s3:vfs_gpfs: Report disk space and usage on GPFS share according to quotas

When a client requests the information about free space and space used,
adjust the reported values according to quotas in the GPFS file system:

- Retrieve quotas for the current user, current group and fileset for
  the top level of the share.
- If the soft block quota grace time has expired, report disk as full.
- If a hard block quota has been exceeded, report disk as full.
- If none of the hard block quotas been exceeded, report
  share size and free space according to the lowest limits found in
  the quotas.
- If no applicable hard block quota has been set, report the
  information from the statfs call.

This feature is disabled by default and has to be enabled by setting the
option gpfs:dfreequota.

docs-xml/manpages-3/vfs_gpfs.8.xml

@@ -221,6 +221,53 @@
 		</varlistentry>
 		<varlistentry>
 
+		<term>gpfs:dfreequota = [ yes | no ]</term>
+		<listitem>
+		<para>
+		Adjust reporting of the size and free space of a share
+		according to quotas. If this setting is "yes", a
+		request for size and free space will also evaluate the
+		following quotas:
+		</para>
+
+		<itemizedlist>
+		<listitem><para>The user quota of the user requesting
+		    the data.</para></listitem>
+		<listitem><para>The group quota of the primary group
+		    of the user.</para></listitem>
+		<listitem><para>The fileset quota for the fileset
+		    containing the top level directory of the share.
+		</para></listitem>
+		</itemizedlist>
+
+		<para>
+		If any of the soft or hard quota limits has been
+		reached, the free space will be reported as 0. If a
+		quota is in place, but the limits have not been
+		reached, the free space will be reported according to
+		the space left in the quota. If more than one quota
+		applies the free space will be reported as the smallest
+		space left in those quotas. The size of the share
+		will be reported according to the quota usage. If more
+		than one quota applies, the smallest size will be
+		reported for the share size according to these quotas.
+		</para>
+
+		<itemizedlist>
+		<listitem><para>
+		<command>yes</command> - include the quotas
+		when reporting the share size and free space
+		</para></listitem>
+		<listitem><para>
+		<command>no(default)</command> - do not include quotas,
+		simply report the size and free space of the file system
+		</para></listitem>
+		</itemizedlist>
+		</listitem>
+
+		</varlistentry>
+		<varlistentry>
+
 		<term>nfs4:mode = [ simple | special ]</term>
 		<listitem>
 		<para>

source3/modules/vfs_gpfs.c

@@ -33,6 +33,7 @@
 #include "nfs4_acls.h"
 #include "vfs_gpfs.h"
 #include "system/filesys.h"
+#include "auth.h"
 
 struct gpfs_config_data {
 	bool sharemodes;
@@ -42,6 +43,7 @@ struct gpfs_config_data {
 	bool winattr;
 	bool ftruncate;
 	bool getrealfilename;
+	bool dfreequota;
 };
 
 
@@ -1385,6 +1387,9 @@ int vfs_gpfs_connect(struct vfs_handle_struct *handle, const char *service,
 	config->getrealfilename = lp_parm_bool(SNUM(handle->conn), "gpfs",
 					       "getrealfilename", true);
 
+	config->dfreequota = lp_parm_bool(SNUM(handle->conn), "gpfs",
+					  "dfreequota", false);
+
 	SMB_VFS_HANDLE_SET_DATA(handle, config,
 				NULL, struct gpfs_config_data,
 				return -1);
@@ -1392,6 +1397,129 @@ int vfs_gpfs_connect(struct vfs_handle_struct *handle, const char *service,
 	return 0;
 }
 
+static int vfs_gpfs_get_quotas(const char *path, uid_t uid, gid_t gid,
+			       int *fset_id,
+			       struct gpfs_quotaInfo *qi_user,
+			       struct gpfs_quotaInfo *qi_group,
+			       struct gpfs_quotaInfo *qi_fset)
+{
+	int err;
+
+	err = get_gpfs_fset_id(path, fset_id);
+	if (err) {
+		DEBUG(0, ("Get fset id failed, errno %d.\n", errno));
+		return err;
+	}
+
+	err = get_gpfs_quota(path, GPFS_USRQUOTA, uid, qi_user);
+	if (err) {
+		return err;
+	}
+
+	err = get_gpfs_quota(path, GPFS_GRPQUOTA, gid, qi_group);
+	if (err) {
+		return err;
+	}
+
+	err = get_gpfs_quota(path, GPFS_FILESETQUOTA, *fset_id, qi_fset);
+	if (err) {
+		return err;
+	}
+
+	return 0;
+}
+
+static void vfs_gpfs_disk_free_quota(struct gpfs_quotaInfo qi, time_t cur_time,
+				     uint64_t *dfree, uint64_t *dsize)
+{
+	uint64_t usage, limit;
+
+	/*
+	 * The quota reporting is done in units of 1024 byte blocks, but
+	 * sys_fsusage uses units of 512 byte blocks, adjust the block number
+	 * accordingly. Also filter possibly negative usage counts from gpfs.
+	 */
+	usage = qi.blockUsage < 0 ? 0 : (uint64_t)qi.blockUsage * 2;
+	limit = (uint64_t)qi.blockHardLimit * 2;
+
+	/*
+	 * When the grace time for the exceeded soft block quota has been
+	 * exceeded, the soft block quota becomes an additional hard limit.
+	 */
+	if (qi.blockGraceTime && cur_time > qi.blockGraceTime) {
+		/* report disk as full */
+		*dfree = 0;
+		*dsize = MIN(*dsize, usage);
+	}
+
+	if (!qi.blockHardLimit)
+		return;
+
+	if (usage >= limit) {
+		/* report disk as full */
+		*dfree = 0;
+		*dsize = MIN(*dsize, usage);
+
+	} else {
+		/* limit has not been reached, determine "free space" */
+		*dfree = MIN(*dfree, limit - usage);
+		*dsize = MIN(*dsize, limit);
+	}
+}
+
+static uint64_t vfs_gpfs_disk_free(vfs_handle_struct *handle, const char *path,
+				   bool small_query, uint64_t *bsize,
+				   uint64_t *dfree, uint64_t *dsize)
+{
+	struct security_unix_token *utok;
+	struct gpfs_quotaInfo qi_user, qi_group, qi_fset;
+	struct gpfs_config_data *config;
+	int err, fset_id;
+	time_t cur_time;
+
+	SMB_VFS_HANDLE_GET_DATA(handle, config, struct gpfs_config_data,
+				return (uint64_t)-1);
+	if (!config->dfreequota) {
+		return SMB_VFS_NEXT_DISK_FREE(handle, path, small_query,
+					      bsize, dfree, dsize);
+	}
+
+	err = sys_fsusage(path, dfree, dsize);
+	if (err) {
+		DEBUG (0, ("Could not get fs usage, errno %d\n", errno));
+		return SMB_VFS_NEXT_DISK_FREE(handle, path, small_query,
+					      bsize, dfree, dsize);
+	}
+
+	/* sys_fsusage returns units of 512 bytes */
+	*bsize = 512;
+
+	DEBUG(10, ("fs dfree %llu, dsize %llu\n",
+		   (unsigned long long)*dfree, (unsigned long long)*dsize));
+
+	utok = handle->conn->session_info->unix_token;
+	err = vfs_gpfs_get_quotas(path, utok->uid, utok->gid, &fset_id,
+				  &qi_user, &qi_group, &qi_fset);
+	if (err) {
+		return SMB_VFS_NEXT_DISK_FREE(handle, path, small_query,
+					      bsize, dfree, dsize);
+	}
+
+	cur_time = time(NULL);
+
+	/* Adjust free space and size according to quota limits. */
+	vfs_gpfs_disk_free_quota(qi_user, cur_time, dfree, dsize);
+	vfs_gpfs_disk_free_quota(qi_group, cur_time, dfree, dsize);
+
+	/* Id 0 indicates the default quota, not an actual quota */
+	if (fset_id != 0) {
+		vfs_gpfs_disk_free_quota(qi_fset, cur_time, dfree, dsize);
+	}
+
+	disk_norm(small_query, bsize, dfree, dsize);
+	return *dfree;
+}
+
 static uint32_t vfs_gpfs_capabilities(struct vfs_handle_struct *handle,
 				      enum timestamp_set_resolution *p_ts_res)
 {
@@ -1429,6 +1557,7 @@ static int vfs_gpfs_open(struct vfs_handle_struct *handle,
 
 static struct vfs_fn_pointers vfs_gpfs_fns = {
 	.connect_fn = vfs_gpfs_connect,
+	.disk_free_fn = vfs_gpfs_disk_free,
 	.fs_capabilities_fn = vfs_gpfs_capabilities,
 	.kernel_flock_fn = vfs_gpfs_kernel_flock,
 	.linux_setlease_fn = vfs_gpfs_setlease,