Tristan Ye
2010-May-21 08:35 UTC
[Ocfs2-devel] [PATCH 1/1] Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2.
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 at oracle.com>
---
fs/ocfs2/ioctl.c | 356 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/ocfs2/ocfs2_ioctl.h | 90 ++++++++++++
2 files changed, 446 insertions(+), 0 deletions(-)
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index 7d9d9c1..7a48681 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -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;
}
diff --git a/fs/ocfs2/ocfs2_ioctl.h b/fs/ocfs2/ocfs2_ioctl.h
index 2d3420a..420ef93 100644
--- a/fs/ocfs2/ocfs2_ioctl.h
+++ b/fs/ocfs2/ocfs2_ioctl.h
@@ -76,4 +76,94 @@ 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 */
+ __u64 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;
+ __u64 ic_clustersize;
+};
+
+struct ocfs2_info_blocksize {
+ struct ocfs2_info_request ib_req;
+ __u64 ib_blocksize;
+};
+
+struct ocfs2_info_maxslots {
+ struct ocfs2_info_request im_req;
+ __u64 im_max_slots;
+};
+
+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;
+ __u64 if_compat_features;
+ __u64 if_incompat_features;
+ __u64 if_ro_compat_features;
+};
+
+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 */
--
1.5.5