linux/uio.h | 1 | ||||
| -rw-r--r-- | mm/iov_iter.c | 27 |
4 files changed, 31 insertions, 22 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index 4b410d5..98040ba 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -1100,7 +1100,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, get_block_t get_block, dio_iodone_t end_io, dio_submit_t submit_io, int flags) { - int seg; unsigned i_blkbits = ACCESS_ONCE(inode->i_blkbits); unsigned blkbits = i_blkbits; unsigned blocksize_mask = (1 << blkbits) - 1; @@ -1108,7 +1107,6 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, loff_t end = offset + iov_iter_count(iter); struct dio *dio; struct dio_submit sdio = { 0, }; - unsigned long user_addr; struct buffer_head map_bh = { 0, }; struct blk_plug plug; unsigned long align = offset | iov_iter_alignment(iter); @@ -1231,12 +1229,7 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, if (unlikely(sdio.blkfactor)) sdio.pages_in_io = 2; - for (seg = 0; seg < iter->nr_segs; seg++) { - user_addr = (unsigned long)iter->iov[seg].iov_base; - sdio.pages_in_io += - ((user_addr + iter->iov[seg].iov_len + PAGE_SIZE-1) / - PAGE_SIZE - user_addr / PAGE_SIZE); - } + sdio.pages_in_io += iov_iter_npages(iter, INT_MAX); blk_start_plug(&plug); diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 7db564d..7026014 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1310,7 +1310,7 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, while (nbytes < *nbytesp && req->num_pages < req->max_pages) { unsigned npages; - size_t start, end, frag_size; + size_t start; unsigned n = req->max_pages - req->num_pages; ssize_t ret = iov_iter_get_pages(ii, &req->pages[req->num_pages], @@ -1344,19 +1344,7 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, static inline int fuse_iter_npages(const struct iov_iter *ii_p) { - struct iov_iter ii = *ii_p; - int npages = 0; - - while (iov_iter_count(&ii) && npages < FUSE_MAX_PAGES_PER_REQ) { - unsigned long user_addr = fuse_get_user_addr(&ii); - unsigned offset = user_addr & ~PAGE_MASK; - size_t frag_size = iov_iter_single_seg_count(&ii); - - npages += (frag_size + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; - iov_iter_advance(&ii, frag_size); - } - - return min(npages, FUSE_MAX_PAGES_PER_REQ); + return iov_iter_npages(ii_p, FUSE_MAX_PAGES_PER_REQ); } ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter, diff --git a/include/linux/uio.h b/include/linux/uio.h index 3419861..2f8825b 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -73,6 +73,7 @@ void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, unsigned long nr_segs, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, size_t *start); +int iov_iter_npages(const struct iov_iter *i, int maxpages); static inline size_t iov_iter_count(struct iov_iter *i) { diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 45204cd..0b677f8 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -262,3 +262,30 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, return (res == n ? len : res * PAGE_SIZE) - *start; } EXPORT_SYMBOL(iov_iter_get_pages); + +int iov_iter_npages(const struct iov_iter *i, int maxpages) +{ + size_t offset = i->iov_offset; + size_t size = i->count; + const struct iovec *iov = i->iov; + int npages = 0; + int n; + + for (n = 0; size && n < i->nr_segs; n++, iov++) { + unsigned long addr = (unsigned long)iov->iov_base + offset; + size_t len = iov->iov_len - offset; + offset = 0; + if (unlikely(!len)) /* empty segment */ + continue; + if (len > size) + len = size; + npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE + - addr / PAGE_SIZE; + if (npages >= maxpages) /* don't bother going further */ + return maxpages; + size -= len; + offset = 0; + } + return min(npages, maxpages); +} +EXPORT_SYMBOL(iov_iter_npages); |
