#define BFITNOENT ((u32)~0)
#define NO_BLOCK ((u64)~0)
-#define RSRV_CONTENTION_FACTOR 4
-#define RGRP_RSRV_MAX_CONTENDERS 2
-
#if BITS_PER_LONG == 32
#define LBITMASK (0x55555555UL)
#define LBITSKIP55 (0x55555555UL)
1, 0, 0, 0
};
+static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 minext,
+ const struct gfs2_inode *ip, bool nowrap);
+
+
/**
* gfs2_setbit - Set a bit in the bitmaps
* @rbm: The position of the bit to set
}
/**
+ * gfs2_rbm_from_block - Set the rbm based upon rgd and block number
+ * @rbm: The rbm with rgd already set correctly
+ * @block: The block number (filesystem relative)
+ *
+ * This sets the bi and offset members of an rbm based on a
+ * resource group and a filesystem relative block number. The
+ * resource group must be set in the rbm on entry, the bi and
+ * offset members will be set by this function.
+ *
+ * Returns: 0 on success, or an error code
+ */
+
+static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block)
+{
+ u64 rblock = block - rbm->rgd->rd_data0;
+ u32 goal = (u32)rblock;
+ int x;
+
+ if (WARN_ON_ONCE(rblock > UINT_MAX))
+ return -EINVAL;
+ if (block >= rbm->rgd->rd_data0 + rbm->rgd->rd_data)
+ return -E2BIG;
+
+ for (x = 0; x < rbm->rgd->rd_length; x++) {
+ rbm->bi = rbm->rgd->rd_bits + x;
+ if (goal < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY) {
+ rbm->offset = goal - (rbm->bi->bi_start * GFS2_NBBY);
+ break;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * gfs2_unaligned_extlen - Look for free blocks which are not byte aligned
+ * @rbm: Position to search (value/result)
+ * @n_unaligned: Number of unaligned blocks to check
+ * @len: Decremented for each block found (terminate on zero)
+ *
+ * Returns: true if a non-free block is encountered
+ */
+
+static bool gfs2_unaligned_extlen(struct gfs2_rbm *rbm, u32 n_unaligned, u32 *len)
+{
+ u64 block;
+ u32 n;
+ u8 res;
+
+ for (n = 0; n < n_unaligned; n++) {
+ res = gfs2_testbit(rbm);
+ if (res != GFS2_BLKST_FREE)
+ return true;
+ (*len)--;
+ if (*len == 0)
+ return true;
+ block = gfs2_rbm_to_block(rbm);
+ if (gfs2_rbm_from_block(rbm, block + 1))
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * gfs2_free_extlen - Return extent length of free blocks
+ * @rbm: Starting position
+ * @len: Max length to check
+ *
+ * Starting at the block specified by the rbm, see how many free blocks
+ * there are, not reading more than len blocks ahead. This can be done
+ * using memchr_inv when the blocks are byte aligned, but has to be done
+ * on a block by block basis in case of unaligned blocks. Also this
+ * function can cope with bitmap boundaries (although it must stop on
+ * a resource group boundary)
+ *
+ * Returns: Number of free blocks in the extent
+ */
+
+static u32 gfs2_free_extlen(const struct gfs2_rbm *rrbm, u32 len)
+{
+ struct gfs2_rbm rbm = *rrbm;
+ u32 n_unaligned = rbm.offset & 3;
+ u32 size = len;
+ u32 bytes;
+ u32 chunk_size;
+ u8 *ptr, *start, *end;
+ u64 block;
+
+ if (n_unaligned &&
+ gfs2_unaligned_extlen(&rbm, 4 - n_unaligned, &len))
+ goto out;
+
+ /* Start is now byte aligned */
+ while (len > 3) {
+ start = rbm.bi->bi_bh->b_data;
+ if (rbm.bi->bi_clone)
+ start = rbm.bi->bi_clone;
+ end = start + rbm.bi->bi_bh->b_size;
+ start += rbm.bi->bi_offset;
+ BUG_ON(rbm.offset & 3);
+ start += (rbm.offset / GFS2_NBBY);
+ bytes = min_t(u32, len / GFS2_NBBY, (end - start));
+ ptr = memchr_inv(start, 0, bytes);
+ chunk_size = ((ptr == NULL) ? bytes : (ptr - start));
+ chunk_size *= GFS2_NBBY;
+ BUG_ON(len < chunk_size);
+ len -= chunk_size;
+ block = gfs2_rbm_to_block(&rbm);
+ gfs2_rbm_from_block(&rbm, block + chunk_size);
+ n_unaligned = 3;
+ if (ptr)
+ break;
+ n_unaligned = len & 3;
+ }
+
+ /* Deal with any bits left over at the end */
+ if (n_unaligned)
+ gfs2_unaligned_extlen(&rbm, n_unaligned, &len);
+out:
+ return size - len;
+}
+
+/**
* gfs2_bitcount - count the number of bits in a certain state
* @rgd: the resource group descriptor
* @buffer: the buffer that holds the bitmaps
trace_gfs2_rs(rs, TRACE_RS_TREEDEL);
rb_erase(&rs->rs_node, &rgd->rd_rstree);
RB_CLEAR_NODE(&rs->rs_node);
- BUG_ON(!rgd->rd_rs_cnt);
- rgd->rd_rs_cnt--;
if (rs->rs_free) {
/* return reserved blocks to the rgrp and the ip */
/**
* rs_insert - insert a new multi-block reservation into the rgrp's rb_tree
- * @bi: the bitmap with the blocks
* @ip: the inode structure
- * @biblk: the 32-bit block number relative to the start of the bitmap
- * @amount: the number of blocks to reserve
*
- * Returns: NULL - reservation was already taken, so not inserted
- * pointer to the inserted reservation
*/
-static struct gfs2_blkreserv *rs_insert(struct gfs2_bitmap *bi,
- struct gfs2_inode *ip, u32 biblk,
- int amount)
+static void rs_insert(struct gfs2_inode *ip)
{
struct rb_node **newn, *parent = NULL;
int rc;
struct gfs2_blkreserv *rs = ip->i_res;
struct gfs2_rgrpd *rgd = rs->rs_rbm.rgd;
- u64 fsblock = gfs2_bi2rgd_blk(bi, biblk) + rgd->rd_data0;
+ u64 fsblock = gfs2_rbm_to_block(&rs->rs_rbm);
- spin_lock(&rgd->rd_rsspin);
- newn = &rgd->rd_rstree.rb_node;
- BUG_ON(!ip->i_res);
BUG_ON(gfs2_rs_active(rs));
- /* Figure out where to put new node */
+ spin_lock(&rgd->rd_rsspin);
+ newn = &rgd->rd_rstree.rb_node;
while (*newn) {
struct gfs2_blkreserv *cur =
rb_entry(*newn, struct gfs2_blkreserv, rs_node);
parent = *newn;
- rc = rs_cmp(fsblock, amount, cur);
+ rc = rs_cmp(fsblock, rs->rs_free, cur);
if (rc > 0)
newn = &((*newn)->rb_right);
else if (rc < 0)
newn = &((*newn)->rb_left);
else {
spin_unlock(&rgd->rd_rsspin);
- return NULL; /* reservation already in use */
+ WARN_ON(1);
+ return;
}
}
- /* Do our reservation work */
- rs = ip->i_res;
- rs->rs_free = amount;
- rs->rs_rbm.offset = biblk;
- rs->rs_rbm.bi = bi;
- rs->rs_inum = ip->i_no_addr;
rb_link_node(&rs->rs_node, parent, newn);
rb_insert_color(&rs->rs_node, &rgd->rd_rstree);
/* Do our rgrp accounting for the reservation */
- rgd->rd_reserved += amount; /* blocks reserved */
- rgd->rd_rs_cnt++; /* number of in-tree reservations */
+ rgd->rd_reserved += rs->rs_free; /* blocks reserved */
spin_unlock(&rgd->rd_rsspin);
trace_gfs2_rs(rs, TRACE_RS_INSERT);
- return rs;
}
/**
- * unclaimed_blocks - return number of blocks that aren't spoken for
- */
-static u32 unclaimed_blocks(struct gfs2_rgrpd *rgd)
-{
- return rgd->rd_free_clone - rgd->rd_reserved;
-}
-
-/**
- * rg_mblk_search - find a group of multiple free blocks
+ * rg_mblk_search - find a group of multiple free blocks to form a reservation
* @rgd: the resource group descriptor
* @ip: pointer to the inode for which we're reserving blocks
* @requested: number of blocks required for this allocation
*
- * This is very similar to rgblk_search, except we're looking for whole
- * 64-bit words that represent a chunk of 32 free blocks. I'm only focusing
- * on aligned dwords for speed's sake.
- *
*/
-static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip, unsigned requested)
+static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
+ unsigned requested)
{
- struct gfs2_bitmap *bi = rgd->rd_bits;
- const u32 length = rgd->rd_length;
- u32 blk;
- unsigned int buf, x, search_bytes;
- u8 *buffer = NULL;
- u8 *ptr, *end, *nonzero;
- u32 goal, rsv_bytes;
- struct gfs2_blkreserv *rs;
- u32 best_rs_bytes, unclaimed;
- int best_rs_blocks;
+ struct gfs2_rbm rbm = { .rgd = rgd, };
+ u64 goal;
+ struct gfs2_blkreserv *rs = ip->i_res;
+ u32 extlen;
+ u32 free_blocks = rgd->rd_free_clone - rgd->rd_reserved;
+ int ret;
- if ((rgd->rd_free_clone < rgd->rd_reserved) ||
- (unclaimed_blocks(rgd) < max(requested, RGRP_RSRV_MINBLKS)))
+ extlen = max_t(u32, atomic_read(&rs->rs_sizehint), requested);
+ extlen = clamp(extlen, RGRP_RSRV_MINBLKS, free_blocks);
+ if ((rgd->rd_free_clone < rgd->rd_reserved) || (free_blocks < extlen))
return;
/* Find bitmap block that contains bits for goal block */
if (rgrp_contains_block(rgd, ip->i_goal))
- goal = ip->i_goal - rgd->rd_data0;
+ goal = ip->i_goal;
else
- goal = rgd->rd_last_alloc;
+ goal = rgd->rd_last_alloc + rgd->rd_data0;
- for (buf = 0; buf < length; buf++) {
- bi = rgd->rd_bits + buf;
- /* Convert scope of "goal" from rgrp-wide to within
- found bit block */
- if (goal < (bi->bi_start + bi->bi_len) * GFS2_NBBY) {
- goal -= bi->bi_start * GFS2_NBBY;
- goto do_search;
- }
- }
- buf = 0;
- goal = 0;
-
-do_search:
- best_rs_blocks = max_t(int, atomic_read(&ip->i_res->rs_sizehint),
- (RGRP_RSRV_MINBLKS * rgd->rd_length));
- best_rs_bytes = (best_rs_blocks *
- (1 + (RSRV_CONTENTION_FACTOR * rgd->rd_rs_cnt))) /
- GFS2_NBBY; /* 1 + is for our not-yet-created reservation */
- best_rs_bytes = ALIGN(best_rs_bytes, sizeof(u64));
- unclaimed = unclaimed_blocks(rgd);
- if (best_rs_bytes * GFS2_NBBY > unclaimed)
- best_rs_bytes = unclaimed >> GFS2_BIT_SIZE;
-
- for (x = 0; x <= length; x++) {
- bi = rgd->rd_bits + buf;
-
- if (test_bit(GBF_FULL, &bi->bi_flags))
- goto skip;
+ if (WARN_ON(gfs2_rbm_from_block(&rbm, goal)))
+ return;
- WARN_ON(!buffer_uptodate(bi->bi_bh));
- if (bi->bi_clone)
- buffer = bi->bi_clone + bi->bi_offset;
- else
- buffer = bi->bi_bh->b_data + bi->bi_offset;
-
- /* We have to keep the reservations aligned on u64 boundaries
- otherwise we could get situations where a byte can't be
- used because it's after a reservation, but a free bit still
- is within the reservation's area. */
- ptr = buffer + ALIGN(goal >> GFS2_BIT_SIZE, sizeof(u64));
- end = (buffer + bi->bi_len);
- while (ptr < end) {
- rsv_bytes = 0;
- if ((ptr + best_rs_bytes) <= end)
- search_bytes = best_rs_bytes;
- else
- search_bytes = end - ptr;
- BUG_ON(!search_bytes);
- nonzero = memchr_inv(ptr, 0, search_bytes);
- /* If the lot is all zeroes, reserve the whole size. If
- there's enough zeroes to satisfy the request, use
- what we can. If there's not enough, keep looking. */
- if (nonzero == NULL)
- rsv_bytes = search_bytes;
- else if ((nonzero - ptr) * GFS2_NBBY >= requested)
- rsv_bytes = (nonzero - ptr);
-
- if (rsv_bytes) {
- blk = ((ptr - buffer) * GFS2_NBBY);
- BUG_ON(blk >= bi->bi_len * GFS2_NBBY);
- rs = rs_insert(bi, ip, blk,
- rsv_bytes * GFS2_NBBY);
- if (rs)
- return;
- }
- ptr += ALIGN(search_bytes, sizeof(u64));
- }
-skip:
- /* Try next bitmap block (wrap back to rgrp header
- if at end) */
- buf++;
- buf %= length;
- goal = 0;
+ ret = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, extlen, ip, true);
+ if (ret == 0) {
+ rs->rs_rbm = rbm;
+ rs->rs_free = extlen;
+ rs->rs_inum = ip->i_no_addr;
+ rs_insert(ip);
}
}
* gfs2_next_unreserved_block - Return next block that is not reserved
* @rgd: The resource group
* @block: The starting block
+ * @length: The required length
* @ip: Ignore any reservations for this inode
*
* If the block does not appear in any reservation, then return the
*/
static u64 gfs2_next_unreserved_block(struct gfs2_rgrpd *rgd, u64 block,
+ u32 length,
const struct gfs2_inode *ip)
{
struct gfs2_blkreserv *rs;
int rc;
spin_lock(&rgd->rd_rsspin);
- n = rb_first(&rgd->rd_rstree);
+ n = rgd->rd_rstree.rb_node;
while (n) {
rs = rb_entry(n, struct gfs2_blkreserv, rs_node);
- rc = rs_cmp(block, 1, rs);
+ rc = rs_cmp(block, length, rs);
if (rc < 0)
n = n->rb_left;
else if (rc > 0)
}
if (n) {
- while ((rs_cmp(block, 1, rs) == 0) && (ip->i_res != rs)) {
+ while ((rs_cmp(block, length, rs) == 0) && (ip->i_res != rs)) {
block = gfs2_rbm_to_block(&rs->rs_rbm) + rs->rs_free;
- n = rb_next(&rs->rs_node);
+ n = n->rb_right;
if (n == NULL)
break;
rs = rb_entry(n, struct gfs2_blkreserv, rs_node);
}
/**
- * gfs2_rbm_from_block - Set the rbm based upon rgd and block number
- * @rbm: The rbm with rgd already set correctly
- * @block: The block number (filesystem relative)
- *
- * This sets the bi and offset members of an rbm based on a
- * resource group and a filesystem relative block number. The
- * resource group must be set in the rbm on entry, the bi and
- * offset members will be set by this function.
- *
- * Returns: 0 on success, or an error code
- */
-
-static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block)
-{
- u64 rblock = block - rbm->rgd->rd_data0;
- u32 goal = (u32)rblock;
- int x;
-
- if (WARN_ON_ONCE(rblock > UINT_MAX))
- return -EINVAL;
- if (block >= rbm->rgd->rd_data0 + rbm->rgd->rd_data)
- return -E2BIG;
-
- for (x = 0; x < rbm->rgd->rd_length; x++) {
- rbm->bi = rbm->rgd->rd_bits + x;
- if (goal < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY) {
- rbm->offset = goal - (rbm->bi->bi_start * GFS2_NBBY);
- break;
- }
- }
-
- return 0;
-}
-
-/**
* gfs2_reservation_check_and_update - Check for reservations during block alloc
* @rbm: The current position in the resource group
+ * @ip: The inode for which we are searching for blocks
+ * @minext: The minimum extent length
*
* This checks the current position in the rgrp to see whether there is
* a reservation covering this block. If not then this function is a
*/
static int gfs2_reservation_check_and_update(struct gfs2_rbm *rbm,
- const struct gfs2_inode *ip)
+ const struct gfs2_inode *ip,
+ u32 minext)
{
u64 block = gfs2_rbm_to_block(rbm);
+ u32 extlen = 1;
u64 nblock;
int ret;
- nblock = gfs2_next_unreserved_block(rbm->rgd, block, ip);
+ /*
+ * If we have a minimum extent length, then skip over any extent
+ * which is less than the min extent length in size.
+ */
+ if (minext) {
+ extlen = gfs2_free_extlen(rbm, minext);
+ nblock = block + extlen;
+ if (extlen < minext)
+ goto fail;
+ }
+
+ /*
+ * Check the extent which has been found against the reservations
+ * and skip if parts of it are already reserved
+ */
+ nblock = gfs2_next_unreserved_block(rbm->rgd, block, extlen, ip);
if (nblock == block)
return 0;
+fail:
ret = gfs2_rbm_from_block(rbm, nblock);
if (ret < 0)
return ret;
* gfs2_rbm_find - Look for blocks of a particular state
* @rbm: Value/result starting position and final position
* @state: The state which we want to find
+ * @minext: The requested extent length (0 for a single block)
* @ip: If set, check for reservations
* @nowrap: Stop looking at the end of the rgrp, rather than wrapping
* around until we've reached the starting point.
* Returns: 0 on success, -ENOSPC if there is no block of the requested state
*/
-static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state,
+static int gfs2_rbm_find(struct gfs2_rbm *rbm, u8 state, u32 minext,
const struct gfs2_inode *ip, bool nowrap)
{
struct buffer_head *bh;
return 0;
initial_bi = rbm->bi;
- ret = gfs2_reservation_check_and_update(rbm, ip);
+ ret = gfs2_reservation_check_and_update(rbm, ip, minext);
if (ret == 0)
return 0;
if (ret > 0) {
while (1) {
down_write(&sdp->sd_log_flush_lock);
- error = gfs2_rbm_find(&rbm, GFS2_BLKST_UNLINKED, NULL, true);
+ error = gfs2_rbm_find(&rbm, GFS2_BLKST_UNLINKED, 0, NULL, true);
up_write(&sdp->sd_log_flush_lock);
if (error == -ENOSPC)
break;
goal = rbm.rgd->rd_last_alloc + rbm.rgd->rd_data0;
gfs2_rbm_from_block(&rbm, goal);
- error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, ip, false);
+ error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, 0, ip, false);
if (error == -ENOSPC) {
gfs2_rbm_from_block(&rbm, goal);
- error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, NULL, false);
+ error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, 0, NULL, false);
}
/* Since all blocks are reserved in advance, this shouldn't happen */
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff