gfs2: perform quota checks against allocation parameters

Use struct gfs2_alloc_parms as an argument to gfs2_quota_check()
and gfs2_quota_lock_check() to check for quota violations while
accounting for the new blocks requested by the current operation
in ap->target.

Previously, the number of new blocks requested during an operation
were not accounted for during quota_check and would allow these
operations to exceed quota. This was not very apparent since most
operations allocated only 1 block at a time and quotas would get
violated in the next operation. i.e. quota excess would only be by
1 block or so. With fallocate, (where we allocate a bunch of blocks
at once) the quota excess is non-trivial and is addressed by this
patch.
Signed-off-by: NAbhi Das <adas@redhat.com>
Signed-off-by: NBob Peterson <rpeterso@redhat.com>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/gfs2/aops.c

@@ -671,12 +671,12 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
 
 	if (alloc_required) {
 		struct gfs2_alloc_parms ap = { .aflags = 0, };
-		error = gfs2_quota_lock_check(ip);
+		requested = data_blocks + ind_blocks;
+		ap.target = requested;
+		error = gfs2_quota_lock_check(ip, &ap);
 		if (error)
 			goto out_unlock;
 
-		requested = data_blocks + ind_blocks;
-		ap.target = requested;
 		error = gfs2_inplace_reserve(ip, &ap);
 		if (error)
 			goto out_qunlock;

fs/gfs2/bmap.c

@@ -1224,7 +1224,7 @@ static int do_grow(struct inode *inode, u64 size)
 
 	if (gfs2_is_stuffed(ip) &&
 	    (size > (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)))) {
-		error = gfs2_quota_lock_check(ip);
+		error = gfs2_quota_lock_check(ip, &ap);
 		if (error)
 			return error;
 

fs/gfs2/file.c

@@ -429,11 +429,11 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (ret)
 		goto out_unlock;
 
-	ret = gfs2_quota_lock_check(ip);
-	if (ret)
-		goto out_unlock;
 	gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
 	ap.target = data_blocks + ind_blocks;
+	ret = gfs2_quota_lock_check(ip, &ap);
+	if (ret)
+		goto out_unlock;
 	ret = gfs2_inplace_reserve(ip, &ap);
 	if (ret)
 		goto out_quota_unlock;
@@ -827,13 +827,13 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
 			offset += bytes;
 			continue;
 		}
-		error = gfs2_quota_lock_check(ip);
-		if (error)
-			return error;
 retry:
 		gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
-
 		ap.target = data_blocks + ind_blocks;
+
+		error = gfs2_quota_lock_check(ip, &ap);
+		if (error)
+			return error;
 		error = gfs2_inplace_reserve(ip, &ap);
 		if (error) {
 			if (error == -ENOSPC && bytes > sdp->sd_sb.sb_bsize) {
@@ -841,6 +841,7 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
 				bytes &= bsize_mask;
 				if (bytes == 0)
 					bytes = sdp->sd_sb.sb_bsize;
+				gfs2_quota_unlock(ip);
 				goto retry;
 			}
 			goto out_qunlock;

fs/gfs2/incore.h

@@ -301,7 +301,7 @@ struct gfs2_blkreserv {
  * to the allocation code.
  */
 struct gfs2_alloc_parms {
-	u32 target;
+	u64 target;
 	u32 aflags;
 };
 

fs/gfs2/inode.c

@@ -382,7 +382,7 @@ static int alloc_dinode(struct gfs2_inode *ip, u32 flags, unsigned *dblocks)
 	struct gfs2_alloc_parms ap = { .target = *dblocks, .aflags = flags, };
 	int error;
 
-	error = gfs2_quota_lock_check(ip);
+	error = gfs2_quota_lock_check(ip, &ap);
 	if (error)
 		goto out;
 
@@ -525,7 +525,7 @@ static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
 	int error;
 
 	if (da->nr_blocks) {
-		error = gfs2_quota_lock_check(dip);
+		error = gfs2_quota_lock_check(dip, &ap);
 		if (error)
 			goto fail_quota_locks;
 
@@ -953,7 +953,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
 
 	if (da.nr_blocks) {
 		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
-		error = gfs2_quota_lock_check(dip);
+		error = gfs2_quota_lock_check(dip, &ap);
 		if (error)
 			goto out_gunlock;
 
@@ -1470,7 +1470,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
 
 	if (da.nr_blocks) {
 		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
-		error = gfs2_quota_lock_check(ndip);
+		error = gfs2_quota_lock_check(ndip, &ap);
 		if (error)
 			goto out_gunlock;
 
@@ -1669,6 +1669,7 @@ static int setattr_chown(struct inode *inode, struct iattr *attr)
 	kuid_t ouid, nuid;
 	kgid_t ogid, ngid;
 	int error;
+	struct gfs2_alloc_parms ap;
 
 	ouid = inode->i_uid;
 	ogid = inode->i_gid;
@@ -1696,9 +1697,11 @@ static int setattr_chown(struct inode *inode, struct iattr *attr)
 	if (error)
 		goto out;
 
+	ap.target = gfs2_get_inode_blocks(&ip->i_inode);
+
 	if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
 	    !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
-		error = gfs2_quota_check(ip, nuid, ngid);
+		error = gfs2_quota_check(ip, nuid, ngid, &ap);
 		if (error)
 			goto out_gunlock_q;
 	}
@@ -1713,9 +1716,8 @@ static int setattr_chown(struct inode *inode, struct iattr *attr)
 
 	if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
 	    !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
-		u64 blocks = gfs2_get_inode_blocks(&ip->i_inode);
-		gfs2_quota_change(ip, -blocks, ouid, ogid);
-		gfs2_quota_change(ip, blocks, nuid, ngid);
+		gfs2_quota_change(ip, -ap.target, ouid, ogid);
+		gfs2_quota_change(ip, ap.target, nuid, ngid);
 	}
 
 out_end_trans:

fs/gfs2/quota.c

@@ -1094,7 +1094,8 @@ static int print_message(struct gfs2_quota_data *qd, char *type)
 	return 0;
 }
 
-int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
+int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid,
+		     struct gfs2_alloc_parms *ap)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 	struct gfs2_quota_data *qd;
@@ -1117,14 +1118,13 @@ int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
 
 		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
 		spin_lock(&qd_lock);
-		value += qd->qd_change;
+		value += qd->qd_change + ap->target;
 		spin_unlock(&qd_lock);
 
 		if (be64_to_cpu(qd->qd_qb.qb_limit) && (s64)be64_to_cpu(qd->qd_qb.qb_limit) < value) {
 			print_message(qd, "exceeded");
 			quota_send_warning(qd->qd_id,
 					   sdp->sd_vfs->s_dev, QUOTA_NL_BHARDWARN);
-
 			error = -EDQUOT;
 			break;
 		} else if (be64_to_cpu(qd->qd_qb.qb_warn) &&

fs/gfs2/quota.h

@@ -24,7 +24,8 @@ extern void gfs2_quota_unhold(struct gfs2_inode *ip);
 extern int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid);
 extern void gfs2_quota_unlock(struct gfs2_inode *ip);
 
-extern int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid);
+extern int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid,
+			    struct gfs2_alloc_parms *ap);
 extern void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
 			      kuid_t uid, kgid_t gid);
 
@@ -37,7 +38,8 @@ extern int gfs2_quotad(void *data);
 
 extern void gfs2_wake_up_statfs(struct gfs2_sbd *sdp);
 
-static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
+static inline int gfs2_quota_lock_check(struct gfs2_inode *ip,
+					struct gfs2_alloc_parms *ap)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
 	int ret;
@@ -48,7 +50,7 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
 		return ret;
 	if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
 		return 0;
-	ret = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
+	ret = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid, ap);
 	if (ret)
 		gfs2_quota_unlock(ip);
 	return ret;

fs/gfs2/xattr.c

@@ -732,7 +732,7 @@ static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
 	if (error)
 		return error;
 
-	error = gfs2_quota_lock_check(ip);
+	error = gfs2_quota_lock_check(ip, &ap);
 	if (error)
 		return error;