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authorChristoph Hellwig <hch@lst.de>2018-06-01 09:04:40 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-01 18:37:33 -0700
commit8a78cb1f1b98e5ea970674e0f049832d19e76ace (patch)
treed338c9b78bc8d9b88fa7b979fdbd19b8368509c8 /fs/buffer.c
parentb84e772299dc5b9da22a40ba87ed519a891397a3 (diff)
fs: move page_cache_seek_hole_data to iomap.c
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@lst.de> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c114
1 files changed, 0 insertions, 114 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;