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2e41ae225f
Set s_id in the superblock to the name of the AFS volume that this superblock corresponds to. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
551 lines
12 KiB
C
551 lines
12 KiB
C
/* AFS superblock handling
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*
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* Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
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*
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* This software may be freely redistributed under the terms of the
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* GNU General Public License.
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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 the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* Authors: David Howells <dhowells@redhat.com>
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* David Woodhouse <dwmw2@infradead.org>
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mount.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/pagemap.h>
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#include <linux/parser.h>
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#include <linux/statfs.h>
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#include <linux/sched.h>
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#include "internal.h"
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#define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
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static void afs_i_init_once(void *foo);
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static struct dentry *afs_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data);
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static void afs_kill_super(struct super_block *sb);
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static struct inode *afs_alloc_inode(struct super_block *sb);
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static void afs_destroy_inode(struct inode *inode);
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static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
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struct file_system_type afs_fs_type = {
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.owner = THIS_MODULE,
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.name = "afs",
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.mount = afs_mount,
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.kill_sb = afs_kill_super,
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.fs_flags = 0,
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};
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static const struct super_operations afs_super_ops = {
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.statfs = afs_statfs,
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.alloc_inode = afs_alloc_inode,
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.drop_inode = afs_drop_inode,
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.destroy_inode = afs_destroy_inode,
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.evict_inode = afs_evict_inode,
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.show_options = generic_show_options,
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};
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static struct kmem_cache *afs_inode_cachep;
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static atomic_t afs_count_active_inodes;
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enum {
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afs_no_opt,
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afs_opt_cell,
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afs_opt_rwpath,
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afs_opt_vol,
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afs_opt_autocell,
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};
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static const match_table_t afs_options_list = {
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{ afs_opt_cell, "cell=%s" },
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{ afs_opt_rwpath, "rwpath" },
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{ afs_opt_vol, "vol=%s" },
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{ afs_opt_autocell, "autocell" },
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{ afs_no_opt, NULL },
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};
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/*
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* initialise the filesystem
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*/
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int __init afs_fs_init(void)
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{
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int ret;
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_enter("");
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/* create ourselves an inode cache */
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atomic_set(&afs_count_active_inodes, 0);
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ret = -ENOMEM;
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afs_inode_cachep = kmem_cache_create("afs_inode_cache",
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sizeof(struct afs_vnode),
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0,
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SLAB_HWCACHE_ALIGN,
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afs_i_init_once);
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if (!afs_inode_cachep) {
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printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
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return ret;
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}
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/* now export our filesystem to lesser mortals */
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ret = register_filesystem(&afs_fs_type);
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if (ret < 0) {
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kmem_cache_destroy(afs_inode_cachep);
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_leave(" = %d", ret);
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return ret;
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}
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_leave(" = 0");
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return 0;
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}
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/*
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* clean up the filesystem
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*/
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void __exit afs_fs_exit(void)
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{
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_enter("");
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afs_mntpt_kill_timer();
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unregister_filesystem(&afs_fs_type);
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if (atomic_read(&afs_count_active_inodes) != 0) {
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printk("kAFS: %d active inode objects still present\n",
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atomic_read(&afs_count_active_inodes));
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BUG();
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}
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kmem_cache_destroy(afs_inode_cachep);
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_leave("");
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}
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/*
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* parse the mount options
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* - this function has been shamelessly adapted from the ext3 fs which
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* shamelessly adapted it from the msdos fs
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*/
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static int afs_parse_options(struct afs_mount_params *params,
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char *options, const char **devname)
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{
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struct afs_cell *cell;
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substring_t args[MAX_OPT_ARGS];
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char *p;
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int token;
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_enter("%s", options);
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options[PAGE_SIZE - 1] = 0;
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while ((p = strsep(&options, ","))) {
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if (!*p)
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continue;
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token = match_token(p, afs_options_list, args);
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switch (token) {
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case afs_opt_cell:
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cell = afs_cell_lookup(args[0].from,
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args[0].to - args[0].from,
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false);
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if (IS_ERR(cell))
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return PTR_ERR(cell);
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afs_put_cell(params->cell);
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params->cell = cell;
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break;
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case afs_opt_rwpath:
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params->rwpath = 1;
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break;
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case afs_opt_vol:
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*devname = args[0].from;
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break;
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case afs_opt_autocell:
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params->autocell = 1;
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break;
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default:
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printk(KERN_ERR "kAFS:"
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" Unknown or invalid mount option: '%s'\n", p);
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return -EINVAL;
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}
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}
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_leave(" = 0");
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return 0;
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}
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/*
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* parse a device name to get cell name, volume name, volume type and R/W
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* selector
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* - this can be one of the following:
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* "%[cell:]volume[.]" R/W volume
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* "#[cell:]volume[.]" R/O or R/W volume (rwpath=0),
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* or R/W (rwpath=1) volume
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* "%[cell:]volume.readonly" R/O volume
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* "#[cell:]volume.readonly" R/O volume
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* "%[cell:]volume.backup" Backup volume
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* "#[cell:]volume.backup" Backup volume
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*/
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static int afs_parse_device_name(struct afs_mount_params *params,
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const char *name)
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{
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struct afs_cell *cell;
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const char *cellname, *suffix;
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int cellnamesz;
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_enter(",%s", name);
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if (!name) {
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printk(KERN_ERR "kAFS: no volume name specified\n");
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return -EINVAL;
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}
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if ((name[0] != '%' && name[0] != '#') || !name[1]) {
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printk(KERN_ERR "kAFS: unparsable volume name\n");
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return -EINVAL;
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}
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/* determine the type of volume we're looking for */
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params->type = AFSVL_ROVOL;
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params->force = false;
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if (params->rwpath || name[0] == '%') {
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params->type = AFSVL_RWVOL;
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params->force = true;
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}
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name++;
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/* split the cell name out if there is one */
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params->volname = strchr(name, ':');
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if (params->volname) {
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cellname = name;
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cellnamesz = params->volname - name;
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params->volname++;
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} else {
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params->volname = name;
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cellname = NULL;
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cellnamesz = 0;
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}
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/* the volume type is further affected by a possible suffix */
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suffix = strrchr(params->volname, '.');
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if (suffix) {
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if (strcmp(suffix, ".readonly") == 0) {
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params->type = AFSVL_ROVOL;
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params->force = true;
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} else if (strcmp(suffix, ".backup") == 0) {
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params->type = AFSVL_BACKVOL;
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params->force = true;
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} else if (suffix[1] == 0) {
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} else {
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suffix = NULL;
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}
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}
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params->volnamesz = suffix ?
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suffix - params->volname : strlen(params->volname);
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_debug("cell %*.*s [%p]",
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cellnamesz, cellnamesz, cellname ?: "", params->cell);
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/* lookup the cell record */
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if (cellname || !params->cell) {
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cell = afs_cell_lookup(cellname, cellnamesz, true);
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if (IS_ERR(cell)) {
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printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
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cellnamesz, cellnamesz, cellname ?: "");
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return PTR_ERR(cell);
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}
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afs_put_cell(params->cell);
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params->cell = cell;
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}
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_debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
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params->cell->name, params->cell,
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params->volnamesz, params->volnamesz, params->volname,
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suffix ?: "-", params->type, params->force ? " FORCE" : "");
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return 0;
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}
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/*
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* check a superblock to see if it's the one we're looking for
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*/
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static int afs_test_super(struct super_block *sb, void *data)
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{
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struct afs_super_info *as1 = data;
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struct afs_super_info *as = sb->s_fs_info;
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return as->volume == as1->volume;
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}
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static int afs_set_super(struct super_block *sb, void *data)
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{
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sb->s_fs_info = data;
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return set_anon_super(sb, NULL);
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}
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/*
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* fill in the superblock
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*/
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static int afs_fill_super(struct super_block *sb,
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struct afs_mount_params *params)
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{
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struct afs_super_info *as = sb->s_fs_info;
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struct afs_fid fid;
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struct dentry *root = NULL;
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struct inode *inode = NULL;
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int ret;
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_enter("");
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/* fill in the superblock */
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sb->s_blocksize = PAGE_CACHE_SIZE;
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sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
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sb->s_magic = AFS_FS_MAGIC;
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sb->s_op = &afs_super_ops;
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sb->s_bdi = &as->volume->bdi;
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strlcpy(sb->s_id, as->volume->vlocation->vldb.name, sizeof(sb->s_id));
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/* allocate the root inode and dentry */
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fid.vid = as->volume->vid;
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fid.vnode = 1;
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fid.unique = 1;
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inode = afs_iget(sb, params->key, &fid, NULL, NULL);
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if (IS_ERR(inode))
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return PTR_ERR(inode);
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if (params->autocell)
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set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
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ret = -ENOMEM;
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root = d_alloc_root(inode);
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if (!root)
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goto error;
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sb->s_d_op = &afs_fs_dentry_operations;
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sb->s_root = root;
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_leave(" = 0");
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return 0;
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error:
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iput(inode);
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_leave(" = %d", ret);
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return ret;
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}
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/*
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* get an AFS superblock
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*/
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static struct dentry *afs_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *options)
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{
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struct afs_mount_params params;
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struct super_block *sb;
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struct afs_volume *vol;
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struct key *key;
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char *new_opts = kstrdup(options, GFP_KERNEL);
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struct afs_super_info *as;
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int ret;
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_enter(",,%s,%p", dev_name, options);
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memset(¶ms, 0, sizeof(params));
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/* parse the options and device name */
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if (options) {
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ret = afs_parse_options(¶ms, options, &dev_name);
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if (ret < 0)
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goto error;
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}
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ret = afs_parse_device_name(¶ms, dev_name);
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if (ret < 0)
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goto error;
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/* try and do the mount securely */
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key = afs_request_key(params.cell);
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if (IS_ERR(key)) {
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_leave(" = %ld [key]", PTR_ERR(key));
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ret = PTR_ERR(key);
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goto error;
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}
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params.key = key;
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/* parse the device name */
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vol = afs_volume_lookup(¶ms);
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if (IS_ERR(vol)) {
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ret = PTR_ERR(vol);
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goto error;
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}
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/* allocate a superblock info record */
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as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
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if (!as) {
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ret = -ENOMEM;
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afs_put_volume(vol);
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goto error;
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}
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as->volume = vol;
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/* allocate a deviceless superblock */
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sb = sget(fs_type, afs_test_super, afs_set_super, as);
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if (IS_ERR(sb)) {
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ret = PTR_ERR(sb);
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afs_put_volume(vol);
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kfree(as);
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goto error;
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}
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if (!sb->s_root) {
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/* initial superblock/root creation */
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_debug("create");
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sb->s_flags = flags;
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ret = afs_fill_super(sb, ¶ms);
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if (ret < 0) {
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deactivate_locked_super(sb);
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goto error;
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}
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save_mount_options(sb, new_opts);
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sb->s_flags |= MS_ACTIVE;
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} else {
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_debug("reuse");
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ASSERTCMP(sb->s_flags, &, MS_ACTIVE);
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afs_put_volume(vol);
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kfree(as);
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}
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afs_put_cell(params.cell);
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kfree(new_opts);
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_leave(" = 0 [%p]", sb);
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return dget(sb->s_root);
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error:
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afs_put_cell(params.cell);
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key_put(params.key);
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kfree(new_opts);
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_leave(" = %d", ret);
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return ERR_PTR(ret);
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}
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static void afs_kill_super(struct super_block *sb)
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{
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struct afs_super_info *as = sb->s_fs_info;
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kill_anon_super(sb);
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afs_put_volume(as->volume);
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kfree(as);
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}
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/*
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* initialise an inode cache slab element prior to any use
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*/
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static void afs_i_init_once(void *_vnode)
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{
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struct afs_vnode *vnode = _vnode;
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memset(vnode, 0, sizeof(*vnode));
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inode_init_once(&vnode->vfs_inode);
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init_waitqueue_head(&vnode->update_waitq);
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mutex_init(&vnode->permits_lock);
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mutex_init(&vnode->validate_lock);
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spin_lock_init(&vnode->writeback_lock);
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spin_lock_init(&vnode->lock);
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INIT_LIST_HEAD(&vnode->writebacks);
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INIT_LIST_HEAD(&vnode->pending_locks);
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INIT_LIST_HEAD(&vnode->granted_locks);
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INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
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INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work);
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}
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/*
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* allocate an AFS inode struct from our slab cache
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*/
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static struct inode *afs_alloc_inode(struct super_block *sb)
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{
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struct afs_vnode *vnode;
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vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
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if (!vnode)
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return NULL;
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atomic_inc(&afs_count_active_inodes);
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memset(&vnode->fid, 0, sizeof(vnode->fid));
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memset(&vnode->status, 0, sizeof(vnode->status));
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vnode->volume = NULL;
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vnode->update_cnt = 0;
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vnode->flags = 1 << AFS_VNODE_UNSET;
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vnode->cb_promised = false;
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_leave(" = %p", &vnode->vfs_inode);
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return &vnode->vfs_inode;
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}
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static void afs_i_callback(struct rcu_head *head)
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{
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struct inode *inode = container_of(head, struct inode, i_rcu);
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struct afs_vnode *vnode = AFS_FS_I(inode);
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INIT_LIST_HEAD(&inode->i_dentry);
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kmem_cache_free(afs_inode_cachep, vnode);
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}
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/*
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* destroy an AFS inode struct
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*/
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static void afs_destroy_inode(struct inode *inode)
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{
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struct afs_vnode *vnode = AFS_FS_I(inode);
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_enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
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_debug("DESTROY INODE %p", inode);
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ASSERTCMP(vnode->server, ==, NULL);
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call_rcu(&inode->i_rcu, afs_i_callback);
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atomic_dec(&afs_count_active_inodes);
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}
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/*
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* return information about an AFS volume
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*/
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static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct afs_volume_status vs;
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struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
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struct key *key;
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int ret;
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|
|
key = afs_request_key(vnode->volume->cell);
|
|
if (IS_ERR(key))
|
|
return PTR_ERR(key);
|
|
|
|
ret = afs_vnode_get_volume_status(vnode, key, &vs);
|
|
key_put(key);
|
|
if (ret < 0) {
|
|
_leave(" = %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
buf->f_type = dentry->d_sb->s_magic;
|
|
buf->f_bsize = AFS_BLOCK_SIZE;
|
|
buf->f_namelen = AFSNAMEMAX - 1;
|
|
|
|
if (vs.max_quota == 0)
|
|
buf->f_blocks = vs.part_max_blocks;
|
|
else
|
|
buf->f_blocks = vs.max_quota;
|
|
buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
|
|
return 0;
|
|
}
|