From ddee5cdb70e6f87de2fc696b87bd7bd184a51eb8 Mon Sep 17 00:00:00 2001 From: Tristan Ye Date: Sat, 22 May 2010 16:26:33 +0800 Subject: 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 Signed-off-by: Joel Becker --- fs/ocfs2/ioctl.c | 356 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 356 insertions(+) (limited to 'fs/ocfs2/ioctl.c') diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c index 7d9d9c132cef..7a4868196152 100644 --- a/fs/ocfs2/ioctl.c +++ b/fs/ocfs2/ioctl.c @@ -26,6 +26,26 @@ #include +#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; } -- cgit