Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v8.

The reason why we need this ioctl is to offer the none-privileged end-user a possibility to get filesys info gathering. We use OCFS2_IOC_INFO to manipulate the new ioctl, userspace passes a structure to kernel containing an array of request pointers and request count, such as, * From userspace: struct ocfs2_info_blocksize oib = { .ib_req = { .ir_magic = OCFS2_INFO_MAGIC, .ir_code = OCFS2_INFO_BLOCKSIZE, ... } ... } struct ocfs2_info_clustersize oic = { ... } uint64_t reqs[2] = {(unsigned long)&oib, (unsigned long)&oic}; struct ocfs2_info info = { .oi_requests = reqs, .oi_count = 2, } ret = ioctl(fd, OCFS2_IOC_INFO, &info); * In kernel: Get the request pointers from *info*, then handle each request one bye one. Idea here is to make the spearated request small enough to guarantee a better backward&forward compatibility since a small piece of request would be less likely to be broken if filesys on raw disk get changed. Currently, the following 7 requests are supported per the requirement from userspace tool o2info, and I believe it will grow over time:-) OCFS2_INFO_CLUSTERSIZE OCFS2_INFO_BLOCKSIZE OCFS2_INFO_MAXSLOTS OCFS2_INFO_LABEL OCFS2_INFO_UUID OCFS2_INFO_FS_FEATURES OCFS2_INFO_JOURNAL_SIZE This ioctl is only specific to OCFS2. Signed-off-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>

Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v8.
The reason why we need this ioctl is to offer the none-privileged end-user a possibility to get filesys info gathering. We use OCFS2_IOC_INFO to manipulate the new ioctl, userspace passes a structure to kernel containing an array of request pointers and request count, such as, * From userspace: struct ocfs2_info_blocksize oib = { .ib_req = { .ir_magic = OCFS2_INFO_MAGIC, .ir_code = OCFS2_INFO_BLOCKSIZE, ... } ... } struct ocfs2_info_clustersize oic = { ... } uint64_t reqs[2] = {(unsigned long)&oib, (unsigned long)&oic}; struct ocfs2_info info = { .oi_requests = reqs, .oi_count = 2, } ret = ioctl(fd, OCFS2_IOC_INFO, &info); * In kernel: Get the request pointers from *info*, then handle each request one bye one. Idea here is to make the spearated request small enough to guarantee a better backward&forward compatibility since a small piece of request would be less likely to be broken if filesys on raw disk get changed. Currently, the following 7 requests are supported per the requirement from userspace tool o2info, and I believe it will grow over time:-) OCFS2_INFO_CLUSTERSIZE OCFS2_INFO_BLOCKSIZE OCFS2_INFO_MAXSLOTS OCFS2_INFO_LABEL OCFS2_INFO_UUID OCFS2_INFO_FS_FEATURES OCFS2_INFO_JOURNAL_SIZE This ioctl is only specific to OCFS2. Signed-off-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
Tristan Ye · Joel Becker
1 parent 152831be91
Showing 2 changed files with 451 additions and 0 deletions Side-by-side Diff
fs/ocfs2/ioctl.c
fs/ocfs2/ocfs2_ioctl.h
@@ -26,6 +26,26 @@
  
 #include <linux/ext2_fs.h>
  
+#define o2info_from_user(a, b)	\
+		copy_from_user(&(a), (b), sizeof(a))
+#define o2info_to_user(a, b)	\
+		copy_to_user((typeof(a) __user *)b, &(a), sizeof(a))
+
+/*
+ * This call is void because we are already reporting an error that may
+ * be -EFAULT.  The error will be returned from the ioctl(2) call.  It's
+ * just a best-effort to tell userspace that this request caused the error.
+ */
+static inline void __o2info_set_request_error(struct ocfs2_info_request *kreq,
+					struct ocfs2_info_request __user *req)
+{
+	kreq->ir_flags |= OCFS2_INFO_FL_ERROR;
+	(void)put_user(kreq->ir_flags, (__u32 __user *)&(req->ir_flags));
+}
+
+#define o2info_set_request_error(a, b) \
+		__o2info_set_request_error((struct ocfs2_info_request *)&(a), b)
+
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {
 	int status;
@@ -109,6 +129,328 @@
 	return status;
 }
  
+int ocfs2_info_handle_blocksize(struct inode *inode,
+				struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_blocksize oib;
+
+	if (o2info_from_user(oib, req))
+		goto bail;
+
+	oib.ib_blocksize = inode->i_sb->s_blocksize;
+	oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oib, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oib, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_clustersize(struct inode *inode,
+				  struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_clustersize oic;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oic, req))
+		goto bail;
+
+	oic.ic_clustersize = osb->s_clustersize;
+	oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oic, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oic, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_maxslots(struct inode *inode,
+			       struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_maxslots oim;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oim, req))
+		goto bail;
+
+	oim.im_max_slots = osb->max_slots;
+	oim.im_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oim, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oim, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_label(struct inode *inode,
+			    struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_label oil;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oil, req))
+		goto bail;
+
+	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
+	oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oil, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oil, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_uuid(struct inode *inode,
+			   struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_uuid oiu;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oiu, req))
+		goto bail;
+
+	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);
+	oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oiu, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oiu, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_fs_features(struct inode *inode,
+				  struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_fs_features oif;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oif, req))
+		goto bail;
+
+	oif.if_compat_features = osb->s_feature_compat;
+	oif.if_incompat_features = osb->s_feature_incompat;
+	oif.if_ro_compat_features = osb->s_feature_ro_compat;
+	oif.if_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oif, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oif, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_journal_size(struct inode *inode,
+				   struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_journal_size oij;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (o2info_from_user(oij, req))
+		goto bail;
+
+	oij.ij_journal_size = osb->journal->j_inode->i_size;
+
+	oij.ij_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oij, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oij, req);
+
+	return status;
+}
+
+int ocfs2_info_handle_unknown(struct inode *inode,
+			      struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_request oir;
+
+	if (o2info_from_user(oir, req))
+		goto bail;
+
+	oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+
+	if (o2info_to_user(oir, req))
+		goto bail;
+
+	status = 0;
+bail:
+	if (status)
+		o2info_set_request_error(oir, req);
+
+	return status;
+}
+
+/*
+ * Validate and distinguish OCFS2_IOC_INFO requests.
+ *
+ * - validate the magic number.
+ * - distinguish different requests.
+ * - validate size of different requests.
+ */
+int ocfs2_info_handle_request(struct inode *inode,
+			      struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_request oir;
+
+	if (o2info_from_user(oir, req))
+		goto bail;
+
+	status = -EINVAL;
+	if (oir.ir_magic != OCFS2_INFO_MAGIC)
+		goto bail;
+
+	switch (oir.ir_code) {
+	case OCFS2_INFO_BLOCKSIZE:
+		if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
+			status = ocfs2_info_handle_blocksize(inode, req);
+		break;
+	case OCFS2_INFO_CLUSTERSIZE:
+		if (oir.ir_size == sizeof(struct ocfs2_info_clustersize))
+			status = ocfs2_info_handle_clustersize(inode, req);
+		break;
+	case OCFS2_INFO_MAXSLOTS:
+		if (oir.ir_size == sizeof(struct ocfs2_info_maxslots))
+			status = ocfs2_info_handle_maxslots(inode, req);
+		break;
+	case OCFS2_INFO_LABEL:
+		if (oir.ir_size == sizeof(struct ocfs2_info_label))
+			status = ocfs2_info_handle_label(inode, req);
+		break;
+	case OCFS2_INFO_UUID:
+		if (oir.ir_size == sizeof(struct ocfs2_info_uuid))
+			status = ocfs2_info_handle_uuid(inode, req);
+		break;
+	case OCFS2_INFO_FS_FEATURES:
+		if (oir.ir_size == sizeof(struct ocfs2_info_fs_features))
+			status = ocfs2_info_handle_fs_features(inode, req);
+		break;
+	case OCFS2_INFO_JOURNAL_SIZE:
+		if (oir.ir_size == sizeof(struct ocfs2_info_journal_size))
+			status = ocfs2_info_handle_journal_size(inode, req);
+		break;
+	default:
+		status = ocfs2_info_handle_unknown(inode, req);
+		break;
+	}
+
+bail:
+	return status;
+}
+
+int ocfs2_get_request_ptr(struct ocfs2_info *info, int idx,
+			  u64 *req_addr, int compat_flag)
+{
+	int status = -EFAULT;
+	u64 __user *bp = NULL;
+
+	if (compat_flag) {
+#ifdef CONFIG_COMPAT
+		/*
+		 * pointer bp stores the base address of a pointers array,
+		 * which collects all addresses of separate request.
+		 */
+		bp = (u64 __user *)(unsigned long)compat_ptr(info->oi_requests);
+#else
+		BUG();
+#endif
+	} else
+		bp = (u64 __user *)(unsigned long)(info->oi_requests);
+
+	if (o2info_from_user(*req_addr, bp + idx))
+		goto bail;
+
+	status = 0;
+bail:
+	return status;
+}
+
+/*
+ * OCFS2_IOC_INFO handles an array of requests passed from userspace.
+ *
+ * ocfs2_info_handle() recevies a large info aggregation, grab and
+ * validate the request count from header, then break it into small
+ * pieces, later specific handlers can handle them one by one.
+ *
+ * Idea here is to make each separate request small enough to ensure
+ * a better backward&forward compatibility, since a small piece of
+ * request will be less likely to be broken if disk layout get changed.
+ */
+int ocfs2_info_handle(struct inode *inode, struct ocfs2_info *info,
+		      int compat_flag)
+{
+	int i, status = 0;
+	u64 req_addr;
+	struct ocfs2_info_request __user *reqp;
+
+	if ((info->oi_count > OCFS2_INFO_MAX_REQUEST) ||
+	    (!info->oi_requests)) {
+		status = -EINVAL;
+		goto bail;
+	}
+
+	for (i = 0; i < info->oi_count; i++) {
+
+		status = ocfs2_get_request_ptr(info, i, &req_addr, compat_flag);
+		if (status)
+			break;
+
+		reqp = (struct ocfs2_info_request *)(unsigned long)req_addr;
+		if (!reqp) {
+			status = -EINVAL;
+			goto bail;
+		}
+
+		status = ocfs2_info_handle_request(inode, reqp);
+		if (status)
+			break;
+	}
+
+bail:
+	return status;
+}
+
 long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	struct inode *inode = filp->f_path.dentry->d_inode;
@@ -120,6 +462,7 @@
 	struct reflink_arguments args;
 	const char *old_path, *new_path;
 	bool preserve;
+	struct ocfs2_info info;
  
 	switch (cmd) {
 	case OCFS2_IOC_GETFLAGS:
@@ -174,6 +517,12 @@
 		preserve = (args.preserve != 0);
  
 		return ocfs2_reflink_ioctl(inode, old_path, new_path, preserve);
+	case OCFS2_IOC_INFO:
+		if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
+				   sizeof(struct ocfs2_info)))
+			return -EFAULT;
+
+		return ocfs2_info_handle(inode, &info, 0);
 	default:
 		return -ENOTTY;
 	}
@@ -185,6 +534,7 @@
 	bool preserve;
 	struct reflink_arguments args;
 	struct inode *inode = file->f_path.dentry->d_inode;
+	struct ocfs2_info info;
  
 	switch (cmd) {
 	case OCFS2_IOC32_GETFLAGS:
@@ -209,6 +559,12 @@
  
 		return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
 					   compat_ptr(args.new_path), preserve);
+	case OCFS2_IOC_INFO:
+		if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
+				   sizeof(struct ocfs2_info)))
+			return -EFAULT;
+
+		return ocfs2_info_handle(inode, &info, 1);
 	default:
 		return -ENOIOCTLCMD;
 	}
@@ -76,5 +76,100 @@
 };
 #define OCFS2_IOC_REFLINK	_IOW('o', 4, struct reflink_arguments)
  
+/* Following definitions dedicated for ocfs2_info_request ioctls. */
+#define OCFS2_INFO_MAX_REQUEST		(50)
+#define OCFS2_TEXT_UUID_LEN		(OCFS2_VOL_UUID_LEN * 2)
+
+/* Magic number of all requests */
+#define OCFS2_INFO_MAGIC		(0x4F32494E)
+
+/*
+ * Always try to separate info request into small pieces to
+ * guarantee the backward&forward compatibility.
+ */
+struct ocfs2_info {
+	__u64 oi_requests;	/* Array of __u64 pointers to requests */
+	__u32 oi_count;		/* Number of requests in info_requests */
+	__u32 oi_pad;
+};
+
+struct ocfs2_info_request {
+/*00*/	__u32 ir_magic;	/* Magic number */
+	__u32 ir_code;	/* Info request code */
+	__u32 ir_size;	/* Size of request */
+	__u32 ir_flags;	/* Request flags */
+/*10*/			/* Request specific fields */
+};
+
+struct ocfs2_info_clustersize {
+	struct ocfs2_info_request ic_req;
+	__u32 ic_clustersize;
+	__u32 ic_pad;
+};
+
+struct ocfs2_info_blocksize {
+	struct ocfs2_info_request ib_req;
+	__u32 ib_blocksize;
+	__u32 ib_pad;
+};
+
+struct ocfs2_info_maxslots {
+	struct ocfs2_info_request im_req;
+	__u32 im_max_slots;
+	__u32 im_pad;
+};
+
+struct ocfs2_info_label {
+	struct ocfs2_info_request il_req;
+	__u8	il_label[OCFS2_MAX_VOL_LABEL_LEN];
+} __attribute__ ((packed));
+
+struct ocfs2_info_uuid {
+	struct ocfs2_info_request iu_req;
+	__u8	iu_uuid_str[OCFS2_TEXT_UUID_LEN + 1];
+} __attribute__ ((packed));
+
+struct ocfs2_info_fs_features {
+	struct ocfs2_info_request if_req;
+	__u32 if_compat_features;
+	__u32 if_incompat_features;
+	__u32 if_ro_compat_features;
+	__u32 if_pad;
+};
+
+struct ocfs2_info_journal_size {
+	struct ocfs2_info_request ij_req;
+	__u64 ij_journal_size;
+};
+
+/* Codes for ocfs2_info_request */
+enum ocfs2_info_type {
+	OCFS2_INFO_CLUSTERSIZE = 1,
+	OCFS2_INFO_BLOCKSIZE,
+	OCFS2_INFO_MAXSLOTS,
+	OCFS2_INFO_LABEL,
+	OCFS2_INFO_UUID,
+	OCFS2_INFO_FS_FEATURES,
+	OCFS2_INFO_JOURNAL_SIZE,
+	OCFS2_INFO_NUM_TYPES
+};
+
+/* Flags for struct ocfs2_info_request */
+/* Filled by the caller */
+#define OCFS2_INFO_FL_NON_COHERENT	(0x00000001)	/* Cluster coherency not
+							   required. This is a hint.
+							   It is up to ocfs2 whether
+							   the request can be fulfilled
+							   without locking. */
+/* Filled by ocfs2 */
+#define OCFS2_INFO_FL_FILLED		(0x40000000)	/* Filesystem understood
+							   this request and
+							   filled in the answer */
+
+#define OCFS2_INFO_FL_ERROR		(0x80000000)	/* Error happened during
+							   request handling. */
+
+#define OCFS2_IOC_INFO		_IOR('o', 5, struct ocfs2_info)
+
 #endif /* OCFS2_IOCTL_H */
...	...	@@ -26,6 +26,26 @@
26	26
27	27	#include <linux/ext2_fs.h>
28	28
	29	+#define o2info_from_user(a, b) \
	30	+ copy_from_user(&(a), (b), sizeof(a))
	31	+#define o2info_to_user(a, b) \
	32	+ copy_to_user((typeof(a) __user *)b, &(a), sizeof(a))
	33	+
	34	+/*
	35	+ * This call is void because we are already reporting an error that may
	36	+ * be -EFAULT. The error will be returned from the ioctl(2) call. It's
	37	+ * just a best-effort to tell userspace that this request caused the error.
	38	+ */
	39	+static inline void __o2info_set_request_error(struct ocfs2_info_request *kreq,
	40	+ struct ocfs2_info_request __user *req)
	41	+{
	42	+ kreq->ir_flags \|= OCFS2_INFO_FL_ERROR;
	43	+ (void)put_user(kreq->ir_flags, (__u32 __user *)&(req->ir_flags));
	44	+}
	45	+
	46	+#define o2info_set_request_error(a, b) \
	47	+ __o2info_set_request_error((struct ocfs2_info_request *)&(a), b)
	48	+
29	49	static int ocfs2_get_inode_attr(struct inode inode, unsigned flags)
30	50	{
31	51	int status;
...	...	@@ -109,6 +129,328 @@
109	129	return status;
110	130	}
111	131
	132	+int ocfs2_info_handle_blocksize(struct inode *inode,
	133	+ struct ocfs2_info_request __user *req)
	134	+{
	135	+ int status = -EFAULT;
	136	+ struct ocfs2_info_blocksize oib;
	137	+
	138	+ if (o2info_from_user(oib, req))
	139	+ goto bail;
	140	+
	141	+ oib.ib_blocksize = inode->i_sb->s_blocksize;
	142	+ oib.ib_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	143	+
	144	+ if (o2info_to_user(oib, req))
	145	+ goto bail;
	146	+
	147	+ status = 0;
	148	+bail:
	149	+ if (status)
	150	+ o2info_set_request_error(oib, req);
	151	+
	152	+ return status;
	153	+}
	154	+
	155	+int ocfs2_info_handle_clustersize(struct inode *inode,
	156	+ struct ocfs2_info_request __user *req)
	157	+{
	158	+ int status = -EFAULT;
	159	+ struct ocfs2_info_clustersize oic;
	160	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	161	+
	162	+ if (o2info_from_user(oic, req))
	163	+ goto bail;
	164	+
	165	+ oic.ic_clustersize = osb->s_clustersize;
	166	+ oic.ic_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	167	+
	168	+ if (o2info_to_user(oic, req))
	169	+ goto bail;
	170	+
	171	+ status = 0;
	172	+bail:
	173	+ if (status)
	174	+ o2info_set_request_error(oic, req);
	175	+
	176	+ return status;
	177	+}
	178	+
	179	+int ocfs2_info_handle_maxslots(struct inode *inode,
	180	+ struct ocfs2_info_request __user *req)
	181	+{
	182	+ int status = -EFAULT;
	183	+ struct ocfs2_info_maxslots oim;
	184	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	185	+
	186	+ if (o2info_from_user(oim, req))
	187	+ goto bail;
	188	+
	189	+ oim.im_max_slots = osb->max_slots;
	190	+ oim.im_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	191	+
	192	+ if (o2info_to_user(oim, req))
	193	+ goto bail;
	194	+
	195	+ status = 0;
	196	+bail:
	197	+ if (status)
	198	+ o2info_set_request_error(oim, req);
	199	+
	200	+ return status;
	201	+}
	202	+
	203	+int ocfs2_info_handle_label(struct inode *inode,
	204	+ struct ocfs2_info_request __user *req)
	205	+{
	206	+ int status = -EFAULT;
	207	+ struct ocfs2_info_label oil;
	208	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	209	+
	210	+ if (o2info_from_user(oil, req))
	211	+ goto bail;
	212	+
	213	+ memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
	214	+ oil.il_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	215	+
	216	+ if (o2info_to_user(oil, req))
	217	+ goto bail;
	218	+
	219	+ status = 0;
	220	+bail:
	221	+ if (status)
	222	+ o2info_set_request_error(oil, req);
	223	+
	224	+ return status;
	225	+}
	226	+
	227	+int ocfs2_info_handle_uuid(struct inode *inode,
	228	+ struct ocfs2_info_request __user *req)
	229	+{
	230	+ int status = -EFAULT;
	231	+ struct ocfs2_info_uuid oiu;
	232	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	233	+
	234	+ if (o2info_from_user(oiu, req))
	235	+ goto bail;
	236	+
	237	+ memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_TEXT_UUID_LEN + 1);
	238	+ oiu.iu_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	239	+
	240	+ if (o2info_to_user(oiu, req))
	241	+ goto bail;
	242	+
	243	+ status = 0;
	244	+bail:
	245	+ if (status)
	246	+ o2info_set_request_error(oiu, req);
	247	+
	248	+ return status;
	249	+}
	250	+
	251	+int ocfs2_info_handle_fs_features(struct inode *inode,
	252	+ struct ocfs2_info_request __user *req)
	253	+{
	254	+ int status = -EFAULT;
	255	+ struct ocfs2_info_fs_features oif;
	256	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	257	+
	258	+ if (o2info_from_user(oif, req))
	259	+ goto bail;
	260	+
	261	+ oif.if_compat_features = osb->s_feature_compat;
	262	+ oif.if_incompat_features = osb->s_feature_incompat;
	263	+ oif.if_ro_compat_features = osb->s_feature_ro_compat;
	264	+ oif.if_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	265	+
	266	+ if (o2info_to_user(oif, req))
	267	+ goto bail;
	268	+
	269	+ status = 0;
	270	+bail:
	271	+ if (status)
	272	+ o2info_set_request_error(oif, req);
	273	+
	274	+ return status;
	275	+}
	276	+
	277	+int ocfs2_info_handle_journal_size(struct inode *inode,
	278	+ struct ocfs2_info_request __user *req)
	279	+{
	280	+ int status = -EFAULT;
	281	+ struct ocfs2_info_journal_size oij;
	282	+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	283	+
	284	+ if (o2info_from_user(oij, req))
	285	+ goto bail;
	286	+
	287	+ oij.ij_journal_size = osb->journal->j_inode->i_size;
	288	+
	289	+ oij.ij_req.ir_flags \|= OCFS2_INFO_FL_FILLED;
	290	+
	291	+ if (o2info_to_user(oij, req))
	292	+ goto bail;
	293	+
	294	+ status = 0;
	295	+bail:
	296	+ if (status)
	297	+ o2info_set_request_error(oij, req);
	298	+
	299	+ return status;
	300	+}
	301	+
	302	+int ocfs2_info_handle_unknown(struct inode *inode,
	303	+ struct ocfs2_info_request __user *req)
	304	+{
	305	+ int status = -EFAULT;
	306	+ struct ocfs2_info_request oir;
	307	+
	308	+ if (o2info_from_user(oir, req))
	309	+ goto bail;
	310	+
	311	+ oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
	312	+
	313	+ if (o2info_to_user(oir, req))
	314	+ goto bail;
	315	+
	316	+ status = 0;
	317	+bail:
	318	+ if (status)
	319	+ o2info_set_request_error(oir, req);
	320	+
	321	+ return status;
	322	+}
	323	+
	324	+/*
	325	+ * Validate and distinguish OCFS2_IOC_INFO requests.
	326	+ *
	327	+ * - validate the magic number.
	328	+ * - distinguish different requests.
	329	+ * - validate size of different requests.
	330	+ */
	331	+int ocfs2_info_handle_request(struct inode *inode,
	332	+ struct ocfs2_info_request __user *req)
	333	+{
	334	+ int status = -EFAULT;
	335	+ struct ocfs2_info_request oir;
	336	+
	337	+ if (o2info_from_user(oir, req))
	338	+ goto bail;
	339	+
	340	+ status = -EINVAL;
	341	+ if (oir.ir_magic != OCFS2_INFO_MAGIC)
	342	+ goto bail;
	343	+
	344	+ switch (oir.ir_code) {
	345	+ case OCFS2_INFO_BLOCKSIZE:
	346	+ if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
	347	+ status = ocfs2_info_handle_blocksize(inode, req);
	348	+ break;
	349	+ case OCFS2_INFO_CLUSTERSIZE:
	350	+ if (oir.ir_size == sizeof(struct ocfs2_info_clustersize))
	351	+ status = ocfs2_info_handle_clustersize(inode, req);
	352	+ break;
	353	+ case OCFS2_INFO_MAXSLOTS:
	354	+ if (oir.ir_size == sizeof(struct ocfs2_info_maxslots))
	355	+ status = ocfs2_info_handle_maxslots(inode, req);
	356	+ break;
	357	+ case OCFS2_INFO_LABEL:
	358	+ if (oir.ir_size == sizeof(struct ocfs2_info_label))
	359	+ status = ocfs2_info_handle_label(inode, req);
	360	+ break;
	361	+ case OCFS2_INFO_UUID:
	362	+ if (oir.ir_size == sizeof(struct ocfs2_info_uuid))
	363	+ status = ocfs2_info_handle_uuid(inode, req);
	364	+ break;
	365	+ case OCFS2_INFO_FS_FEATURES:
	366	+ if (oir.ir_size == sizeof(struct ocfs2_info_fs_features))
	367	+ status = ocfs2_info_handle_fs_features(inode, req);
	368	+ break;
	369	+ case OCFS2_INFO_JOURNAL_SIZE:
	370	+ if (oir.ir_size == sizeof(struct ocfs2_info_journal_size))
	371	+ status = ocfs2_info_handle_journal_size(inode, req);
	372	+ break;
	373	+ default:
	374	+ status = ocfs2_info_handle_unknown(inode, req);
	375	+ break;
	376	+ }
	377	+
	378	+bail:
	379	+ return status;
	380	+}
	381	+
	382	+int ocfs2_get_request_ptr(struct ocfs2_info *info, int idx,
	383	+ u64 *req_addr, int compat_flag)
	384	+{
	385	+ int status = -EFAULT;
	386	+ u64 __user *bp = NULL;
	387	+
	388	+ if (compat_flag) {
	389	+#ifdef CONFIG_COMPAT
	390	+ /*
	391	+ * pointer bp stores the base address of a pointers array,
	392	+ * which collects all addresses of separate request.
	393	+ */
	394	+ bp = (u64 __user *)(unsigned long)compat_ptr(info->oi_requests);
	395	+#else
	396	+ BUG();
	397	+#endif
	398	+ } else
	399	+ bp = (u64 __user *)(unsigned long)(info->oi_requests);
	400	+
	401	+ if (o2info_from_user(*req_addr, bp + idx))
	402	+ goto bail;
	403	+
	404	+ status = 0;
	405	+bail:
	406	+ return status;
	407	+}
	408	+
	409	+/*
	410	+ * OCFS2_IOC_INFO handles an array of requests passed from userspace.
	411	+ *
	412	+ * ocfs2_info_handle() recevies a large info aggregation, grab and
	413	+ * validate the request count from header, then break it into small
	414	+ * pieces, later specific handlers can handle them one by one.
	415	+ *
	416	+ * Idea here is to make each separate request small enough to ensure
	417	+ * a better backward&forward compatibility, since a small piece of
	418	+ * request will be less likely to be broken if disk layout get changed.
	419	+ */
	420	+int ocfs2_info_handle(struct inode inode, struct ocfs2_info info,
	421	+ int compat_flag)
	422	+{
	423	+ int i, status = 0;
	424	+ u64 req_addr;
	425	+ struct ocfs2_info_request __user *reqp;
	426	+
	427	+ if ((info->oi_count > OCFS2_INFO_MAX_REQUEST) \|\|
	428	+ (!info->oi_requests)) {
	429	+ status = -EINVAL;
	430	+ goto bail;
	431	+ }
	432	+
	433	+ for (i = 0; i < info->oi_count; i++) {
	434	+
	435	+ status = ocfs2_get_request_ptr(info, i, &req_addr, compat_flag);
	436	+ if (status)
	437	+ break;
	438	+
	439	+ reqp = (struct ocfs2_info_request *)(unsigned long)req_addr;
	440	+ if (!reqp) {
	441	+ status = -EINVAL;
	442	+ goto bail;
	443	+ }
	444	+
	445	+ status = ocfs2_info_handle_request(inode, reqp);
	446	+ if (status)
	447	+ break;
	448	+ }
	449	+
	450	+bail:
	451	+ return status;
	452	+}
	453	+
112	454	long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
113	455	{
114	456	struct inode *inode = filp->f_path.dentry->d_inode;
...	...	@@ -120,6 +462,7 @@
120	462	struct reflink_arguments args;
121	463	const char old_path, new_path;
122	464	bool preserve;
	465	+ struct ocfs2_info info;
123	466
124	467	switch (cmd) {
125	468	case OCFS2_IOC_GETFLAGS:
...	...	@@ -174,6 +517,12 @@
174	517	preserve = (args.preserve != 0);
175	518
176	519	return ocfs2_reflink_ioctl(inode, old_path, new_path, preserve);
	520	+ case OCFS2_IOC_INFO:
	521	+ if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
	522	+ sizeof(struct ocfs2_info)))
	523	+ return -EFAULT;
	524	+
	525	+ return ocfs2_info_handle(inode, &info, 0);
177	526	default:
178	527	return -ENOTTY;
179	528	}
...	...	@@ -185,6 +534,7 @@
185	534	bool preserve;
186	535	struct reflink_arguments args;
187	536	struct inode *inode = file->f_path.dentry->d_inode;
	537	+ struct ocfs2_info info;
188	538
189	539	switch (cmd) {
190	540	case OCFS2_IOC32_GETFLAGS:
...	...	@@ -209,6 +559,12 @@
209	559
210	560	return ocfs2_reflink_ioctl(inode, compat_ptr(args.old_path),
211	561	compat_ptr(args.new_path), preserve);
	562	+ case OCFS2_IOC_INFO:
	563	+ if (copy_from_user(&info, (struct ocfs2_info __user *)arg,
	564	+ sizeof(struct ocfs2_info)))
	565	+ return -EFAULT;
	566	+
	567	+ return ocfs2_info_handle(inode, &info, 1);
212	568	default:
213	569	return -ENOIOCTLCMD;
214	570	}
...	...	@@ -76,5 +76,100 @@
76	76	};
77	77	#define OCFS2_IOC_REFLINK _IOW('o', 4, struct reflink_arguments)
78	78
	79	+/* Following definitions dedicated for ocfs2_info_request ioctls. */
	80	+#define OCFS2_INFO_MAX_REQUEST (50)
	81	+#define OCFS2_TEXT_UUID_LEN (OCFS2_VOL_UUID_LEN * 2)
	82	+
	83	+/* Magic number of all requests */
	84	+#define OCFS2_INFO_MAGIC (0x4F32494E)
	85	+
	86	+/*
	87	+ * Always try to separate info request into small pieces to
	88	+ * guarantee the backward&forward compatibility.
	89	+ */
	90	+struct ocfs2_info {
	91	+ __u64 oi_requests; /* Array of __u64 pointers to requests */
	92	+ __u32 oi_count; /* Number of requests in info_requests */
	93	+ __u32 oi_pad;
	94	+};
	95	+
	96	+struct ocfs2_info_request {
	97	+/00/ __u32 ir_magic; /* Magic number */
	98	+ __u32 ir_code; /* Info request code */
	99	+ __u32 ir_size; /* Size of request */
	100	+ __u32 ir_flags; /* Request flags */
	101	+/10/ /* Request specific fields */
	102	+};
	103	+
	104	+struct ocfs2_info_clustersize {
	105	+ struct ocfs2_info_request ic_req;
	106	+ __u32 ic_clustersize;
	107	+ __u32 ic_pad;
	108	+};
	109	+
	110	+struct ocfs2_info_blocksize {
	111	+ struct ocfs2_info_request ib_req;
	112	+ __u32 ib_blocksize;
	113	+ __u32 ib_pad;
	114	+};
	115	+
	116	+struct ocfs2_info_maxslots {
	117	+ struct ocfs2_info_request im_req;
	118	+ __u32 im_max_slots;
	119	+ __u32 im_pad;
	120	+};
	121	+
	122	+struct ocfs2_info_label {
	123	+ struct ocfs2_info_request il_req;
	124	+ __u8 il_label[OCFS2_MAX_VOL_LABEL_LEN];
	125	+} __attribute__ ((packed));
	126	+
	127	+struct ocfs2_info_uuid {
	128	+ struct ocfs2_info_request iu_req;
	129	+ __u8 iu_uuid_str[OCFS2_TEXT_UUID_LEN + 1];
	130	+} __attribute__ ((packed));
	131	+
	132	+struct ocfs2_info_fs_features {
	133	+ struct ocfs2_info_request if_req;
	134	+ __u32 if_compat_features;
	135	+ __u32 if_incompat_features;
	136	+ __u32 if_ro_compat_features;
	137	+ __u32 if_pad;
	138	+};
	139	+
	140	+struct ocfs2_info_journal_size {
	141	+ struct ocfs2_info_request ij_req;
	142	+ __u64 ij_journal_size;
	143	+};
	144	+
	145	+/* Codes for ocfs2_info_request */
	146	+enum ocfs2_info_type {
	147	+ OCFS2_INFO_CLUSTERSIZE = 1,
	148	+ OCFS2_INFO_BLOCKSIZE,
	149	+ OCFS2_INFO_MAXSLOTS,
	150	+ OCFS2_INFO_LABEL,
	151	+ OCFS2_INFO_UUID,
	152	+ OCFS2_INFO_FS_FEATURES,
	153	+ OCFS2_INFO_JOURNAL_SIZE,
	154	+ OCFS2_INFO_NUM_TYPES
	155	+};
	156	+
	157	+/* Flags for struct ocfs2_info_request */
	158	+/* Filled by the caller */
	159	+#define OCFS2_INFO_FL_NON_COHERENT (0x00000001) /* Cluster coherency not
	160	+ required. This is a hint.
	161	+ It is up to ocfs2 whether
	162	+ the request can be fulfilled
	163	+ without locking. */
	164	+/* Filled by ocfs2 */
	165	+#define OCFS2_INFO_FL_FILLED (0x40000000) /* Filesystem understood
	166	+ this request and
	167	+ filled in the answer */
	168	+
	169	+#define OCFS2_INFO_FL_ERROR (0x80000000) /* Error happened during
	170	+ request handling. */
	171	+
	172	+#define OCFS2_IOC_INFO _IOR('o', 5, struct ocfs2_info)
	173	+
79	174	#endif /* OCFS2_IOCTL_H */