a099027c77
Synopsis
size[4] TLock tag[2] fid[4] flock[n]
size[4] RLock tag[2] status[1]
Description
Tlock is used to acquire/release byte range posix locks on a file
identified by given fid. The reply contains status of the lock request
flock structure:
type[1] - Type of lock: F_RDLCK, F_WRLCK, F_UNLCK
flags[4] - Flags could be either of
P9_LOCK_FLAGS_BLOCK - Blocked lock request, if there is a
conflicting lock exists, wait for that lock to be released.
P9_LOCK_FLAGS_RECLAIM - Reclaim lock request, used when client is
trying to reclaim a lock after a server restrart (due to crash)
start[8] - Starting offset for lock
length[8] - Number of bytes to lock
If length is 0, lock all bytes starting at the location 'start'
through to the end of file
pid[4] - PID of the process that wants to take lock
client_id[4] - Unique client id
status[1] - Status of the lock request, can be
P9_LOCK_SUCCESS(0), P9_LOCK_BLOCKED(1), P9_LOCK_ERROR(2) or
P9_LOCK_GRACE(3)
P9_LOCK_SUCCESS - Request was successful
P9_LOCK_BLOCKED - A conflicting lock is held by another process
P9_LOCK_ERROR - Error while processing the lock request
P9_LOCK_GRACE - Server is in grace period, it can't accept new lock
requests in this period (except locks with
P9_LOCK_FLAGS_RECLAIM flag set)
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
69 lines
2.8 KiB
C
69 lines
2.8 KiB
C
/*
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* V9FS VFS extensions.
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*
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* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
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* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to:
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* Free Software Foundation
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* 51 Franklin Street, Fifth Floor
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* Boston, MA 02111-1301 USA
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*
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*/
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/* plan9 semantics are that created files are implicitly opened.
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* But linux semantics are that you call create, then open.
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* the plan9 approach is superior as it provides an atomic
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* open.
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* we track the create fid here. When the file is opened, if fidopen is
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* non-zero, we use the fid and can skip some steps.
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* there may be a better way to do this, but I don't know it.
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* one BAD way is to clunk the fid on create, then open it again:
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* you lose the atomicity of file open
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*/
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/* special case:
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* unlink calls remove, which is an implicit clunk. So we have to track
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* that kind of thing so that we don't try to clunk a dead fid.
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*/
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extern struct file_system_type v9fs_fs_type;
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extern const struct address_space_operations v9fs_addr_operations;
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extern const struct file_operations v9fs_file_operations;
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extern const struct file_operations v9fs_file_operations_dotl;
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extern const struct file_operations v9fs_dir_operations;
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extern const struct file_operations v9fs_dir_operations_dotl;
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extern const struct dentry_operations v9fs_dentry_operations;
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extern const struct dentry_operations v9fs_cached_dentry_operations;
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#ifdef CONFIG_9P_FSCACHE
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struct inode *v9fs_alloc_inode(struct super_block *sb);
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void v9fs_destroy_inode(struct inode *inode);
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#endif
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struct inode *v9fs_get_inode(struct super_block *sb, int mode);
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void v9fs_evict_inode(struct inode *inode);
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ino_t v9fs_qid2ino(struct p9_qid *qid);
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void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
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void v9fs_stat2inode_dotl(struct p9_stat_dotl *, struct inode *);
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int v9fs_dir_release(struct inode *inode, struct file *filp);
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int v9fs_file_open(struct inode *inode, struct file *file);
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void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
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void v9fs_dentry_release(struct dentry *);
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int v9fs_uflags2omode(int uflags, int extended);
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ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);
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void v9fs_blank_wstat(struct p9_wstat *wstat);
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int v9fs_vfs_setattr_dotl(struct dentry *, struct iattr *);
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#define P9_LOCK_TIMEOUT (30*HZ)
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