[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, 22 insertions, 81 deletions

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index a45982045509..b68eb6b4a4c1 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -32,7 +32,6 @@
 #include "recovery.h"
 #include "rgrp.h"
 #include "super.h"
-#include "unlinked.h"
 #include "sys.h"
 #include "util.h"
 
@@ -80,10 +79,6 @@ static struct gfs2_sbd *init_sbd(struct super_block *sb)
 	spin_lock_init(&sdp->sd_jindex_spin);
 	mutex_init(&sdp->sd_jindex_mutex);
 
-	INIT_LIST_HEAD(&sdp->sd_unlinked_list);
-	spin_lock_init(&sdp->sd_unlinked_spin);
-	mutex_init(&sdp->sd_unlinked_mutex);
-
 	INIT_LIST_HEAD(&sdp->sd_quota_list);
 	spin_lock_init(&sdp->sd_quota_spin);
 	mutex_init(&sdp->sd_quota_mutex);
@@ -248,19 +243,19 @@ static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 
 	return 0;
 
- fail_trans:
+fail_trans:
 	gfs2_glock_put(sdp->sd_trans_gl);
 
- fail_rename:
+fail_rename:
 	gfs2_glock_put(sdp->sd_rename_gl);
 
- fail_live:
+fail_live:
 	gfs2_glock_dq_uninit(&sdp->sd_live_gh);
 
- fail_mount:
+fail_mount:
 	gfs2_glock_dq_uninit(mount_gh);
 
- fail:
+fail:
 	while (sdp->sd_glockd_num--)
 		kthread_stop(sdp->sd_glockd_process[sdp->sd_glockd_num]);
 
@@ -269,28 +264,10 @@ static int init_locking(struct gfs2_sbd *sdp, struct gfs2_holder *mount_gh,
 	return error;
 }
 
-static struct inode *gfs2_lookup_root(struct gfs2_sbd *sdp,
-				      const struct gfs2_inum *inum)
+static struct inode *gfs2_lookup_root(struct super_block *sb,
+				      struct gfs2_inum *inum)
 {
-        int error;
-	struct gfs2_glock *gl;
-	struct gfs2_inode *ip;
-	struct inode *inode;
-
-	error = gfs2_glock_get(sdp, inum->no_addr, &gfs2_inode_glops,
-			       CREATE, &gl);
-        if (!error) {
-               	error = gfs2_inode_get(gl, inum, CREATE, &ip);
-		if (!error) {
-			gfs2_inode_min_init(ip, DT_DIR);
-			inode = gfs2_ip2v(ip);
-			gfs2_inode_put(ip);
-			gfs2_glock_put(gl);
-			return inode;
-		}
-                gfs2_glock_put(gl);
-        }
-        return ERR_PTR(error);
+	return gfs2_inode_lookup(sb, inum, DT_DIR);
 }
 
 static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
@@ -305,8 +282,7 @@ static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
 		return 0;
 	}
 	
-	error = gfs2_glock_nq_num(sdp,
-				 GFS2_SB_LOCK, &gfs2_meta_glops,
+	error = gfs2_glock_nq_num(sdp, GFS2_SB_LOCK, &gfs2_meta_glops,
 				 LM_ST_SHARED, 0, &sb_gh);
 	if (error) {
 		fs_err(sdp, "can't acquire superblock glock: %d\n", error);
@@ -345,7 +321,7 @@ static int init_sb(struct gfs2_sbd *sdp, int silent, int undo)
 	inum = &sdp->sd_sb.sb_root_dir;
 	if (sb->s_type == &gfs2meta_fs_type)
 		inum = &sdp->sd_sb.sb_master_dir;
-	inode = gfs2_lookup_root(sdp, inum);
+	inode = gfs2_lookup_root(sb, inum);
 	if (IS_ERR(inode)) {
 		error = PTR_ERR(inode);
 		fs_err(sdp, "can't read in root inode: %d\n", error);
@@ -382,7 +358,7 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 		fs_err(sdp, "can't lookup journal index: %d\n", error);
 		return PTR_ERR(sdp->sd_jindex);
 	}
-	ip = sdp->sd_jindex->u.generic_ip;
+	ip = GFS2_I(sdp->sd_jindex);
 	set_bit(GLF_STICKY, &ip->i_gl->gl_flags);
 
 	/* Load in the journal index special file */
@@ -413,8 +389,7 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 		}
 		sdp->sd_jdesc = gfs2_jdesc_find(sdp, sdp->sd_lockstruct.ls_jid);
 
-		error = gfs2_glock_nq_num(sdp,
-					  sdp->sd_lockstruct.ls_jid,
+		error = gfs2_glock_nq_num(sdp, sdp->sd_lockstruct.ls_jid,
 					  &gfs2_journal_glops,
 					  LM_ST_EXCLUSIVE, LM_FLAG_NOEXP,
 					  &sdp->sd_journal_gh);
@@ -423,9 +398,8 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 			goto fail_jindex;
 		}
 
-		ip = sdp->sd_jdesc->jd_inode->u.generic_ip;
-		error = gfs2_glock_nq_init(ip->i_gl,
-					   LM_ST_SHARED,
+		ip = GFS2_I(sdp->sd_jdesc->jd_inode);
+		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
 					   LM_FLAG_NOEXP | GL_EXACT,
 					   &sdp->sd_jinode_gh);
 		if (error) {
@@ -509,7 +483,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 	if (undo)
 		goto fail_qinode;
 
-	inode = gfs2_lookup_root(sdp, &sdp->sd_sb.sb_master_dir);
+	inode = gfs2_lookup_root(sdp->sd_vfs, &sdp->sd_sb.sb_master_dir);
 	if (IS_ERR(inode)) {
 		error = PTR_ERR(inode);
 		fs_err(sdp, "can't read in master directory: %d\n", error);
@@ -545,7 +519,7 @@ static int init_inodes(struct gfs2_sbd *sdp, int undo)
 		fs_err(sdp, "can't get resource index inode: %d\n", error);
 		goto fail_statfs;
 	}
-	ip = sdp->sd_rindex->u.generic_ip;
+	ip = GFS2_I(sdp->sd_rindex);
 	set_bit(GLF_STICKY, &ip->i_gl->gl_flags);
 	sdp->sd_rindex_vn = ip->i_gl->gl_vn - 1;
 
@@ -614,14 +588,6 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 		goto fail_ir_i;
 	}
 
-	sprintf(buf, "unlinked_tag%u", sdp->sd_jdesc->jd_jid);
-	sdp->sd_ut_inode = gfs2_lookup_simple(pn, buf);
-	if (IS_ERR(sdp->sd_ut_inode)) {
-		error = PTR_ERR(sdp->sd_ut_inode);
-		fs_err(sdp, "can't find local \"ut\" file: %d\n", error);
-		goto fail_sc_i;
-	}
-
 	sprintf(buf, "quota_change%u", sdp->sd_jdesc->jd_jid);
 	sdp->sd_qc_inode = gfs2_lookup_simple(pn, buf);
 	if (IS_ERR(sdp->sd_qc_inode)) {
@@ -633,7 +599,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	iput(pn);
 	pn = NULL;
 
-	ip = sdp->sd_ir_inode->u.generic_ip;
+	ip = GFS2_I(sdp->sd_ir_inode);
 	error = gfs2_glock_nq_init(ip->i_gl,
 				   LM_ST_EXCLUSIVE, 0,
 				   &sdp->sd_ir_gh);
@@ -642,7 +608,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 		goto fail_qc_i;
 	}
 
-	ip = sdp->sd_sc_inode->u.generic_ip;
+	ip = GFS2_I(sdp->sd_sc_inode);
 	error = gfs2_glock_nq_init(ip->i_gl,
 				   LM_ST_EXCLUSIVE, 0,
 				   &sdp->sd_sc_gh);
@@ -651,16 +617,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 		goto fail_ir_gh;
 	}
 
-	ip = sdp->sd_ut_inode->u.generic_ip;
-	error = gfs2_glock_nq_init(ip->i_gl,
-				   LM_ST_EXCLUSIVE, 0,
-				   &sdp->sd_ut_gh);
-	if (error) {
-		fs_err(sdp, "can't lock local \"ut\" file: %d\n", error);
-		goto fail_sc_gh;
-	}
-
-	ip = sdp->sd_qc_inode->u.generic_ip;
+	ip = GFS2_I(sdp->sd_qc_inode);
 	error = gfs2_glock_nq_init(ip->i_gl,
 				   LM_ST_EXCLUSIVE, 0,
 				   &sdp->sd_qc_gh);
@@ -675,9 +632,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	gfs2_glock_dq_uninit(&sdp->sd_qc_gh);
 
  fail_ut_gh:
-	gfs2_glock_dq_uninit(&sdp->sd_ut_gh);
 
- fail_sc_gh:
 	gfs2_glock_dq_uninit(&sdp->sd_sc_gh);
 
  fail_ir_gh:
@@ -687,9 +642,7 @@ static int init_per_node(struct gfs2_sbd *sdp, int undo)
 	iput(sdp->sd_qc_inode);
 
  fail_ut_i:
-	iput(sdp->sd_ut_inode);
 
- fail_sc_i:
 	iput(sdp->sd_sc_inode);
 
  fail_ir_i:
@@ -707,7 +660,7 @@ static int init_threads(struct gfs2_sbd *sdp, int undo)
 	int error = 0;
 
 	if (undo)
-		goto fail_inoded;
+		goto fail_quotad;
 
 	sdp->sd_log_flush_time = jiffies;
 	sdp->sd_jindex_refresh_time = jiffies;
@@ -731,25 +684,13 @@ static int init_threads(struct gfs2_sbd *sdp, int undo)
 	}
 	sdp->sd_quotad_process = p;
 
-	p = kthread_run(gfs2_inoded, sdp, "gfs2_inoded");
-	error = IS_ERR(p);
-	if (error) {
-		fs_err(sdp, "can't start inoded thread: %d\n", error);
-		goto fail_quotad;
-	}
-	sdp->sd_inoded_process = p;
-
 	return 0;
 
- fail_inoded:
-	kthread_stop(sdp->sd_inoded_process);
 
- fail_quotad:
+fail_quotad:
 	kthread_stop(sdp->sd_quotad_process);
-
- fail:
+fail:
 	kthread_stop(sdp->sd_logd_process);
-	
 	return error;
 }