On Wed, May 23, 2018 at 04:43:26PM +0200, Christoph Hellwig wrote:
> This function is only used by the iomap code, depends on being called
> from it, and will soon stop poking into buffer head internals.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/buffer.c | 114 -----------------------------------
> fs/iomap.c | 116 ++++++++++++++++++++++++++++++++++++
> include/linux/buffer_head.h | 2 -
> 3 files changed, 116 insertions(+), 116 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index bd964b2ad99a..aba2a948b235 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -3430,120 +3430,6 @@ 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 f2456d0d8ddd..4a01d2f4e8e9 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>
> @@ -588,6 +589,121 @@ 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;
>
> --
> 2.17.0
>
> --
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