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![Kirill A. Shutemov](/assets/img/avatar_default.png)
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
557 lines
12 KiB
C
557 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 <linux/nsproxy.h>
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#include <net/net_namespace.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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MODULE_ALIAS_FS("afs");
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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|SLAB_ACCOUNT,
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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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/*
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* Make sure all delayed rcu free inodes are flushed before we
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* destroy cache.
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*/
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rcu_barrier();
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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 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_SIZE;
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sb->s_blocksize_bits = PAGE_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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sb->s_root = d_make_root(inode);
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if (!sb->s_root)
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goto error;
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sb->s_d_op = &afs_fs_dentry_operations;
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_leave(" = 0");
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return 0;
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error:
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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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ret = -EINVAL;
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if (current->nsproxy->net_ns != &init_net)
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goto error;
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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, flags, 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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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;
|
|
vnode->cb_promised = false;
|
|
|
|
_leave(" = %p", &vnode->vfs_inode);
|
|
return &vnode->vfs_inode;
|
|
}
|
|
|
|
static void afs_i_callback(struct rcu_head *head)
|
|
{
|
|
struct inode *inode = container_of(head, struct inode, i_rcu);
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
|
kmem_cache_free(afs_inode_cachep, vnode);
|
|
}
|
|
|
|
/*
|
|
* destroy an AFS inode struct
|
|
*/
|
|
static void afs_destroy_inode(struct inode *inode)
|
|
{
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
|
|
|
_enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
|
|
|
|
_debug("DESTROY INODE %p", inode);
|
|
|
|
ASSERTCMP(vnode->server, ==, NULL);
|
|
|
|
call_rcu(&inode->i_rcu, afs_i_callback);
|
|
atomic_dec(&afs_count_active_inodes);
|
|
}
|
|
|
|
/*
|
|
* return information about an AFS volume
|
|
*/
|
|
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
|
|
{
|
|
struct afs_volume_status vs;
|
|
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
|
|
struct key *key;
|
|
int ret;
|
|
|
|
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;
|
|
}
|