5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: J. Bruce Fields bfields@redhat.com
[ Upstream commit 7f024fcd5c97dc70bb9121c80407cf3cf9be7159 ]
We shouldn't really be using a read-only file descriptor to take a write lock.
Most filesystems will put up with it. But NFS, for example, won't.
Signed-off-by: J. Bruce Fields bfields@redhat.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/lockd/svc4proc.c | 4 +- fs/lockd/svclock.c | 25 ++++++--- fs/lockd/svcproc.c | 4 +- fs/lockd/svcsubs.c | 102 +++++++++++++++++++++++++----------- fs/nfsd/lockd.c | 8 ++- include/linux/lockd/bind.h | 3 +- include/linux/lockd/lockd.h | 9 +++- 7 files changed, 111 insertions(+), 44 deletions(-)
diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c index bc496bbd696b8..e10ae2c41279e 100644 --- a/fs/lockd/svc4proc.c +++ b/fs/lockd/svc4proc.c @@ -40,13 +40,15 @@ nlm4svc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp,
/* Obtain file pointer. Not used by FREE_ALL call. */ if (filp != NULL) { + int mode = lock_to_openmode(&lock->fl); + error = nlm_lookup_file(rqstp, &file, lock); if (error) goto no_locks; *filp = file;
/* Set up the missing parts of the file_lock structure */ - lock->fl.fl_file = file->f_file; + lock->fl.fl_file = file->f_file[mode]; lock->fl.fl_pid = current->tgid; lock->fl.fl_lmops = &nlmsvc_lock_operations; nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid); diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c index bcd180ba99576..a7b4c51667ada 100644 --- a/fs/lockd/svclock.c +++ b/fs/lockd/svclock.c @@ -471,6 +471,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file, { struct nlm_block *block = NULL; int error; + int mode; __be32 ret;
dprintk("lockd: nlmsvc_lock(%s/%ld, ty=%d, pi=%d, %Ld-%Ld, bl=%d)\n", @@ -524,7 +525,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
if (!wait) lock->fl.fl_flags &= ~FL_SLEEP; - error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); + mode = lock_to_openmode(&lock->fl); + error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP;
dprintk("lockd: vfs_lock_file returned %d\n", error); @@ -577,6 +579,7 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, struct nlm_lock *conflock, struct nlm_cookie *cookie) { int error; + int mode; __be32 ret; struct nlm_lockowner *test_owner;
@@ -595,7 +598,8 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, /* If there's a conflicting lock, remember to clean up the test lock */ test_owner = (struct nlm_lockowner *)lock->fl.fl_owner;
- error = vfs_test_lock(file->f_file, &lock->fl); + mode = lock_to_openmode(&lock->fl); + error = vfs_test_lock(file->f_file[mode], &lock->fl); if (error) { /* We can't currently deal with deferred test requests */ if (error == FILE_LOCK_DEFERRED) @@ -641,7 +645,7 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, __be32 nlmsvc_unlock(struct net *net, struct nlm_file *file, struct nlm_lock *lock) { - int error; + int error = 0;
dprintk("lockd: nlmsvc_unlock(%s/%ld, pi=%d, %Ld-%Ld)\n", nlmsvc_file_inode(file)->i_sb->s_id, @@ -654,7 +658,12 @@ nlmsvc_unlock(struct net *net, struct nlm_file *file, struct nlm_lock *lock) nlmsvc_cancel_blocked(net, file, lock);
lock->fl.fl_type = F_UNLCK; - error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); + if (file->f_file[O_RDONLY]) + error = vfs_lock_file(file->f_file[O_RDONLY], F_SETLK, + &lock->fl, NULL); + if (file->f_file[O_WRONLY]) + error = vfs_lock_file(file->f_file[O_WRONLY], F_SETLK, + &lock->fl, NULL);
return (error < 0)? nlm_lck_denied_nolocks : nlm_granted; } @@ -671,6 +680,7 @@ nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *l { struct nlm_block *block; int status = 0; + int mode;
dprintk("lockd: nlmsvc_cancel(%s/%ld, pi=%d, %Ld-%Ld)\n", nlmsvc_file_inode(file)->i_sb->s_id, @@ -686,7 +696,8 @@ nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *l block = nlmsvc_lookup_block(file, lock); mutex_unlock(&file->f_mutex); if (block != NULL) { - vfs_cancel_lock(block->b_file->f_file, + mode = lock_to_openmode(&lock->fl); + vfs_cancel_lock(block->b_file->f_file[mode], &block->b_call->a_args.lock.fl); status = nlmsvc_unlink_block(block); nlmsvc_release_block(block); @@ -803,6 +814,7 @@ nlmsvc_grant_blocked(struct nlm_block *block) { struct nlm_file *file = block->b_file; struct nlm_lock *lock = &block->b_call->a_args.lock; + int mode; int error; loff_t fl_start, fl_end;
@@ -828,7 +840,8 @@ nlmsvc_grant_blocked(struct nlm_block *block) lock->fl.fl_flags |= FL_SLEEP; fl_start = lock->fl.fl_start; fl_end = lock->fl.fl_end; - error = vfs_lock_file(file->f_file, F_SETLK, &lock->fl, NULL); + mode = lock_to_openmode(&lock->fl); + error = vfs_lock_file(file->f_file[mode], F_SETLK, &lock->fl, NULL); lock->fl.fl_flags &= ~FL_SLEEP; lock->fl.fl_start = fl_start; lock->fl.fl_end = fl_end; diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c index f4e5e0eb30fd1..99696d3f6dd66 100644 --- a/fs/lockd/svcproc.c +++ b/fs/lockd/svcproc.c @@ -55,6 +55,7 @@ nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp, struct nlm_host *host = NULL; struct nlm_file *file = NULL; struct nlm_lock *lock = &argp->lock; + int mode; __be32 error = 0;
/* nfsd callbacks must have been installed for this procedure */ @@ -75,7 +76,8 @@ nlmsvc_retrieve_args(struct svc_rqst *rqstp, struct nlm_args *argp, *filp = file;
/* Set up the missing parts of the file_lock structure */ - lock->fl.fl_file = file->f_file; + mode = lock_to_openmode(&lock->fl); + lock->fl.fl_file = file->f_file[mode]; lock->fl.fl_pid = current->tgid; lock->fl.fl_lmops = &nlmsvc_lock_operations; nlmsvc_locks_init_private(&lock->fl, host, (pid_t)lock->svid); diff --git a/fs/lockd/svcsubs.c b/fs/lockd/svcsubs.c index 13e6ffc219ec9..cb3a7512c33ec 100644 --- a/fs/lockd/svcsubs.c +++ b/fs/lockd/svcsubs.c @@ -71,14 +71,35 @@ static inline unsigned int file_hash(struct nfs_fh *f) 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. - * - * 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. */ __be32 nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, @@ -87,42 +108,38 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, 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)) + 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_unlock; + 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);
- /* - * 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. - */ - nfserr = nlmsvc_ops->fopen(rqstp, &lock->fh, &file->f_file); - if (nfserr) { - dprintk("lockd: open failed (error %d)\n", nfserr); - goto out_free; - } + nfserr = nlm_do_fopen(rqstp, file, mode); + if (nfserr) + goto out_unlock;
hlist_add_head(&file->f_list, &nlm_files[hash]);
@@ -130,7 +147,6 @@ nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result, 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); @@ -150,13 +166,34 @@ 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); + 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) +{ + struct file_lock lock; + struct file *f; + + lock.fl_type = F_UNLCK; + lock.fl_start = 0; + lock.fl_end = OFFSET_MAX; + for (f = file->f_file[0]; f <= file->f_file[1]; f++) { + if (f && vfs_lock_file(f, F_SETLK, &lock, NULL) < 0) { + pr_warn("lockd: unlock failure in %s:%d\n", + __FILE__, __LINE__); + return 1; + } + } + return 0; +} + /* * Loop over all locks on the given file and perform the specified * action. @@ -184,17 +221,10 @@ nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host; if (match(lockhost, host)) { - struct file_lock lock = *fl;
spin_unlock(&flctx->flc_lock); - lock.fl_type = F_UNLCK; - lock.fl_start = 0; - lock.fl_end = OFFSET_MAX; - if (vfs_lock_file(file->f_file, F_SETLK, &lock, NULL) < 0) { - printk("lockd: unlock failure in %s:%d\n", - __FILE__, __LINE__); + if (nlm_unlock_files(file)) return 1; - } goto again; } } @@ -248,6 +278,15 @@ nlm_file_inuse(struct nlm_file *file) return 0; }
+static void nlm_close_files(struct nlm_file *file) +{ + struct file *f; + + for (f = file->f_file[0]; f <= file->f_file[1]; f++) + if (f) + nlmsvc_ops->fclose(f); +} + /* * Loop over all files in the file table. */ @@ -278,7 +317,7 @@ nlm_traverse_files(void *data, nlm_host_match_fn_t match, 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); + nlm_close_files(file); kfree(file); } } @@ -412,6 +451,7 @@ nlmsvc_invalidate_all(void) nlm_traverse_files(NULL, nlmsvc_is_client, NULL); }
+ static int nlmsvc_match_sb(void *datap, struct nlm_file *file) { diff --git a/fs/nfsd/lockd.c b/fs/nfsd/lockd.c index 3f5b3d7b62b71..606fa155c28ad 100644 --- a/fs/nfsd/lockd.c +++ b/fs/nfsd/lockd.c @@ -25,9 +25,11 @@ * Note: we hold the dentry use count while the file is open. */ static __be32 -nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp) +nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp, + int mode) { __be32 nfserr; + int access; struct svc_fh fh;
/* must initialize before using! but maxsize doesn't matter */ @@ -36,7 +38,9 @@ nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp) memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size); fh.fh_export = NULL;
- nfserr = nfsd_open(rqstp, &fh, S_IFREG, NFSD_MAY_LOCK, filp); + access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ; + access |= NFSD_MAY_LOCK; + nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp); fh_put(&fh); /* We return nlm error codes as nlm doesn't know * about nfsd, but nfsd does know about nlm.. diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h index 0520c0cd73f42..3bc9f7410e213 100644 --- a/include/linux/lockd/bind.h +++ b/include/linux/lockd/bind.h @@ -27,7 +27,8 @@ struct rpc_task; struct nlmsvc_binding { __be32 (*fopen)(struct svc_rqst *, struct nfs_fh *, - struct file **); + struct file **, + int mode); void (*fclose)(struct file *); };
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h index 81b71ad2040ac..c4ae6506b8b36 100644 --- a/include/linux/lockd/lockd.h +++ b/include/linux/lockd/lockd.h @@ -10,6 +10,8 @@ #ifndef LINUX_LOCKD_LOCKD_H #define LINUX_LOCKD_LOCKD_H
+/* XXX: a lot of this should really be under fs/lockd. */ + #include <linux/in.h> #include <linux/in6.h> #include <net/ipv6.h> @@ -154,7 +156,8 @@ struct nlm_rqst { struct nlm_file { struct hlist_node f_list; /* linked list */ struct nfs_fh f_handle; /* NFS file handle */ - struct file * f_file; /* VFS file pointer */ + struct file * f_file[2]; /* VFS file pointers, + indexed by O_ flags */ struct nlm_share * f_shares; /* DOS shares */ struct list_head f_blocks; /* blocked locks */ unsigned int f_locks; /* guesstimate # of locks */ @@ -267,6 +270,7 @@ typedef int (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref); /* * Server-side lock handling */ +int lock_to_openmode(struct file_lock *); __be32 nlmsvc_lock(struct svc_rqst *, struct nlm_file *, struct nlm_host *, struct nlm_lock *, int, struct nlm_cookie *, int); @@ -301,7 +305,8 @@ int nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
static inline struct inode *nlmsvc_file_inode(struct nlm_file *file) { - return locks_inode(file->f_file); + return locks_inode(file->f_file[O_RDONLY] ? + file->f_file[O_RDONLY] : file->f_file[O_WRONLY]); }
static inline int __nlm_privileged_request4(const struct sockaddr *sap)