[GFS2] Fix unlinked file handling

This patch fixes the way we have been dealing with unlinked,
but still open files. It removes all limits (other than memory
for inodes, as per every other filesystem) on numbers of these
which we can support on GFS2. It also means that (like other
fs) its the responsibility of the last process to close the file
to deallocate the storage, rather than the person who did the
unlinking. Note that with GFS2, those two events might take place
on different nodes.

Also there are a number of other changes:

 o We use the Linux inode subsystem as it was intended to be
used, wrt allocating GFS2 inodes
 o The Linux inode cache is now the point which we use for
local enforcement of only holding one copy of the inode in
core at once (previous to this we used the glock layer).
 o We no longer use the unlinked "special" file. We just ignore it
completely. This makes unlinking more efficient.
 o We now use the 4th block allocation state. The previously unused
state is used to track unlinked but still open inodes.
 o gfs2_inoded is no longer needed
 o Several fields are now no longer needed (and removed) from the in
core struct gfs2_inode
 o Several fields are no longer needed (and removed) from the in core
superblock

There are a number of future possible optimisations and clean ups
which have been made possible by this patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 67 insertions, 51 deletions

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 691e6f3ce43b..75df79eb50ba 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -34,17 +34,19 @@
 /*
  * These routines are used by the resource group routines (rgrp.c)
  * to keep track of block allocation.  Each block is represented by two
- * bits.  One bit indicates whether or not the block is used.  (1=used,
- * 0=free)  The other bit indicates whether or not the block contains a
- * dinode or not.  (1=dinode, 0=not-dinode) So, each byte represents
- * GFS2_NBBY (i.e. 4) blocks.
+ * bits.  So, each byte represents GFS2_NBBY (i.e. 4) blocks.
+ *
+ * 0 = Free
+ * 1 = Used (not metadata)
+ * 2 = Unlinked (still in use) inode
+ * 3 = Used (metadata)
  */
 
 static const char valid_change[16] = {
                 /* current */
-        /* n */ 0, 1, 0, 1,
+        /* n */ 0, 1, 1, 1,
         /* e */ 1, 0, 0, 0,
-        /* w */ 0, 0, 0, 0,
+        /* w */ 0, 0, 0, 1,
                 1, 0, 0, 0
 };
 
@@ -228,26 +230,27 @@ void gfs2_rgrp_verify(struct gfs2_rgrpd *rgd)
         tmp = rgd->rd_ri.ri_data -
                 rgd->rd_rg.rg_free -
                 rgd->rd_rg.rg_dinodes;
-        if (count[1] != tmp) {
+        if (count[1] + count[2] != tmp) {
                 if (gfs2_consist_rgrpd(rgd))
                         fs_err(sdp, "used data mismatch:  %u != %u\n",
                                count[1], tmp);
                 return;
         }
 
-        if (count[2]) {
+        if (count[3] != rgd->rd_rg.rg_dinodes) {
                 if (gfs2_consist_rgrpd(rgd))
-                        fs_err(sdp, "free metadata mismatch:  %u != 0\n",
-                               count[2]);
+                        fs_err(sdp, "used metadata mismatch:  %u != %u\n",
+                               count[3], rgd->rd_rg.rg_dinodes);
                 return;
         }
 
-        if (count[3] != rgd->rd_rg.rg_dinodes) {
+        if (count[2] > count[3]) {
                 if (gfs2_consist_rgrpd(rgd))
-                        fs_err(sdp, "used metadata mismatch:  %u != %u\n",
-                               count[3], rgd->rd_rg.rg_dinodes);
+                        fs_err(sdp, "unlinked inodes > inodes:  %u\n",
+                               count[2]);
                 return;
         }
+
 }
 
 static inline int rgrp_contains_block(struct gfs2_rindex *ri, uint64_t block)
@@ -368,6 +371,9 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
         uint32_t bytes_left, bytes;
         int x;
 
+        if (!length)
+                return -EINVAL;
+
         rgd->rd_bits = kcalloc(length, sizeof(struct gfs2_bitmap), GFP_KERNEL);
         if (!rgd->rd_bits)
                 return -ENOMEM;
@@ -433,14 +439,16 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
 
 static int gfs2_ri_update(struct gfs2_inode *ip)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
-        struct inode *inode = ip->i_vnode;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+        struct inode *inode = &ip->i_inode;
         struct gfs2_rgrpd *rgd;
         char buf[sizeof(struct gfs2_rindex)];
         struct file_ra_state ra_state;
         uint64_t junk = ip->i_di.di_size;
         int error;
 
+        printk(KERN_INFO "gfs2_ri_update inode=%p\n", inode);
+
         if (do_div(junk, sizeof(struct gfs2_rindex))) {
                 gfs2_consist_inode(ip);
                 return -EIO;
@@ -448,9 +456,12 @@ static int gfs2_ri_update(struct gfs2_inode *ip)
 
         clear_rgrpdi(sdp);
 
+        printk(KERN_INFO "rgrps cleared\n");
+
         file_ra_state_init(&ra_state, inode->i_mapping);
         for (sdp->sd_rgrps = 0;; sdp->sd_rgrps++) {
                 loff_t pos = sdp->sd_rgrps * sizeof(struct gfs2_rindex);
+                printk(KERN_INFO "reading rgrp %d\n", sdp->sd_rgrps);
                 error = gfs2_internal_read(ip, &ra_state, buf, &pos,
                                             sizeof(struct gfs2_rindex));
                 if (!error)
@@ -474,13 +485,15 @@ static int gfs2_ri_update(struct gfs2_inode *ip)
                 list_add_tail(&rgd->rd_list_mru, &sdp->sd_rindex_mru_list);
 
                 gfs2_rindex_in(&rgd->rd_ri, buf);
-
+                printk(KERN_INFO "compute bitstructs\n");
                 error = compute_bitstructs(rgd);
                 if (error)
                         goto fail;
 
+                printk(KERN_INFO "gfs2_glock_get\n");
                 error = gfs2_glock_get(sdp, rgd->rd_ri.ri_addr,
                                        &gfs2_rgrp_glops, CREATE, &rgd->rd_gl);
+                printk(KERN_INFO "gfs2_glock_got one\n");
                 if (error)
                         goto fail;
 
@@ -488,13 +501,14 @@ static int gfs2_ri_update(struct gfs2_inode *ip)
                 rgd->rd_rg_vn = rgd->rd_gl->gl_vn - 1;
         }
 
+        printk(KERN_INFO "ok, finished\n");
         sdp->sd_rindex_vn = ip->i_gl->gl_vn;
-
         return 0;
 
- fail:
+fail:
+        printk(KERN_INFO "fail\n");
         clear_rgrpdi(sdp);
-
+        printk(KERN_INFO "cleared rgrps\n");
         return error;
 }
 
@@ -518,7 +532,7 @@ static int gfs2_ri_update(struct gfs2_inode *ip)
 
 int gfs2_rindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ri_gh)
 {
-        struct gfs2_inode *ip = sdp->sd_rindex->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(sdp->sd_rindex);
         struct gfs2_glock *gl = ip->i_gl;
         int error;
 
@@ -583,8 +597,7 @@ int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
                 error = gfs2_meta_reread(sdp, bi->bi_bh, DIO_WAIT);
                 if (error)
                         goto fail;
-                if (gfs2_metatype_check(sdp, bi->bi_bh,
-                                        (y) ? GFS2_METATYPE_RB :
+                if (gfs2_metatype_check(sdp, bi->bi_bh, y ? GFS2_METATYPE_RB :
                                               GFS2_METATYPE_RG)) {
                         error = -EIO;
                         goto fail;
@@ -605,7 +618,7 @@ int gfs2_rgrp_bh_get(struct gfs2_rgrpd *rgd)
 
         return 0;
 
- fail:
+fail:
         while (x--) {
                 bi = rgd->rd_bits + x;
                 brelse(bi->bi_bh);
@@ -667,8 +680,7 @@ void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
                 if (!bi->bi_clone)
                         continue;
                 memcpy(bi->bi_clone + bi->bi_offset,
-                       bi->bi_bh->b_data + bi->bi_offset,
-                       bi->bi_len);
+                       bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
         }
 
         spin_lock(&sdp->sd_rindex_spin);
@@ -757,13 +769,11 @@ static struct gfs2_rgrpd *recent_rgrp_first(struct gfs2_sbd *sdp,
                         goto out;
         }
 
- first:
+first:
         rgd = list_entry(sdp->sd_rindex_recent_list.next, struct gfs2_rgrpd,
                          rd_recent);
-
- out:
+out:
         spin_unlock(&sdp->sd_rindex_spin);
-
         return rgd;
 }
 
@@ -805,9 +815,8 @@ static struct gfs2_rgrpd *recent_rgrp_next(struct gfs2_rgrpd *cur_rgd,
         if (!list_empty(head))
                 rgd = list_entry(head->next, struct gfs2_rgrpd, rd_recent);
 
- out:
+out:
         spin_unlock(&sdp->sd_rindex_spin);
-
         return rgd;
 }
 
@@ -835,7 +844,7 @@ static void recent_rgrp_add(struct gfs2_rgrpd *new_rgd)
         }
         list_add_tail(&new_rgd->rd_recent, &sdp->sd_rindex_recent_list);
 
- out:
+out:
         spin_unlock(&sdp->sd_rindex_spin);
 }
 
@@ -898,7 +907,7 @@ static void forward_rgrp_set(struct gfs2_sbd *sdp, struct gfs2_rgrpd *rgd)
 
 static int get_local_rgrp(struct gfs2_inode *ip)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_rgrpd *rgd, *begin = NULL;
         struct gfs2_alloc *al = &ip->i_alloc;
         int flags = LM_FLAG_TRY;
@@ -965,7 +974,7 @@ static int get_local_rgrp(struct gfs2_inode *ip)
                 }
         }
 
- out:
+out:
         ip->i_last_rg_alloc = rgd->rd_ri.ri_addr;
 
         if (begin) {
@@ -988,7 +997,7 @@ static int get_local_rgrp(struct gfs2_inode *ip)
 
 int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_alloc *al = &ip->i_alloc;
         int error;
 
@@ -1020,7 +1029,7 @@ int gfs2_inplace_reserve_i(struct gfs2_inode *ip, char *file, unsigned int line)
 
 void gfs2_inplace_release(struct gfs2_inode *ip)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_alloc *al = &ip->i_alloc;
 
         if (gfs2_assert_warn(sdp, al->al_alloced <= al->al_requested) == -1)
@@ -1061,8 +1070,7 @@ unsigned char gfs2_get_block_type(struct gfs2_rgrpd *rgd, uint64_t block)
         gfs2_assert(rgd->rd_sbd, buf < length);
         buf_block = rgrp_block - bi->bi_start * GFS2_NBBY;
 
-        type = gfs2_testbit(rgd,
-                           bi->bi_bh->b_data + bi->bi_offset,
+        type = gfs2_testbit(rgd, bi->bi_bh->b_data + bi->bi_offset,
                            bi->bi_len, buf_block);
 
         return type;
@@ -1210,7 +1218,7 @@ static struct gfs2_rgrpd *rgblk_free(struct gfs2_sbd *sdp, uint64_t bstart,
 
 uint64_t gfs2_alloc_data(struct gfs2_inode *ip)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_alloc *al = &ip->i_alloc;
         struct gfs2_rgrpd *rgd = al->al_rgd;
         uint32_t goal, blk;
@@ -1254,7 +1262,7 @@ uint64_t gfs2_alloc_data(struct gfs2_inode *ip)
 
 uint64_t gfs2_alloc_meta(struct gfs2_inode *ip)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_alloc *al = &ip->i_alloc;
         struct gfs2_rgrpd *rgd = al->al_rgd;
         uint32_t goal, blk;
@@ -1299,7 +1307,7 @@ uint64_t gfs2_alloc_meta(struct gfs2_inode *ip)
 
 uint64_t gfs2_alloc_di(struct gfs2_inode *dip)
 {
-        struct gfs2_sbd *sdp = dip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
         struct gfs2_alloc *al = &dip->i_alloc;
         struct gfs2_rgrpd *rgd = al->al_rgd;
         uint32_t blk;
@@ -1341,7 +1349,7 @@ uint64_t gfs2_alloc_di(struct gfs2_inode *dip)
 
 void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_rgrpd *rgd;
 
         rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
@@ -1370,7 +1378,7 @@ void gfs2_free_data(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 
 void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
 {
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
         struct gfs2_rgrpd *rgd;
 
         rgd = rgblk_free(sdp, bstart, blen, GFS2_BLKST_FREE);
@@ -1385,11 +1393,25 @@ void gfs2_free_meta(struct gfs2_inode *ip, uint64_t bstart, uint32_t blen)
         gfs2_trans_add_rg(rgd);
 
         gfs2_statfs_change(sdp, 0, +blen, 0);
-        gfs2_quota_change(ip, -(int64_t)blen,
-                         ip->i_di.di_uid, ip->i_di.di_gid);
+        gfs2_quota_change(ip, -(int64_t)blen, ip->i_di.di_uid, ip->i_di.di_gid);
         gfs2_meta_wipe(ip, bstart, blen);
 }
 
+void gfs2_unlink_di(struct inode *inode)
+{
+        struct gfs2_inode *ip = GFS2_I(inode);
+        struct gfs2_sbd *sdp = GFS2_SB(inode);
+        struct gfs2_rgrpd *rgd;
+        u64 blkno = ip->i_num.no_addr;
+
+        rgd = rgblk_free(sdp, blkno, 1, GFS2_BLKST_UNLINKED);
+        if (!rgd)
+                return;
+        gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
+        gfs2_rgrp_out(&rgd->rd_rg, rgd->rd_bits[0].bi_bh->b_data);
+        gfs2_trans_add_rg(rgd);
+}
+
 void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno)
 {
         struct gfs2_sbd *sdp = rgd->rd_sbd;
@@ -1412,12 +1434,6 @@ void gfs2_free_uninit_di(struct gfs2_rgrpd *rgd, uint64_t blkno)
         gfs2_trans_add_rg(rgd);
 }
 
-/**
- * gfs2_free_uninit_di - free a dinode block
- * @rgd: the resource group that contains the dinode
- * @ip: the inode
- *
- */
 
 void gfs2_free_di(struct gfs2_rgrpd *rgd, struct gfs2_inode *ip)
 {