GFS2: Extend the life of the reservations

This patch lengthens the lifespan of the reservations structure for
inodes. Before, they were allocated and deallocated for every write
operation. With this patch, they are allocated when the first write
occurs, and deallocated when the last process closes the file.
It's more efficient to do it this way because it saves GFS2 a lot of
unnecessary allocates and frees. It also gives us more flexibility
for the future: (1) we can now fold the qadata structure back into
the structure and save those alloc/frees, (2) we can use this for
multi-block reservations.

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

1 files changed, 22 insertions, 1 deletions

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index a9ba244..2a1b4b5 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -667,6 +667,10 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	if (!name->len || name->len > GFS2_FNAMESIZE)
 		return -ENAMETOOLONG;
 
+	error = gfs2_rs_alloc(dip);
+	if (error)
+		return error;
+
 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
 	if (error)
 		goto fail;
@@ -704,6 +708,11 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	if (error)
 		goto fail_gunlock2;
 
+	/* the new inode needs a reservation so it can allocate xattrs. */
+	error = gfs2_rs_alloc(GFS2_I(inode));
+	if (error)
+		goto fail_gunlock2;
+
 	error = gfs2_acl_create(dip, inode);
 	if (error)
 		goto fail_gunlock2;
@@ -722,7 +731,7 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 	gfs2_trans_end(sdp);
 	/* Check if we reserved space in the rgrp. Function link_dinode may
 	   not, depending on whether alloc is required. */
-	if (dip->i_res)
+	if (gfs2_mb_reserved(dip))
 		gfs2_inplace_release(dip);
 	gfs2_quota_unlock(dip);
 	gfs2_qadata_put(dip);
@@ -819,6 +828,10 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 	if (S_ISDIR(inode->i_mode))
 		return -EPERM;
 
+	error = gfs2_rs_alloc(dip);
+	if (error)
+		return error;
+
 	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, ghs);
 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, ghs + 1);
 
@@ -1234,6 +1247,10 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 	if (error)
 		return error;
 
+	error = gfs2_rs_alloc(ndip);
+	if (error)
+		return error;
+
 	if (odip != ndip) {
 		error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
 					   0, &r_gh);
@@ -1644,6 +1661,10 @@ static int gfs2_setattr(struct dentry *dentry, struct iattr *attr)
 	struct gfs2_holder i_gh;
 	int error;
 
+	error = gfs2_rs_alloc(ip);
+	if (error)
+		return error;
+
 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
 	if (error)
 		return error;