gfs2: Add local resource group locking

Prepare for treating resource group glocks as exclusive among nodes but
shared among all tasks running on a node: introduce another layer of
node-specific locking that the local tasks can use to coordinate their
accesses.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 2679ba5..92f5a92 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -20,6 +20,7 @@
 #include <linux/percpu.h>
 #include <linux/lockref.h>
 #include <linux/rhashtable.h>
+#include <linux/mutex.h>
 
 #define DIO_WAIT       0x00000010
 #define DIO_METADATA   0x00000020
@@ -123,6 +124,7 @@ struct gfs2_rgrpd {
 #define GFS2_RDF_PREFERRED     0x80000000 /* This rgrp is preferred */
 #define GFS2_RDF_MASK          0xf0000000 /* mask for internal flags */
        spinlock_t rd_rsspin;           /* protects reservation related vars */
+       struct mutex rd_mutex;
        struct rb_root rd_rstree;       /* multi-block reservation tree */
 };
 

diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 802bc15..dffa6cc 100644 (file)
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -76,8 +76,9 @@ static void maybe_release_space(struct gfs2_bufdata *bd)
        unsigned int index = bd->bd_bh->b_blocknr - gl->gl_name.ln_number;
        struct gfs2_bitmap *bi = rgd->rd_bits + index;
 
+       rgrp_lock_local(rgd);
        if (bi->bi_clone == NULL)
-               return;
+               goto out;
        if (sdp->sd_args.ar_discard)
                gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bd->bd_bh, bi, 1, NULL);
        memcpy(bi->bi_clone + bi->bi_offset,
@@ -86,6 +87,9 @@ static void maybe_release_space(struct gfs2_bufdata *bd)
        rgd->rd_free_clone = rgd->rd_free;
        BUG_ON(rgd->rd_free_clone < rgd->rd_reserved);
        rgd->rd_extfail_pt = rgd->rd_free;
+
+out:
+       rgrp_unlock_local(rgd);
 }
 
 /**

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index f1df5e7..f45b787 100644 (file)
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -920,6 +920,7 @@ static int read_rindex_entry(struct gfs2_inode *ip)
        rgd->rd_data = be32_to_cpu(buf.ri_data);
        rgd->rd_bitbytes = be32_to_cpu(buf.ri_bitbytes);
        spin_lock_init(&rgd->rd_rsspin);
+       mutex_init(&rgd->rd_mutex);
 
        error = compute_bitstructs(rgd);
        if (error)
@@ -1449,9 +1450,11 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
                        /* Trim each bitmap in the rgrp */
                        for (x = 0; x < rgd->rd_length; x++) {
                                struct gfs2_bitmap *bi = rgd->rd_bits + x;
+                               rgrp_lock_local(rgd);
                                ret = gfs2_rgrp_send_discards(sdp,
                                                rgd->rd_data0, NULL, bi, minlen,
                                                &amt);
+                               rgrp_unlock_local(rgd);
                                if (ret) {
                                        gfs2_glock_dq_uninit(&gh);
                                        goto out;
@@ -1463,9 +1466,11 @@ int gfs2_fitrim(struct file *filp, void __user *argp)
                        ret = gfs2_trans_begin(sdp, RES_RG_HDR, 0);
                        if (ret == 0) {
                                bh = rgd->rd_bits[0].bi_bh;
+                               rgrp_lock_local(rgd);
                                rgd->rd_flags |= GFS2_RGF_TRIMMED;
                                gfs2_trans_add_meta(rgd->rd_gl, bh);
                                gfs2_rgrp_out(rgd, bh->b_data);
+                               rgrp_unlock_local(rgd);
                                gfs2_trans_end(sdp);
                        }
                }
@@ -2050,7 +2055,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
        struct gfs2_rgrpd *begin = NULL;
        struct gfs2_blkreserv *rs = &ip->i_res;
-       int error = 0, rg_locked, flags = 0;
+       int error = 0, flags = 0;
+       bool rg_locked;
        u64 last_unlinked = NO_BLOCK;
        u32 target = ap->target;
        int loops = 0;
@@ -2079,10 +2085,10 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
        while (loops < 3) {
                struct gfs2_rgrpd *rgd;
 
-               rg_locked = 1;
-
-               if (!gfs2_glock_is_locked_by_me(rs->rs_rgd->rd_gl)) {
-                       rg_locked = 0;
+               rg_locked = gfs2_glock_is_locked_by_me(rs->rs_rgd->rd_gl);
+               if (rg_locked) {
+                       rgrp_lock_local(rs->rs_rgd);
+               } else {
                        if (skip && skip--)
                                goto next_rgrp;
                        if (!gfs2_rs_active(rs)) {
@@ -2099,12 +2105,14 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
                                                   &ip->i_rgd_gh);
                        if (unlikely(error))
                                return error;
+                       rgrp_lock_local(rs->rs_rgd);
                        if (!gfs2_rs_active(rs) && (loops < 2) &&
                            gfs2_rgrp_congested(rs->rs_rgd, loops))
                                goto skip_rgrp;
                        if (sdp->sd_args.ar_rgrplvb) {
                                error = update_rgrp_lvb(rs->rs_rgd);
                                if (unlikely(error)) {
+                                       rgrp_unlock_local(rs->rs_rgd);
                                        gfs2_glock_dq_uninit(&ip->i_rgd_gh);
                                        return error;
                                }
@@ -2142,6 +2150,7 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, struct gfs2_alloc_parms *ap)
                        rs->rs_reserved = blocks_available;
                rgd->rd_reserved += rs->rs_reserved;
                spin_unlock(&rgd->rd_rsspin);
+               rgrp_unlock_local(rs->rs_rgd);
                return 0;
 check_rgrp:
                /* Check for unlinked inodes which can be reclaimed */
@@ -2149,6 +2158,8 @@ check_rgrp:
                        try_rgrp_unlink(rs->rs_rgd, &last_unlinked,
                                        ip->i_no_addr);
 skip_rgrp:
+               rgrp_unlock_local(rs->rs_rgd);
+
                /* Drop reservation, if we couldn't use reserved rgrp */
                if (gfs2_rs_active(rs))
                        gfs2_rs_deltree(rs);
@@ -2293,6 +2304,7 @@ void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_rgrpd *rgd,
        struct gfs2_blkreserv *trs;
        const struct rb_node *n;
 
+       spin_lock(&rgd->rd_rsspin);
        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,
@@ -2306,7 +2318,6 @@ void gfs2_rgrp_dump(struct seq_file *seq, struct gfs2_rgrpd *rgd,
                               be32_to_cpu(rgl->rl_free),
                               be32_to_cpu(rgl->rl_dinodes));
        }
-       spin_lock(&rgd->rd_rsspin);
        for (n = rb_first(&rgd->rd_rstree); n; n = rb_next(&trs->rs_node)) {
                trs = rb_entry(n, struct gfs2_blkreserv, rs_node);
                dump_rs(seq, trs, fs_id_buf);
@@ -2421,6 +2432,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
 
        BUG_ON(ip->i_res.rs_reserved < *nblocks);
 
+       rgrp_lock_local(rbm.rgd);
        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);
@@ -2477,6 +2489,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
 
        gfs2_trans_add_meta(rbm.rgd->rd_gl, rbm.rgd->rd_bits[0].bi_bh);
        gfs2_rgrp_out(rbm.rgd, rbm.rgd->rd_bits[0].bi_bh->b_data);
+       rgrp_unlock_local(rbm.rgd);
 
        gfs2_statfs_change(sdp, 0, -(s64)*nblocks, dinode ? 1 : 0);
        if (dinode)
@@ -2490,6 +2503,7 @@ int gfs2_alloc_blocks(struct gfs2_inode *ip, u64 *bn, unsigned int *nblocks,
        return 0;
 
 rgrp_error:
+       rgrp_unlock_local(rbm.rgd);
        gfs2_rgrp_error(rbm.rgd);
        return -EIO;
 }
@@ -2509,12 +2523,14 @@ void __gfs2_free_blocks(struct gfs2_inode *ip, struct gfs2_rgrpd *rgd,
 {
        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 
+       rgrp_lock_local(rgd);
        rgblk_free(sdp, rgd, bstart, blen, GFS2_BLKST_FREE);
        trace_gfs2_block_alloc(ip, rgd, bstart, blen, GFS2_BLKST_FREE);
        rgd->rd_free += blen;
        rgd->rd_flags &= ~GFS2_RGF_TRIMMED;
        gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
        gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
+       rgrp_unlock_local(rgd);
 
        /* Directories keep their data in the metadata address space */
        if (meta || ip->i_depth || gfs2_is_jdata(ip))
@@ -2550,17 +2566,20 @@ void gfs2_unlink_di(struct inode *inode)
        rgd = gfs2_blk2rgrpd(sdp, blkno, true);
        if (!rgd)
                return;
+       rgrp_lock_local(rgd);
        rgblk_free(sdp, rgd, blkno, 1, GFS2_BLKST_UNLINKED);
        trace_gfs2_block_alloc(ip, rgd, blkno, 1, GFS2_BLKST_UNLINKED);
        gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
        gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
        be32_add_cpu(&rgd->rd_rgl->rl_unlinked, 1);
+       rgrp_unlock_local(rgd);
 }
 
 void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
 {
        struct gfs2_sbd *sdp = rgd->rd_sbd;
 
+       rgrp_lock_local(rgd);
        rgblk_free(sdp, rgd, ip->i_no_addr, 1, GFS2_BLKST_FREE);
        if (!rgd->rd_dinodes)
                gfs2_consist_rgrpd(rgd);
@@ -2569,6 +2588,7 @@ void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
 
        gfs2_trans_add_meta(rgd->rd_gl, rgd->rd_bits[0].bi_bh);
        gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
+       rgrp_unlock_local(rgd);
        be32_add_cpu(&rgd->rd_rgl->rl_unlinked, -1);
 
        gfs2_statfs_change(sdp, 0, +1, -1);
@@ -2583,6 +2603,10 @@ void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
  * @no_addr: The block number to check
  * @type: The block type we are looking for
  *
+ * The inode glock of @no_addr must be held.  The @type to check for is either
+ * GFS2_BLKST_DINODE or GFS2_BLKST_UNLINKED; checking for type GFS2_BLKST_FREE
+ * or GFS2_BLKST_USED would make no sense.
+ *
  * Returns: 0 if the block type matches the expected type
  *          -ESTALE if it doesn't match
  *          or -ve errno if something went wrong while checking
@@ -2606,6 +2630,13 @@ int gfs2_check_blk_type(struct gfs2_sbd *sdp, u64 no_addr, unsigned int type)
        rbm.rgd = rgd;
        error = gfs2_rbm_from_block(&rbm, no_addr);
        if (!WARN_ON_ONCE(error)) {
+               /*
+                * No need to take the local resource group lock here; the
+                * inode glock of @no_addr provides the necessary
+                * synchronization in case the block is an inode.  (In case
+                * the block is not an inode, the block type will not match
+                * the @type we are looking for.)
+                */
                if (gfs2_testbit(&rbm, false) != type)
                        error = -ESTALE;
        }
@@ -2730,3 +2761,14 @@ void gfs2_rlist_free(struct gfs2_rgrp_list *rlist)
        }
 }
 
+void rgrp_lock_local(struct gfs2_rgrpd *rgd)
+{
+       BUG_ON(!gfs2_glock_is_held_excl(rgd->rd_gl) &&
+              !test_bit(SDF_NORECOVERY, &rgd->rd_sbd->sd_flags));
+       mutex_lock(&rgd->rd_mutex);
+}
+
+void rgrp_unlock_local(struct gfs2_rgrpd *rgd)
+{
+       mutex_unlock(&rgd->rd_mutex);
+}

diff --git a/fs/gfs2/rgrp.h b/fs/gfs2/rgrp.h
index be1b203..a6855fd 100644 (file)
--- a/fs/gfs2/rgrp.h
+++ b/fs/gfs2/rgrp.h
@@ -88,4 +88,8 @@ static inline int rgrp_contains_block(struct gfs2_rgrpd *rgd, u64 block)
 }
 
 extern void check_and_update_goal(struct gfs2_inode *ip);
+
+extern void rgrp_lock_local(struct gfs2_rgrpd *rgd);
+extern void rgrp_unlock_local(struct gfs2_rgrpd *rgd);
+
 #endif /* __RGRP_DOT_H__ */