diff options
Diffstat (limited to 'fs/xfs/xfs_reflink.c')
-rw-r--r-- | fs/xfs/xfs_reflink.c | 92 |
1 files changed, 89 insertions, 3 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 0a010870f380..437ce227368e 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1659,6 +1659,83 @@ xfs_reflink_remap_adjust_rtlen( #endif /* CONFIG_XFS_RT */ /* + * Check the alignment of a remap request when the allocation unit size isn't a + * power of two. The VFS helpers use (fast) bitmask-based alignment checks, + * but here we have to use slow long division. + */ +static int +xfs_reflink_remap_check_rtalign( + struct xfs_inode *ip_in, + loff_t pos_in, + struct xfs_inode *ip_out, + loff_t pos_out, + loff_t *req_len, + unsigned int remap_flags) +{ + struct xfs_mount *mp = ip_in->i_mount; + uint32_t rextbytes; + loff_t in_size, out_size; + loff_t new_length, length = *req_len; + loff_t blen; + + rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize); + in_size = i_size_read(VFS_I(ip_in)); + out_size = i_size_read(VFS_I(ip_out)); + + /* The start of both ranges must be aligned to a rt extent. */ + if (!isaligned_64(pos_in, rextbytes) || + !isaligned_64(pos_out, rextbytes)) + return -EINVAL; + + if (length == 0) + length = in_size - pos_in; + + /* + * If the user wanted us to exchange up to the infile's EOF, round up + * to the next block boundary for this check. + * + * Otherwise, reject the range length if it's not extent aligned. We + * already confirmed the starting offsets' extent alignment. + */ + if (pos_in + length == in_size) + blen = roundup_64(in_size, rextbytes) - pos_in; + else + blen = rounddown_64(length, rextbytes); + + /* Don't allow overlapped remappings within the same file. */ + if (ip_in == ip_out && + pos_out + blen > pos_in && + pos_in + blen > pos_out) + return -EINVAL; + + /* + * Ensure that we don't exchange a partial EOF extent into the middle + * of another file. + */ + if (isaligned_64(length, rextbytes)) + return 0; + + new_length = length; + if (pos_out + length < out_size) + new_length = rounddown_64(new_length, rextbytes); + + if (new_length == length) + return 0; + + /* + * Return the shortened request if the caller permits it. If the + * request was shortened to zero rt extents, we know that the original + * arguments weren't valid in the first place. + */ + if ((remap_flags & REMAP_FILE_CAN_SHORTEN) && new_length > 0) { + *req_len = new_length; + return 0; + } + + return (remap_flags & REMAP_FILE_DEDUP) ? -EBADE : -EINVAL; +} + +/* * Prepare two files for range cloning. Upon a successful return both inodes * will have the iolock and mmaplock held, the page cache of the out file will * be truncated, and any leases on the out file will have been broken. This @@ -1701,6 +1778,7 @@ xfs_reflink_remap_prep( struct inode *inode_out = file_inode(file_out); struct xfs_inode *dest = XFS_I(inode_out); const struct iomap_ops *dax_read_ops = NULL; + unsigned int alloc_unit = xfs_inode_alloc_unitsize(dest); int ret; /* Lock both files against IO */ @@ -1718,14 +1796,22 @@ xfs_reflink_remap_prep( if (IS_DAX(inode_in) != IS_DAX(inode_out)) goto out_unlock; - ASSERT(is_power_of_2(xfs_inode_alloc_unitsize(dest))); + /* Check non-power of two alignment issues, if necessary. */ + if (XFS_IS_REALTIME_INODE(dest) && !is_power_of_2(alloc_unit)) { + ret = xfs_reflink_remap_check_rtalign(src, pos_in, dest, + pos_out, len, remap_flags); + if (ret) + goto out_unlock; + + /* Do the VFS checks with the regular block alignment. */ + alloc_unit = src->i_mount->m_sb.sb_blocksize; + } if (IS_DAX(inode_in)) dax_read_ops = &xfs_read_iomap_ops; ret = __generic_remap_file_range_prep(file_in, pos_in, file_out, - pos_out, len, remap_flags, dax_read_ops, - xfs_inode_alloc_unitsize(dest)); + pos_out, len, remap_flags, dax_read_ops, alloc_unit); if (ret || *len == 0) goto out_unlock; |