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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-04 20:36:50 -1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-05-04 20:36:50 -1000 |
| commit | 2e171ffcdf62a90ea7a0192728f81c1ac288de50 (patch) | |
| tree | d337070832c1666ed28fc0fc2cfda70b76426739 | |
| parent | 4148d3884a4c842a5b3ee2976c2ebbdb7bbd0559 (diff) | |
| parent | 021ba8e98fe5c6691b3cc3669faafa02403aa211 (diff) | |
Merge tag 'xfs-4.17-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
"I've got one more bug fix for xfs for 4.17-rc4, which caps the amount
of data we try to handle in one dedupe request so that userspace can't
livelock the kernel.
This series has been run through a full xfstests run during the week
and through a quick xfstests run against this morning's master, with
no ajor failures reported.
Summary:
- Cap the maximum length of a deduplication request at MAX_RW_COUNT/2
to avoid kernel livelock due to excessively large IO requests"
* tag 'xfs-4.17-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: cap the length of deduplication requests
| -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) |