| /* |
| * 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/mutex.h> |
| #include <linux/sunrpc/svc.h> |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/nfsd/nfsfh.h> |
| #include <linux/nfsd/export.h> |
| #include <linux/lockd/lockd.h> |
| #include <linux/lockd/share.h> |
| #include <linux/lockd/sm_inter.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 NFSD_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 = file->f_file->f_dentry->d_inode; |
| |
| 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); |
| } |
| |
| /* |
| * Lookup file info. If it doesn't exist, create a file info struct |
| * and open a (VFS) file for the given inode. |
| * |
| * FIXME: |
| * Note that we open the file O_RDONLY even when creating write locks. |
| * This is not quite right, but for now, we assume the client performs |
| * the proper R/W checking. |
| */ |
| u32 |
| nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, |
| struct nfs_fh *f) |
| { |
| struct hlist_node *pos; |
| struct nlm_file *file; |
| unsigned int hash; |
| u32 nfserr; |
| |
| nlm_debug_print_fh("nlm_file_lookup", f); |
| |
| hash = file_hash(f); |
| |
| /* Lock file table */ |
| mutex_lock(&nlm_file_mutex); |
| |
| hlist_for_each_entry(file, pos, &nlm_files[hash], f_list) |
| if (!nfs_compare_fh(&file->f_handle, f)) |
| goto found; |
| |
| nlm_debug_print_fh("creating file for", f); |
| |
| nfserr = nlm_lck_denied_nolocks; |
| file = kzalloc(sizeof(*file), GFP_KERNEL); |
| if (!file) |
| goto out_unlock; |
| |
| memcpy(&file->f_handle, f, sizeof(struct nfs_fh)); |
| mutex_init(&file->f_mutex); |
| INIT_HLIST_NODE(&file->f_list); |
| INIT_LIST_HEAD(&file->f_blocks); |
| |
| /* Open the file. Note that this must not sleep for too long, else |
| * we would lock up lockd:-) So no NFS re-exports, folks. |
| * |
| * We have to make sure we have the right credential to open |
| * the file. |
| */ |
| if ((nfserr = nlmsvc_ops->fopen(rqstp, f, &file->f_file)) != 0) { |
| dprintk("lockd: open failed (error %d)\n", nfserr); |
| goto out_free; |
| } |
| |
| 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++; |
| nfserr = 0; |
| |
| out_unlock: |
| mutex_unlock(&nlm_file_mutex); |
| return nfserr; |
| |
| out_free: |
| kfree(file); |
| #ifdef CONFIG_LOCKD_V4 |
| if (nfserr == 1) |
| nfserr = nlm4_stale_fh; |
| else |
| #endif |
| nfserr = nlm_lck_denied; |
| 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); |
| nlmsvc_ops->fclose(file->f_file); |
| kfree(file); |
| } else { |
| printk(KERN_WARNING "lockd: attempt to release unknown file!\n"); |
| } |
| } |
| |
| /* |
| * 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 nlm_host *lockhost; |
| |
| again: |
| file->f_locks = 0; |
| for (fl = inode->i_flock; fl; fl = fl->fl_next) { |
| if (fl->fl_lmops != &nlmsvc_lock_operations) |
| continue; |
| |
| /* update current lock count */ |
| file->f_locks++; |
| |
| lockhost = (struct nlm_host *) fl->fl_owner; |
| if (match(lockhost, host)) { |
| struct file_lock lock = *fl; |
| |
| lock.fl_type = F_UNLCK; |
| lock.fl_start = 0; |
| lock.fl_end = OFFSET_MAX; |
| if (posix_lock_file(file->f_file, &lock) < 0) { |
| printk("lockd: unlock failure in %s:%d\n", |
| __FILE__, __LINE__); |
| return 1; |
| } |
| goto again; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * 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; |
| |
| if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares) |
| return 1; |
| |
| for (fl = inode->i_flock; fl; fl = fl->fl_next) { |
| if (fl->fl_lmops == &nlmsvc_lock_operations) |
| return 1; |
| } |
| file->f_locks = 0; |
| return 0; |
| } |
| |
| /* |
| * Loop over all files in the file table. |
| */ |
| static int |
| nlm_traverse_files(struct nlm_host *host, nlm_host_match_fn_t match) |
| { |
| struct hlist_node *pos, *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, pos, next, &nlm_files[i], f_list) { |
| 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(host, 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); |
| nlmsvc_ops->fclose(file->f_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. |
| * 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(struct nlm_host *host, struct nlm_host *dummy) |
| { |
| host->h_inuse = 1; |
| return 0; |
| } |
| |
| static int |
| nlmsvc_same_host(struct nlm_host *host, struct nlm_host *other) |
| { |
| return host == other; |
| } |
| |
| static int |
| nlmsvc_is_client(struct nlm_host *host, struct nlm_host *dummy) |
| { |
| return host->h_server; |
| } |
| |
| /* |
| * Mark all hosts that still hold resources |
| */ |
| void |
| nlmsvc_mark_resources(void) |
| { |
| dprintk("lockd: nlmsvc_mark_resources\n"); |
| nlm_traverse_files(NULL, nlmsvc_mark_host); |
| } |
| |
| /* |
| * 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)) { |
| printk(KERN_WARNING |
| "lockd: couldn't remove all locks held by %s\n", |
| host->h_name); |
| BUG(); |
| } |
| } |
| |
| /* |
| * Remove all locks held for clients |
| */ |
| void |
| nlmsvc_invalidate_all(void) |
| { |
| /* Release all locks held by NFS clients. |
| * 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); |
| } |