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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 <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
hifive-unleashed-5.1
Joel Becker 2008-02-01 12:06:54 -08:00 committed by Mark Fasheh
parent fb86b1f071
commit 386a2ef857
3 changed files with 133 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
fs/ocfs2/ocfs2.h
View File

@ -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))

31
fs/ocfs2/ocfs2_fs.h
View File

@ -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

110
fs/ocfs2/slot_map.c
View File

@ -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 status, i;
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 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;