gfs2: Add gfs2_max_stuffed_size

Add a small inline function for computing the maximum size of a stuffed
inode instead of open coding that in several places throughout the code.

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

fs/gfs2/aops.c

@@ -482,8 +482,8 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 		return error;
 
 	kaddr = kmap_atomic(page);
-	if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
-		dsize = (dibh->b_size - sizeof(struct gfs2_dinode));
+	if (dsize > gfs2_max_stuffed_size(ip))
+		dsize = gfs2_max_stuffed_size(ip);
 	memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
 	memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
 	kunmap_atomic(kaddr);
@@ -723,7 +723,7 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
 
 	if (gfs2_is_stuffed(ip)) {
 		error = 0;
-		if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
+		if (pos + len > gfs2_max_stuffed_size(ip)) {
 			error = gfs2_unstuff_dinode(ip, page);
 			if (error == 0)
 				goto prepare_write;
@@ -830,7 +830,8 @@ static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh,
 	void *kaddr;
 	unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode);
 
-	BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode)));
+	BUG_ON(pos + len > gfs2_max_stuffed_size(ip));
+
 	kaddr = kmap_atomic(page);
 	memcpy(buf + pos, kaddr + pos, copied);
 	flush_dcache_page(page);

fs/gfs2/bmap.c

@@ -69,8 +69,8 @@ static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
 		void *kaddr = kmap(page);
 		u64 dsize = i_size_read(inode);
  
-		if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
-			dsize = dibh->b_size - sizeof(struct gfs2_dinode);
+		if (dsize > gfs2_max_stuffed_size(ip))
+			dsize = gfs2_max_stuffed_size(ip);
 
 		memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
 		memset(kaddr + dsize, 0, PAGE_SIZE - dsize);
@@ -1692,8 +1692,7 @@ static int do_grow(struct inode *inode, u64 size)
 	int error;
 	int unstuff = 0;
 
-	if (gfs2_is_stuffed(ip) &&
-	    (size > (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)))) {
+	if (gfs2_is_stuffed(ip) && size > gfs2_max_stuffed_size(ip)) {
 		error = gfs2_quota_lock_check(ip, &ap);
 		if (error)
 			return error;
@@ -1928,8 +1927,7 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
 		return 0;
 
 	if (gfs2_is_stuffed(ip)) {
-		if (offset + len >
-		    sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
+		if (offset + len > gfs2_max_stuffed_size(ip))
 			return 1;
 		return 0;
 	}

fs/gfs2/dir.c

@@ -170,8 +170,7 @@ static int gfs2_dir_write_data(struct gfs2_inode *ip, const char *buf,
 	if (!size)
 		return 0;
 
-	if (gfs2_is_stuffed(ip) &&
-	    offset + size <= sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
+	if (gfs2_is_stuffed(ip) && offset + size <= gfs2_max_stuffed_size(ip))
 		return gfs2_dir_write_stuffed(ip, buf, (unsigned int)offset,
 					      size);
 

fs/gfs2/incore.h

@@ -861,5 +861,10 @@ static inline void gfs2_sbstats_inc(const struct gfs2_glock *gl, int which)
 
 extern struct gfs2_rgrpd *gfs2_glock2rgrp(struct gfs2_glock *gl);
 
+static inline unsigned gfs2_max_stuffed_size(const struct gfs2_inode *ip)
+{
+	return GFS2_SB(&ip->i_inode)->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
+}
+
 #endif /* __INCORE_DOT_H__ */
 

fs/gfs2/inode.c

@@ -1184,11 +1184,10 @@ out_inodes:
 static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
 			const char *symname)
 {
-	struct gfs2_sbd *sdp = GFS2_SB(dir);
 	unsigned int size;
 
 	size = strlen(symname);
-	if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode) - 1)
+	if (size >= gfs2_max_stuffed_size(GFS2_I(dir)))
 		return -ENAMETOOLONG;
 
 	return gfs2_create_inode(dir, dentry, NULL, S_IFLNK | S_IRWXUGO, 0, symname, size, 0, NULL);
@@ -1205,8 +1204,7 @@ static int gfs2_symlink(struct inode *dir, struct dentry *dentry,
 
 static int gfs2_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
-	struct gfs2_sbd *sdp = GFS2_SB(dir);
-	unsigned dsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode);
+	unsigned dsize = gfs2_max_stuffed_size(GFS2_I(dir));
 	return gfs2_create_inode(dir, dentry, NULL, S_IFDIR | mode, 0, NULL, dsize, 0, NULL);
 }