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author | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-23 05:35:42 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-10-06 00:23:56 +0200 |
commit | 82c156f853840645604acd7c2cebcb75ed1b6652 (patch) | |
tree | 19d74fbaafb300aa05523ad0ecb60f24f82c5d1f /mm/shmem.c | |
parent | new iov_iter flavour: pipe-backed (diff) | |
download | linux-82c156f853840645604acd7c2cebcb75ed1b6652.tar.xz linux-82c156f853840645604acd7c2cebcb75ed1b6652.zip |
switch generic_file_splice_read() to use of ->read_iter()
... and kill the ->splice_read() instances that can be switched to it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r-- | mm/shmem.c | 115 |
1 files changed, 1 insertions, 114 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 971fc83e6402..d86b5e455fef 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2311,119 +2311,6 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to) return retval ? retval : error; } -static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos, - struct pipe_inode_info *pipe, size_t len, - unsigned int flags) -{ - struct address_space *mapping = in->f_mapping; - struct inode *inode = mapping->host; - unsigned int loff, nr_pages, req_pages; - struct page *pages[PIPE_DEF_BUFFERS]; - struct partial_page partial[PIPE_DEF_BUFFERS]; - struct page *page; - pgoff_t index, end_index; - loff_t isize, left; - int error, page_nr; - struct splice_pipe_desc spd = { - .pages = pages, - .partial = partial, - .nr_pages_max = PIPE_DEF_BUFFERS, - .flags = flags, - .ops = &page_cache_pipe_buf_ops, - .spd_release = spd_release_page, - }; - - isize = i_size_read(inode); - if (unlikely(*ppos >= isize)) - return 0; - - left = isize - *ppos; - if (unlikely(left < len)) - len = left; - - if (splice_grow_spd(pipe, &spd)) - return -ENOMEM; - - index = *ppos >> PAGE_SHIFT; - loff = *ppos & ~PAGE_MASK; - req_pages = (len + loff + PAGE_SIZE - 1) >> PAGE_SHIFT; - nr_pages = min(req_pages, spd.nr_pages_max); - - spd.nr_pages = find_get_pages_contig(mapping, index, - nr_pages, spd.pages); - index += spd.nr_pages; - error = 0; - - while (spd.nr_pages < nr_pages) { - error = shmem_getpage(inode, index, &page, SGP_CACHE); - if (error) - break; - unlock_page(page); - spd.pages[spd.nr_pages++] = page; - index++; - } - - index = *ppos >> PAGE_SHIFT; - nr_pages = spd.nr_pages; - spd.nr_pages = 0; - - for (page_nr = 0; page_nr < nr_pages; page_nr++) { - unsigned int this_len; - - if (!len) - break; - - this_len = min_t(unsigned long, len, PAGE_SIZE - loff); - page = spd.pages[page_nr]; - - if (!PageUptodate(page) || page->mapping != mapping) { - error = shmem_getpage(inode, index, &page, SGP_CACHE); - if (error) - break; - unlock_page(page); - put_page(spd.pages[page_nr]); - spd.pages[page_nr] = page; - } - - isize = i_size_read(inode); - end_index = (isize - 1) >> PAGE_SHIFT; - if (unlikely(!isize || index > end_index)) - break; - - if (end_index == index) { - unsigned int plen; - - plen = ((isize - 1) & ~PAGE_MASK) + 1; - if (plen <= loff) - break; - - this_len = min(this_len, plen - loff); - len = this_len; - } - - spd.partial[page_nr].offset = loff; - spd.partial[page_nr].len = this_len; - len -= this_len; - loff = 0; - spd.nr_pages++; - index++; - } - - while (page_nr < nr_pages) - put_page(spd.pages[page_nr++]); - - if (spd.nr_pages) - error = splice_to_pipe(pipe, &spd); - - splice_shrink_spd(&spd); - - if (error > 0) { - *ppos += error; - file_accessed(in); - } - return error; -} - /* * llseek SEEK_DATA or SEEK_HOLE through the radix_tree. */ @@ -3786,7 +3673,7 @@ static const struct file_operations shmem_file_operations = { .read_iter = shmem_file_read_iter, .write_iter = generic_file_write_iter, .fsync = noop_fsync, - .splice_read = shmem_file_splice_read, + .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .fallocate = shmem_fallocate, #endif |