diff options
| -rw-r--r-- | fs/xfs/scrub/scrub.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index 78b00ab85c9c..43af5ce1f99f 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -792,6 +792,37 @@ xfs_scrubv_check_barrier( return 0; } +/* + * If the caller provided us with a nonzero inode number that isn't the ioctl + * file, try to grab a reference to it to eliminate all further untrusted inode + * lookups. If we can't get the inode, let each scrub function try again. + */ +STATIC struct xfs_inode * +xchk_scrubv_open_by_handle( + struct xfs_mount *mp, + const struct xfs_scrub_vec_head *head) +{ + struct xfs_trans *tp; + struct xfs_inode *ip; + int error; + + error = xfs_trans_alloc_empty(mp, &tp); + if (error) + return NULL; + + error = xfs_iget(mp, tp, head->svh_ino, XCHK_IGET_FLAGS, 0, &ip); + xfs_trans_cancel(tp); + if (error) + return NULL; + + if (VFS_I(ip)->i_generation != head->svh_gen) { + xfs_irele(ip); + return NULL; + } + + return ip; +} + /* Vectored scrub implementation to reduce ioctl calls. */ int xfs_ioc_scrubv_metadata( @@ -804,6 +835,7 @@ xfs_ioc_scrubv_metadata( struct xfs_scrub_vec __user *uvectors; struct xfs_inode *ip_in = XFS_I(file_inode(file)); struct xfs_mount *mp = ip_in->i_mount; + struct xfs_inode *handle_ip = NULL; struct xfs_scrub_vec *v; size_t vec_bytes; unsigned int i; @@ -848,6 +880,17 @@ xfs_ioc_scrubv_metadata( trace_xchk_scrubv_item(mp, &head, i, v); } + /* + * If the caller wants us to do a scrub-by-handle and the file used to + * call the ioctl is not the same file, load the incore inode and pin + * it across all the scrubv actions to avoid repeated UNTRUSTED + * lookups. The reference is not passed to deeper layers of scrub + * because each scrubber gets to decide its own strategy and return + * values for getting an inode. + */ + if (head.svh_ino && head.svh_ino != ip_in->i_ino) + handle_ip = xchk_scrubv_open_by_handle(mp, &head); + /* Run all the scrubbers. */ for (i = 0, v = vectors; i < head.svh_nr; i++, v++) { struct xfs_scrub_metadata sm = { @@ -895,6 +938,8 @@ xfs_ioc_scrubv_metadata( } out_free: + if (handle_ip) + xfs_irele(handle_ip); kfree(vectors); return error; } |