diff options
| -rw-r--r-- | fs/buffer.c | 114 | ||||
| -rw-r--r-- | fs/iomap.c | 116 | ||||
| -rw-r--r-- | include/linux/buffer_head.h | 2 |
3 files changed, 116 insertions, 116 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 249b83fafe48..cabc045f483d 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3427,120 +3427,6 @@ int bh_submit_read(struct buffer_head *bh) } EXPORT_SYMBOL(bh_submit_read); -/* - * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff. - * - * Returns the offset within the file on success, and -ENOENT otherwise. - */ -static loff_t -page_seek_hole_data(struct page *page, loff_t lastoff, int whence) -{ - loff_t offset = page_offset(page); - struct buffer_head *bh, *head; - bool seek_data = whence == SEEK_DATA; - - if (lastoff < offset) - lastoff = offset; - - bh = head = page_buffers(page); - do { - offset += bh->b_size; - if (lastoff >= offset) - continue; - - /* - * Unwritten extents that have data in the page cache covering - * them can be identified by the BH_Unwritten state flag. - * Pages with multiple buffers might have a mix of holes, data - * and unwritten extents - any buffer with valid data in it - * should have BH_Uptodate flag set on it. - */ - - if ((buffer_unwritten(bh) || buffer_uptodate(bh)) == seek_data) - return lastoff; - - lastoff = offset; - } while ((bh = bh->b_this_page) != head); - return -ENOENT; -} - -/* - * Seek for SEEK_DATA / SEEK_HOLE in the page cache. - * - * Within unwritten extents, the page cache determines which parts are holes - * and which are data: unwritten and uptodate buffer heads count as data; - * everything else counts as a hole. - * - * Returns the resulting offset on successs, and -ENOENT otherwise. - */ -loff_t -page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length, - int whence) -{ - pgoff_t index = offset >> PAGE_SHIFT; - pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE); - loff_t lastoff = offset; - struct pagevec pvec; - - if (length <= 0) - return -ENOENT; - - pagevec_init(&pvec); - - do { - unsigned nr_pages, i; - - nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index, - end - 1); - if (nr_pages == 0) - break; - - for (i = 0; i < nr_pages; i++) { - struct page *page = pvec.pages[i]; - - /* - * At this point, the page may be truncated or - * invalidated (changing page->mapping to NULL), or - * even swizzled back from swapper_space to tmpfs file - * mapping. However, page->index will not change - * because we have a reference on the page. - * - * If current page offset is beyond where we've ended, - * we've found a hole. - */ - if (whence == SEEK_HOLE && - lastoff < page_offset(page)) - goto check_range; - - lock_page(page); - if (likely(page->mapping == inode->i_mapping) && - page_has_buffers(page)) { - lastoff = page_seek_hole_data(page, lastoff, whence); - if (lastoff >= 0) { - unlock_page(page); - goto check_range; - } - } - unlock_page(page); - lastoff = page_offset(page) + PAGE_SIZE; - } - pagevec_release(&pvec); - } while (index < end); - - /* When no page at lastoff and we are not done, we found a hole. */ - if (whence != SEEK_HOLE) - goto not_found; - -check_range: - if (lastoff < offset + length) - goto out; -not_found: - lastoff = -ENOENT; -out: - pagevec_release(&pvec); - return lastoff; -} - void __init buffer_init(void) { unsigned long nrpages; diff --git a/fs/iomap.c b/fs/iomap.c index b0bc928672af..fe3b9222dd46 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -20,6 +20,7 @@ #include <linux/mm.h> #include <linux/swap.h> #include <linux/pagemap.h> +#include <linux/pagevec.h> #include <linux/file.h> #include <linux/uio.h> #include <linux/backing-dev.h> @@ -592,6 +593,121 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, } EXPORT_SYMBOL_GPL(iomap_fiemap); +/* + * Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff. + * + * Returns the offset within the file on success, and -ENOENT otherwise. + */ +static loff_t +page_seek_hole_data(struct page *page, loff_t lastoff, int whence) +{ + loff_t offset = page_offset(page); + struct buffer_head *bh, *head; + bool seek_data = whence == SEEK_DATA; + + if (lastoff < offset) + lastoff = offset; + + bh = head = page_buffers(page); + do { + offset += bh->b_size; + if (lastoff >= offset) + continue; + + /* + * Unwritten extents that have data in the page cache covering + * them can be identified by the BH_Unwritten state flag. + * Pages with multiple buffers might have a mix of holes, data + * and unwritten extents - any buffer with valid data in it + * should have BH_Uptodate flag set on it. + */ + + if ((buffer_unwritten(bh) || buffer_uptodate(bh)) == seek_data) + return lastoff; + + lastoff = offset; + } while ((bh = bh->b_this_page) != head); + return -ENOENT; +} + +/* + * Seek for SEEK_DATA / SEEK_HOLE in the page cache. + * + * Within unwritten extents, the page cache determines which parts are holes + * and which are data: unwritten and uptodate buffer heads count as data; + * everything else counts as a hole. + * + * Returns the resulting offset on successs, and -ENOENT otherwise. + */ +static loff_t +page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length, + int whence) +{ + pgoff_t index = offset >> PAGE_SHIFT; + pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE); + loff_t lastoff = offset; + struct pagevec pvec; + + if (length <= 0) + return -ENOENT; + + pagevec_init(&pvec); + + do { + unsigned nr_pages, i; + + nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index, + end - 1); + if (nr_pages == 0) + break; + + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + /* + * At this point, the page may be truncated or + * invalidated (changing page->mapping to NULL), or + * even swizzled back from swapper_space to tmpfs file + * mapping. However, page->index will not change + * because we have a reference on the page. + * + * If current page offset is beyond where we've ended, + * we've found a hole. + */ + if (whence == SEEK_HOLE && + lastoff < page_offset(page)) + goto check_range; + + lock_page(page); + if (likely(page->mapping == inode->i_mapping) && + page_has_buffers(page)) { + lastoff = page_seek_hole_data(page, lastoff, whence); + if (lastoff >= 0) { + unlock_page(page); + goto check_range; + } + } + unlock_page(page); + lastoff = page_offset(page) + PAGE_SIZE; + } + pagevec_release(&pvec); + } while (index < end); + + /* When no page at lastoff and we are not done, we found a hole. */ + if (whence != SEEK_HOLE) + goto not_found; + +check_range: + if (lastoff < offset + length) + goto out; +not_found: + lastoff = -ENOENT; +out: + pagevec_release(&pvec); + return lastoff; +} + + static loff_t iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length, void *data, struct iomap *iomap) diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 894e5d125de6..96225a77c112 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -205,8 +205,6 @@ void write_boundary_block(struct block_device *bdev, sector_t bblock, unsigned blocksize); int bh_uptodate_or_lock(struct buffer_head *bh); int bh_submit_read(struct buffer_head *bh); -loff_t page_cache_seek_hole_data(struct inode *inode, loff_t offset, - loff_t length, int whence); extern int buffer_heads_over_limit; |