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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>
hifive-unleashed-5.1
Tristan Ye 2010-05-22 16:26:33 +08:00 committed by Joel Becker
parent 152831be91
commit ddee5cdb70
2 changed files with 451 additions and 0 deletions
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356
fs/ocfs2/ioctl.c
View File

@ -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 @@ 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 (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 @@ 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 +517,12 @@ 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 +534,7 @@ 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 +559,12 @@ 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;
}

95
fs/ocfs2/ocfs2_ioctl.h
View File

@ -76,4 +76,99 @@ struct reflink_arguments {
};
#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 */