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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /fs/orangefs/devorangefs-req.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/orangefs/devorangefs-req.c')
-rw-r--r-- | fs/orangefs/devorangefs-req.c | 814 |
1 files changed, 814 insertions, 0 deletions
diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c new file mode 100644 index 000000000..33ee8cb32 --- /dev/null +++ b/fs/orangefs/devorangefs-req.c @@ -0,0 +1,814 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * (C) 2001 Clemson University and The University of Chicago + * + * Changes by Acxiom Corporation to add protocol version to kernel + * communication, Copyright Acxiom Corporation, 2005. + * + * See COPYING in top-level directory. + */ + +#include "protocol.h" +#include "orangefs-kernel.h" +#include "orangefs-dev-proto.h" +#include "orangefs-bufmap.h" +#include "orangefs-debugfs.h" + +#include <linux/debugfs.h> +#include <linux/slab.h> + +/* this file implements the /dev/pvfs2-req device node */ + +uint32_t orangefs_userspace_version; + +static int open_access_count; + +static DEFINE_MUTEX(devreq_mutex); + +#define DUMP_DEVICE_ERROR() \ +do { \ + gossip_err("*****************************************************\n");\ + gossip_err("ORANGEFS Device Error: You cannot open the device file "); \ + gossip_err("\n/dev/%s more than once. Please make sure that\nthere " \ + "are no ", ORANGEFS_REQDEVICE_NAME); \ + gossip_err("instances of a program using this device\ncurrently " \ + "running. (You must verify this!)\n"); \ + gossip_err("For example, you can use the lsof program as follows:\n");\ + gossip_err("'lsof | grep %s' (run this as root)\n", \ + ORANGEFS_REQDEVICE_NAME); \ + gossip_err(" open_access_count = %d\n", open_access_count); \ + gossip_err("*****************************************************\n");\ +} while (0) + +static int hash_func(__u64 tag, int table_size) +{ + return do_div(tag, (unsigned int)table_size); +} + +static void orangefs_devreq_add_op(struct orangefs_kernel_op_s *op) +{ + int index = hash_func(op->tag, hash_table_size); + + list_add_tail(&op->list, &orangefs_htable_ops_in_progress[index]); +} + +/* + * find the op with this tag and remove it from the in progress + * hash table. + */ +static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag) +{ + struct orangefs_kernel_op_s *op, *next; + int index; + + index = hash_func(tag, hash_table_size); + + spin_lock(&orangefs_htable_ops_in_progress_lock); + list_for_each_entry_safe(op, + next, + &orangefs_htable_ops_in_progress[index], + list) { + if (op->tag == tag && !op_state_purged(op) && + !op_state_given_up(op)) { + list_del_init(&op->list); + spin_unlock(&orangefs_htable_ops_in_progress_lock); + return op; + } + } + + spin_unlock(&orangefs_htable_ops_in_progress_lock); + return NULL; +} + +/* Returns whether any FS are still pending remounted */ +static int mark_all_pending_mounts(void) +{ + int unmounted = 1; + struct orangefs_sb_info_s *orangefs_sb = NULL; + + spin_lock(&orangefs_superblocks_lock); + list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) { + /* All of these file system require a remount */ + orangefs_sb->mount_pending = 1; + unmounted = 0; + } + spin_unlock(&orangefs_superblocks_lock); + return unmounted; +} + +/* + * Determine if a given file system needs to be remounted or not + * Returns -1 on error + * 0 if already mounted + * 1 if needs remount + */ +static int fs_mount_pending(__s32 fsid) +{ + int mount_pending = -1; + struct orangefs_sb_info_s *orangefs_sb = NULL; + + spin_lock(&orangefs_superblocks_lock); + list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) { + if (orangefs_sb->fs_id == fsid) { + mount_pending = orangefs_sb->mount_pending; + break; + } + } + spin_unlock(&orangefs_superblocks_lock); + return mount_pending; +} + +static int orangefs_devreq_open(struct inode *inode, struct file *file) +{ + int ret = -EINVAL; + + /* in order to ensure that the filesystem driver sees correct UIDs */ + if (file->f_cred->user_ns != &init_user_ns) { + gossip_err("%s: device cannot be opened outside init_user_ns\n", + __func__); + goto out; + } + + if (!(file->f_flags & O_NONBLOCK)) { + gossip_err("%s: device cannot be opened in blocking mode\n", + __func__); + goto out; + } + ret = -EACCES; + gossip_debug(GOSSIP_DEV_DEBUG, "client-core: opening device\n"); + mutex_lock(&devreq_mutex); + + if (open_access_count == 0) { + open_access_count = 1; + ret = 0; + } else { + DUMP_DEVICE_ERROR(); + } + mutex_unlock(&devreq_mutex); + +out: + + gossip_debug(GOSSIP_DEV_DEBUG, + "pvfs2-client-core: open device complete (ret = %d)\n", + ret); + return ret; +} + +/* Function for read() callers into the device */ +static ssize_t orangefs_devreq_read(struct file *file, + char __user *buf, + size_t count, loff_t *offset) +{ + struct orangefs_kernel_op_s *op, *temp; + __s32 proto_ver = ORANGEFS_KERNEL_PROTO_VERSION; + static __s32 magic = ORANGEFS_DEVREQ_MAGIC; + struct orangefs_kernel_op_s *cur_op; + unsigned long ret; + + /* We do not support blocking IO. */ + if (!(file->f_flags & O_NONBLOCK)) { + gossip_err("%s: blocking read from client-core.\n", + __func__); + return -EINVAL; + } + + /* + * The client will do an ioctl to find MAX_DEV_REQ_UPSIZE, then + * always read with that size buffer. + */ + if (count != MAX_DEV_REQ_UPSIZE) { + gossip_err("orangefs: client-core tried to read wrong size\n"); + return -EINVAL; + } + + /* Check for an empty list before locking. */ + if (list_empty(&orangefs_request_list)) + return -EAGAIN; + +restart: + cur_op = NULL; + /* Get next op (if any) from top of list. */ + spin_lock(&orangefs_request_list_lock); + list_for_each_entry_safe(op, temp, &orangefs_request_list, list) { + __s32 fsid; + /* This lock is held past the end of the loop when we break. */ + spin_lock(&op->lock); + if (unlikely(op_state_purged(op) || op_state_given_up(op))) { + spin_unlock(&op->lock); + continue; + } + + fsid = fsid_of_op(op); + if (fsid != ORANGEFS_FS_ID_NULL) { + int ret; + /* Skip ops whose filesystem needs to be mounted. */ + ret = fs_mount_pending(fsid); + if (ret == 1) { + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: mount pending, skipping op tag " + "%llu %s\n", + __func__, + llu(op->tag), + get_opname_string(op)); + spin_unlock(&op->lock); + continue; + /* + * Skip ops whose filesystem we don't know about unless + * it is being mounted or unmounted. It is possible for + * a filesystem we don't know about to be unmounted if + * it fails to mount in the kernel after userspace has + * been sent the mount request. + */ + /* XXX: is there a better way to detect this? */ + } else if (ret == -1 && + !(op->upcall.type == + ORANGEFS_VFS_OP_FS_MOUNT || + op->upcall.type == + ORANGEFS_VFS_OP_GETATTR || + op->upcall.type == + ORANGEFS_VFS_OP_FS_UMOUNT)) { + gossip_debug(GOSSIP_DEV_DEBUG, + "orangefs: skipping op tag %llu %s\n", + llu(op->tag), get_opname_string(op)); + gossip_err( + "orangefs: ERROR: fs_mount_pending %d\n", + fsid); + spin_unlock(&op->lock); + continue; + } + } + /* + * Either this op does not pertain to a filesystem, is mounting + * a filesystem, or pertains to a mounted filesystem. Let it + * through. + */ + cur_op = op; + break; + } + + /* + * At this point we either have a valid op and can continue or have not + * found an op and must ask the client to try again later. + */ + if (!cur_op) { + spin_unlock(&orangefs_request_list_lock); + return -EAGAIN; + } + + gossip_debug(GOSSIP_DEV_DEBUG, "%s: reading op tag %llu %s\n", + __func__, + llu(cur_op->tag), + get_opname_string(cur_op)); + + /* + * Such an op should never be on the list in the first place. If so, we + * will abort. + */ + if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) { + gossip_err("orangefs: ERROR: Current op already queued.\n"); + list_del_init(&cur_op->list); + spin_unlock(&cur_op->lock); + spin_unlock(&orangefs_request_list_lock); + return -EAGAIN; + } + + list_del_init(&cur_op->list); + spin_unlock(&orangefs_request_list_lock); + + spin_unlock(&cur_op->lock); + + /* Push the upcall out. */ + ret = copy_to_user(buf, &proto_ver, sizeof(__s32)); + if (ret != 0) + goto error; + ret = copy_to_user(buf + sizeof(__s32), &magic, sizeof(__s32)); + if (ret != 0) + goto error; + ret = copy_to_user(buf + 2 * sizeof(__s32), + &cur_op->tag, + sizeof(__u64)); + if (ret != 0) + goto error; + ret = copy_to_user(buf + 2 * sizeof(__s32) + sizeof(__u64), + &cur_op->upcall, + sizeof(struct orangefs_upcall_s)); + if (ret != 0) + goto error; + + spin_lock(&orangefs_htable_ops_in_progress_lock); + spin_lock(&cur_op->lock); + if (unlikely(op_state_given_up(cur_op))) { + spin_unlock(&cur_op->lock); + spin_unlock(&orangefs_htable_ops_in_progress_lock); + complete(&cur_op->waitq); + goto restart; + } + + /* + * Set the operation to be in progress and move it between lists since + * it has been sent to the client. + */ + set_op_state_inprogress(cur_op); + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: 1 op:%s: op_state:%d: process:%s:\n", + __func__, + get_opname_string(cur_op), + cur_op->op_state, + current->comm); + orangefs_devreq_add_op(cur_op); + spin_unlock(&cur_op->lock); + spin_unlock(&orangefs_htable_ops_in_progress_lock); + + /* The client only asks to read one size buffer. */ + return MAX_DEV_REQ_UPSIZE; +error: + /* + * We were unable to copy the op data to the client. Put the op back in + * list. If client has crashed, the op will be purged later when the + * device is released. + */ + gossip_err("orangefs: Failed to copy data to user space\n"); + spin_lock(&orangefs_request_list_lock); + spin_lock(&cur_op->lock); + if (likely(!op_state_given_up(cur_op))) { + set_op_state_waiting(cur_op); + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: 2 op:%s: op_state:%d: process:%s:\n", + __func__, + get_opname_string(cur_op), + cur_op->op_state, + current->comm); + list_add(&cur_op->list, &orangefs_request_list); + spin_unlock(&cur_op->lock); + } else { + spin_unlock(&cur_op->lock); + complete(&cur_op->waitq); + } + spin_unlock(&orangefs_request_list_lock); + return -EFAULT; +} + +/* + * Function for writev() callers into the device. + * + * Userspace should have written: + * - __u32 version + * - __u32 magic + * - __u64 tag + * - struct orangefs_downcall_s + * - trailer buffer (in the case of READDIR operations) + */ +static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, + struct iov_iter *iter) +{ + ssize_t ret; + struct orangefs_kernel_op_s *op = NULL; + struct { + __u32 version; + __u32 magic; + __u64 tag; + } head; + int total = ret = iov_iter_count(iter); + int downcall_size = sizeof(struct orangefs_downcall_s); + int head_size = sizeof(head); + + gossip_debug(GOSSIP_DEV_DEBUG, "%s: total:%d: ret:%zd:\n", + __func__, + total, + ret); + + if (total < MAX_DEV_REQ_DOWNSIZE) { + gossip_err("%s: total:%d: must be at least:%u:\n", + __func__, + total, + (unsigned int) MAX_DEV_REQ_DOWNSIZE); + return -EFAULT; + } + + if (!copy_from_iter_full(&head, head_size, iter)) { + gossip_err("%s: failed to copy head.\n", __func__); + return -EFAULT; + } + + if (head.version < ORANGEFS_MINIMUM_USERSPACE_VERSION) { + gossip_err("%s: userspace claims version" + "%d, minimum version required: %d.\n", + __func__, + head.version, + ORANGEFS_MINIMUM_USERSPACE_VERSION); + return -EPROTO; + } + + if (head.magic != ORANGEFS_DEVREQ_MAGIC) { + gossip_err("Error: Device magic number does not match.\n"); + return -EPROTO; + } + + if (!orangefs_userspace_version) { + orangefs_userspace_version = head.version; + } else if (orangefs_userspace_version != head.version) { + gossip_err("Error: userspace version changes\n"); + return -EPROTO; + } + + /* remove the op from the in progress hash table */ + op = orangefs_devreq_remove_op(head.tag); + if (!op) { + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: No one's waiting for tag %llu\n", + __func__, llu(head.tag)); + return ret; + } + + if (!copy_from_iter_full(&op->downcall, downcall_size, iter)) { + gossip_err("%s: failed to copy downcall.\n", __func__); + goto Efault; + } + + if (op->downcall.status) + goto wakeup; + + /* + * We've successfully peeled off the head and the downcall. + * Something has gone awry if total doesn't equal the + * sum of head_size, downcall_size and trailer_size. + */ + if ((head_size + downcall_size + op->downcall.trailer_size) != total) { + gossip_err("%s: funky write, head_size:%d" + ": downcall_size:%d: trailer_size:%lld" + ": total size:%d:\n", + __func__, + head_size, + downcall_size, + op->downcall.trailer_size, + total); + goto Efault; + } + + /* Only READDIR operations should have trailers. */ + if ((op->downcall.type != ORANGEFS_VFS_OP_READDIR) && + (op->downcall.trailer_size != 0)) { + gossip_err("%s: %x operation with trailer.", + __func__, + op->downcall.type); + goto Efault; + } + + /* READDIR operations should always have trailers. */ + if ((op->downcall.type == ORANGEFS_VFS_OP_READDIR) && + (op->downcall.trailer_size == 0)) { + gossip_err("%s: %x operation with no trailer.", + __func__, + op->downcall.type); + goto Efault; + } + + if (op->downcall.type != ORANGEFS_VFS_OP_READDIR) + goto wakeup; + + op->downcall.trailer_buf = vzalloc(op->downcall.trailer_size); + if (!op->downcall.trailer_buf) + goto Enomem; + + if (!copy_from_iter_full(op->downcall.trailer_buf, + op->downcall.trailer_size, iter)) { + gossip_err("%s: failed to copy trailer.\n", __func__); + vfree(op->downcall.trailer_buf); + goto Efault; + } + +wakeup: + /* + * Return to vfs waitqueue, and back to service_operation + * through wait_for_matching_downcall. + */ + spin_lock(&op->lock); + if (unlikely(op_is_cancel(op))) { + spin_unlock(&op->lock); + put_cancel(op); + } else if (unlikely(op_state_given_up(op))) { + spin_unlock(&op->lock); + complete(&op->waitq); + } else { + set_op_state_serviced(op); + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: op:%s: op_state:%d: process:%s:\n", + __func__, + get_opname_string(op), + op->op_state, + current->comm); + spin_unlock(&op->lock); + } + return ret; + +Efault: + op->downcall.status = -(ORANGEFS_ERROR_BIT | 9); + ret = -EFAULT; + goto wakeup; + +Enomem: + op->downcall.status = -(ORANGEFS_ERROR_BIT | 8); + ret = -ENOMEM; + goto wakeup; +} + +/* + * NOTE: gets called when the last reference to this device is dropped. + * Using the open_access_count variable, we enforce a reference count + * on this file so that it can be opened by only one process at a time. + * the devreq_mutex is used to make sure all i/o has completed + * before we call orangefs_bufmap_finalize, and similar such tricky + * situations + */ +static int orangefs_devreq_release(struct inode *inode, struct file *file) +{ + int unmounted = 0; + + gossip_debug(GOSSIP_DEV_DEBUG, + "%s:pvfs2-client-core: exiting, closing device\n", + __func__); + + mutex_lock(&devreq_mutex); + orangefs_bufmap_finalize(); + + open_access_count = -1; + + unmounted = mark_all_pending_mounts(); + gossip_debug(GOSSIP_DEV_DEBUG, "ORANGEFS Device Close: Filesystem(s) %s\n", + (unmounted ? "UNMOUNTED" : "MOUNTED")); + + purge_waiting_ops(); + purge_inprogress_ops(); + + orangefs_bufmap_run_down(); + + gossip_debug(GOSSIP_DEV_DEBUG, + "pvfs2-client-core: device close complete\n"); + open_access_count = 0; + orangefs_userspace_version = 0; + mutex_unlock(&devreq_mutex); + return 0; +} + +int is_daemon_in_service(void) +{ + int in_service; + + /* + * What this function does is checks if client-core is alive + * based on the access count we maintain on the device. + */ + mutex_lock(&devreq_mutex); + in_service = open_access_count == 1 ? 0 : -EIO; + mutex_unlock(&devreq_mutex); + return in_service; +} + +bool __is_daemon_in_service(void) +{ + return open_access_count == 1; +} + +static inline long check_ioctl_command(unsigned int command) +{ + /* Check for valid ioctl codes */ + if (_IOC_TYPE(command) != ORANGEFS_DEV_MAGIC) { + gossip_err("device ioctl magic numbers don't match! Did you rebuild pvfs2-client-core/libpvfs2? [cmd %x, magic %x != %x]\n", + command, + _IOC_TYPE(command), + ORANGEFS_DEV_MAGIC); + return -EINVAL; + } + /* and valid ioctl commands */ + if (_IOC_NR(command) >= ORANGEFS_DEV_MAXNR || _IOC_NR(command) <= 0) { + gossip_err("Invalid ioctl command number [%d >= %d]\n", + _IOC_NR(command), ORANGEFS_DEV_MAXNR); + return -ENOIOCTLCMD; + } + return 0; +} + +static long dispatch_ioctl_command(unsigned int command, unsigned long arg) +{ + static __s32 magic = ORANGEFS_DEVREQ_MAGIC; + static __s32 max_up_size = MAX_DEV_REQ_UPSIZE; + static __s32 max_down_size = MAX_DEV_REQ_DOWNSIZE; + struct ORANGEFS_dev_map_desc user_desc; + int ret = 0; + int upstream_kmod = 1; + struct orangefs_sb_info_s *orangefs_sb; + + /* mtmoore: add locking here */ + + switch (command) { + case ORANGEFS_DEV_GET_MAGIC: + return ((put_user(magic, (__s32 __user *) arg) == -EFAULT) ? + -EIO : + 0); + case ORANGEFS_DEV_GET_MAX_UPSIZE: + return ((put_user(max_up_size, + (__s32 __user *) arg) == -EFAULT) ? + -EIO : + 0); + case ORANGEFS_DEV_GET_MAX_DOWNSIZE: + return ((put_user(max_down_size, + (__s32 __user *) arg) == -EFAULT) ? + -EIO : + 0); + case ORANGEFS_DEV_MAP: + ret = copy_from_user(&user_desc, + (struct ORANGEFS_dev_map_desc __user *) + arg, + sizeof(struct ORANGEFS_dev_map_desc)); + /* WTF -EIO and not -EFAULT? */ + return ret ? -EIO : orangefs_bufmap_initialize(&user_desc); + case ORANGEFS_DEV_REMOUNT_ALL: + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: got ORANGEFS_DEV_REMOUNT_ALL\n", + __func__); + + /* + * remount all mounted orangefs volumes to regain the lost + * dynamic mount tables (if any) -- NOTE: this is done + * without keeping the superblock list locked due to the + * upcall/downcall waiting. also, the request mutex is + * used to ensure that no operations will be serviced until + * all of the remounts are serviced (to avoid ops between + * mounts to fail) + */ + ret = mutex_lock_interruptible(&orangefs_request_mutex); + if (ret < 0) + return ret; + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: priority remount in progress\n", + __func__); + spin_lock(&orangefs_superblocks_lock); + list_for_each_entry(orangefs_sb, &orangefs_superblocks, list) { + /* + * We have to drop the spinlock, so entries can be + * removed. They can't be freed, though, so we just + * keep the forward pointers and zero the back ones - + * that way we can get to the rest of the list. + */ + if (!orangefs_sb->list.prev) + continue; + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: Remounting SB %p\n", + __func__, + orangefs_sb); + + spin_unlock(&orangefs_superblocks_lock); + ret = orangefs_remount(orangefs_sb); + spin_lock(&orangefs_superblocks_lock); + if (ret) { + gossip_debug(GOSSIP_DEV_DEBUG, + "SB %p remount failed\n", + orangefs_sb); + break; + } + } + spin_unlock(&orangefs_superblocks_lock); + gossip_debug(GOSSIP_DEV_DEBUG, + "%s: priority remount complete\n", + __func__); + mutex_unlock(&orangefs_request_mutex); + return ret; + + case ORANGEFS_DEV_UPSTREAM: + ret = copy_to_user((void __user *)arg, + &upstream_kmod, + sizeof(upstream_kmod)); + + if (ret != 0) + return -EIO; + else + return ret; + + case ORANGEFS_DEV_CLIENT_MASK: + return orangefs_debugfs_new_client_mask((void __user *)arg); + case ORANGEFS_DEV_CLIENT_STRING: + return orangefs_debugfs_new_client_string((void __user *)arg); + case ORANGEFS_DEV_DEBUG: + return orangefs_debugfs_new_debug((void __user *)arg); + default: + return -ENOIOCTLCMD; + } + return -ENOIOCTLCMD; +} + +static long orangefs_devreq_ioctl(struct file *file, + unsigned int command, unsigned long arg) +{ + long ret; + + /* Check for properly constructed commands */ + ret = check_ioctl_command(command); + if (ret < 0) + return (int)ret; + + return (int)dispatch_ioctl_command(command, arg); +} + +#ifdef CONFIG_COMPAT /* CONFIG_COMPAT is in .config */ + +/* Compat structure for the ORANGEFS_DEV_MAP ioctl */ +struct ORANGEFS_dev_map_desc32 { + compat_uptr_t ptr; + __s32 total_size; + __s32 size; + __s32 count; +}; + +/* + * 32 bit user-space apps' ioctl handlers when kernel modules + * is compiled as a 64 bit one + */ +static long orangefs_devreq_compat_ioctl(struct file *filp, unsigned int cmd, + unsigned long args) +{ + long ret; + + /* Check for properly constructed commands */ + ret = check_ioctl_command(cmd); + if (ret < 0) + return ret; + if (cmd == ORANGEFS_DEV_MAP) { + struct ORANGEFS_dev_map_desc desc; + struct ORANGEFS_dev_map_desc32 d32; + + if (copy_from_user(&d32, (void __user *)args, sizeof(d32))) + return -EFAULT; + + desc.ptr = compat_ptr(d32.ptr); + desc.total_size = d32.total_size; + desc.size = d32.size; + desc.count = d32.count; + return orangefs_bufmap_initialize(&desc); + } + /* no other ioctl requires translation */ + return dispatch_ioctl_command(cmd, args); +} + +#endif /* CONFIG_COMPAT is in .config */ + +static __poll_t orangefs_devreq_poll(struct file *file, + struct poll_table_struct *poll_table) +{ + __poll_t poll_revent_mask = 0; + + poll_wait(file, &orangefs_request_list_waitq, poll_table); + + if (!list_empty(&orangefs_request_list)) + poll_revent_mask |= EPOLLIN; + return poll_revent_mask; +} + +/* the assigned character device major number */ +static int orangefs_dev_major; + +static const struct file_operations orangefs_devreq_file_operations = { + .owner = THIS_MODULE, + .read = orangefs_devreq_read, + .write_iter = orangefs_devreq_write_iter, + .open = orangefs_devreq_open, + .release = orangefs_devreq_release, + .unlocked_ioctl = orangefs_devreq_ioctl, + +#ifdef CONFIG_COMPAT /* CONFIG_COMPAT is in .config */ + .compat_ioctl = orangefs_devreq_compat_ioctl, +#endif + .poll = orangefs_devreq_poll +}; + +/* + * Initialize orangefs device specific state: + * Must be called at module load time only + */ +int orangefs_dev_init(void) +{ + /* register orangefs-req device */ + orangefs_dev_major = register_chrdev(0, + ORANGEFS_REQDEVICE_NAME, + &orangefs_devreq_file_operations); + if (orangefs_dev_major < 0) { + gossip_debug(GOSSIP_DEV_DEBUG, + "Failed to register /dev/%s (error %d)\n", + ORANGEFS_REQDEVICE_NAME, orangefs_dev_major); + return orangefs_dev_major; + } + + gossip_debug(GOSSIP_DEV_DEBUG, + "*** /dev/%s character device registered ***\n", + ORANGEFS_REQDEVICE_NAME); + gossip_debug(GOSSIP_DEV_DEBUG, "'mknod /dev/%s c %d 0'.\n", + ORANGEFS_REQDEVICE_NAME, orangefs_dev_major); + return 0; +} + +void orangefs_dev_cleanup(void) +{ + unregister_chrdev(orangefs_dev_major, ORANGEFS_REQDEVICE_NAME); + gossip_debug(GOSSIP_DEV_DEBUG, + "*** /dev/%s character device unregistered ***\n", + ORANGEFS_REQDEVICE_NAME); +} |