diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /fs/lockd/svcsubs.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | fs/lockd/svcsubs.c | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c new file mode 100644 index 000000000..3515f17ea --- /dev/null +++ b/fs/lockd/svcsubs.c @@ -0,0 +1,505 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/lockd/svcsubs.c + * + * Various support routines for the NLM server. + * + * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> + */ + +#include <linux/types.h> +#include <linux/string.h> +#include <linux/time.h> +#include <linux/in.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/sunrpc/svc.h> +#include <linux/sunrpc/addr.h> +#include <linux/lockd/lockd.h> +#include <linux/lockd/share.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <uapi/linux/nfs2.h> + +#define NLMDBG_FACILITY NLMDBG_SVCSUBS + + +/* + * Global file hash table + */ +#define FILE_HASH_BITS 7 +#define FILE_NRHASH (1<<FILE_HASH_BITS) +static struct hlist_head nlm_files[FILE_NRHASH]; +static DEFINE_MUTEX(nlm_file_mutex); + +#ifdef CONFIG_SUNRPC_DEBUG +static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f) +{ + u32 *fhp = (u32*)f->data; + + /* print the first 32 bytes of the fh */ + dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n", + msg, fhp[0], fhp[1], fhp[2], fhp[3], + fhp[4], fhp[5], fhp[6], fhp[7]); +} + +static inline void nlm_debug_print_file(char *msg, struct nlm_file *file) +{ + struct inode *inode = nlmsvc_file_inode(file); + + dprintk("lockd: %s %s/%ld\n", + msg, inode->i_sb->s_id, inode->i_ino); +} +#else +static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f) +{ + return; +} + +static inline void nlm_debug_print_file(char *msg, struct nlm_file *file) +{ + return; +} +#endif + +static inline unsigned int file_hash(struct nfs_fh *f) +{ + unsigned int tmp=0; + int i; + for (i=0; i<NFS2_FHSIZE;i++) + tmp += f->data[i]; + return tmp & (FILE_NRHASH - 1); +} + +int lock_to_openmode(struct file_lock *lock) +{ + return (lock->fl_type == F_WRLCK) ? O_WRONLY : O_RDONLY; +} + +/* + * Open the file. Note that if we're reexporting, for example, + * this could block the lockd thread for a while. + * + * We have to make sure we have the right credential to open + * the file. + */ +static __be32 nlm_do_fopen(struct svc_rqst *rqstp, + struct nlm_file *file, int mode) +{ + struct file **fp = &file->f_file[mode]; + __be32 nfserr; + + if (*fp) + return 0; + nfserr = nlmsvc_ops->fopen(rqstp, &file->f_handle, fp, mode); + if (nfserr) + dprintk("lockd: open failed (error %d)\n", nfserr); + return nfserr; +} + +/* + * Lookup file info. If it doesn't exist, create a file info struct + * and open a (VFS) file for the given inode. + */ +__be32 +nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, + struct nlm_lock *lock) +{ + struct nlm_file *file; + unsigned int hash; + __be32 nfserr; + int mode; + + nlm_debug_print_fh("nlm_lookup_file", &lock->fh); + + hash = file_hash(&lock->fh); + mode = lock_to_openmode(&lock->fl); + + /* Lock file table */ + mutex_lock(&nlm_file_mutex); + + hlist_for_each_entry(file, &nlm_files[hash], f_list) + if (!nfs_compare_fh(&file->f_handle, &lock->fh)) { + mutex_lock(&file->f_mutex); + nfserr = nlm_do_fopen(rqstp, file, mode); + mutex_unlock(&file->f_mutex); + goto found; + } + nlm_debug_print_fh("creating file for", &lock->fh); + + nfserr = nlm_lck_denied_nolocks; + file = kzalloc(sizeof(*file), GFP_KERNEL); + if (!file) + goto out_free; + + memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh)); + mutex_init(&file->f_mutex); + INIT_HLIST_NODE(&file->f_list); + INIT_LIST_HEAD(&file->f_blocks); + + nfserr = nlm_do_fopen(rqstp, file, mode); + if (nfserr) + goto out_unlock; + + hlist_add_head(&file->f_list, &nlm_files[hash]); + +found: + dprintk("lockd: found file %p (count %d)\n", file, file->f_count); + *result = file; + file->f_count++; + +out_unlock: + mutex_unlock(&nlm_file_mutex); + return nfserr; + +out_free: + kfree(file); + goto out_unlock; +} + +/* + * Delete a file after having released all locks, blocks and shares + */ +static inline void +nlm_delete_file(struct nlm_file *file) +{ + nlm_debug_print_file("closing file", file); + if (!hlist_unhashed(&file->f_list)) { + hlist_del(&file->f_list); + if (file->f_file[O_RDONLY]) + nlmsvc_ops->fclose(file->f_file[O_RDONLY]); + if (file->f_file[O_WRONLY]) + nlmsvc_ops->fclose(file->f_file[O_WRONLY]); + kfree(file); + } else { + printk(KERN_WARNING "lockd: attempt to release unknown file!\n"); + } +} + +static int nlm_unlock_files(struct nlm_file *file, const struct file_lock *fl) +{ + struct file_lock lock; + + locks_init_lock(&lock); + lock.fl_type = F_UNLCK; + lock.fl_start = 0; + lock.fl_end = OFFSET_MAX; + lock.fl_owner = fl->fl_owner; + lock.fl_pid = fl->fl_pid; + lock.fl_flags = FL_POSIX; + + lock.fl_file = file->f_file[O_RDONLY]; + if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL)) + goto out_err; + lock.fl_file = file->f_file[O_WRONLY]; + if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL)) + goto out_err; + return 0; +out_err: + pr_warn("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__); + return 1; +} + +/* + * Loop over all locks on the given file and perform the specified + * action. + */ +static int +nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file, + nlm_host_match_fn_t match) +{ + struct inode *inode = nlmsvc_file_inode(file); + struct file_lock *fl; + struct file_lock_context *flctx = inode->i_flctx; + struct nlm_host *lockhost; + + if (!flctx || list_empty_careful(&flctx->flc_posix)) + return 0; +again: + file->f_locks = 0; + spin_lock(&flctx->flc_lock); + list_for_each_entry(fl, &flctx->flc_posix, fl_list) { + if (fl->fl_lmops != &nlmsvc_lock_operations) + continue; + + /* update current lock count */ + file->f_locks++; + + lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host; + if (match(lockhost, host)) { + + spin_unlock(&flctx->flc_lock); + if (nlm_unlock_files(file, fl)) + return 1; + goto again; + } + } + spin_unlock(&flctx->flc_lock); + + return 0; +} + +static int +nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2) +{ + return 1; +} + +/* + * Inspect a single file + */ +static inline int +nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match) +{ + nlmsvc_traverse_blocks(host, file, match); + nlmsvc_traverse_shares(host, file, match); + return nlm_traverse_locks(host, file, match); +} + +/* + * Quick check whether there are still any locks, blocks or + * shares on a given file. + */ +static inline int +nlm_file_inuse(struct nlm_file *file) +{ + struct inode *inode = nlmsvc_file_inode(file); + struct file_lock *fl; + struct file_lock_context *flctx = inode->i_flctx; + + if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares) + return 1; + + if (flctx && !list_empty_careful(&flctx->flc_posix)) { + spin_lock(&flctx->flc_lock); + list_for_each_entry(fl, &flctx->flc_posix, fl_list) { + if (fl->fl_lmops == &nlmsvc_lock_operations) { + spin_unlock(&flctx->flc_lock); + return 1; + } + } + spin_unlock(&flctx->flc_lock); + } + file->f_locks = 0; + return 0; +} + +static void nlm_close_files(struct nlm_file *file) +{ + if (file->f_file[O_RDONLY]) + nlmsvc_ops->fclose(file->f_file[O_RDONLY]); + if (file->f_file[O_WRONLY]) + nlmsvc_ops->fclose(file->f_file[O_WRONLY]); +} + +/* + * Loop over all files in the file table. + */ +static int +nlm_traverse_files(void *data, nlm_host_match_fn_t match, + int (*is_failover_file)(void *data, struct nlm_file *file)) +{ + struct hlist_node *next; + struct nlm_file *file; + int i, ret = 0; + + mutex_lock(&nlm_file_mutex); + for (i = 0; i < FILE_NRHASH; i++) { + hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) { + if (is_failover_file && !is_failover_file(data, file)) + continue; + file->f_count++; + mutex_unlock(&nlm_file_mutex); + + /* Traverse locks, blocks and shares of this file + * and update file->f_locks count */ + if (nlm_inspect_file(data, file, match)) + ret = 1; + + mutex_lock(&nlm_file_mutex); + file->f_count--; + /* No more references to this file. Let go of it. */ + if (list_empty(&file->f_blocks) && !file->f_locks + && !file->f_shares && !file->f_count) { + hlist_del(&file->f_list); + nlm_close_files(file); + kfree(file); + } + } + } + mutex_unlock(&nlm_file_mutex); + return ret; +} + +/* + * Release file. If there are no more remote locks on this file, + * close it and free the handle. + * + * Note that we can't do proper reference counting without major + * contortions because the code in fs/locks.c creates, deletes and + * splits locks without notification. Our only way is to walk the + * entire lock list each time we remove a lock. + */ +void +nlm_release_file(struct nlm_file *file) +{ + dprintk("lockd: nlm_release_file(%p, ct = %d)\n", + file, file->f_count); + + /* Lock file table */ + mutex_lock(&nlm_file_mutex); + + /* If there are no more locks etc, delete the file */ + if (--file->f_count == 0 && !nlm_file_inuse(file)) + nlm_delete_file(file); + + mutex_unlock(&nlm_file_mutex); +} + +/* + * Helpers function for resource traversal + * + * nlmsvc_mark_host: + * used by the garbage collector; simply sets h_inuse only for those + * hosts, which passed network check. + * Always returns 0. + * + * nlmsvc_same_host: + * returns 1 iff the two hosts match. Used to release + * all resources bound to a specific host. + * + * nlmsvc_is_client: + * returns 1 iff the host is a client. + * Used by nlmsvc_invalidate_all + */ + +static int +nlmsvc_mark_host(void *data, struct nlm_host *hint) +{ + struct nlm_host *host = data; + + if ((hint->net == NULL) || + (host->net == hint->net)) + host->h_inuse = 1; + return 0; +} + +static int +nlmsvc_same_host(void *data, struct nlm_host *other) +{ + struct nlm_host *host = data; + + return host == other; +} + +static int +nlmsvc_is_client(void *data, struct nlm_host *dummy) +{ + struct nlm_host *host = data; + + if (host->h_server) { + /* we are destroying locks even though the client + * hasn't asked us too, so don't unmonitor the + * client + */ + if (host->h_nsmhandle) + host->h_nsmhandle->sm_sticky = 1; + return 1; + } else + return 0; +} + +/* + * Mark all hosts that still hold resources + */ +void +nlmsvc_mark_resources(struct net *net) +{ + struct nlm_host hint; + + dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0); + hint.net = net; + nlm_traverse_files(&hint, nlmsvc_mark_host, NULL); +} + +/* + * Release all resources held by the given client + */ +void +nlmsvc_free_host_resources(struct nlm_host *host) +{ + dprintk("lockd: nlmsvc_free_host_resources\n"); + + if (nlm_traverse_files(host, nlmsvc_same_host, NULL)) { + printk(KERN_WARNING + "lockd: couldn't remove all locks held by %s\n", + host->h_name); + BUG(); + } +} + +/** + * nlmsvc_invalidate_all - remove all locks held for clients + * + * Release all locks held by NFS clients. + * + */ +void +nlmsvc_invalidate_all(void) +{ + /* + * Previously, the code would call + * nlmsvc_free_host_resources for each client in + * turn, which is about as inefficient as it gets. + * Now we just do it once in nlm_traverse_files. + */ + nlm_traverse_files(NULL, nlmsvc_is_client, NULL); +} + + +static int +nlmsvc_match_sb(void *datap, struct nlm_file *file) +{ + struct super_block *sb = datap; + + return sb == nlmsvc_file_inode(file)->i_sb; +} + +/** + * nlmsvc_unlock_all_by_sb - release locks held on this file system + * @sb: super block + * + * Release all locks held by clients accessing this file system. + */ +int +nlmsvc_unlock_all_by_sb(struct super_block *sb) +{ + int ret; + + ret = nlm_traverse_files(sb, nlmsvc_always_match, nlmsvc_match_sb); + return ret ? -EIO : 0; +} +EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_sb); + +static int +nlmsvc_match_ip(void *datap, struct nlm_host *host) +{ + return rpc_cmp_addr(nlm_srcaddr(host), datap); +} + +/** + * nlmsvc_unlock_all_by_ip - release local locks by IP address + * @server_addr: server's IP address as seen by clients + * + * Release all locks held by clients accessing this host + * via the passed in IP address. + */ +int +nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr) +{ + int ret; + + ret = nlm_traverse_files(server_addr, nlmsvc_match_ip, NULL); + return ret ? -EIO : 0; +} +EXPORT_SYMBOL_GPL(nlmsvc_unlock_all_by_ip); |