From: Andreas Gruenbacher <[email protected]> [ Upstream commit 39c3a948ecf6e7b8f55f0e91a5febc924fede4d7 ]
When punching a hole in a file, use filemap_write_and_wait_range to write back any dirty pages in the range of the hole. As a side effect, if the hole isn't page aligned, this marks unaligned pages at the beginning and the end of the hole read-only. This is required when the block size is smaller than the page size: when those pages are written to again after the hole punching, we must make sure that page_mkwrite is called for those pages so that the page will be fully allocated and any blocks turned into holes from the hole punching will be reallocated. (If a page is writably mapped, page_mkwrite won't be called.) Fixes xfstest generic/567. Signed-off-by: Andreas Gruenbacher <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- fs/gfs2/bmap.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index adbb8fef22162..4846e0c47e6af 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -2442,8 +2442,16 @@ int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length) struct inode *inode = file_inode(file); struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); + unsigned int blocksize = i_blocksize(inode); + loff_t start, end; int error; + start = round_down(offset, blocksize); + end = round_up(offset + length, blocksize) - 1; + error = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (error) + return error; + if (gfs2_is_jdata(ip)) error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA, GFS2_JTRUNC_REVOKES); @@ -2457,9 +2465,8 @@ int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length) if (error) goto out; } else { - unsigned int start_off, end_len, blocksize; + unsigned int start_off, end_len; - blocksize = i_blocksize(inode); start_off = offset & (blocksize - 1); end_len = (offset + length) & (blocksize - 1); if (start_off) { -- 2.25.1
