From: Joel Becker Date: Fri, 1 Feb 2008 20:06:54 +0000 (-0800) Subject: ocfs2: New slot map format X-Git-Tag: v2.6.26-rc1~1143^2~57 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=386a2ef8576e966076c293f6496b9e3d7e3d9035;p=linux-2.6 ocfs2: New slot map format The old slot map had a few limitations: - It was limited to one block, so the maximum slot count was 255. - Each slot was signed 16bits, limiting node numbers to INT16_MAX. - An empty slot was marked by the magic 0xFFFF (-1). The new slot map format provides 32bit node numbers (UINT32_MAX), a separate space to mark a slot in use, and extra room to grow. The slot map is now bounded by i_size, not a block. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 95f783dbe8..f78e9ed532 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -374,6 +374,13 @@ static inline int ocfs2_mount_local(struct ocfs2_super *osb) return (osb->s_feature_incompat & OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT); } +static inline int ocfs2_uses_extended_slot_map(struct ocfs2_super *osb) +{ + return (osb->s_feature_incompat & + OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP); +} + + #define OCFS2_IS_VALID_DINODE(ptr) \ (!strcmp((ptr)->i_signature, OCFS2_INODE_SIGNATURE)) diff --git a/fs/ocfs2/ocfs2_fs.h b/fs/ocfs2/ocfs2_fs.h index 3299116b80..c49502329a 100644 --- a/fs/ocfs2/ocfs2_fs.h +++ b/fs/ocfs2/ocfs2_fs.h @@ -88,7 +88,8 @@ #define OCFS2_FEATURE_COMPAT_SUPP OCFS2_FEATURE_COMPAT_BACKUP_SB #define OCFS2_FEATURE_INCOMPAT_SUPP (OCFS2_FEATURE_INCOMPAT_LOCAL_MOUNT \ | OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC \ - | OCFS2_FEATURE_INCOMPAT_INLINE_DATA) + | OCFS2_FEATURE_INCOMPAT_INLINE_DATA \ + | OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP) #define OCFS2_FEATURE_RO_COMPAT_SUPP OCFS2_FEATURE_RO_COMPAT_UNWRITTEN /* @@ -125,6 +126,10 @@ /* Support for data packed into inode blocks */ #define OCFS2_FEATURE_INCOMPAT_INLINE_DATA 0x0040 +/* Support for the extended slot map */ +#define OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP 0x100 + + /* * backup superblock flag is used to indicate that this volume * has backup superblocks. @@ -476,7 +481,8 @@ struct ocfs2_extent_block /* * On disk slot map for OCFS2. This defines the contents of the "slot_map" - * system file. + * system file. A slot is valid if it contains a node number >= 0. The + * value -1 (0xFFFF) is OCFS2_INVALID_SLOT. This marks a slot empty. */ struct ocfs2_slot_map { /*00*/ __le16 sm_slots[0]; @@ -486,6 +492,27 @@ struct ocfs2_slot_map { */ }; +struct ocfs2_extended_slot { +/*00*/ __u8 es_valid; + __u8 es_reserved1[3]; + __le32 es_node_num; +/*10*/ +}; + +/* + * The extended slot map, used when OCFS2_FEATURE_INCOMPAT_EXTENDED_SLOT_MAP + * is set. It separates out the valid marker from the node number, and + * has room to grow. Unlike the old slot map, this format is defined by + * i_size. + */ +struct ocfs2_slot_map_extended { +/*00*/ struct ocfs2_extended_slot se_slots[0]; +/* + * Actual size is i_size of the slot_map system file. It should + * match s_max_slots * sizeof(struct ocfs2_extended_slot) + */ +}; + /* * On disk superblock for OCFS2 * Note that it is contained inside an ocfs2_dinode, so all offsets diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c index e7e7a74156..63fb1b26d9 100644 --- a/fs/ocfs2/slot_map.c +++ b/fs/ocfs2/slot_map.c @@ -49,6 +49,8 @@ struct ocfs2_slot { }; struct ocfs2_slot_info { + int si_extended; + int si_slots_per_block; struct inode *si_inode; unsigned int si_blocks; struct buffer_head **si_bh; @@ -78,17 +80,37 @@ static void ocfs2_set_slot(struct ocfs2_slot_info *si, si->si_slots[slot_num].sl_node_num = node_num; } +/* This version is for the extended slot map */ +static void ocfs2_update_slot_info_extended(struct ocfs2_slot_info *si) +{ + int b, i, slotno; + struct ocfs2_slot_map_extended *se; + + slotno = 0; + for (b = 0; b < si->si_blocks; b++) { + se = (struct ocfs2_slot_map_extended *)si->si_bh[b]->b_data; + for (i = 0; + (i < si->si_slots_per_block) && + (slotno < si->si_num_slots); + i++, slotno++) { + if (se->se_slots[i].es_valid) + ocfs2_set_slot(si, slotno, + le32_to_cpu(se->se_slots[i].es_node_num)); + else + ocfs2_invalidate_slot(si, slotno); + } + } +} + /* * Post the slot information on disk into our slot_info struct. * Must be protected by osb_lock. */ -static void ocfs2_update_slot_info(struct ocfs2_slot_info *si) +static void ocfs2_update_slot_info_old(struct ocfs2_slot_info *si) { int i; struct ocfs2_slot_map *sm; - /* we don't read the slot block here as ocfs2_super_lock - * should've made sure we have the most recent copy. */ sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data; for (i = 0; i < si->si_num_slots; i++) { @@ -99,6 +121,18 @@ static void ocfs2_update_slot_info(struct ocfs2_slot_info *si) } } +static void ocfs2_update_slot_info(struct ocfs2_slot_info *si) +{ + /* + * The slot data will have been refreshed when ocfs2_super_lock + * was taken. + */ + if (si->si_extended) + ocfs2_update_slot_info_extended(si); + else + ocfs2_update_slot_info_old(si); +} + int ocfs2_refresh_slot_info(struct ocfs2_super *osb) { int ret; @@ -131,13 +165,31 @@ int ocfs2_refresh_slot_info(struct ocfs2_super *osb) /* post the our slot info stuff into it's destination bh and write it * out. */ -static int ocfs2_update_disk_slots(struct ocfs2_super *osb, - struct ocfs2_slot_info *si) +static void ocfs2_update_disk_slot_extended(struct ocfs2_slot_info *si, + int slot_num, + struct buffer_head **bh) +{ + int blkind = slot_num / si->si_slots_per_block; + int slotno = slot_num % si->si_slots_per_block; + struct ocfs2_slot_map_extended *se; + + BUG_ON(blkind >= si->si_blocks); + + se = (struct ocfs2_slot_map_extended *)si->si_bh[blkind]->b_data; + se->se_slots[slotno].es_valid = si->si_slots[slot_num].sl_valid; + if (si->si_slots[slot_num].sl_valid) + se->se_slots[slotno].es_node_num = + cpu_to_le32(si->si_slots[slot_num].sl_node_num); + *bh = si->si_bh[blkind]; +} + +static void ocfs2_update_disk_slot_old(struct ocfs2_slot_info *si, + int slot_num, + struct buffer_head **bh) { - int status, i; + int i; struct ocfs2_slot_map *sm; - spin_lock(&osb->osb_lock); sm = (struct ocfs2_slot_map *)si->si_bh[0]->b_data; for (i = 0; i < si->si_num_slots; i++) { if (si->si_slots[i].sl_valid) @@ -146,9 +198,24 @@ static int ocfs2_update_disk_slots(struct ocfs2_super *osb, else sm->sm_slots[i] = cpu_to_le16(OCFS2_INVALID_SLOT); } + *bh = si->si_bh[0]; +} + +static int ocfs2_update_disk_slot(struct ocfs2_super *osb, + struct ocfs2_slot_info *si, + int slot_num) +{ + int status; + struct buffer_head *bh; + + spin_lock(&osb->osb_lock); + if (si->si_extended) + ocfs2_update_disk_slot_extended(si, slot_num, &bh); + else + ocfs2_update_disk_slot_old(si, slot_num, &bh); spin_unlock(&osb->osb_lock); - status = ocfs2_write_block(osb, si->si_bh[0], si->si_inode); + status = ocfs2_write_block(osb, bh, si->si_inode); if (status < 0) mlog_errno(status); @@ -165,7 +232,12 @@ static int ocfs2_slot_map_physical_size(struct ocfs2_super *osb, { unsigned long long bytes_needed; - bytes_needed = osb->max_slots * sizeof(__le16); + if (ocfs2_uses_extended_slot_map(osb)) { + bytes_needed = osb->max_slots * + sizeof(struct ocfs2_extended_slot); + } else { + bytes_needed = osb->max_slots * sizeof(__le16); + } if (bytes_needed > i_size_read(inode)) { mlog(ML_ERROR, "Slot map file is too small! (size %llu, needed %llu)\n", @@ -279,7 +351,7 @@ int ocfs2_clear_slot(struct ocfs2_super *osb, int slot_num) ocfs2_invalidate_slot(si, slot_num); spin_unlock(&osb->osb_lock); - return ocfs2_update_disk_slots(osb, osb->slot_info); + return ocfs2_update_disk_slot(osb, osb->slot_info, slot_num); } static int ocfs2_map_slot_buffers(struct ocfs2_super *osb, @@ -301,6 +373,16 @@ static int ocfs2_map_slot_buffers(struct ocfs2_super *osb, if (!si->si_blocks) goto bail; + if (si->si_extended) + si->si_slots_per_block = + (osb->sb->s_blocksize / + sizeof(struct ocfs2_extended_slot)); + else + si->si_slots_per_block = osb->sb->s_blocksize / sizeof(__le16); + + /* The size checks above should ensure this */ + BUG_ON((osb->max_slots / si->si_slots_per_block) > blocks); + mlog(0, "Slot map needs %u buffers for %llu bytes\n", si->si_blocks, bytes); @@ -352,6 +434,7 @@ int ocfs2_init_slot_info(struct ocfs2_super *osb) goto bail; } + si->si_extended = ocfs2_uses_extended_slot_map(osb); si->si_num_slots = osb->max_slots; si->si_slots = (struct ocfs2_slot *)((char *)si + sizeof(struct ocfs2_slot_info)); @@ -425,7 +508,7 @@ int ocfs2_find_slot(struct ocfs2_super *osb) mlog(0, "taking node slot %d\n", osb->slot_num); - status = ocfs2_update_disk_slots(osb, si); + status = ocfs2_update_disk_slot(osb, si, osb->slot_num); if (status < 0) mlog_errno(status); @@ -436,7 +519,7 @@ bail: void ocfs2_put_slot(struct ocfs2_super *osb) { - int status; + int status, slot_num; struct ocfs2_slot_info *si = osb->slot_info; if (!si) @@ -445,11 +528,12 @@ void ocfs2_put_slot(struct ocfs2_super *osb) spin_lock(&osb->osb_lock); ocfs2_update_slot_info(si); + slot_num = osb->slot_num; ocfs2_invalidate_slot(si, osb->slot_num); osb->slot_num = OCFS2_INVALID_SLOT; spin_unlock(&osb->osb_lock); - status = ocfs2_update_disk_slots(osb, si); + status = ocfs2_update_disk_slot(osb, si, slot_num); if (status < 0) { mlog_errno(status); goto bail;