gfs2: Add per-reservation reserved block accounting
Add a rs_reserved field to struct gfs2_blkreserv to keep track of the number of
blocks reserved by this particular reservation, and a rd_reserved field to
struct gfs2_rgrpd to keep track of the total number of reserved blocks in the
resource group. Those blocks are exclusively reserved, as opposed to the
rs_requested / rd_requested blocks which are tracked in the reservation tree
(rd_rstree) and which can be stolen if necessary.
When making a reservation with gfs2_inplace_reserve, rs_reserved is set to
somewhere between ap->min_target and ap->target depending on the number of free
blocks in the resource group. When allocating blocks with gfs2_alloc_blocks,
rs_reserved is decremented accordingly. Eventually, any reserved but not
consumed blocks are returned to the resource group by gfs2_inplace_release.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index bc8d1ab..f1df5e75 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -1229,6 +1229,7 @@ static int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
rgrp_set_bitmap_flags(rgd);
rgd->rd_flags |= (GFS2_RDF_UPTODATE | GFS2_RDF_CHECK);
rgd->rd_free_clone = rgd->rd_free;
+ BUG_ON(rgd->rd_reserved);
/* max out the rgrp allocation failure point */
rgd->rd_extfail_pt = rgd->rd_free;
}
@@ -1278,6 +1279,7 @@ static int update_rgrp_lvb(struct gfs2_rgrpd *rgd)
rgd->rd_free = be32_to_cpu(rgd->rd_rgl->rl_free);
rgrp_set_bitmap_flags(rgd);
rgd->rd_free_clone = rgd->rd_free;
+ BUG_ON(rgd->rd_reserved);
/* max out the rgrp allocation failure point */
rgd->rd_extfail_pt = rgd->rd_free;
rgd->rd_dinodes = be32_to_cpu(rgd->rd_rgl->rl_dinodes);
@@ -1568,17 +1570,26 @@ static void rg_mblk_search(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip,
u64 goal;
struct gfs2_blkreserv *rs = &ip->i_res;
u32 extlen;
- u32 free_blocks = rgd_free(rgd, rs);
+ u32 free_blocks, blocks_available;
int ret;
struct inode *inode = &ip->i_inode;
+ spin_lock(&rgd->rd_rsspin);
+ free_blocks = rgd_free(rgd, rs);
+ if (rgd->rd_free_clone < rgd->rd_requested)
+ free_blocks = 0;
+ blocks_available = rgd->rd_free_clone - rgd->rd_reserved;
+ if (rgd == rs->rs_rgd)
+ blocks_available += rs->rs_reserved;
+ spin_unlock(&rgd->rd_rsspin);
+
if (S_ISDIR(inode->i_mode))
extlen = 1;
else {
extlen = max_t(u32, atomic_read(&ip->i_sizehint), ap->target);
extlen = clamp(extlen, (u32)RGRP_RSRV_MINBLKS, free_blocks);
}
- if ((rgd->rd_free_clone < rgd->rd_requested) || (free_blocks < extlen))
+ if (free_blocks < extlen || blocks_available < extlen)
return;
/* Find bitmap block that contains bits for goal block */
@@ -2027,8 +2038,7 @@ static inline int fast_to_acquire(struct gfs2_rgrpd *rgd)
* We try our best to find an rgrp that has at least ap->target blocks
* available. After a couple of passes (loops == 2), the prospects of finding
* such an rgrp diminish. At this stage, we return the first rgrp that has
- * at least ap->min_target blocks available. Either way, we set ap->allowed to
- * the number of blocks available in the chosen rgrp.
+ * at least ap->min_target blocks available.
*
* Returns: 0 on success,
* -ENOMEM if a suitable rgrp can't be found
@@ -2044,7 +2054,9 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
u64 last_unlinked = NO_BLOCK;
u32 target = ap->target;
int loops = 0;
- u32 free_blocks, skip = 0;
+ u32 free_blocks, blocks_available, skip = 0;
+
+ BUG_ON(rs->rs_reserved);
if (sdp->sd_args.ar_rgrplvb)
flags |= GL_SKIP;
@@ -2065,6 +2077,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
return -EBADSLT;
while (loops < 3) {
+ struct gfs2_rgrpd *rgd;
+
rg_locked = 1;
if (!gfs2_glock_is_locked_by_me(rs->rs_rgd->rd_gl)) {
@@ -2115,11 +2129,20 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
goto check_rgrp;
/* If rgrp has enough free space, use it */
- free_blocks = rgd_free(rs->rs_rgd, rs);
- if (free_blocks >= target) {
- ap->allowed = free_blocks;
- return 0;
+ rgd = rs->rs_rgd;
+ spin_lock(&rgd->rd_rsspin);
+ free_blocks = rgd_free(rgd, rs);
+ blocks_available = rgd->rd_free_clone - rgd->rd_reserved;
+ if (free_blocks < target || blocks_available < target) {
+ spin_unlock(&rgd->rd_rsspin);
+ goto check_rgrp;
}
+ rs->rs_reserved = ap->target;
+ if (rs->rs_reserved > blocks_available)
+ rs->rs_reserved = blocks_available;
+ rgd->rd_reserved += rs->rs_reserved;
+ spin_unlock(&rgd->rd_rsspin);
+ return 0;
check_rgrp:
/* Check for unlinked inodes which can be reclaimed */
if (rs->rs_rgd->rd_flags & GFS2_RDF_CHECK)
@@ -2172,6 +2195,17 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
void gfs2_inplace_release(struct gfs2_inode *ip)
{
+ struct gfs2_blkreserv *rs = &ip->i_res;
+
+ if (rs->rs_reserved) {
+ struct gfs2_rgrpd *rgd = rs->rs_rgd;
+
+ spin_lock(&rgd->rd_rsspin);
+ BUG_ON(rgd->rd_reserved < rs->rs_reserved);
+ rgd->rd_reserved -= rs->rs_reserved;
+ spin_unlock(&rgd->rd_rsspin);
+ rs->rs_reserved = 0;
+ }
if (gfs2_holder_initialized(&ip->i_rgd_gh))
gfs2_glock_dq_uninit(&ip->i_rgd_gh);
}
@@ -2259,11 +2293,11 @@ void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_rgrpd *rgd,
struct gfs2_blkreserv *trs;
const struct rb_node *n;
- gfs2_print_dbg(seq, "%s R: n:%llu f:%02x b:%u/%u i:%u r:%u e:%u\n",
+ gfs2_print_dbg(seq, "%s R: n:%llu f:%02x b:%u/%u i:%u q:%u r:%u e:%u\n",
fs_id_buf,
(unsigned long long)rgd->rd_addr, rgd->rd_flags,
rgd->rd_free, rgd->rd_free_clone, rgd->rd_dinodes,
- rgd->rd_requested, rgd->rd_extfail_pt);
+ rgd->rd_requested, rgd->rd_reserved, rgd->rd_extfail_pt);
if (rgd->rd_sbd->sd_args.ar_rgrplvb) {
struct gfs2_rgrp_lvb *rgl = rgd->rd_rgl;
@@ -2310,7 +2344,8 @@ static void gfs2_adjust_reservation(struct gfs2_inode *ip,
struct gfs2_blkreserv *rs = &ip->i_res;
struct gfs2_rgrpd *rgd = rbm->rgd;
- spin_lock(&rgd->rd_rsspin);
+ BUG_ON(rs->rs_reserved < len);
+ rs->rs_reserved -= len;
if (gfs2_rs_active(rs)) {
u64 start = gfs2_rbm_to_block(rbm);
@@ -2324,15 +2359,13 @@ static void gfs2_adjust_reservation(struct gfs2_inode *ip,
trace_gfs2_rs(rs, TRACE_RS_CLAIM);
if (rs->rs_start < rgd->rd_data0 + rgd->rd_data &&
rs->rs_requested)
- goto out;
+ return;
/* We used up our block reservation, so we should
reserve more blocks next time. */
atomic_add(RGRP_RSRV_ADDBLKS, &ip->i_sizehint);
}
__rs_deltree(rs);
}
-out:
- spin_unlock(&rgd->rd_rsspin);
}
/**
@@ -2386,6 +2419,8 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
u32 minext = 1;
int error = -ENOSPC;
+ BUG_ON(ip->i_res.rs_reserved < *nblocks);
+
if (gfs2_rs_active(&ip->i_res)) {
gfs2_set_alloc_start(&rbm, ip, dinode);
error = gfs2_rbm_find(&rbm, GFS2_BLKST_FREE, &minext, &ip->i_res, false);
@@ -2407,8 +2442,6 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
gfs2_alloc_extent(&rbm, dinode, nblocks);
block = gfs2_rbm_to_block(&rbm);
rbm.rgd->rd_last_alloc = block - rbm.rgd->rd_data0;
- if (gfs2_rs_active(&ip->i_res))
- gfs2_adjust_reservation(ip, &rbm, *nblocks);
if (!dinode) {
ip->i_goal = block + *nblocks - 1;
error = gfs2_meta_inode_buffer(ip, &dibh);
@@ -2421,12 +2454,20 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
brelse(dibh);
}
}
- if (rbm.rgd->rd_free < *nblocks) {
+ spin_lock(&rbm.rgd->rd_rsspin);
+ gfs2_adjust_reservation(ip, &rbm, *nblocks);
+ if (rbm.rgd->rd_free < *nblocks || rbm.rgd->rd_reserved < *nblocks) {
fs_warn(sdp, "nblocks=%u\n", *nblocks);
+ spin_unlock(&rbm.rgd->rd_rsspin);
goto rgrp_error;
}
-
+ BUG_ON(rbm.rgd->rd_reserved < *nblocks);
+ BUG_ON(rbm.rgd->rd_free_clone < *nblocks);
+ BUG_ON(rbm.rgd->rd_free < *nblocks);
+ rbm.rgd->rd_reserved -= *nblocks;
+ rbm.rgd->rd_free_clone -= *nblocks;
rbm.rgd->rd_free -= *nblocks;
+ spin_unlock(&rbm.rgd->rd_rsspin);
if (dinode) {
rbm.rgd->rd_dinodes++;
*generation = rbm.rgd->rd_igeneration++;
@@ -2443,7 +2484,6 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
gfs2_quota_change(ip, *nblocks, ip->i_inode.i_uid, ip->i_inode.i_gid);
- rbm.rgd->rd_free_clone -= *nblocks;
trace_gfs2_block_alloc(ip, rbm.rgd, block, *nblocks,
dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
*bn = block;
