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authorJan Kara <jack@suse.cz>2021-11-05 13:34:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 13:30:32 -0700
commitc7c14a369de936957946b3843aae050d92451472 (patch)
tree3ecf6a1fa67c80708aba476215cee03cf84d4064 /fs/ocfs2
parent839b63860eb3835da165642923120d305925561d (diff)
ocfs2: do not zero pages beyond i_size
ocfs2_zero_range_for_truncate() can try to zero pages beyond current inode size despite the fact that underlying blocks should be already zeroed out and writeback will skip writing such pages anyway. Avoid the pointless work. Link: https://lkml.kernel.org/r/20211025151332.11301-2-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Jun Piao <piaojun@huawei.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mark@fasheh.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2')
-rw-r--r--fs/ocfs2/alloc.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 1550f18be451..bb247bc349e4 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -6923,13 +6923,12 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end,
}
/*
- * Zero the area past i_size but still within an allocated
- * cluster. This avoids exposing nonzero data on subsequent file
- * extends.
+ * Zero partial cluster for a hole punch or truncate. This avoids exposing
+ * nonzero data on subsequent file extends.
*
* We need to call this before i_size is updated on the inode because
* otherwise block_write_full_page() will skip writeout of pages past
- * i_size. The new_i_size parameter is passed for this reason.
+ * i_size.
*/
int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
u64 range_start, u64 range_end)
@@ -6947,6 +6946,15 @@ int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
if (!ocfs2_sparse_alloc(OCFS2_SB(sb)))
return 0;
+ /*
+ * Avoid zeroing pages fully beyond current i_size. It is pointless as
+ * underlying blocks of those pages should be already zeroed out and
+ * page writeback will skip them anyway.
+ */
+ range_end = min_t(u64, range_end, i_size_read(inode));
+ if (range_start >= range_end)
+ return 0;
+
pages = kcalloc(ocfs2_pages_per_cluster(sb),
sizeof(struct page *), GFP_NOFS);
if (pages == NULL) {
@@ -6955,9 +6963,6 @@ int ocfs2_zero_range_for_truncate(struct inode *inode, handle_t *handle,
goto out;
}
- if (range_start == range_end)
- goto out;
-
ret = ocfs2_extent_map_get_blocks(inode,
range_start >> sb->s_blocksize_bits,
&phys, NULL, &ext_flags);