diff options
Diffstat (limited to 'fs/xfs/xfs_mount.c')
-rw-r--r-- | fs/xfs/xfs_mount.c | 162 |
1 files changed, 152 insertions, 10 deletions
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 00b53f479ece..0b690bc119d7 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -171,19 +171,16 @@ xfs_readsb( ASSERT(mp->m_ddev_targp != NULL); /* - * For the initial read, we must guess at the sector - * size based on the block device. It's enough to - * get the sb_sectsize out of the superblock and - * then reread with the proper length. - * We don't verify it yet, because it may not be complete. + * In the first pass, use the device sector size to just read enough + * of the superblock to extract the XFS sector size. + * + * The device sector size must be smaller than or equal to the XFS + * sector size and thus we can always read the superblock. Once we know + * the XFS sector size, re-read it and run the buffer verifier. */ - sector_size = xfs_getsize_buftarg(mp->m_ddev_targp); + sector_size = mp->m_ddev_targp->bt_logical_sectorsize; buf_ops = NULL; - /* - * Allocate a (locked) buffer to hold the superblock. This will be kept - * around at all times to optimize access to the superblock. - */ reread: error = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR, BTOBB(sector_size), &bp, buf_ops); @@ -247,6 +244,10 @@ reread: /* no need to be quiet anymore, so reset the buf ops */ bp->b_ops = &xfs_sb_buf_ops; + /* + * Keep a pointer of the sb buffer around instead of caching it in the + * buffer cache because we access it frequently. + */ mp->m_sb_bp = bp; xfs_buf_unlock(bp); return 0; @@ -666,6 +667,138 @@ xfs_agbtree_compute_maxlevels( mp->m_agbtree_maxlevels = max(levels, mp->m_refc_maxlevels); } +/* Maximum atomic write IO size that the kernel allows. */ +static inline xfs_extlen_t xfs_calc_atomic_write_max(struct xfs_mount *mp) +{ + return rounddown_pow_of_two(XFS_B_TO_FSB(mp, MAX_RW_COUNT)); +} + +static inline unsigned int max_pow_of_two_factor(const unsigned int nr) +{ + return 1 << (ffs(nr) - 1); +} + +/* + * If the underlying device advertises atomic write support, limit the size of + * atomic writes to the greatest power-of-two factor of the group size so + * that every atomic write unit aligns with the start of every group. This is + * required so that the allocations for an atomic write will always be + * aligned compatibly with the alignment requirements of the storage. + * + * If the device doesn't advertise atomic writes, then there are no alignment + * restrictions and the largest out-of-place write we can do ourselves is the + * number of blocks that user files can allocate from any group. + */ +static xfs_extlen_t +xfs_calc_group_awu_max( + struct xfs_mount *mp, + enum xfs_group_type type) +{ + struct xfs_groups *g = &mp->m_groups[type]; + struct xfs_buftarg *btp = xfs_group_type_buftarg(mp, type); + + if (g->blocks == 0) + return 0; + if (btp && btp->bt_awu_min > 0) + return max_pow_of_two_factor(g->blocks); + return rounddown_pow_of_two(g->blocks); +} + +/* Compute the maximum atomic write unit size for each section. */ +static inline void +xfs_calc_atomic_write_unit_max( + struct xfs_mount *mp, + enum xfs_group_type type) +{ + struct xfs_groups *g = &mp->m_groups[type]; + + const xfs_extlen_t max_write = xfs_calc_atomic_write_max(mp); + const xfs_extlen_t max_ioend = xfs_reflink_max_atomic_cow(mp); + const xfs_extlen_t max_gsize = xfs_calc_group_awu_max(mp, type); + + g->awu_max = min3(max_write, max_ioend, max_gsize); + trace_xfs_calc_atomic_write_unit_max(mp, type, max_write, max_ioend, + max_gsize, g->awu_max); +} + +/* + * Try to set the atomic write maximum to a new value that we got from + * userspace via mount option. + */ +int +xfs_set_max_atomic_write_opt( + struct xfs_mount *mp, + unsigned long long new_max_bytes) +{ + const xfs_filblks_t new_max_fsbs = XFS_B_TO_FSBT(mp, new_max_bytes); + const xfs_extlen_t max_write = xfs_calc_atomic_write_max(mp); + const xfs_extlen_t max_group = + max(mp->m_groups[XG_TYPE_AG].blocks, + mp->m_groups[XG_TYPE_RTG].blocks); + const xfs_extlen_t max_group_write = + max(xfs_calc_group_awu_max(mp, XG_TYPE_AG), + xfs_calc_group_awu_max(mp, XG_TYPE_RTG)); + int error; + + if (new_max_bytes == 0) + goto set_limit; + + ASSERT(max_write <= U32_MAX); + + /* generic_atomic_write_valid enforces power of two length */ + if (!is_power_of_2(new_max_bytes)) { + xfs_warn(mp, + "max atomic write size of %llu bytes is not a power of 2", + new_max_bytes); + return -EINVAL; + } + + if (new_max_bytes & mp->m_blockmask) { + xfs_warn(mp, + "max atomic write size of %llu bytes not aligned with fsblock", + new_max_bytes); + return -EINVAL; + } + + if (new_max_fsbs > max_write) { + xfs_warn(mp, + "max atomic write size of %lluk cannot be larger than max write size %lluk", + new_max_bytes >> 10, + XFS_FSB_TO_B(mp, max_write) >> 10); + return -EINVAL; + } + + if (new_max_fsbs > max_group) { + xfs_warn(mp, + "max atomic write size of %lluk cannot be larger than allocation group size %lluk", + new_max_bytes >> 10, + XFS_FSB_TO_B(mp, max_group) >> 10); + return -EINVAL; + } + + if (new_max_fsbs > max_group_write) { + xfs_warn(mp, + "max atomic write size of %lluk cannot be larger than max allocation group write size %lluk", + new_max_bytes >> 10, + XFS_FSB_TO_B(mp, max_group_write) >> 10); + return -EINVAL; + } + +set_limit: + error = xfs_calc_atomic_write_reservation(mp, new_max_fsbs); + if (error) { + xfs_warn(mp, + "cannot support completing atomic writes of %lluk", + new_max_bytes >> 10); + return error; + } + + xfs_calc_atomic_write_unit_max(mp, XG_TYPE_AG); + xfs_calc_atomic_write_unit_max(mp, XG_TYPE_RTG); + mp->m_awu_max_bytes = new_max_bytes; + return 0; +} + /* Compute maximum possible height for realtime btree types for this fs. */ static inline void xfs_rtbtree_compute_maxlevels( @@ -1082,6 +1215,15 @@ xfs_mountfs( xfs_zone_gc_start(mp); } + /* + * Pre-calculate atomic write unit max. This involves computations + * derived from transaction reservations, so we must do this after the + * log is fully initialized. + */ + error = xfs_set_max_atomic_write_opt(mp, mp->m_awu_max_bytes); + if (error) + goto out_agresv; + return 0; out_agresv: |