diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_inode_buf.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_inode_buf.c | 46 |
1 files changed, 42 insertions, 4 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c index 5c9a7440d9e4..f3254a4f4cb4 100644 --- a/fs/xfs/libxfs/xfs_inode_buf.c +++ b/fs/xfs/libxfs/xfs_inode_buf.c @@ -559,8 +559,17 @@ xfs_dinode_calc_crc( /* * Validate di_extsize hint. * - * The rules are documented at xfs_ioctl_setattr_check_extsize(). - * These functions must be kept in sync with each other. + * 1. Extent size hint is only valid for directories and regular files. + * 2. FS_XFLAG_EXTSIZE is only valid for regular files. + * 3. FS_XFLAG_EXTSZINHERIT is only valid for directories. + * 4. Hint cannot be larger than MAXTEXTLEN. + * 5. Can be changed on directories at any time. + * 6. Hint value of 0 turns off hints, clears inode flags. + * 7. Extent size must be a multiple of the appropriate block size. + * For realtime files, this is the rt extent size. + * 8. For non-realtime files, the extent size hint must be limited + * to half the AG size to avoid alignment extending the extent beyond the + * limits of the AG. */ xfs_failaddr_t xfs_inode_validate_extsize( @@ -580,6 +589,28 @@ xfs_inode_validate_extsize( inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT); extsize_bytes = XFS_FSB_TO_B(mp, extsize); + /* + * This comment describes a historic gap in this verifier function. + * + * On older kernels, the extent size hint verifier doesn't check that + * the extent size hint is an integer multiple of the realtime extent + * size on a directory with both RTINHERIT and EXTSZINHERIT flags set. + * The verifier has always enforced the alignment rule for regular + * files with the REALTIME flag set. + * + * If a directory with a misaligned extent size hint is allowed to + * propagate that hint into a new regular realtime file, the result + * is that the inode cluster buffer verifier will trigger a corruption + * shutdown the next time it is run. + * + * Unfortunately, there could be filesystems with these misconfigured + * directories in the wild, so we cannot add a check to this verifier + * at this time because that will result a new source of directory + * corruption errors when reading an existing filesystem. Instead, we + * permit the misconfiguration to pass through the verifiers so that + * callers of this function can correct and mitigate externally. + */ + if (rt_flag) blocksize_bytes = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog; else @@ -616,8 +647,15 @@ xfs_inode_validate_extsize( /* * Validate di_cowextsize hint. * - * The rules are documented at xfs_ioctl_setattr_check_cowextsize(). - * These functions must be kept in sync with each other. + * 1. CoW extent size hint can only be set if reflink is enabled on the fs. + * The inode does not have to have any shared blocks, but it must be a v3. + * 2. FS_XFLAG_COWEXTSIZE is only valid for directories and regular files; + * for a directory, the hint is propagated to new files. + * 3. Can be changed on files & directories at any time. + * 4. Hint value of 0 turns off hints, clears inode flags. + * 5. Extent size must be a multiple of the appropriate block size. + * 6. The extent size hint must be limited to half the AG size to avoid + * alignment extending the extent beyond the limits of the AG. */ xfs_failaddr_t xfs_inode_validate_cowextsize( |