cregit-Linux how code gets into the kernel

Release 4.16 fs/afs/super.c

Directory: fs/afs
/* AFS superblock handling
 *
 * Copyright (c) 2002, 2007 Red Hat, Inc. All rights reserved.
 *
 * This software may be freely redistributed under the terms of the
 * GNU General Public License.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Authors: David Howells <dhowells@redhat.com>
 *          David Woodhouse <dwmw2@infradead.org>
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/parser.h>
#include <linux/statfs.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <linux/magic.h>
#include <net/net_namespace.h>
#include "internal.h"

static void afs_i_init_once(void *foo);
static struct dentry *afs_mount(struct file_system_type *fs_type,
		      int flags, const char *dev_name, void *data);
static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int afs_show_devname(struct seq_file *m, struct dentry *root);
static int afs_show_options(struct seq_file *m, struct dentry *root);


struct file_system_type afs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "afs",
	.mount		= afs_mount,
	.kill_sb	= afs_kill_super,
	.fs_flags	= 0,
};
MODULE_ALIAS_FS("afs");


static const struct super_operations afs_super_ops = {
	.statfs		= afs_statfs,
	.alloc_inode	= afs_alloc_inode,
	.drop_inode	= afs_drop_inode,
	.destroy_inode	= afs_destroy_inode,
	.evict_inode	= afs_evict_inode,
	.show_devname	= afs_show_devname,
	.show_options	= afs_show_options,
};


static struct kmem_cache *afs_inode_cachep;

static atomic_t afs_count_active_inodes;


enum {
	
afs_no_opt,
	
afs_opt_cell,
	
afs_opt_dyn,
	
afs_opt_rwpath,
	
afs_opt_vol,
	
afs_opt_autocell,
};


static const match_table_t afs_options_list = {
	{ afs_opt_cell,		"cell=%s"	},
	{ afs_opt_dyn,		"dyn"		},
	{ afs_opt_rwpath,	"rwpath"	},
	{ afs_opt_vol,		"vol=%s"	},
	{ afs_opt_autocell,	"autocell"	},
	{ afs_no_opt,		NULL		},
};

/*
 * initialise the filesystem
 */

int __init afs_fs_init(void) { int ret; _enter(""); /* create ourselves an inode cache */ atomic_set(&afs_count_active_inodes, 0); ret = -ENOMEM; afs_inode_cachep = kmem_cache_create("afs_inode_cache", sizeof(struct afs_vnode), 0, SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, afs_i_init_once); if (!afs_inode_cachep) { printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n"); return ret; } /* now export our filesystem to lesser mortals */ ret = register_filesystem(&afs_fs_type); if (ret < 0) { kmem_cache_destroy(afs_inode_cachep); _leave(" = %d", ret); return ret; } _leave(" = 0"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells10396.26%360.00%
Andrew Morton21.87%120.00%
Vladimir Davydov21.87%120.00%
Total107100.00%5100.00%

/* * clean up the filesystem */
void __exit afs_fs_exit(void) { _enter(""); afs_mntpt_kill_timer(); unregister_filesystem(&afs_fs_type); if (atomic_read(&afs_count_active_inodes) != 0) { printk("kAFS: %d active inode objects still present\n", atomic_read(&afs_count_active_inodes)); BUG(); } /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(afs_inode_cachep); _leave(""); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells5893.55%375.00%
Kirill A. Shutemov46.45%125.00%
Total62100.00%4100.00%

/* * Display the mount device name in /proc/mounts. */
static int afs_show_devname(struct seq_file *m, struct dentry *root) { struct afs_super_info *as = AFS_FS_S(root->d_sb); struct afs_volume *volume = as->volume; struct afs_cell *cell = as->cell; const char *suf = ""; char pref = '%'; if (as->dyn_root) { seq_puts(m, "none"); return 0; } switch (volume->type) { case AFSVL_RWVOL: break; case AFSVL_ROVOL: pref = '#'; if (volume->type_force) suf = ".readonly"; break; case AFSVL_BACKVOL: pref = '#'; suf = ".backup"; break; } seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells140100.00%3100.00%
Total140100.00%3100.00%

/* * Display the mount options in /proc/mounts. */
static int afs_show_options(struct seq_file *m, struct dentry *root) { struct afs_super_info *as = AFS_FS_S(root->d_sb); if (as->dyn_root) seq_puts(m, ",dyn"); if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags)) seq_puts(m, ",autocell"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells69100.00%2100.00%
Total69100.00%2100.00%

/* * parse the mount options * - this function has been shamelessly adapted from the ext3 fs which * shamelessly adapted it from the msdos fs */
static int afs_parse_options(struct afs_mount_params *params, char *options, const char **devname) { struct afs_cell *cell; substring_t args[MAX_OPT_ARGS]; char *p; int token; _enter("%s", options); options[PAGE_SIZE - 1] = 0; while ((p = strsep(&options, ","))) { if (!*p) continue; token = match_token(p, afs_options_list, args); switch (token) { case afs_opt_cell: rcu_read_lock(); cell = afs_lookup_cell_rcu(params->net, args[0].from, args[0].to - args[0].from); rcu_read_unlock(); if (IS_ERR(cell)) return PTR_ERR(cell); afs_put_cell(params->net, params->cell); params->cell = cell; break; case afs_opt_rwpath: params->rwpath = true; break; case afs_opt_vol: *devname = args[0].from; break; case afs_opt_autocell: params->autocell = true; break; case afs_opt_dyn: params->dyn_root = true; break; default: printk(KERN_ERR "kAFS:" " Unknown or invalid mount option: '%s'\n", p); return -EINVAL; } } _leave(" = 0"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells22195.67%981.82%
Wang Lei93.90%19.09%
Linus Torvalds10.43%19.09%
Total231100.00%11100.00%

/* * parse a device name to get cell name, volume name, volume type and R/W * selector * - this can be one of the following: * "%[cell:]volume[.]" R/W volume * "#[cell:]volume[.]" R/O or R/W volume (rwpath=0), * or R/W (rwpath=1) volume * "%[cell:]volume.readonly" R/O volume * "#[cell:]volume.readonly" R/O volume * "%[cell:]volume.backup" Backup volume * "#[cell:]volume.backup" Backup volume */
static int afs_parse_device_name(struct afs_mount_params *params, const char *name) { struct afs_cell *cell; const char *cellname, *suffix; int cellnamesz; _enter(",%s", name); if (!name) { printk(KERN_ERR "kAFS: no volume name specified\n"); return -EINVAL; } if ((name[0] != '%' && name[0] != '#') || !name[1]) { printk(KERN_ERR "kAFS: unparsable volume name\n"); return -EINVAL; } /* determine the type of volume we're looking for */ params->type = AFSVL_ROVOL; params->force = false; if (params->rwpath || name[0] == '%') { params->type = AFSVL_RWVOL; params->force = true; } name++; /* split the cell name out if there is one */ params->volname = strchr(name, ':'); if (params->volname) { cellname = name; cellnamesz = params->volname - name; params->volname++; } else { params->volname = name; cellname = NULL; cellnamesz = 0; } /* the volume type is further affected by a possible suffix */ suffix = strrchr(params->volname, '.'); if (suffix) { if (strcmp(suffix, ".readonly") == 0) { params->type = AFSVL_ROVOL; params->force = true; } else if (strcmp(suffix, ".backup") == 0) { params->type = AFSVL_BACKVOL; params->force = true; } else if (suffix[1] == 0) { } else { suffix = NULL; } } params->volnamesz = suffix ? suffix - params->volname : strlen(params->volname); _debug("cell %*.*s [%p]", cellnamesz, cellnamesz, cellname ?: "", params->cell); /* lookup the cell record */ if (cellname || !params->cell) { cell = afs_lookup_cell(params->net, cellname, cellnamesz, NULL, false); if (IS_ERR(cell)) { printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n", cellnamesz, cellnamesz, cellname ?: ""); return PTR_ERR(cell); } afs_put_cell(params->net, params->cell); params->cell = cell; } _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s", params->cell->name, params->cell, params->volnamesz, params->volnamesz, params->volname, suffix ?: "-", params->type, params->force ? " FORCE" : ""); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells43098.62%480.00%
Wang Lei61.38%120.00%
Total436100.00%5100.00%

/* * check a superblock to see if it's the one we're looking for */
static int afs_test_super(struct super_block *sb, void *data) { struct afs_super_info *as1 = data; struct afs_super_info *as = AFS_FS_S(sb); return (as->net == as1->net && as->volume && as->volume->vid == as1->volume->vid); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells5186.44%466.67%
Linus Torvalds58.47%116.67%
Al Viro35.08%116.67%
Total59100.00%6100.00%


static int afs_dynroot_test_super(struct super_block *sb, void *data) { return false; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells1794.44%266.67%
Linus Torvalds15.56%133.33%
Total18100.00%3100.00%


static int afs_set_super(struct super_block *sb, void *data) { struct afs_super_info *as = data; sb->s_fs_info = as; return set_anon_super(sb, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells2158.33%375.00%
Al Viro1541.67%125.00%
Total36100.00%4100.00%

/* * fill in the superblock */
static int afs_fill_super(struct super_block *sb, struct afs_mount_params *params) { struct afs_super_info *as = AFS_FS_S(sb); struct afs_fid fid; struct inode *inode = NULL; int ret; _enter(""); /* fill in the superblock */ sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; sb->s_magic = AFS_FS_MAGIC; sb->s_op = &afs_super_ops; if (!as->dyn_root) sb->s_xattr = afs_xattr_handlers; ret = super_setup_bdi(sb); if (ret) return ret; sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE; /* allocate the root inode and dentry */ if (as->dyn_root) { inode = afs_iget_pseudo_dir(sb, true); sb->s_flags |= SB_RDONLY; } else { sprintf(sb->s_id, "%u", as->volume->vid); afs_activate_volume(as->volume); fid.vid = as->volume->vid; fid.vnode = 1; fid.unique = 1; inode = afs_iget(sb, params->key, &fid, NULL, NULL, NULL); } if (IS_ERR(inode)) return PTR_ERR(inode); if (params->autocell || params->dyn_root) set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags); ret = -ENOMEM; sb->s_root = d_make_root(inode); if (!sb->s_root) goto error; sb->s_d_op = &afs_fs_dentry_operations; _leave(" = 0"); return 0; error: _leave(" = %d", ret); return ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells20972.57%952.94%
Al Viro3010.42%317.65%
Jan Kara217.29%15.88%
Wang Lei196.60%15.88%
Andrew Morton41.39%15.88%
Jens Axboe31.04%15.88%
Kirill A. Shutemov20.69%15.88%
Total288100.00%17100.00%


static struct afs_super_info *afs_alloc_sbi(struct afs_mount_params *params) { struct afs_super_info *as; as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL); if (as) { as->net = afs_get_net(params->net); if (params->dyn_root) as->dyn_root = true; else as->cell = afs_get_cell(params->cell); } return as; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells75100.00%2100.00%
Total75100.00%2100.00%


static void afs_destroy_sbi(struct afs_super_info *as) { if (as) { afs_put_volume(as->cell, as->volume); afs_put_cell(as->net, as->cell); afs_put_net(as->net); kfree(as); } }

Contributors

PersonTokensPropCommitsCommitProp
David Howells51100.00%2100.00%
Total51100.00%2100.00%

/* * get an AFS superblock */
static struct dentry *afs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *options) { struct afs_mount_params params; struct super_block *sb; struct afs_volume *candidate; struct key *key; struct afs_super_info *as; int ret; _enter(",,%s,%p", dev_name, options); memset(&params, 0, sizeof(params)); params.net = &__afs_net; ret = -EINVAL; if (current->nsproxy->net_ns != &init_net) goto error; /* parse the options and device name */ if (options) { ret = afs_parse_options(&params, options, &dev_name); if (ret < 0) goto error; } if (!params.dyn_root) { ret = afs_parse_device_name(&params, dev_name); if (ret < 0) goto error; /* try and do the mount securely */ key = afs_request_key(params.cell); if (IS_ERR(key)) { _leave(" = %ld [key]", PTR_ERR(key)); ret = PTR_ERR(key); goto error; } params.key = key; } /* allocate a superblock info record */ ret = -ENOMEM; as = afs_alloc_sbi(&params); if (!as) goto error_key; if (!params.dyn_root) { /* Assume we're going to need a volume record; at the very * least we can use it to update the volume record if we have * one already. This checks that the volume exists within the * cell. */ candidate = afs_create_volume(&params); if (IS_ERR(candidate)) { ret = PTR_ERR(candidate); goto error_as; } as->volume = candidate; } /* allocate a deviceless superblock */ sb = sget(fs_type, as->dyn_root ? afs_dynroot_test_super : afs_test_super, afs_set_super, flags, as); if (IS_ERR(sb)) { ret = PTR_ERR(sb); goto error_as; } if (!sb->s_root) { /* initial superblock/root creation */ _debug("create"); ret = afs_fill_super(sb, &params); if (ret < 0) goto error_sb; as = NULL; sb->s_flags |= SB_ACTIVE; } else { _debug("reuse"); ASSERTCMP(sb->s_flags, &, SB_ACTIVE); afs_destroy_sbi(as); as = NULL; } afs_put_cell(params.net, params.cell); key_put(params.key); _leave(" = 0 [%p]", sb); return dget(sb->s_root); error_sb: deactivate_locked_super(sb); goto error_key; error_as: afs_destroy_sbi(as); error_key: key_put(params.key); error: afs_put_cell(params.net, params.cell); _leave(" = %d", ret); return ERR_PTR(ret); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells41388.82%1263.16%
Al Viro286.02%315.79%
Eric W. Biedermann194.09%15.26%
Miklos Szeredi20.43%15.26%
Linus Torvalds20.43%15.26%
Andries E. Brouwer10.22%15.26%
Total465100.00%19100.00%


static void afs_kill_super(struct super_block *sb) { struct afs_super_info *as = AFS_FS_S(sb); /* Clear the callback interests (which will do ilookup5) before * deactivating the superblock. */ if (as->volume) afs_clear_callback_interests(as->net, as->volume->servers); kill_anon_super(sb); if (as->volume) afs_deactivate_volume(as->volume); afs_destroy_sbi(as); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells6093.75%583.33%
Al Viro46.25%116.67%
Total64100.00%6100.00%

/* * Initialise an inode cache slab element prior to any use. Note that * afs_alloc_inode() *must* reset anything that could incorrectly leak from one * inode to another. */
static void afs_i_init_once(void *_vnode) { struct afs_vnode *vnode = _vnode; memset(vnode, 0, sizeof(*vnode)); inode_init_once(&vnode->vfs_inode); mutex_init(&vnode->io_lock); mutex_init(&vnode->validate_lock); spin_lock_init(&vnode->wb_lock); spin_lock_init(&vnode->lock); INIT_LIST_HEAD(&vnode->wb_keys); INIT_LIST_HEAD(&vnode->pending_locks); INIT_LIST_HEAD(&vnode->granted_locks); INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work); seqlock_init(&vnode->cb_lock); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells10795.54%880.00%
Christoph Lameter32.68%110.00%
Andrew Morton21.79%110.00%
Total112100.00%10100.00%

/* * allocate an AFS inode struct from our slab cache */
static struct inode *afs_alloc_inode(struct super_block *sb) { struct afs_vnode *vnode; vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL); if (!vnode) return NULL; atomic_inc(&afs_count_active_inodes); /* Reset anything that shouldn't leak from one inode to the next. */ memset(&vnode->fid, 0, sizeof(vnode->fid)); memset(&vnode->status, 0, sizeof(vnode->status)); vnode->volume = NULL; vnode->lock_key = NULL; vnode->permit_cache = NULL; vnode->cb_interest = NULL; #ifdef CONFIG_AFS_FSCACHE vnode->cache = NULL; #endif vnode->flags = 1 << AFS_VNODE_UNSET; vnode->cb_type = 0; vnode->lock_state = AFS_VNODE_LOCK_NONE; _leave(" = %p", &vnode->vfs_inode); return &vnode->vfs_inode; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells14497.96%571.43%
Andrew Morton21.36%114.29%
Christoph Lameter10.68%114.29%
Total147100.00%7100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin43100.00%1100.00%
Total43100.00%1100.00%

/* * 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->cb_interest, ==, NULL); call_rcu(&inode->i_rcu, afs_i_callback); atomic_dec(&afs_count_active_inodes); }

Contributors

PersonTokensPropCommitsCommitProp
David Howells6891.89%583.33%
Nicholas Piggin68.11%116.67%
Total74100.00%6100.00%

/* * return information about an AFS volume */
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct afs_super_info *as = AFS_FS_S(dentry->d_sb); struct afs_fs_cursor fc; struct afs_volume_status vs; struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry)); struct key *key; int ret; buf->f_type = dentry->d_sb->s_magic; buf->f_bsize = AFS_BLOCK_SIZE; buf->f_namelen = AFSNAMEMAX - 1; if (as->dyn_root) { buf->f_blocks = 1; buf->f_bavail = 0; buf->f_bfree = 0; return 0; } key = afs_request_key(vnode->volume->cell); if (IS_ERR(key)) return PTR_ERR(key); ret = -ERESTARTSYS; if (afs_begin_vnode_operation(&fc, vnode, key)) { fc.flags |= AFS_FS_CURSOR_NO_VSLEEP; while (afs_select_fileserver(&fc)) { fc.cb_break = vnode->cb_break + vnode->cb_s_break; afs_fs_get_volume_status(&fc, &vs); } afs_check_for_remote_deletion(&fc, fc.vnode); afs_vnode_commit_status(&fc, vnode, fc.cb_break); ret = afs_end_vnode_operation(&fc); } key_put(key); if (ret == 0) { 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 ret; }

Contributors

PersonTokensPropCommitsCommitProp
David Howells277100.00%4100.00%
Total277100.00%4100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
David Howells276590.15%2749.09%
Al Viro963.13%610.91%
Wang Lei501.63%11.82%
Nicholas Piggin491.60%11.82%
Eric W. Biedermann300.98%23.64%
Jan Kara210.68%11.82%
Andrew Morton150.49%23.64%
Linus Torvalds90.29%23.64%
Christoph Lameter90.29%35.45%
Kirill A. Shutemov60.20%23.64%
Miklos Szeredi40.13%11.82%
Jens Axboe30.10%11.82%
Alexey Dobriyan30.10%11.82%
Andries E. Brouwer20.07%11.82%
Vladimir Davydov20.07%11.82%
Steven Whitehouse10.03%11.82%
David Woodhouse10.03%11.82%
Josef 'Jeff' Sipek10.03%11.82%
Total3067100.00%55100.00%
Directory: fs/afs
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