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iomap: use mapping_seek_hole_data
Enhance mapping_seek_hole_data() to handle partially uptodate pages and convert the iomap seek code to call it. Link: https://lkml.kernel.org/r/20201112212641.27837-9-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <dchinner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
41139aa4c3
commit
54fa39ac2e
2 changed files with 43 additions and 119 deletions
125
fs/iomap/seek.c
125
fs/iomap/seek.c
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@ -10,122 +10,17 @@
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#include <linux/pagemap.h>
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#include <linux/pagemap.h>
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#include <linux/pagevec.h>
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#include <linux/pagevec.h>
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/*
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* Seek for SEEK_DATA / SEEK_HOLE within @page, starting at @lastoff.
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* Returns true if found and updates @lastoff to the offset in file.
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*/
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static bool
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page_seek_hole_data(struct inode *inode, struct page *page, loff_t *lastoff,
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int whence)
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{
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const struct address_space_operations *ops = inode->i_mapping->a_ops;
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unsigned int bsize = i_blocksize(inode), off;
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bool seek_data = whence == SEEK_DATA;
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loff_t poff = page_offset(page);
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if (WARN_ON_ONCE(*lastoff >= poff + PAGE_SIZE))
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return false;
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if (*lastoff < poff) {
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/*
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* Last offset smaller than the start of the page means we found
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* a hole:
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*/
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if (whence == SEEK_HOLE)
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return true;
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*lastoff = poff;
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}
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/*
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* Just check the page unless we can and should check block ranges:
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*/
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if (bsize == PAGE_SIZE || !ops->is_partially_uptodate)
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return PageUptodate(page) == seek_data;
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lock_page(page);
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if (unlikely(page->mapping != inode->i_mapping))
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goto out_unlock_not_found;
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for (off = 0; off < PAGE_SIZE; off += bsize) {
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if (offset_in_page(*lastoff) >= off + bsize)
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continue;
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if (ops->is_partially_uptodate(page, off, bsize) == seek_data) {
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unlock_page(page);
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return true;
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}
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*lastoff = poff + off + bsize;
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}
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out_unlock_not_found:
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unlock_page(page);
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return false;
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}
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/*
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* Seek for SEEK_DATA / SEEK_HOLE in the page cache.
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*
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* Within unwritten extents, the page cache determines which parts are holes
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* and which are data: uptodate buffer heads count as data; everything else
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* counts as a hole.
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*
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* Returns the resulting offset on successs, and -ENOENT otherwise.
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*/
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static loff_t
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static loff_t
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page_cache_seek_hole_data(struct inode *inode, loff_t offset, loff_t length,
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iomap_seek_hole_actor(struct inode *inode, loff_t start, loff_t length,
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int whence)
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{
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pgoff_t index = offset >> PAGE_SHIFT;
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pgoff_t end = DIV_ROUND_UP(offset + length, PAGE_SIZE);
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loff_t lastoff = offset;
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struct pagevec pvec;
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if (length <= 0)
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return -ENOENT;
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pagevec_init(&pvec);
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do {
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unsigned nr_pages, i;
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nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, &index,
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end - 1);
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if (nr_pages == 0)
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break;
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for (i = 0; i < nr_pages; i++) {
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struct page *page = pvec.pages[i];
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if (page_seek_hole_data(inode, page, &lastoff, whence))
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goto check_range;
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lastoff = page_offset(page) + PAGE_SIZE;
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}
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pagevec_release(&pvec);
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} while (index < end);
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/* When no page at lastoff and we are not done, we found a hole. */
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if (whence != SEEK_HOLE)
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goto not_found;
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check_range:
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if (lastoff < offset + length)
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goto out;
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not_found:
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lastoff = -ENOENT;
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out:
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pagevec_release(&pvec);
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return lastoff;
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}
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static loff_t
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iomap_seek_hole_actor(struct inode *inode, loff_t offset, loff_t length,
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void *data, struct iomap *iomap, struct iomap *srcmap)
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void *data, struct iomap *iomap, struct iomap *srcmap)
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{
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{
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loff_t offset = start;
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switch (iomap->type) {
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switch (iomap->type) {
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case IOMAP_UNWRITTEN:
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case IOMAP_UNWRITTEN:
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offset = page_cache_seek_hole_data(inode, offset, length,
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offset = mapping_seek_hole_data(inode->i_mapping, start,
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SEEK_HOLE);
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start + length, SEEK_HOLE);
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if (offset < 0)
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if (offset == start + length)
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return length;
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return length;
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fallthrough;
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fallthrough;
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case IOMAP_HOLE:
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case IOMAP_HOLE:
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@ -164,15 +59,17 @@ iomap_seek_hole(struct inode *inode, loff_t offset, const struct iomap_ops *ops)
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EXPORT_SYMBOL_GPL(iomap_seek_hole);
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EXPORT_SYMBOL_GPL(iomap_seek_hole);
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static loff_t
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static loff_t
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iomap_seek_data_actor(struct inode *inode, loff_t offset, loff_t length,
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iomap_seek_data_actor(struct inode *inode, loff_t start, loff_t length,
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void *data, struct iomap *iomap, struct iomap *srcmap)
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void *data, struct iomap *iomap, struct iomap *srcmap)
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{
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{
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loff_t offset = start;
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switch (iomap->type) {
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switch (iomap->type) {
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case IOMAP_HOLE:
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case IOMAP_HOLE:
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return length;
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return length;
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case IOMAP_UNWRITTEN:
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case IOMAP_UNWRITTEN:
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offset = page_cache_seek_hole_data(inode, offset, length,
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offset = mapping_seek_hole_data(inode->i_mapping, start,
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SEEK_DATA);
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start + length, SEEK_DATA);
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if (offset < 0)
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if (offset < 0)
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return length;
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return length;
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fallthrough;
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fallthrough;
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37
mm/filemap.c
37
mm/filemap.c
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@ -2553,11 +2553,36 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
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}
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}
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EXPORT_SYMBOL(generic_file_read_iter);
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EXPORT_SYMBOL(generic_file_read_iter);
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static inline bool page_seek_match(struct page *page, bool seek_data)
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static inline loff_t page_seek_hole_data(struct xa_state *xas,
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struct address_space *mapping, struct page *page,
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loff_t start, loff_t end, bool seek_data)
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{
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{
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const struct address_space_operations *ops = mapping->a_ops;
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size_t offset, bsz = i_blocksize(mapping->host);
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if (xa_is_value(page) || PageUptodate(page))
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if (xa_is_value(page) || PageUptodate(page))
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return seek_data;
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return seek_data ? start : end;
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return !seek_data;
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if (!ops->is_partially_uptodate)
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return seek_data ? end : start;
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xas_pause(xas);
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rcu_read_unlock();
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lock_page(page);
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if (unlikely(page->mapping != mapping))
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goto unlock;
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offset = offset_in_thp(page, start) & ~(bsz - 1);
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do {
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if (ops->is_partially_uptodate(page, offset, bsz) == seek_data)
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break;
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start = (start + bsz) & ~(bsz - 1);
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offset += bsz;
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} while (offset < thp_size(page));
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unlock:
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unlock_page(page);
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rcu_read_lock();
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return start;
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}
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}
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static inline
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static inline
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@ -2607,9 +2632,11 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start,
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start = pos;
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start = pos;
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}
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}
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if (page_seek_match(page, seek_data))
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pos += seek_page_size(&xas, page);
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start = page_seek_hole_data(&xas, mapping, page, start, pos,
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seek_data);
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if (start < pos)
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goto unlock;
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goto unlock;
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start = pos + seek_page_size(&xas, page);
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if (!xa_is_value(page))
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if (!xa_is_value(page))
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put_page(page);
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put_page(page);
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}
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}
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