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Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

PATCH New Tristan Ye 2 participants 4 messages Apr 19, 2010 – Apr 20, 2010 OCFS2

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Tristan Ye

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#0 lore raw

PATCH 1/1 Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

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, following 8 ioctls get implemented 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

This ioctl is only specific to OCFS2.

Signed-off-by Tristan Ye <[email protected]>
---
 fs/ocfs2/ioctl.c       |  281 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/ocfs2_ioctl.h |   81 ++++++++++++++
 2 files changed, 362 insertions(+), 0 deletions(-)
fs/ocfs2/ioctl.c +281 -0
index 7d9d9c1..930e3ba 100644
@@ -23,8 +23,13 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
+#include "buffer_head_io.h"
+#include "suballoc.h"
+
 
 #include <linux/ext2_fs.h>
+#include <linux/compat.h>
 
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {

@@ -109,6 +114,268 @@ bail:
 	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 (copy_from_user(&oib, req, sizeof(struct ocfs2_info_blocksize)))
+		goto bail;
+
+	oib.ib_blocksize = inode->i_sb->s_blocksize;
+	oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_blocksize __user *)req, &oib,
+			 sizeof(struct ocfs2_info_blocksize)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oic, req, sizeof(struct ocfs2_info_clustersize)))
+		goto bail;
+
+	oic.ic_clustersize = osb->s_clustersize;
+	oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_clustersize __user *)req, &oic,
+			 sizeof(struct ocfs2_info_clustersize)))
+		goto bail;
+	
+	status = 0;
+bail:
+	return status;
+}
+
+int ocfs2_info_handle_maxslots(struct inode *inode,
+			       struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_maxslots ois;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (copy_from_user(&ois, req, sizeof(struct ocfs2_info_maxslots)))
+		goto bail;
+
+	ois.is_max_slots = osb->max_slots;
+	ois.is_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_maxslots __user *)req, &ois,
+			 sizeof(struct ocfs2_info_maxslots)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oil, req, sizeof(struct ocfs2_info_label)))
+		goto bail;
+
+	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
+	oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_label __user *)req, &oil,
+			 sizeof(struct ocfs2_info_label)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oiu, req, sizeof(struct ocfs2_info_uuid)))
+		goto bail;
+
+	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_INFO_VOL_UUIDSTR_LEN);
+	oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_uuid __user *)req, &oiu,
+			 sizeof(struct ocfs2_info_uuid)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oif, req, sizeof(struct ocfs2_info_fs_features)))
+		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 (copy_to_user((struct ocfs2_info_fs_features __user *)req, &oif,
+			 sizeof(struct ocfs2_info_fs_features)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request)))
+		goto bail;
+
+	oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user(req, &oir, sizeof(struct ocfs2_info_request)))
+		goto bail;
+
+	status = 0;
+bail:
+	return status;
+}
+
+int ocfs2_info_handle_request(struct inode *inode,
+			      struct ocfs2_info_request __user *req)
+{
+	int status = 0;
+	struct ocfs2_info_request oir;
+
+	if (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request))) {
+		status = -EFAULT;
+		goto bail;
+	}
+
+	if (oir.ir_magic != OCFS2_INFO_MAGIC) {
+		status = -EINVAL;
+		goto bail;
+	}
+
+	switch (oir.ir_code) {
+	case OCFS2_INFO_BLOCKSIZE:
+		if (oir.ir_size != sizeof(struct ocfs2_info_blocksize)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_blocksize(inode, req);
+		break;
+	case OCFS2_INFO_CLUSTERSIZE:
+		if (oir.ir_size != sizeof(struct ocfs2_info_clustersize)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_clustersize(inode, req);
+		break;
+	case OCFS2_INFO_MAXSLOTS:
+		if (oir.ir_size != sizeof(struct ocfs2_info_maxslots)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_maxslots(inode, req);
+		break;
+	case OCFS2_INFO_LABEL:
+		if (oir.ir_size != sizeof(struct ocfs2_info_label)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_label(inode, req);
+		break;
+	case OCFS2_INFO_UUID:
+		if (oir.ir_size != sizeof(struct ocfs2_info_uuid)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_uuid(inode, req);
+		break;
+	case OCFS2_INFO_FS_FEATURES:
+		if (oir.ir_size != sizeof(struct ocfs2_info_fs_features)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_fs_features(inode, req);
+		break;
+	default:
+		status = ocfs2_info_handle_unknown(inode, req);
+		break;
+	}
+
+bail:
+	mlog_exit(status);
+	return status;
+}
+
+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 = -EFAULT;
+		if (compat_flag) {
+			if (get_user(req_addr,
+			     (u64 __user *)compat_ptr(info->oi_requests) + i))
+				goto bail;
+		} else {
+			if (get_user(req_addr,
+				     (u64 __user *)(info->oi_requests) + i))
+				goto bail;
+		}
+
+		reqp = (struct ocfs2_info_request *)req_addr;
+		if (!reqp) {
+			status = -EINVAL;
+			goto bail;
+		}
+
+		status = ocfs2_info_handle_request(inode, reqp);
+		if (status)
+			goto bail;
+	}
+
+bail:
+	mlog_exit(status);
+	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 +387,7 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	struct reflink_arguments args;
 	const char *old_path, *new_path;
 	bool preserve;
+	struct ocfs2_info info;
 
 	switch (cmd) {
 	case OCFS2_IOC_GETFLAGS:

@@ -174,6 +442,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		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 +459,7 @@ long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	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 +484,12 @@ long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 
 		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;
 	}
fs/ocfs2/ocfs2_ioctl.h +81 -0

85 lines not on this page · raw message

Signature · 1 line
1.5.5
#1 lore raw

PATCH 1/1 Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

Much better. Comments inlined.

Quoted 23 lines · Tristan Ye

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,

Quoted 9 lines
                    (unsigned long)&oic};

struct ocfs2_info info = {
.oi_requests = reqs,
.oi_count = 2,
}

ret = ioctl(fd, OCFS2_IOC_INFO, &info);

Can you add this description atop ocfs2_info_handle() too.

Quoted 59 lines

* 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, following 8 ioctls get implemented 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

This ioctl is only specific to OCFS2.

Signed-off-by Tristan Ye <[email protected]>
---
 fs/ocfs2/ioctl.c       |  281 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/ocfs2/ocfs2_ioctl.h |   81 ++++++++++++++
 2 files changed, 362 insertions(+), 0 deletions(-)
fs/ocfs2/ioctl.c +16 -0
index 7d9d9c1..930e3ba 100644
@@ -23,8 +23,13 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
+#include "buffer_head_io.h"
+#include "suballoc.h"
+
 
 #include <linux/ext2_fs.h>
+#include <linux/compat.h>
 
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {

@@ -109,6 +114,268 @@ bail:
 	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 (copy_from_user(&oib, req, sizeof(struct ocfs2_info_blocksize)))
+		goto bail;
+
+	oib.ib_blocksize = inode->i_sb->s_blocksize;
+	oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;

fs/ocfs2/ioctl.c bail: · line 137

Quoted 10 lines
fs/ocfs2/ioctl.c +9 -0
+
+	if (copy_to_user((struct ocfs2_info_blocksize __user *)req, &oib,
+			 sizeof(struct ocfs2_info_blocksize)))
+		goto bail;
+
+	status = 0;
+bail:
+	return status;
+}

Why not use the error code returned by copy_from/to?

+ int status;
+ struct ocfs2_info_blocksize oib;
+
+ status = o2info_copy_from_user(oib, req);
+ if (!status) {
+ oib.ib_blocksize = inode->i_sb->s_blocksize;
+ oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+ status = o2info_copy_to_user(oib, req);
+ }
+
+ return status;

Quoted 139 lines
fs/ocfs2/ioctl.c +139 -0
+
+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 (copy_from_user(&oic, req, sizeof(struct ocfs2_info_clustersize)))
+		goto bail;
+
+	oic.ic_clustersize = osb->s_clustersize;
+	oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_clustersize __user *)req, &oic,
+			 sizeof(struct ocfs2_info_clustersize)))
+		goto bail;
+	
+	status = 0;
+bail:
+	return status;
+}
+
+int ocfs2_info_handle_maxslots(struct inode *inode,
+			       struct ocfs2_info_request __user *req)
+{
+	int status = -EFAULT;
+	struct ocfs2_info_maxslots ois;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+	if (copy_from_user(&ois, req, sizeof(struct ocfs2_info_maxslots)))
+		goto bail;
+
+	ois.is_max_slots = osb->max_slots;
+	ois.is_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_maxslots __user *)req, &ois,
+			 sizeof(struct ocfs2_info_maxslots)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oil, req, sizeof(struct ocfs2_info_label)))
+		goto bail;
+
+	memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
+	oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_label __user *)req, &oil,
+			 sizeof(struct ocfs2_info_label)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oiu, req, sizeof(struct ocfs2_info_uuid)))
+		goto bail;
+
+	memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_INFO_VOL_UUIDSTR_LEN);
+	oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user((struct ocfs2_info_uuid __user *)req, &oiu,
+			 sizeof(struct ocfs2_info_uuid)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oif, req, sizeof(struct ocfs2_info_fs_features)))
+		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 (copy_to_user((struct ocfs2_info_fs_features __user *)req, &oif,
+			 sizeof(struct ocfs2_info_fs_features)))
+		goto bail;
+
+	status = 0;
+bail:
+	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 (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request)))
+		goto bail;
+
+	oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+
+	if (copy_to_user(req, &oir, sizeof(struct ocfs2_info_request)))
+		goto bail;
+
+	status = 0;
+bail:
+	return status;
+}
+
+int ocfs2_info_handle_request(struct inode *inode,
+			      struct ocfs2_info_request __user *req)
+{
+	int status = 0;
+	struct ocfs2_info_request oir;
+
+	if (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request))) {

fs/ocfs2/ioctl.c bail:

Quoted 10 lines
fs/ocfs2/ioctl.c +9 -0
+		status = -EFAULT;
+		goto bail;
+	}
+
+	if (oir.ir_magic != OCFS2_INFO_MAGIC) {
+		status = -EINVAL;
+		goto bail;
+	}
+

status = -EINVAL;

fs/ocfs2/ioctl.c bail:

Quoted 9 lines
fs/ocfs2/ioctl.c +8 -0
+	switch (oir.ir_code) {
+	case OCFS2_INFO_BLOCKSIZE:
+		if (oir.ir_size != sizeof(struct ocfs2_info_blocksize)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_blocksize(inode, req);
+		break;

+ case OCFS2_INFO_BLOCKSIZE:
+ if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
+ status = ocfs2_info_handle_blocksize(inode, req);
+ break;

Do same below.

Quoted 33 lines
fs/ocfs2/ioctl.c +32 -0
+	case OCFS2_INFO_CLUSTERSIZE:
+		if (oir.ir_size != sizeof(struct ocfs2_info_clustersize)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_clustersize(inode, req);
+		break;
+	case OCFS2_INFO_MAXSLOTS:
+		if (oir.ir_size != sizeof(struct ocfs2_info_maxslots)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_maxslots(inode, req);
+		break;
+	case OCFS2_INFO_LABEL:
+		if (oir.ir_size != sizeof(struct ocfs2_info_label)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_label(inode, req);
+		break;
+	case OCFS2_INFO_UUID:
+		if (oir.ir_size != sizeof(struct ocfs2_info_uuid)) {
+			status = -EINVAL;
+			goto bail;
+		}
+		status = ocfs2_info_handle_uuid(inode, req);
+		break;
+	case OCFS2_INFO_FS_FEATURES:
+		if (oir.ir_size != sizeof(struct ocfs2_info_fs_features)) {
+			status = -EINVAL;
+			goto bail;

fs/ocfs2/ioctl.c bail: · line 334

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+		}
+		status = ocfs2_info_handle_fs_features(inode, req);
+		break;
+	default:
+		status = ocfs2_info_handle_unknown(inode, req);
+		break;
+	}
+
+bail:
+	mlog_exit(status);

No need for mlog.

Quoted 32 lines
fs/ocfs2/ioctl.c +31 -0
+	return status;
+}
+
+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 = -EFAULT;
+		if (compat_flag) {
+			if (get_user(req_addr,
+			     (u64 __user *)compat_ptr(info->oi_requests) + i))
+				goto bail;
+		} else {
+			if (get_user(req_addr,
+				     (u64 __user *)(info->oi_requests) + i))
+				goto bail;
+		}
+
+		reqp = (struct ocfs2_info_request *)req_addr;
+		if (!reqp) {
+			status = -EINVAL;

fs/ocfs2/ioctl.c bail: · line 375

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+			goto bail;
+		}
+
+		status = ocfs2_info_handle_request(inode, reqp);
+		if (status)
+			goto bail;
+	}
+
+bail:
+	mlog_exit(status);

Remove mlog.

Quoted 139 lines
fs/ocfs2/ioctl.c +3 -0
+	return status;
+}
+

long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) {

fs/ocfs2/ioctl.c +14 -0
 	struct inode *inode = filp->f_path.dentry->d_inode;

@@ -120,6 +387,7 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	struct reflink_arguments args;
 	const char *old_path, *new_path;
 	bool preserve;
+	struct ocfs2_info info;
 
 	switch (cmd) {
 	case OCFS2_IOC_GETFLAGS:

@@ -174,6 +442,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		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 +459,7 @@ long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 	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 +484,12 @@ long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 
 		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;
 	}
fs/ocfs2/ocfs2_ioctl.h +81 -0
index 2d3420a..50f237a 100644
@@ -76,4 +76,85 @@ struct reflink_arguments {
 };
 #define OCFS2_IOC_REFLINK	_IOW('o', 4, struct reflink_arguments)
 
+/* Following definitions dedicated for ocfs2_info_request ioctls. */
+#define OCFS2_INFO_VOL_UUIDSTR_LEN	(OCFS2_VOL_UUID_LEN * 2 + 1)
+#define OCFS2_INFO_MAX_REQUEST		(50)
+
+/* 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 */
+};
+
+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;
+};
+
+struct ocfs2_info_blocksize {
+	struct ocfs2_info_request ib_req;
+	__u32 ib_blocksize;
+};
+
+struct ocfs2_info_maxslots {
+	struct ocfs2_info_request is_req;
+	__u16 is_max_slots;
+};
+
+struct ocfs2_info_label {
+	struct ocfs2_info_request il_req;
+	__u8	il_label[OCFS2_MAX_VOL_LABEL_LEN];
+};
+
+struct ocfs2_info_uuid {
+	struct ocfs2_info_request iu_req;
+	__u8	iu_uuid_str[OCFS2_INFO_VOL_UUIDSTR_LEN];
+};
+
+struct ocfs2_info_fs_features {
+	struct ocfs2_info_request if_req;
+	__u32 if_compat_features;
+	__u32 if_incompat_features;
+	__u32 if_ro_compat_features;
+};
+
+/* 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_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		(0x80000000)	/* Filesystem understood
+							   this request and
+							   filled in the answer */
+
+#define OCFS2_IOC_INFO		_IOR('o', 5, struct ocfs2_info)
+
 #endif /* OCFS2_IOCTL_H */
author
#2 lore raw

PATCH 1/1 Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

Quoted 113 lines · Sunil Mushran

Much better. Comments inlined.

Quoted 25 lines · Tristan Ye

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};

Quoted 6 lines

struct ocfs2_info info = {
.oi_requests = reqs,
.oi_count = 2,
}

ret = ioctl(fd, OCFS2_IOC_INFO, &info);

Can you add this description atop ocfs2_info_handle() too.

Quoted 59 lines

* 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, following 8 ioctls get implemented 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

This ioctl is only specific to OCFS2.

Signed-off-by Tristan Ye <[email protected]>

---
fs/ocfs2/ioctl.c | 281 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ocfs2/ocfs2_ioctl.h | 81 ++++++++++++++

2 files changed, 362 insertions(+), 0 deletions(-)
fs/ocfs2/ioctl.c +15 -0
index 7d9d9c1..930e3ba 100644
@@ -23,8 +23,13 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
+#include "buffer_head_io.h"
+#include "suballoc.h"
+
 
 #include <linux/ext2_fs.h>
+#include <linux/compat.h>
 
 static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
 {

@@ -109,6 +114,268 @@ bail:
 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 (copy_from_user(&oib, req, sizeof(struct ocfs2_info_blocksize)))
+ goto bail;
+
+ oib.ib_blocksize = inode->i_sb->s_blocksize;

fs/ocfs2/ioctl.c bail: · line 136

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_blocksize __user *)req, &oib,
+ sizeof(struct ocfs2_info_blocksize)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}

Why not use the error code returned by copy_from/to?

+ int status;
+ struct ocfs2_info_blocksize oib;

fs/ocfs2/ioctl.c bail: · line 157

Quoted 9 lines
fs/ocfs2/ioctl.c +9 -0
+
+ status = o2info_copy_from_user(oib, req);
+ if (!status) {
+ oib.ib_blocksize = inode->i_sb->s_blocksize;
+ oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+ status = o2info_copy_to_user(oib, req);
+ }
+
+ return status;

I agree on the idea about using macros to automatically handle the info type, however, I'd prefer to return -EFAULT instead of returning copy_from/to_user()'s ret code directly, since the ret code of these functions represent nothing but a number of failing bytes which has not been successfully transfered. Here we'd better return a real err code, and a -EFAULT makes more sense I guess.

Quoted 402 lines
Quoted 139 lines
fs/ocfs2/ioctl.c +138 -0
+
+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 (copy_from_user(&oic, req, sizeof(struct ocfs2_info_clustersize)))
+ goto bail;
+
+ oic.ic_clustersize = osb->s_clustersize;
+ oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_clustersize __user *)req, &oic,
+ sizeof(struct ocfs2_info_clustersize)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}
+
+int ocfs2_info_handle_maxslots(struct inode *inode,
+ struct ocfs2_info_request __user *req)
+{
+ int status = -EFAULT;
+ struct ocfs2_info_maxslots ois;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ if (copy_from_user(&ois, req, sizeof(struct ocfs2_info_maxslots)))
+ goto bail;
+
+ ois.is_max_slots = osb->max_slots;
+ ois.is_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_maxslots __user *)req, &ois,
+ sizeof(struct ocfs2_info_maxslots)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oil, req, sizeof(struct ocfs2_info_label)))
+ goto bail;
+
+ memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
+ oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_label __user *)req, &oil,
+ sizeof(struct ocfs2_info_label)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oiu, req, sizeof(struct ocfs2_info_uuid)))
+ goto bail;
+
+ memcpy(oiu.iu_uuid_str, osb->uuid_str, OCFS2_INFO_VOL_UUIDSTR_LEN);
+ oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_uuid __user *)req, &oiu,
+ sizeof(struct ocfs2_info_uuid)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oif, req, sizeof(struct ocfs2_info_fs_features)))
+ 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 (copy_to_user((struct ocfs2_info_fs_features __user *)req, &oif,
+ sizeof(struct ocfs2_info_fs_features)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request)))
+ goto bail;
+
+ oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user(req, &oir, sizeof(struct ocfs2_info_request)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}
+
+int ocfs2_info_handle_request(struct inode *inode,
+ struct ocfs2_info_request __user *req)
+{
+ int status = 0;
+ struct ocfs2_info_request oir;
+

fs/ocfs2/ioctl.c bail: · line 284

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ if (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request))) {
+ status = -EFAULT;
+ goto bail;
+ }
+
+ if (oir.ir_magic != OCFS2_INFO_MAGIC) {
+ status = -EINVAL;
+ goto bail;
+ }
+

status = -EINVAL;

fs/ocfs2/ioctl.c bail: · line 292

Quoted 8 lines
fs/ocfs2/ioctl.c +8 -0
+ switch (oir.ir_code) {
+ case OCFS2_INFO_BLOCKSIZE:
+ if (oir.ir_size != sizeof(struct ocfs2_info_blocksize)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_blocksize(inode, req);
+ break;

+ case OCFS2_INFO_BLOCKSIZE:
+ if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
+ status = ocfs2_info_handle_blocksize(inode, req);
+ break;

Do same below.

Quoted 32 lines
fs/ocfs2/ioctl.c +32 -0
+ case OCFS2_INFO_CLUSTERSIZE:
+ if (oir.ir_size != sizeof(struct ocfs2_info_clustersize)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_clustersize(inode, req);
+ break;
+ case OCFS2_INFO_MAXSLOTS:
+ if (oir.ir_size != sizeof(struct ocfs2_info_maxslots)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_maxslots(inode, req);
+ break;
+ case OCFS2_INFO_LABEL:
+ if (oir.ir_size != sizeof(struct ocfs2_info_label)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_label(inode, req);
+ break;
+ case OCFS2_INFO_UUID:
+ if (oir.ir_size != sizeof(struct ocfs2_info_uuid)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_uuid(inode, req);
+ break;
+ case OCFS2_INFO_FS_FEATURES:
+ if (oir.ir_size != sizeof(struct ocfs2_info_fs_features)) {
+ status = -EINVAL;
+ goto bail;

fs/ocfs2/ioctl.c bail: · line 334

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ }
+ status = ocfs2_info_handle_fs_features(inode, req);
+ break;
+ default:
+ status = ocfs2_info_handle_unknown(inode, req);
+ break;
+ }
+
+bail:
+ mlog_exit(status);

No need for mlog.

Quoted 31 lines
fs/ocfs2/ioctl.c +31 -0
+ return status;
+}
+
+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 = -EFAULT;
+ if (compat_flag) {
+ if (get_user(req_addr,
+ (u64 __user *)compat_ptr(info->oi_requests) + i))
+ goto bail;
+ } else {
+ if (get_user(req_addr,
+ (u64 __user *)(info->oi_requests) + i))
+ goto bail;
+ }
+
+ reqp = (struct ocfs2_info_request *)req_addr;
+ if (!reqp) {
+ status = -EINVAL;

fs/ocfs2/ioctl.c bail: · line 375

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ goto bail;
+ }
+
+ status = ocfs2_info_handle_request(inode, reqp);
+ if (status)
+ goto bail;
+ }
+
+bail:
+ mlog_exit(status);

Remove mlog.

Quoted 143 lines
fs/ocfs2/ioctl.c +4 -0
+ 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 +387,7 @@ long ocfs2_ioctl(struct file *filp, unsigned int 
 cmd, unsigned long arg)
 struct reflink_arguments args;
 const char *old_path, *new_path;
 bool preserve;
+ struct ocfs2_info info;
 
 switch (cmd) {

case OCFS2_IOC_GETFLAGS:

fs/ocfs2/ioctl.c +6 -0
@@ -174,6 +442,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int 
 cmd, unsigned long arg)
 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;
}

fs/ocfs2/ioctl.c +1 -0
@@ -185,6 +459,7 @@ long ocfs2_compat_ioctl(struct file *file, 
 unsigned cmd, unsigned long arg)
 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:

fs/ocfs2/ioctl.c +6 -0
@@ -209,6 +484,12 @@ long ocfs2_compat_ioctl(struct file *file, 
 unsigned cmd, unsigned long arg)
 
 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;
}

fs/ocfs2/ocfs2_ioctl.h +70 -0
index 2d3420a..50f237a 100644
@@ -76,4 +76,85 @@ struct reflink_arguments {
 };
 #define OCFS2_IOC_REFLINK _IOW('o', 4, struct reflink_arguments)
 
+/* Following definitions dedicated for ocfs2_info_request ioctls. */
+#define OCFS2_INFO_VOL_UUIDSTR_LEN (OCFS2_VOL_UUID_LEN * 2 + 1)
+#define OCFS2_INFO_MAX_REQUEST (50)
+
+/* 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 */
+};
+
+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;
+};
+
+struct ocfs2_info_blocksize {
+ struct ocfs2_info_request ib_req;
+ __u32 ib_blocksize;
+};
+
+struct ocfs2_info_maxslots {
+ struct ocfs2_info_request is_req;
+ __u16 is_max_slots;
+};
+
+struct ocfs2_info_label {
+ struct ocfs2_info_request il_req;
+ __u8 il_label[OCFS2_MAX_VOL_LABEL_LEN];
+};
+
+struct ocfs2_info_uuid {
+ struct ocfs2_info_request iu_req;
+ __u8 iu_uuid_str[OCFS2_INFO_VOL_UUIDSTR_LEN];
+};
+
+struct ocfs2_info_fs_features {
+ struct ocfs2_info_request if_req;
+ __u32 if_compat_features;
+ __u32 if_incompat_features;
+ __u32 if_ro_compat_features;
+};
+
+/* 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_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. */

fs/ocfs2/ocfs2_ioctl.h +7 -0
+/* Filled by ocfs2 */
+#define OCFS2_INFO_FL_FILLED (0x80000000) /* Filesystem understood
+ this request and
+ filled in the answer */
+
+#define OCFS2_IOC_INFO _IOR('o', 5, struct ocfs2_info)
+

#endif /* OCFS2_IOCTL_H */

#3 lore raw

PATCH 1/1 Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v7.

Ok

Quoted 552 lines · tristan
Quoted 121 lines · Sunil Mushran

Much better. Comments inlined.

Quoted 27 lines · Tristan Ye

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};

Quoted 6 lines

struct ocfs2_info info = {
.oi_requests = reqs,
.oi_count = 2,
}

ret = ioctl(fd, OCFS2_IOC_INFO, &info);

Can you add this description atop ocfs2_info_handle() too.

Quoted 65 lines

* 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, following 8 ioctls get implemented 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

This ioctl is only specific to OCFS2.

Signed-off-by Tristan Ye <[email protected]>

---
fs/ocfs2/ioctl.c | 281 ++++++++++++++++++++++++++++++++++++++++++++
++++
fs/ocfs2/ocfs2_ioctl.h | 81 ++++++++++++++

2 files changed, 362 insertions(+), 0 deletions(-)
fs/ocfs2/ioctl.c +5 -0
index 7d9d9c1..930e3ba 100644
@@ -23,8 +23,13 @@
 #include "ioctl.h"
 #include "resize.h"
 #include "refcounttree.h"
+#include "sysfile.h"
+#include "buffer_head_io.h"
+#include "suballoc.h"
+
 
 #include <linux/ext2_fs.h>
+#include <linux/compat.h>

static int ocfs2_get_inode_attr(struct inode *inode, unsigned *flags)
{

fs/ocfs2/ioctl.c +10 -0
@@ -109,6 +114,268 @@ bail:
 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 (copy_from_user(&oib, req, sizeof(struct  
 ocfs2_info_blocksize)))
+ goto bail;
+
+ oib.ib_blocksize = inode->i_sb->s_blocksize;

fs/ocfs2/ioctl.c bail: · line 137

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_blocksize __user *)req, &oib,
+ sizeof(struct ocfs2_info_blocksize)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}

Why not use the error code returned by copy_from/to?

+ int status;
+ struct ocfs2_info_blocksize oib;

fs/ocfs2/ioctl.c bail: · line 157

Quoted 9 lines
fs/ocfs2/ioctl.c +9 -0
+
+ status = o2info_copy_from_user(oib, req);
+ if (!status) {
+ oib.ib_blocksize = inode->i_sb->s_blocksize;
+ oib.ib_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+ status = o2info_copy_to_user(oib, req);
+ }
+
+ return status;

I agree on the idea about using macros to automatically handle the info type, however, I'd prefer to return -EFAULT instead of returning copy_from/to_user()'s ret code directly, since the ret code of these functions represent nothing but a number of failing bytes which has not been successfully transfered. Here we'd better return a real err code, and a -EFAULT makes more sense I guess.

Quoted 410 lines
Quoted 149 lines
fs/ocfs2/ioctl.c +78 -0
+
+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 (copy_from_user(&oic, req, sizeof(struct  
 ocfs2_info_clustersize)))
+ goto bail;
+
+ oic.ic_clustersize = osb->s_clustersize;
+ oic.ic_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_clustersize __user *)req,  
 &oic,
+ sizeof(struct ocfs2_info_clustersize)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}
+
+int ocfs2_info_handle_maxslots(struct inode *inode,
+ struct ocfs2_info_request __user *req)
+{
+ int status = -EFAULT;
+ struct ocfs2_info_maxslots ois;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ if (copy_from_user(&ois, req, sizeof(struct ocfs2_info_maxslots)))
+ goto bail;
+
+ ois.is_max_slots = osb->max_slots;
+ ois.is_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_maxslots __user *)req, &ois,
+ sizeof(struct ocfs2_info_maxslots)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oil, req, sizeof(struct ocfs2_info_label)))
+ goto bail;
+
+ memcpy(oil.il_label, osb->vol_label, OCFS2_MAX_VOL_LABEL_LEN);
+ oil.il_req.ir_flags |= OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user((struct ocfs2_info_label __user *)req, &oil,
+ sizeof(struct ocfs2_info_label)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oiu, req, sizeof(struct ocfs2_info_uuid)))
+ goto bail;
+
+ memcpy(oiu.iu_uuid_str, osb->uuid_str,

OCFS2_INFO_VOL_UUIDSTR_LEN);
+ oiu.iu_req.ir_flags |= OCFS2_INFO_FL_FILLED;

fs/ocfs2/ioctl.c +18 -0
+
+ if (copy_to_user((struct ocfs2_info_uuid __user *)req, &oiu,
+ sizeof(struct ocfs2_info_uuid)))
+ goto bail;
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oif, req, sizeof(struct

ocfs2_info_fs_features)))
+ goto bail;

fs/ocfs2/ioctl.c +7 -0
+
+ 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 (copy_to_user((struct ocfs2_info_fs_features __user *)req,

&oif,
+ sizeof(struct ocfs2_info_fs_features)))
+ goto bail;

fs/ocfs2/ioctl.c +32 -0
+
+ status = 0;
+bail:
+ 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 (copy_from_user(&oir, req, sizeof(struct ocfs2_info_request)))
+ goto bail;
+
+ oir.ir_flags &= ~OCFS2_INFO_FL_FILLED;
+
+ if (copy_to_user(req, &oir, sizeof(struct ocfs2_info_request)))
+ goto bail;
+
+ status = 0;
+bail:
+ return status;
+}
+
+int ocfs2_info_handle_request(struct inode *inode,
+ struct ocfs2_info_request __user *req)
+{
+ int status = 0;
+ struct ocfs2_info_request oir;
+
+ if (copy_from_user(&oir, req, sizeof(struct

ocfs2_info_request))) {
+ status = -EFAULT;
+ goto bail;
+ }

fs/ocfs2/ioctl.c bail: · line 284

Quoted 6 lines
fs/ocfs2/ioctl.c +6 -0
+
+ if (oir.ir_magic != OCFS2_INFO_MAGIC) {
+ status = -EINVAL;
+ goto bail;
+ }
+

status = -EINVAL;

Quoted 8 lines

+ switch (oir.ir_code) {
+ case OCFS2_INFO_BLOCKSIZE:
+ if (oir.ir_size != sizeof(struct ocfs2_info_blocksize)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_blocksize(inode, req);
+ break;

+ case OCFS2_INFO_BLOCKSIZE:
+ if (oir.ir_size == sizeof(struct ocfs2_info_blocksize))
+ status = ocfs2_info_handle_blocksize(inode, req);
+ break;

Do same below.

Quoted 39 lines

+ case OCFS2_INFO_CLUSTERSIZE:
+ if (oir.ir_size != sizeof(struct ocfs2_info_clustersize)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_clustersize(inode, req);
+ break;
+ case OCFS2_INFO_MAXSLOTS:
+ if (oir.ir_size != sizeof(struct ocfs2_info_maxslots)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_maxslots(inode, req);
+ break;
+ case OCFS2_INFO_LABEL:
+ if (oir.ir_size != sizeof(struct ocfs2_info_label)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_label(inode, req);
+ break;
+ case OCFS2_INFO_UUID:
+ if (oir.ir_size != sizeof(struct ocfs2_info_uuid)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_uuid(inode, req);
+ break;
+ case OCFS2_INFO_FS_FEATURES:
+ if (oir.ir_size != sizeof(struct ocfs2_info_fs_features)) {
+ status = -EINVAL;
+ goto bail;
+ }
+ status = ocfs2_info_handle_fs_features(inode, req);
+ break;
+ default:
+ status = ocfs2_info_handle_unknown(inode, req);
+ break;
+ }

fs/ocfs2/ioctl.c bail: · line 334

Quoted 3 lines
fs/ocfs2/ioctl.c +3 -0
+
+bail:
+ mlog_exit(status);

No need for mlog.

Quoted 31 lines

+ return status;

fs/ocfs2/ioctl.c +30 -0
+}
+
+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 = -EFAULT;
+ if (compat_flag) {
+ if (get_user(req_addr,
+ (u64 __user *)compat_ptr(info->oi_requests) + i))
+ goto bail;
+ } else {
+ if (get_user(req_addr,
+ (u64 __user *)(info->oi_requests) + i))
+ goto bail;
+ }
+
+ reqp = (struct ocfs2_info_request *)req_addr;
+ if (!reqp) {
+ status = -EINVAL;

fs/ocfs2/ioctl.c bail: · line 375

Quoted 10 lines
fs/ocfs2/ioctl.c +10 -0
+ goto bail;
+ }
+
+ status = ocfs2_info_handle_request(inode, reqp);
+ if (status)
+ goto bail;
+ }
+
+bail:
+ mlog_exit(status);

Remove mlog.

Quoted 145 lines

+ return status;

fs/ocfs2/ioctl.c +2 -0
+}
+

long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = filp->f_path.dentry->d_inode;

fs/ocfs2/ioctl.c +1 -0
@@ -120,6 +387,7 @@ long ocfs2_ioctl(struct file *filp, unsigned  
 int cmd, unsigned long arg)
 struct reflink_arguments args;
 const char *old_path, *new_path;
 bool preserve;
+ struct ocfs2_info info;
 
 switch (cmd) {

case OCFS2_IOC_GETFLAGS:

fs/ocfs2/ioctl.c +6 -0
@@ -174,6 +442,12 @@ long ocfs2_ioctl(struct file *filp, unsigned  
 int cmd, unsigned long arg)
 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;
}

fs/ocfs2/ioctl.c +1 -0
@@ -185,6 +459,7 @@ long ocfs2_compat_ioctl(struct file *file,  
 unsigned cmd, unsigned long arg)
 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:

fs/ocfs2/ioctl.c +6 -0
@@ -209,6 +484,12 @@ long ocfs2_compat_ioctl(struct file *file,  
 unsigned cmd, unsigned long arg)
 
 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;
}

fs/ocfs2/ocfs2_ioctl.h +70 -0
index 2d3420a..50f237a 100644
@@ -76,4 +76,85 @@ struct reflink_arguments {
 };
 #define OCFS2_IOC_REFLINK _IOW('o', 4, struct reflink_arguments)
 
+/* Following definitions dedicated for ocfs2_info_request ioctls.  
 */
+#define OCFS2_INFO_VOL_UUIDSTR_LEN (OCFS2_VOL_UUID_LEN * 2 + 1)
+#define OCFS2_INFO_MAX_REQUEST (50)
+
+/* 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 */
+};
+
+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;
+};
+
+struct ocfs2_info_blocksize {
+ struct ocfs2_info_request ib_req;
+ __u32 ib_blocksize;
+};
+
+struct ocfs2_info_maxslots {
+ struct ocfs2_info_request is_req;
+ __u16 is_max_slots;
+};
+
+struct ocfs2_info_label {
+ struct ocfs2_info_request il_req;
+ __u8 il_label[OCFS2_MAX_VOL_LABEL_LEN];
+};
+
+struct ocfs2_info_uuid {
+ struct ocfs2_info_request iu_req;
+ __u8 iu_uuid_str[OCFS2_INFO_VOL_UUIDSTR_LEN];
+};
+
+struct ocfs2_info_fs_features {
+ struct ocfs2_info_request if_req;
+ __u32 if_compat_features;
+ __u32 if_incompat_features;
+ __u32 if_ro_compat_features;
+};
+
+/* 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_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. */

fs/ocfs2/ocfs2_ioctl.h +7 -0
+/* Filled by ocfs2 */
+#define OCFS2_INFO_FL_FILLED (0x80000000) /* Filesystem understood
+ this request and
+ filled in the answer */
+
+#define OCFS2_IOC_INFO _IOR('o', 5, struct ocfs2_info)
+

#endif /* OCFS2_IOCTL_H */