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iomap: zero newly allocated mapped blocks 

File systems like gfs2 don't support delayed allocations or unwritten
extents and thus allocate normal mapped blocks to fill holes.  To
cover the case of such file systems allocating new blocks to fill holes
also zero out mapped blocks with the new flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
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>
This commit is contained in:
Christoph Hellwig 2019-10-17 13:12:12 -07:00 committed by Darrick J. Wong
parent 760fea8bfb
commit 009d8d849d
1 changed files with 10 additions and 2 deletions
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12
fs/iomap/buffered-io.c
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@ -203,6 +203,14 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
SetPageUptodate(page);
}
static inline bool iomap_block_needs_zeroing(struct inode *inode,
struct iomap *iomap, loff_t pos)
{
return iomap->type != IOMAP_MAPPED ||
(iomap->flags & IOMAP_F_NEW) ||
pos >= i_size_read(inode);
}
static loff_t
iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
struct iomap *iomap)
@ -226,7 +234,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
if (plen == 0)
goto done;
if (iomap->type != IOMAP_MAPPED || pos >= i_size_read(inode)) {
if (iomap_block_needs_zeroing(inode, iomap, pos)) {
zero_user(page, poff, plen);
iomap_set_range_uptodate(page, poff, plen);
goto done;
@ -532,7 +540,7 @@ iomap_read_page_sync(struct inode *inode, loff_t block_start, struct page *page,
struct bio_vec bvec;
struct bio bio;
if (iomap->type != IOMAP_MAPPED || block_start >= i_size_read(inode)) {
if (iomap_block_needs_zeroing(inode, iomap, block_start)) {
zero_user_segments(page, poff, from, to, poff + plen);
iomap_set_range_uptodate(page, poff, plen);
return 0;