f085312204
SYNOPSIS
size[4] Tgetattr tag[2] fid[4] request_mask[8]
size[4] Rgetattr tag[2] lstat[n]
DESCRIPTION
The getattr transaction inquires about the file identified by fid.
request_mask is a bit mask that specifies which fields of the
stat structure is the client interested in.
The reply will contain a machine-independent directory entry,
laid out as follows:
st_result_mask[8]
Bit mask that indicates which fields in the stat structure
have been populated by the server
qid.type[1]
the type of the file (directory, etc.), represented as a bit
vector corresponding to the high 8 bits of the file's mode
word.
qid.vers[4]
version number for given path
qid.path[8]
the file server's unique identification for the file
st_mode[4]
Permission and flags
st_uid[4]
User id of owner
st_gid[4]
Group ID of owner
st_nlink[8]
Number of hard links
st_rdev[8]
Device ID (if special file)
st_size[8]
Size, in bytes
st_blksize[8]
Block size for file system IO
st_blocks[8]
Number of file system blocks allocated
st_atime_sec[8]
Time of last access, seconds
st_atime_nsec[8]
Time of last access, nanoseconds
st_mtime_sec[8]
Time of last modification, seconds
st_mtime_nsec[8]
Time of last modification, nanoseconds
st_ctime_sec[8]
Time of last status change, seconds
st_ctime_nsec[8]
Time of last status change, nanoseconds
st_btime_sec[8]
Time of creation (birth) of file, seconds
st_btime_nsec[8]
Time of creation (birth) of file, nanoseconds
st_gen[8]
Inode generation
st_data_version[8]
Data version number
request_mask and result_mask bit masks contain the following bits
#define P9_STATS_MODE 0x00000001ULL
#define P9_STATS_NLINK 0x00000002ULL
#define P9_STATS_UID 0x00000004ULL
#define P9_STATS_GID 0x00000008ULL
#define P9_STATS_RDEV 0x00000010ULL
#define P9_STATS_ATIME 0x00000020ULL
#define P9_STATS_MTIME 0x00000040ULL
#define P9_STATS_CTIME 0x00000080ULL
#define P9_STATS_INO 0x00000100ULL
#define P9_STATS_SIZE 0x00000200ULL
#define P9_STATS_BLOCKS 0x00000400ULL
#define P9_STATS_BTIME 0x00000800ULL
#define P9_STATS_GEN 0x00001000ULL
#define P9_STATS_DATA_VERSION 0x00002000ULL
#define P9_STATS_BASIC 0x000007ffULL
#define P9_STATS_ALL 0x00003fffULL
This patch implements the client side of getattr implementation for
9P2000.L. It introduces a new structure p9_stat_dotl for getting
Linux stat information along with QID. The data layout is similar to
stat structure in Linux user space with the following major
differences:
inode (st_ino) is not part of data. Instead qid is.
device (st_dev) is not part of data because this doesn't make sense
on the client.
All time variables are 64 bit wide on the wire. The kernel seems to use
32 bit variables for these variables. However, some of the architectures
have used 64 bit variables and glibc exposes 64 bit variables to user
space on some architectures. Hence to be on the safer side we have made
these 64 bit in the protocol. Refer to the comments in
include/asm-generic/stat.h
There are some additional fields: st_btime_sec, st_btime_nsec, st_gen,
st_data_version apart from the bitmask, st_result_mask. The bit mask
is filled by the server to indicate which stat fields have been
populated by the server. Currently there is no clean way for the
server to obtain these additional fields, so it sends back just the
basic fields.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Signed-off-by: Eric Van Hensbegren <ericvh@gmail.com>
67 lines
2.7 KiB
C
67 lines
2.7 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_clear_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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