diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2018-04-16 23:07:36 -0700 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-05-02 09:21:33 -0700 |
| commit | 021ba8e98fe5c6691b3cc3669faafa02403aa211 (patch) | |
| tree | 9b4b92b15794cb1e2c7a70f7dae329b3923679b2 | |
| parent | 7b38460dc8e4eafba06c78f8e37099d3b34d473c (diff) | |
xfs: cap the length of deduplication requestsxfs-4.17-fixes-2
Since deduplication potentially has to read in all the pages in both
files in order to compare the contents, cap the deduplication request
length at MAX_RW_COUNT/2 (roughly 1GB) so that we have /some/ upper bound
on the request length and can't just lock up the kernel forever. Found
by running generic/304 after commit 1ddae54555b62 ("common/rc: add
missing 'local' keywords").
Reported-by: matorola@gmail.com
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
| -rw-r--r-- | fs/xfs/xfs_file.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index eed073cc4778..e70fb8ccecea 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -880,8 +880,18 @@ xfs_file_dedupe_range( struct file *dst_file, u64 dst_loff) { + struct inode *srci = file_inode(src_file); + u64 max_dedupe; int error; + /* + * Since we have to read all these pages in to compare them, cut + * it off at MAX_RW_COUNT/2 rounded down to the nearest block. + * That means we won't do more than MAX_RW_COUNT IO per request. + */ + max_dedupe = (MAX_RW_COUNT >> 1) & ~(i_blocksize(srci) - 1); + if (len > max_dedupe) + len = max_dedupe; error = xfs_reflink_remap_range(src_file, loff, dst_file, dst_loff, len, true); if (error) |