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![Linus Torvalds](/assets/img/avatar_default.png)
This release introduces support for the CB_RECALL_ANY operation. NFSD can send this operation to request that clients return any delegations they choose. The server uses this operation to handle low memory scenarios or indicate to a client when that client has reached the maximum number of delegations the server supports. The NFSv4.2 READ_PLUS operation has been simplified temporarily whilst support for sparse files in local filesystems and the VFS is improved. Two major data structure fixes appear in this release: * The nfs4_file hash table is replaced with a resizable hash table to reduce the latency of NFSv4 OPEN operations. * Reference counting in the NFSD filecache has been hardened against races. In furtherance of removing support for NFSv2 in a subsequent kernel release, a new Kconfig option enables server-side support for NFSv2 to be left out of a kernel build. MAINTAINERS has been updated to indicate that changes to fs/exportfs should go through the NFSD tree. -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEKLLlsBKG3yQ88j7+M2qzM29mf5cFAmOXPE4ACgkQM2qzM29m f5faaRAAh7YT5V61afPbfgBybO5AbDzztpZSNjNjLZs78piSnFp6hP75yNtTviwQ 1o7St13/NkCmDaIdGUpr02U01zbM1BDOq2wGckImOJLNSgb7xHV5r4PqkRiFkh0t QYSnwG+wp8fDUJeCL/nAOAu9I9EQUqHzWchxiU/h8ln2hN3rXUlIRSeo17Wy7zkD cNIcoAjTi9fzY3dE6H4r+lZTdNCYH+AdzChmKrHdRZQwq0Xs3FWv4gAMTLbDuD4P B6NDHz0Umn6XnFsJGptwozkwaWeMQw4GyJj/3iUiO8JF209SaoYXMPjJAyG6tYYa fUrgv4UXGeXjigDbLBA5IYxfhX7GXjMQSaj3edhzyrl8P74q4/Cq/8fDUnAZ841m E+TGSCPIQD0QuIjdXxLv9KLY8JNThSfcAt6jr5GBXhPZQr8xpS0BqK/Onr68fgZC Lpull5xN68L4A1B7cf2GNPuMyvkBKxwSGXOehldh/BkvpVMjFwqd4/q5xWC+6CcQ tbOkjTbbSS71nzJwZip0NphaYCa3qQPzKT4SZzn/I4I9W5otbwYBx734Bw46gTDE ZPUXTuJ00VPgX07wbLRahg521Fwzr+8sk1WnVYq82PoaMh1l9FjzLNGouQWBdo3E UzIo/KUfQKmoZce6O723L6OI4ffdK5oMtfaTpe+SiUPpV1lUAcA= =jNlu -----END PGP SIGNATURE----- Merge tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd updates from Chuck Lever: "This release introduces support for the CB_RECALL_ANY operation. NFSD can send this operation to request that clients return any delegations they choose. The server uses this operation to handle low memory scenarios or indicate to a client when that client has reached the maximum number of delegations the server supports. The NFSv4.2 READ_PLUS operation has been simplified temporarily whilst support for sparse files in local filesystems and the VFS is improved. Two major data structure fixes appear in this release: - The nfs4_file hash table is replaced with a resizable hash table to reduce the latency of NFSv4 OPEN operations. - Reference counting in the NFSD filecache has been hardened against races. In furtherance of removing support for NFSv2 in a subsequent kernel release, a new Kconfig option enables server-side support for NFSv2 to be left out of a kernel build. MAINTAINERS has been updated to indicate that changes to fs/exportfs should go through the NFSD tree" * tag 'nfsd-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (49 commits) NFSD: Avoid clashing function prototypes SUNRPC: Fix crasher in unwrap_integ_data() SUNRPC: Make the svc_authenticate tracepoint conditional NFSD: Use only RQ_DROPME to signal the need to drop a reply SUNRPC: Clean up xdr_write_pages() SUNRPC: Don't leak netobj memory when gss_read_proxy_verf() fails NFSD: add CB_RECALL_ANY tracepoints NFSD: add delegation reaper to react to low memory condition NFSD: add support for sending CB_RECALL_ANY NFSD: refactoring courtesy_client_reaper to a generic low memory shrinker trace: Relocate event helper files NFSD: pass range end to vfs_fsync_range() instead of count lockd: fix file selection in nlmsvc_cancel_blocked lockd: ensure we use the correct file descriptor when unlocking lockd: set missing fl_flags field when retrieving args NFSD: Use struct_size() helper in alloc_session() nfsd: return error if nfs4_setacl fails lockd: set other missing fields when unlocking files NFSD: Add an nfsd_file_fsync tracepoint sunrpc: svc: Remove an unused static function svc_ungetu32() ...
505 lines
12 KiB
C
505 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/fs/lockd/svcsubs.c
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*
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* Various support routines for the NLM server.
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*
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* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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*/
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/time.h>
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#include <linux/in.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/sunrpc/addr.h>
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#include <linux/lockd/lockd.h>
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#include <linux/lockd/share.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <uapi/linux/nfs2.h>
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#define NLMDBG_FACILITY NLMDBG_SVCSUBS
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/*
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* Global file hash table
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*/
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#define FILE_HASH_BITS 7
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#define FILE_NRHASH (1<<FILE_HASH_BITS)
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static struct hlist_head nlm_files[FILE_NRHASH];
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static DEFINE_MUTEX(nlm_file_mutex);
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#ifdef CONFIG_SUNRPC_DEBUG
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static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
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{
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u32 *fhp = (u32*)f->data;
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/* print the first 32 bytes of the fh */
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dprintk("lockd: %s (%08x %08x %08x %08x %08x %08x %08x %08x)\n",
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msg, fhp[0], fhp[1], fhp[2], fhp[3],
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fhp[4], fhp[5], fhp[6], fhp[7]);
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}
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static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
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{
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struct inode *inode = nlmsvc_file_inode(file);
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dprintk("lockd: %s %s/%ld\n",
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msg, inode->i_sb->s_id, inode->i_ino);
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}
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#else
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static inline void nlm_debug_print_fh(char *msg, struct nfs_fh *f)
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{
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return;
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}
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static inline void nlm_debug_print_file(char *msg, struct nlm_file *file)
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{
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return;
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}
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#endif
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static inline unsigned int file_hash(struct nfs_fh *f)
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{
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unsigned int tmp=0;
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int i;
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for (i=0; i<NFS2_FHSIZE;i++)
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tmp += f->data[i];
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return tmp & (FILE_NRHASH - 1);
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}
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int lock_to_openmode(struct file_lock *lock)
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{
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return (lock->fl_type == F_WRLCK) ? O_WRONLY : O_RDONLY;
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}
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/*
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* Open the file. Note that if we're reexporting, for example,
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* this could block the lockd thread for a while.
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*
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* We have to make sure we have the right credential to open
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* the file.
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*/
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static __be32 nlm_do_fopen(struct svc_rqst *rqstp,
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struct nlm_file *file, int mode)
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{
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struct file **fp = &file->f_file[mode];
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__be32 nfserr;
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if (*fp)
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return 0;
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nfserr = nlmsvc_ops->fopen(rqstp, &file->f_handle, fp, mode);
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if (nfserr)
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dprintk("lockd: open failed (error %d)\n", nfserr);
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return nfserr;
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}
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/*
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* Lookup file info. If it doesn't exist, create a file info struct
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* and open a (VFS) file for the given inode.
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*/
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__be32
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nlm_lookup_file(struct svc_rqst *rqstp, struct nlm_file **result,
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struct nlm_lock *lock)
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{
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struct nlm_file *file;
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unsigned int hash;
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__be32 nfserr;
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int mode;
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nlm_debug_print_fh("nlm_lookup_file", &lock->fh);
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hash = file_hash(&lock->fh);
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mode = lock_to_openmode(&lock->fl);
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/* Lock file table */
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mutex_lock(&nlm_file_mutex);
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hlist_for_each_entry(file, &nlm_files[hash], f_list)
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if (!nfs_compare_fh(&file->f_handle, &lock->fh)) {
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mutex_lock(&file->f_mutex);
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nfserr = nlm_do_fopen(rqstp, file, mode);
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mutex_unlock(&file->f_mutex);
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goto found;
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}
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nlm_debug_print_fh("creating file for", &lock->fh);
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nfserr = nlm_lck_denied_nolocks;
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file = kzalloc(sizeof(*file), GFP_KERNEL);
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if (!file)
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goto out_free;
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memcpy(&file->f_handle, &lock->fh, sizeof(struct nfs_fh));
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mutex_init(&file->f_mutex);
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INIT_HLIST_NODE(&file->f_list);
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INIT_LIST_HEAD(&file->f_blocks);
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nfserr = nlm_do_fopen(rqstp, file, mode);
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if (nfserr)
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goto out_unlock;
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hlist_add_head(&file->f_list, &nlm_files[hash]);
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found:
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dprintk("lockd: found file %p (count %d)\n", file, file->f_count);
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*result = file;
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file->f_count++;
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out_unlock:
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mutex_unlock(&nlm_file_mutex);
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return nfserr;
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out_free:
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kfree(file);
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goto out_unlock;
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}
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/*
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* Delete a file after having released all locks, blocks and shares
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*/
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static inline void
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nlm_delete_file(struct nlm_file *file)
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{
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nlm_debug_print_file("closing file", file);
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if (!hlist_unhashed(&file->f_list)) {
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hlist_del(&file->f_list);
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if (file->f_file[O_RDONLY])
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nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
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if (file->f_file[O_WRONLY])
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nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
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kfree(file);
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} else {
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printk(KERN_WARNING "lockd: attempt to release unknown file!\n");
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}
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}
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static int nlm_unlock_files(struct nlm_file *file, const struct file_lock *fl)
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{
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struct file_lock lock;
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locks_init_lock(&lock);
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lock.fl_type = F_UNLCK;
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lock.fl_start = 0;
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lock.fl_end = OFFSET_MAX;
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lock.fl_owner = fl->fl_owner;
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lock.fl_pid = fl->fl_pid;
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lock.fl_flags = FL_POSIX;
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lock.fl_file = file->f_file[O_RDONLY];
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if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL))
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goto out_err;
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lock.fl_file = file->f_file[O_WRONLY];
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if (lock.fl_file && vfs_lock_file(lock.fl_file, F_SETLK, &lock, NULL))
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goto out_err;
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return 0;
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out_err:
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pr_warn("lockd: unlock failure in %s:%d\n", __FILE__, __LINE__);
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return 1;
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}
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/*
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* Loop over all locks on the given file and perform the specified
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* action.
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*/
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static int
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nlm_traverse_locks(struct nlm_host *host, struct nlm_file *file,
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nlm_host_match_fn_t match)
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{
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struct inode *inode = nlmsvc_file_inode(file);
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struct file_lock *fl;
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struct file_lock_context *flctx = locks_inode_context(inode);
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struct nlm_host *lockhost;
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if (!flctx || list_empty_careful(&flctx->flc_posix))
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return 0;
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again:
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file->f_locks = 0;
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spin_lock(&flctx->flc_lock);
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list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
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if (fl->fl_lmops != &nlmsvc_lock_operations)
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continue;
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/* update current lock count */
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file->f_locks++;
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lockhost = ((struct nlm_lockowner *)fl->fl_owner)->host;
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if (match(lockhost, host)) {
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spin_unlock(&flctx->flc_lock);
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if (nlm_unlock_files(file, fl))
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return 1;
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goto again;
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}
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}
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spin_unlock(&flctx->flc_lock);
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return 0;
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}
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static int
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nlmsvc_always_match(void *dummy1, struct nlm_host *dummy2)
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{
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return 1;
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}
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/*
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* Inspect a single file
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*/
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static inline int
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nlm_inspect_file(struct nlm_host *host, struct nlm_file *file, nlm_host_match_fn_t match)
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{
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nlmsvc_traverse_blocks(host, file, match);
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nlmsvc_traverse_shares(host, file, match);
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return nlm_traverse_locks(host, file, match);
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}
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/*
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* Quick check whether there are still any locks, blocks or
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* shares on a given file.
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*/
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static inline int
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nlm_file_inuse(struct nlm_file *file)
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{
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struct inode *inode = nlmsvc_file_inode(file);
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struct file_lock *fl;
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struct file_lock_context *flctx = locks_inode_context(inode);
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if (file->f_count || !list_empty(&file->f_blocks) || file->f_shares)
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return 1;
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if (flctx && !list_empty_careful(&flctx->flc_posix)) {
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spin_lock(&flctx->flc_lock);
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list_for_each_entry(fl, &flctx->flc_posix, fl_list) {
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if (fl->fl_lmops == &nlmsvc_lock_operations) {
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spin_unlock(&flctx->flc_lock);
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return 1;
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}
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}
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spin_unlock(&flctx->flc_lock);
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}
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file->f_locks = 0;
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return 0;
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}
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static void nlm_close_files(struct nlm_file *file)
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{
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if (file->f_file[O_RDONLY])
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nlmsvc_ops->fclose(file->f_file[O_RDONLY]);
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if (file->f_file[O_WRONLY])
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nlmsvc_ops->fclose(file->f_file[O_WRONLY]);
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}
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/*
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* Loop over all files in the file table.
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*/
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static int
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nlm_traverse_files(void *data, nlm_host_match_fn_t match,
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int (*is_failover_file)(void *data, struct nlm_file *file))
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{
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struct hlist_node *next;
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struct nlm_file *file;
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int i, ret = 0;
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mutex_lock(&nlm_file_mutex);
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for (i = 0; i < FILE_NRHASH; i++) {
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hlist_for_each_entry_safe(file, next, &nlm_files[i], f_list) {
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if (is_failover_file && !is_failover_file(data, file))
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continue;
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file->f_count++;
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mutex_unlock(&nlm_file_mutex);
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/* Traverse locks, blocks and shares of this file
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* and update file->f_locks count */
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if (nlm_inspect_file(data, file, match))
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ret = 1;
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mutex_lock(&nlm_file_mutex);
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file->f_count--;
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/* No more references to this file. Let go of it. */
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if (list_empty(&file->f_blocks) && !file->f_locks
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&& !file->f_shares && !file->f_count) {
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hlist_del(&file->f_list);
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nlm_close_files(file);
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kfree(file);
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}
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}
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}
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mutex_unlock(&nlm_file_mutex);
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return ret;
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}
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/*
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* Release file. If there are no more remote locks on this file,
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* close it and free the handle.
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*
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* Note that we can't do proper reference counting without major
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* contortions because the code in fs/locks.c creates, deletes and
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* splits locks without notification. Our only way is to walk the
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* entire lock list each time we remove a lock.
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*/
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void
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nlm_release_file(struct nlm_file *file)
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{
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dprintk("lockd: nlm_release_file(%p, ct = %d)\n",
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file, file->f_count);
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/* Lock file table */
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mutex_lock(&nlm_file_mutex);
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/* If there are no more locks etc, delete the file */
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if (--file->f_count == 0 && !nlm_file_inuse(file))
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nlm_delete_file(file);
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mutex_unlock(&nlm_file_mutex);
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}
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/*
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* Helpers function for resource traversal
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*
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* nlmsvc_mark_host:
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* used by the garbage collector; simply sets h_inuse only for those
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* hosts, which passed network check.
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* Always returns 0.
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*
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* nlmsvc_same_host:
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* returns 1 iff the two hosts match. Used to release
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* all resources bound to a specific host.
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*
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* nlmsvc_is_client:
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* returns 1 iff the host is a client.
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* Used by nlmsvc_invalidate_all
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*/
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static int
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nlmsvc_mark_host(void *data, struct nlm_host *hint)
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{
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struct nlm_host *host = data;
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if ((hint->net == NULL) ||
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(host->net == hint->net))
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host->h_inuse = 1;
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return 0;
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}
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static int
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nlmsvc_same_host(void *data, struct nlm_host *other)
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{
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struct nlm_host *host = data;
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return host == other;
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}
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static int
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nlmsvc_is_client(void *data, struct nlm_host *dummy)
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{
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struct nlm_host *host = data;
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if (host->h_server) {
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/* we are destroying locks even though the client
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* hasn't asked us too, so don't unmonitor the
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* client
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*/
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if (host->h_nsmhandle)
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host->h_nsmhandle->sm_sticky = 1;
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return 1;
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} else
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return 0;
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}
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/*
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* Mark all hosts that still hold resources
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*/
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void
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nlmsvc_mark_resources(struct net *net)
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{
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struct nlm_host hint;
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dprintk("lockd: %s for net %x\n", __func__, net ? net->ns.inum : 0);
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hint.net = net;
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nlm_traverse_files(&hint, nlmsvc_mark_host, NULL);
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}
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/*
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* Release all resources held by the given client
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*/
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void
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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);
|