[GFS2] Make journaled data files identical to normal files on disk

This is a very large patch, with a few still to be resolved issues
so you might want to check out the previous head of the tree since
this is known to be unstable. Fixes for the various bugs will be
forthcoming shortly.

This patch removes the special data format which has been used
up till now for journaled data files. Directories still retain the
old format so that they will remain on disk compatible with earlier
releases. As a result you can now do the following with journaled
data files:

 1) mmap them
 2) export them over NFS
 3) convert to/from normal files whenever you want to (the zero length
    restriction is gone)

In addition the level at which GFS' locking is done has changed for all
files (since they all now use the page cache) such that the locking is
done at the page cache level rather than the level of the fs operations.
This should mean that things like loopback mounts and other things which
touch the page cache directly should now work.

Current known issues:

 1. There is a lock mode inversion problem related to the resource
    group hold function which needs to be resolved.
 2. Any significant amount of I/O causes an oops with an offset of hex 320
    (NULL pointer dereference) which appears to be related to a journaled data
    buffer appearing on a list where it shouldn't be.
 3. Direct I/O writes are disabled for the time being (will reappear later)
 4. There is probably a deadlock between the page lock and GFS' locks under
    certain combinations of mmap and fs operation I/O.
 5. Issue relating to ref counting on internally used inodes causes a hang
    on umount (discovered before this patch, and not fixed by it)
 6. One part of the directory metadata is different from GFS1 and will need
    to be resolved before next release.

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

1 files changed, 12 insertions, 47 deletions

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index bd194f645c52..4efcd8a39e98 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -18,12 +18,12 @@
 #include "bmap.h"
 #include "glock.h"
 #include "inode.h"
-#include "jdata.h"
 #include "meta_io.h"
 #include "page.h"
 #include "quota.h"
 #include "rgrp.h"
 #include "trans.h"
+#include "dir.h"
 
 /* This doesn't need to be that large as max 64 bit pointers in a 4k
  * block is 512, so __u16 is fine for that. It saves stack space to
@@ -90,7 +90,7 @@ int gfs2_unstuff_dinode(struct gfs2_inode *ip, gfs2_unstuffer_t unstuffer,
 {
 	struct buffer_head *bh, *dibh;
 	uint64_t block = 0;
-	int journaled = gfs2_is_jdata(ip);
+	int isdir = gfs2_is_dir(ip);
 	int error;
 
 	down_write(&ip->i_rw_mutex);
@@ -103,10 +103,10 @@ int gfs2_unstuff_dinode(struct gfs2_inode *ip, gfs2_unstuffer_t unstuffer,
 		/* Get a free block, fill it with the stuffed data,
 		   and write it out to disk */
 
-		if (journaled) {
+		if (isdir) {
 			block = gfs2_alloc_meta(ip);
 
-			error = gfs2_jdata_get_buffer(ip, block, 1, &bh);
+			error = gfs2_dir_get_buffer(ip, block, 1, &bh);
 			if (error)
 				goto out_brelse;
 			gfs2_buffer_copy_tail(bh,
@@ -168,7 +168,7 @@ static unsigned int calc_tree_height(struct gfs2_inode *ip, uint64_t size)
 	if (ip->i_di.di_size > size)
 		size = ip->i_di.di_size;
 
-	if (gfs2_is_jdata(ip)) {
+	if (gfs2_is_dir(ip)) {
 		arr = sdp->sd_jheightsize;
 		max = sdp->sd_max_jheight;
 	} else {
@@ -377,7 +377,7 @@ static void lookup_block(struct gfs2_inode *ip, struct buffer_head *bh,
 		return;
 
 	if (height == ip->i_di.di_height - 1 &&
-	    !gfs2_is_jdata(ip))
+	    !gfs2_is_dir(ip))
 		*block = gfs2_alloc_data(ip);
 	else
 		*block = gfs2_alloc_meta(ip);
@@ -430,7 +430,7 @@ int gfs2_block_map(struct gfs2_inode *ip, uint64_t lblock, int *new,
 	if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
 		goto out;
 
-	bsize = (gfs2_is_jdata(ip)) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
+	bsize = (gfs2_is_dir(ip)) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
 
 	height = calc_tree_height(ip, (lblock + 1) * bsize);
 	if (ip->i_di.di_height < height) {
@@ -618,7 +618,7 @@ static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh,
 		sm->sm_first = 0;
 	}
 
-	metadata = (height != ip->i_di.di_height - 1) || gfs2_is_jdata(ip);
+	metadata = (height != ip->i_di.di_height - 1);
 	if (metadata)
 		revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs;
 
@@ -814,33 +814,6 @@ static int do_grow(struct gfs2_inode *ip, uint64_t size)
 	return error;
 }
 
-static int truncator_journaled(struct gfs2_inode *ip, uint64_t size)
-{
-	uint64_t lbn, dbn;
-	uint32_t off;
-	struct buffer_head *bh;
-	int new = 0;
-	int error;
-
-	lbn = size;
-	off = do_div(lbn, ip->i_sbd->sd_jbsize);
-
-	error = gfs2_block_map(ip, lbn, &new, &dbn, NULL);
-	if (error || !dbn)
-		return error;
-
-	error = gfs2_jdata_get_buffer(ip, dbn, 0, &bh);
-	if (error)
-		return error;
-
-	gfs2_trans_add_bh(ip->i_gl, bh, 1);
-	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header) + off);
-
-	brelse(bh);
-
-	return 0;
-}
-
 static int trunc_start(struct gfs2_inode *ip, uint64_t size)
 {
 	struct gfs2_sbd *sdp = ip->i_sbd;
@@ -866,12 +839,7 @@ static int trunc_start(struct gfs2_inode *ip, uint64_t size)
 		error = 1;
 
 	} else {
-		if (journaled) {
-			uint64_t junk = size;
-			/* we're just interested in the modulus */
-			if (do_div(junk, sdp->sd_jbsize))
-				error = truncator_journaled(ip, size);
-		} else if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1))
+		if (size & (uint64_t)(sdp->sd_sb.sb_bsize - 1))
 			error = gfs2_block_truncate_page(ip->i_vnode->i_mapping);
 
 		if (!error) {
@@ -900,10 +868,7 @@ static int trunc_dealloc(struct gfs2_inode *ip, uint64_t size)
 
 	if (!size)
 		lblock = 0;
-	else if (gfs2_is_jdata(ip)) {
-		lblock = size - 1;
-		do_div(lblock, ip->i_sbd->sd_jbsize);
-	} else
+	else
 		lblock = (size - 1) >> ip->i_sbd->sd_sb.sb_bsize_shift;
 
 	find_metapath(ip, lblock, &mp);
@@ -1051,7 +1016,7 @@ void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len,
 	struct gfs2_sbd *sdp = ip->i_sbd;
 	unsigned int tmp;
 
-	if (gfs2_is_jdata(ip)) {
+	if (gfs2_is_dir(ip)) {
 		*data_blocks = DIV_RU(len, sdp->sd_jbsize) + 2;
 		*ind_blocks = 3 * (sdp->sd_max_jheight - 1);
 	} else {
@@ -1096,7 +1061,7 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, uint64_t offset,
 		return 0;
 	}
 
-	if (gfs2_is_jdata(ip)) {
+	if (gfs2_is_dir(ip)) {
 		unsigned int bsize = sdp->sd_jbsize;
 		lblock = offset;
 		do_div(lblock, bsize);