diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_log_rlimit.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_log_rlimit.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_log_rlimit.c b/fs/xfs/libxfs/xfs_log_rlimit.c index 9975b93a74..d3bd6a86c8 100644 --- a/fs/xfs/libxfs/xfs_log_rlimit.c +++ b/fs/xfs/libxfs/xfs_log_rlimit.c @@ -17,6 +17,34 @@ #include "xfs_trace.h" /* + * Shortly after enabling the large extents count feature in 2023, longstanding + * bugs were found in the code that computes the minimum log size. Luckily, + * the bugs resulted in over-estimates of that size, so there's no impact to + * existing users. However, we don't want to reduce the minimum log size + * because that can create the situation where a newer mkfs writes a new + * filesystem that an older kernel won't mount. + * + * Several years prior, we also discovered that the transaction reservations + * for rmap and reflink operations were unnecessarily large. That was fixed, + * but the minimum log size computation was left alone to avoid the + * compatibility problems noted above. Fix that too. + * + * Therefore, we only may correct the computation starting with filesystem + * features that didn't exist in 2023. In other words, only turn this on if + * the filesystem has parent pointers. + * + * This function can be called before the XFS_HAS_* flags have been set up, + * (e.g. mkfs) so we must check the ondisk superblock. + */ +static inline bool +xfs_want_minlogsize_fixes( + struct xfs_sb *sb) +{ + return xfs_sb_is_v5(sb) && + xfs_sb_has_incompat_feature(sb, XFS_SB_FEAT_INCOMPAT_PARENT); +} + +/* * Calculate the maximum length in bytes that would be required for a local * attribute value as large attributes out of line are not logged. */ @@ -31,6 +59,15 @@ xfs_log_calc_max_attrsetm_res( MAXNAMELEN - 1; nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK); nblks += XFS_B_TO_FSB(mp, size); + + /* + * If the feature set is new enough, correct a unit conversion error in + * the xattr transaction reservation code that resulted in oversized + * minimum log size computations. + */ + if (xfs_want_minlogsize_fixes(&mp->m_sb)) + size = XFS_B_TO_FSB(mp, size); + nblks += XFS_NEXTENTADD_SPACE_RES(mp, size, XFS_ATTR_FORK); return M_RES(mp)->tr_attrsetm.tr_logres + @@ -49,6 +86,15 @@ xfs_log_calc_trans_resv_for_minlogblocks( unsigned int rmap_maxlevels = mp->m_rmap_maxlevels; /* + * If the feature set is new enough, drop the oversized minimum log + * size computation introduced by the original reflink code. + */ + if (xfs_want_minlogsize_fixes(&mp->m_sb)) { + xfs_trans_resv_calc(mp, resv); + return; + } + + /* * In the early days of rmap+reflink, we always set the rmap maxlevels * to 9 even if the AG was small enough that it would never grow to * that height. Transaction reservation sizes influence the minimum |