/* * linux/fs/lockd/svcsubs.c * * Various support routines for the NLM server. * * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ #include <linux/config.h> #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 5 #define FILE_NRHASH (1<<FILE_HASH_BITS) static struct nlm_file * 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 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); for (file = nlm_files[hash]; file; file = file->f_next) if (!nfs_compare_fh(&file->f_handle, f)) goto found; nlm_debug_print_fh("creating file for", f); nfserr = nlm_lck_denied_nolocks; file = (struct nlm_file *) kmalloc(sizeof(*file), GFP_KERNEL); if (!file) goto out_unlock; memset(file, 0, sizeof(*file)); memcpy(&file->f_handle, f, sizeof(struct nfs_fh)); file->f_hash = hash; init_MUTEX(&file->f_sema); /* 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 (nfserr %d)\n", ntohl(nfserr)); goto out_free; } file->f_next = nlm_files[hash]; nlm_files[hash] = file; 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) { struct nlm_file **fp, *f; nlm_debug_print_file("closing file", file); fp = nlm_files + file->f_hash; while ((f = *fp) != NULL) { if (f == file) { *fp = file->f_next; nlmsvc_ops->fclose(file->f_file); kfree(file); return; } fp = &f->f_next; } 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, int action) { 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 (action == NLM_ACT_MARK) lockhost->h_inuse = 1; else if (action == NLM_ACT_CHECK) return 1; else if (action == NLM_ACT_UNLOCK) { struct file_lock lock = *fl; if (host && lockhost != host) continue; 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; } /* * Operate on a single file */ static inline int nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, int action) { if (action == NLM_ACT_CHECK) { /* Fast path for mark and sweep garbage collection */ if (file->f_count || file->f_blocks || file->f_shares) return 1; } else { nlmsvc_traverse_blocks(host, file, action); nlmsvc_traverse_shares(host, file, action); } return nlm_traverse_locks(host, file, action); } /* * Loop over all files in the file table. */ static int nlm_traverse_files(struct nlm_host *host, int action) { struct nlm_file *file, **fp; int i; mutex_lock(&nlm_file_mutex); for (i = 0; i < FILE_NRHASH; i++) { fp = nlm_files + i; while ((file = *fp) != NULL) { /* Traverse locks, blocks and shares of this file * and update file->f_locks count */ if (nlm_inspect_file(host, file, action)) { mutex_unlock(&nlm_file_mutex); return 1; } /* No more references to this file. Let go of it. */ if (!file->f_blocks && !file->f_locks && !file->f_shares && !file->f_count) { *fp = file->f_next; nlmsvc_ops->fclose(file->f_file); kfree(file); } else { fp = &file->f_next; } } } mutex_unlock(&nlm_file_mutex); return 0; } /* * 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) { if(!nlm_inspect_file(NULL, file, NLM_ACT_CHECK)) nlm_delete_file(file); } mutex_unlock(&nlm_file_mutex); } /* * Mark all hosts that still hold resources */ void nlmsvc_mark_resources(void) { dprintk("lockd: nlmsvc_mark_resources\n"); nlm_traverse_files(NULL, NLM_ACT_MARK); } /* * 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, NLM_ACT_UNLOCK)) printk(KERN_WARNING "lockd: couldn't remove all locks held by %s", host->h_name); } /* * delete all hosts structs for clients */ void nlmsvc_invalidate_all(void) { struct nlm_host *host; while ((host = nlm_find_client()) != NULL) { nlmsvc_free_host_resources(host); host->h_expires = 0; host->h_killed = 1; nlm_release_host(host); } }