[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, 11 insertions, 12 deletions

diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
index c504ac1b831d..7aabc03e4abd 100644
--- a/fs/gfs2/recovery.c
+++ b/fs/gfs2/recovery.c
@@ -32,14 +32,14 @@
 int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
                            struct buffer_head **bh)
 {
-        struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
+        struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
         struct gfs2_glock *gl = ip->i_gl;
         int new = 0;
         uint64_t dblock;
         uint32_t extlen;
         int error;
 
-        error = gfs2_extent_map(ip->i_vnode, blk, &new, &dblock, &extlen);
+        error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
         if (error)
                 return error;
         if (!dblock) {
@@ -190,7 +190,7 @@ static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
                         *blk = 0;
 
                 if (*blk == orig_blk) {
-                        gfs2_consist_inode(jd->jd_inode->u.generic_ip);
+                        gfs2_consist_inode(GFS2_I(jd->jd_inode));
                         return -EIO;
                 }
         }
@@ -224,7 +224,7 @@ static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
                         continue;
 
                 if (lh.lh_sequence == head->lh_sequence) {
-                        gfs2_consist_inode(jd->jd_inode->u.generic_ip);
+                        gfs2_consist_inode(GFS2_I(jd->jd_inode));
                         return -EIO;
                 }
                 if (lh.lh_sequence < head->lh_sequence)
@@ -300,8 +300,7 @@ int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
                               unsigned int end, int pass)
 {
-        struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
         struct buffer_head *bh;
         struct gfs2_log_descriptor *ld;
         int error = 0;
@@ -330,7 +329,7 @@ static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
                                 continue;
                         }
                         if (error == 1) {
-                                gfs2_consist_inode(jd->jd_inode->u.generic_ip);
+                                gfs2_consist_inode(GFS2_I(jd->jd_inode));
                                 error = -EIO;
                         }
                         brelse(bh);
@@ -367,8 +366,8 @@ static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
 
 static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 {
-        struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+        struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
         unsigned int lblock;
         int new = 0;
         uint64_t dblock;
@@ -380,7 +379,7 @@ static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 
         lblock = head->lh_blkno;
         gfs2_replay_incr_blk(sdp, &lblock);
-        error = gfs2_block_map(ip->i_vnode, lblock, &new, &dblock, &boundary);
+        error = gfs2_block_map(&ip->i_inode, lblock, &new, &dblock, &boundary);
         if (error)
                 return error;
         if (!dblock) {
@@ -426,8 +425,8 @@ static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
 
 int gfs2_recover_journal(struct gfs2_jdesc *jd)
 {
-        struct gfs2_inode *ip = jd->jd_inode->u.generic_ip;
-        struct gfs2_sbd *sdp = ip->i_sbd;
+        struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+        struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
         struct gfs2_log_header head;
         struct gfs2_holder j_gh, ji_gh, t_gh;
         unsigned long t;