linux/fs/afs/dir.c
wanglei bec5eb6141 AFS: Implement an autocell mount capability [ver #2]
Implement the ability for the root directory of a mounted AFS filesystem to
accept lookups of arbitrary directory names, to interpet the names as the names
of cells, to look the cell names up in the DNS for AFSDB records and to mount
the root.cell volume of the nominated cell on the pseudo-directory created by
lookup.

This facility is requested by passing:

	-o autocell

to the mountpoint for which this is desired, usually the /afs mount.

To use this facility, a DNS upcall program is required for AFSDB records.  This
can be obtained from:

	http://people.redhat.com/~dhowells/afs/dns.afsdb.c

It should be compiled with -lresolv and -lkeyutils and installed as, say:

	/usr/sbin/dns.afsdb

Then the following line needs to be added to /sbin/request-key.conf:

	create	dns_resolver afsdb:*	*	/usr/sbin/dns.afsdb %k

This can be tested by mounting AFS, say:

	insmod dns_resolver.ko
	insmod af-rxrpc.ko
	insmod kafs.ko rootcell=grand.central.org
	mount -t afs "#grand.central.org:root.cell." /afs -o autocell

and doing:

	ls /afs/grand.central.org/

which should show:

	archive/  cvs/  doc/  local/  project/  service/  software/  user/  www/

if it works.

Signed-off-by: Wang Lei <wang840925@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2010-08-11 17:11:29 +00:00

1182 lines
27 KiB
C

/* dir.c: AFS filesystem directory handling
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
#include "internal.h"
static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd);
static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
static int afs_d_delete(struct dentry *dentry);
static void afs_d_release(struct dentry *dentry);
static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd);
static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
static int afs_rmdir(struct inode *dir, struct dentry *dentry);
static int afs_unlink(struct inode *dir, struct dentry *dentry);
static int afs_link(struct dentry *from, struct inode *dir,
struct dentry *dentry);
static int afs_symlink(struct inode *dir, struct dentry *dentry,
const char *content);
static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
const struct file_operations afs_dir_file_operations = {
.open = afs_dir_open,
.release = afs_release,
.readdir = afs_readdir,
.lock = afs_lock,
.llseek = generic_file_llseek,
};
const struct inode_operations afs_dir_inode_operations = {
.create = afs_create,
.lookup = afs_lookup,
.link = afs_link,
.unlink = afs_unlink,
.symlink = afs_symlink,
.mkdir = afs_mkdir,
.rmdir = afs_rmdir,
.rename = afs_rename,
.permission = afs_permission,
.getattr = afs_getattr,
.setattr = afs_setattr,
};
static const struct dentry_operations afs_fs_dentry_operations = {
.d_revalidate = afs_d_revalidate,
.d_delete = afs_d_delete,
.d_release = afs_d_release,
};
#define AFS_DIR_HASHTBL_SIZE 128
#define AFS_DIR_DIRENT_SIZE 32
#define AFS_DIRENT_PER_BLOCK 64
union afs_dirent {
struct {
uint8_t valid;
uint8_t unused[1];
__be16 hash_next;
__be32 vnode;
__be32 unique;
uint8_t name[16];
uint8_t overflow[4]; /* if any char of the name (inc
* NUL) reaches here, consume
* the next dirent too */
} u;
uint8_t extended_name[32];
};
/* AFS directory page header (one at the beginning of every 2048-byte chunk) */
struct afs_dir_pagehdr {
__be16 npages;
__be16 magic;
#define AFS_DIR_MAGIC htons(1234)
uint8_t nentries;
uint8_t bitmap[8];
uint8_t pad[19];
};
/* directory block layout */
union afs_dir_block {
struct afs_dir_pagehdr pagehdr;
struct {
struct afs_dir_pagehdr pagehdr;
uint8_t alloc_ctrs[128];
/* dir hash table */
uint16_t hashtable[AFS_DIR_HASHTBL_SIZE];
} hdr;
union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
};
/* layout on a linux VM page */
struct afs_dir_page {
union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
};
struct afs_lookup_cookie {
struct afs_fid fid;
const char *name;
size_t nlen;
int found;
};
/*
* check that a directory page is valid
*/
static inline void afs_dir_check_page(struct inode *dir, struct page *page)
{
struct afs_dir_page *dbuf;
loff_t latter;
int tmp, qty;
#if 0
/* check the page count */
qty = desc.size / sizeof(dbuf->blocks[0]);
if (qty == 0)
goto error;
if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
__func__, dir->i_ino, qty,
ntohs(dbuf->blocks[0].pagehdr.npages));
goto error;
}
#endif
/* determine how many magic numbers there should be in this page */
latter = dir->i_size - page_offset(page);
if (latter >= PAGE_SIZE)
qty = PAGE_SIZE;
else
qty = latter;
qty /= sizeof(union afs_dir_block);
/* check them */
dbuf = page_address(page);
for (tmp = 0; tmp < qty; tmp++) {
if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
__func__, dir->i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].pagehdr.magic));
goto error;
}
}
SetPageChecked(page);
return;
error:
SetPageChecked(page);
SetPageError(page);
}
/*
* discard a page cached in the pagecache
*/
static inline void afs_dir_put_page(struct page *page)
{
kunmap(page);
page_cache_release(page);
}
/*
* get a page into the pagecache
*/
static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
struct key *key)
{
struct page *page;
_enter("{%lu},%lu", dir->i_ino, index);
page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
if (!IS_ERR(page)) {
kmap(page);
if (!PageChecked(page))
afs_dir_check_page(dir, page);
if (PageError(page))
goto fail;
}
return page;
fail:
afs_dir_put_page(page);
_leave(" = -EIO");
return ERR_PTR(-EIO);
}
/*
* open an AFS directory file
*/
static int afs_dir_open(struct inode *inode, struct file *file)
{
_enter("{%lu}", inode->i_ino);
BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
return -ENOENT;
return afs_open(inode, file);
}
/*
* deal with one block in an AFS directory
*/
static int afs_dir_iterate_block(unsigned *fpos,
union afs_dir_block *block,
unsigned blkoff,
void *cookie,
filldir_t filldir)
{
union afs_dirent *dire;
unsigned offset, next, curr;
size_t nlen;
int tmp, ret;
_enter("%u,%x,%p,,",*fpos,blkoff,block);
curr = (*fpos - blkoff) / sizeof(union afs_dirent);
/* walk through the block, an entry at a time */
for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
offset < AFS_DIRENT_PER_BLOCK;
offset = next
) {
next = offset + 1;
/* skip entries marked unused in the bitmap */
if (!(block->pagehdr.bitmap[offset / 8] &
(1 << (offset % 8)))) {
_debug("ENT[%Zu.%u]: unused",
blkoff / sizeof(union afs_dir_block), offset);
if (offset >= curr)
*fpos = blkoff +
next * sizeof(union afs_dirent);
continue;
}
/* got a valid entry */
dire = &block->dirents[offset];
nlen = strnlen(dire->u.name,
sizeof(*block) -
offset * sizeof(union afs_dirent));
_debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
blkoff / sizeof(union afs_dir_block), offset,
(offset < curr ? "skip" : "fill"),
nlen, dire->u.name);
/* work out where the next possible entry is */
for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
if (next >= AFS_DIRENT_PER_BLOCK) {
_debug("ENT[%Zu.%u]:"
" %u travelled beyond end dir block"
" (len %u/%Zu)",
blkoff / sizeof(union afs_dir_block),
offset, next, tmp, nlen);
return -EIO;
}
if (!(block->pagehdr.bitmap[next / 8] &
(1 << (next % 8)))) {
_debug("ENT[%Zu.%u]:"
" %u unmarked extension (len %u/%Zu)",
blkoff / sizeof(union afs_dir_block),
offset, next, tmp, nlen);
return -EIO;
}
_debug("ENT[%Zu.%u]: ext %u/%Zu",
blkoff / sizeof(union afs_dir_block),
next, tmp, nlen);
next++;
}
/* skip if starts before the current position */
if (offset < curr)
continue;
/* found the next entry */
ret = filldir(cookie,
dire->u.name,
nlen,
blkoff + offset * sizeof(union afs_dirent),
ntohl(dire->u.vnode),
filldir == afs_lookup_filldir ?
ntohl(dire->u.unique) : DT_UNKNOWN);
if (ret < 0) {
_leave(" = 0 [full]");
return 0;
}
*fpos = blkoff + next * sizeof(union afs_dirent);
}
_leave(" = 1 [more]");
return 1;
}
/*
* iterate through the data blob that lists the contents of an AFS directory
*/
static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
filldir_t filldir, struct key *key)
{
union afs_dir_block *dblock;
struct afs_dir_page *dbuf;
struct page *page;
unsigned blkoff, limit;
int ret;
_enter("{%lu},%u,,", dir->i_ino, *fpos);
if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
_leave(" = -ESTALE");
return -ESTALE;
}
/* round the file position up to the next entry boundary */
*fpos += sizeof(union afs_dirent) - 1;
*fpos &= ~(sizeof(union afs_dirent) - 1);
/* walk through the blocks in sequence */
ret = 0;
while (*fpos < dir->i_size) {
blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
/* fetch the appropriate page from the directory */
page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
if (IS_ERR(page)) {
ret = PTR_ERR(page);
break;
}
limit = blkoff & ~(PAGE_SIZE - 1);
dbuf = page_address(page);
/* deal with the individual blocks stashed on this page */
do {
dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
sizeof(union afs_dir_block)];
ret = afs_dir_iterate_block(fpos, dblock, blkoff,
cookie, filldir);
if (ret != 1) {
afs_dir_put_page(page);
goto out;
}
blkoff += sizeof(union afs_dir_block);
} while (*fpos < dir->i_size && blkoff < limit);
afs_dir_put_page(page);
ret = 0;
}
out:
_leave(" = %d", ret);
return ret;
}
/*
* read an AFS directory
*/
static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
{
unsigned fpos;
int ret;
_enter("{%Ld,{%lu}}",
file->f_pos, file->f_path.dentry->d_inode->i_ino);
ASSERT(file->private_data != NULL);
fpos = file->f_pos;
ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
cookie, filldir, file->private_data);
file->f_pos = fpos;
_leave(" = %d", ret);
return ret;
}
/*
* search the directory for a name
* - if afs_dir_iterate_block() spots this function, it'll pass the FID
* uniquifier through dtype
*/
static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype)
{
struct afs_lookup_cookie *cookie = _cookie;
_enter("{%s,%Zu},%s,%u,,%llu,%u",
cookie->name, cookie->nlen, name, nlen,
(unsigned long long) ino, dtype);
/* insanity checks first */
BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
_leave(" = 0 [no]");
return 0;
}
cookie->fid.vnode = ino;
cookie->fid.unique = dtype;
cookie->found = 1;
_leave(" = -1 [found]");
return -1;
}
/*
* do a lookup in a directory
* - just returns the FID the dentry name maps to if found
*/
static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
struct afs_fid *fid, struct key *key)
{
struct afs_lookup_cookie cookie;
struct afs_super_info *as;
unsigned fpos;
int ret;
_enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
as = dir->i_sb->s_fs_info;
/* search the directory */
cookie.name = dentry->d_name.name;
cookie.nlen = dentry->d_name.len;
cookie.fid.vid = as->volume->vid;
cookie.found = 0;
fpos = 0;
ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
key);
if (ret < 0) {
_leave(" = %d [iter]", ret);
return ret;
}
ret = -ENOENT;
if (!cookie.found) {
_leave(" = -ENOENT [not found]");
return -ENOENT;
}
*fid = cookie.fid;
_leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
return 0;
}
/*
* Try to auto mount the mountpoint with pseudo directory, if the autocell
* operation is setted.
*/
static struct inode *afs_try_auto_mntpt(
int ret, struct dentry *dentry, struct inode *dir, struct key *key,
struct afs_fid *fid)
{
const char *devname = dentry->d_name.name;
struct afs_vnode *vnode = AFS_FS_I(dir);
struct inode *inode;
_enter("%d, %p{%s}, {%x:%u}, %p",
ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
if (ret != -ENOENT ||
!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
goto out;
inode = afs_iget_autocell(dir, devname, strlen(devname), key);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto out;
}
*fid = AFS_FS_I(inode)->fid;
_leave("= %p", inode);
return inode;
out:
_leave("= %d", ret);
return ERR_PTR(ret);
}
/*
* look up an entry in a directory
*/
static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct afs_vnode *vnode;
struct afs_fid fid;
struct inode *inode;
struct key *key;
int ret;
vnode = AFS_FS_I(dir);
_enter("{%x:%u},%p{%s},",
vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
ASSERTCMP(dentry->d_inode, ==, NULL);
if (dentry->d_name.len >= AFSNAMEMAX) {
_leave(" = -ENAMETOOLONG");
return ERR_PTR(-ENAMETOOLONG);
}
if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
_leave(" = -ESTALE");
return ERR_PTR(-ESTALE);
}
key = afs_request_key(vnode->volume->cell);
if (IS_ERR(key)) {
_leave(" = %ld [key]", PTR_ERR(key));
return ERR_CAST(key);
}
ret = afs_validate(vnode, key);
if (ret < 0) {
key_put(key);
_leave(" = %d [val]", ret);
return ERR_PTR(ret);
}
ret = afs_do_lookup(dir, dentry, &fid, key);
if (ret < 0) {
inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
if (!IS_ERR(inode)) {
key_put(key);
goto success;
}
ret = PTR_ERR(inode);
key_put(key);
if (ret == -ENOENT) {
d_add(dentry, NULL);
_leave(" = NULL [negative]");
return NULL;
}
_leave(" = %d [do]", ret);
return ERR_PTR(ret);
}
dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
/* instantiate the dentry */
inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
key_put(key);
if (IS_ERR(inode)) {
_leave(" = %ld", PTR_ERR(inode));
return ERR_CAST(inode);
}
success:
dentry->d_op = &afs_fs_dentry_operations;
d_add(dentry, inode);
_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
fid.vnode,
fid.unique,
dentry->d_inode->i_ino,
(unsigned long long)dentry->d_inode->i_version);
return NULL;
}
/*
* check that a dentry lookup hit has found a valid entry
* - NOTE! the hit can be a negative hit too, so we can't assume we have an
* inode
*/
static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct afs_vnode *vnode, *dir;
struct afs_fid uninitialized_var(fid);
struct dentry *parent;
struct key *key;
void *dir_version;
int ret;
vnode = AFS_FS_I(dentry->d_inode);
if (dentry->d_inode)
_enter("{v={%x:%u} n=%s fl=%lx},",
vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
vnode->flags);
else
_enter("{neg n=%s}", dentry->d_name.name);
key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
if (IS_ERR(key))
key = NULL;
/* lock down the parent dentry so we can peer at it */
parent = dget_parent(dentry);
if (!parent->d_inode)
goto out_bad;
dir = AFS_FS_I(parent->d_inode);
/* validate the parent directory */
if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
afs_validate(dir, key);
if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
_debug("%s: parent dir deleted", dentry->d_name.name);
goto out_bad;
}
dir_version = (void *) (unsigned long) dir->status.data_version;
if (dentry->d_fsdata == dir_version)
goto out_valid; /* the dir contents are unchanged */
_debug("dir modified");
/* search the directory for this vnode */
ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
switch (ret) {
case 0:
/* the filename maps to something */
if (!dentry->d_inode)
goto out_bad;
if (is_bad_inode(dentry->d_inode)) {
printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
parent->d_name.name, dentry->d_name.name);
goto out_bad;
}
/* if the vnode ID has changed, then the dirent points to a
* different file */
if (fid.vnode != vnode->fid.vnode) {
_debug("%s: dirent changed [%u != %u]",
dentry->d_name.name, fid.vnode,
vnode->fid.vnode);
goto not_found;
}
/* if the vnode ID uniqifier has changed, then the file has
* been deleted and replaced, and the original vnode ID has
* been reused */
if (fid.unique != vnode->fid.unique) {
_debug("%s: file deleted (uq %u -> %u I:%llu)",
dentry->d_name.name, fid.unique,
vnode->fid.unique,
(unsigned long long)dentry->d_inode->i_version);
spin_lock(&vnode->lock);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
spin_unlock(&vnode->lock);
goto not_found;
}
goto out_valid;
case -ENOENT:
/* the filename is unknown */
_debug("%s: dirent not found", dentry->d_name.name);
if (dentry->d_inode)
goto not_found;
goto out_valid;
default:
_debug("failed to iterate dir %s: %d",
parent->d_name.name, ret);
goto out_bad;
}
out_valid:
dentry->d_fsdata = dir_version;
out_skip:
dput(parent);
key_put(key);
_leave(" = 1 [valid]");
return 1;
/* the dirent, if it exists, now points to a different vnode */
not_found:
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_NFSFS_RENAMED;
spin_unlock(&dentry->d_lock);
out_bad:
if (dentry->d_inode) {
/* don't unhash if we have submounts */
if (have_submounts(dentry))
goto out_skip;
}
_debug("dropping dentry %s/%s",
parent->d_name.name, dentry->d_name.name);
shrink_dcache_parent(dentry);
d_drop(dentry);
dput(parent);
key_put(key);
_leave(" = 0 [bad]");
return 0;
}
/*
* allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
* sleep)
* - called from dput() when d_count is going to 0.
* - return 1 to request dentry be unhashed, 0 otherwise
*/
static int afs_d_delete(struct dentry *dentry)
{
_enter("%s", dentry->d_name.name);
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
goto zap;
if (dentry->d_inode &&
(test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dentry->d_inode)->flags) ||
test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
goto zap;
_leave(" = 0 [keep]");
return 0;
zap:
_leave(" = 1 [zap]");
return 1;
}
/*
* handle dentry release
*/
static void afs_d_release(struct dentry *dentry)
{
_enter("%s", dentry->d_name.name);
}
/*
* create a directory on an AFS filesystem
*/
static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct afs_file_status status;
struct afs_callback cb;
struct afs_server *server;
struct afs_vnode *dvnode, *vnode;
struct afs_fid fid;
struct inode *inode;
struct key *key;
int ret;
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%s},%o",
dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
mode |= S_IFDIR;
ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
mode, &fid, &status, &cb, &server);
if (ret < 0)
goto mkdir_error;
inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
if (IS_ERR(inode)) {
/* ENOMEM at a really inconvenient time - just abandon the new
* directory on the server */
ret = PTR_ERR(inode);
goto iget_error;
}
/* apply the status report we've got for the new vnode */
vnode = AFS_FS_I(inode);
spin_lock(&vnode->lock);
vnode->update_cnt++;
spin_unlock(&vnode->lock);
afs_vnode_finalise_status_update(vnode, server);
afs_put_server(server);
d_instantiate(dentry, inode);
if (d_unhashed(dentry)) {
_debug("not hashed");
d_rehash(dentry);
}
key_put(key);
_leave(" = 0");
return 0;
iget_error:
afs_put_server(server);
mkdir_error:
key_put(key);
error:
d_drop(dentry);
_leave(" = %d", ret);
return ret;
}
/*
* remove a directory from an AFS filesystem
*/
static int afs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct afs_vnode *dvnode, *vnode;
struct key *key;
int ret;
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%s}",
dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
if (ret < 0)
goto rmdir_error;
if (dentry->d_inode) {
vnode = AFS_FS_I(dentry->d_inode);
clear_nlink(&vnode->vfs_inode);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
afs_discard_callback_on_delete(vnode);
}
key_put(key);
_leave(" = 0");
return 0;
rmdir_error:
key_put(key);
error:
_leave(" = %d", ret);
return ret;
}
/*
* remove a file from an AFS filesystem
*/
static int afs_unlink(struct inode *dir, struct dentry *dentry)
{
struct afs_vnode *dvnode, *vnode;
struct key *key;
int ret;
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%s}",
dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
if (dentry->d_inode) {
vnode = AFS_FS_I(dentry->d_inode);
/* make sure we have a callback promise on the victim */
ret = afs_validate(vnode, key);
if (ret < 0)
goto error;
}
ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
if (ret < 0)
goto remove_error;
if (dentry->d_inode) {
/* if the file wasn't deleted due to excess hard links, the
* fileserver will break the callback promise on the file - if
* it had one - before it returns to us, and if it was deleted,
* it won't
*
* however, if we didn't have a callback promise outstanding,
* or it was outstanding on a different server, then it won't
* break it either...
*/
vnode = AFS_FS_I(dentry->d_inode);
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
_debug("AFS_VNODE_DELETED");
if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
_debug("AFS_VNODE_CB_BROKEN");
set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
ret = afs_validate(vnode, key);
_debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
}
key_put(key);
_leave(" = 0");
return 0;
remove_error:
key_put(key);
error:
_leave(" = %d", ret);
return ret;
}
/*
* create a regular file on an AFS filesystem
*/
static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct afs_file_status status;
struct afs_callback cb;
struct afs_server *server;
struct afs_vnode *dvnode, *vnode;
struct afs_fid fid;
struct inode *inode;
struct key *key;
int ret;
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%s},%o,",
dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
mode |= S_IFREG;
ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
mode, &fid, &status, &cb, &server);
if (ret < 0)
goto create_error;
inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
if (IS_ERR(inode)) {
/* ENOMEM at a really inconvenient time - just abandon the new
* directory on the server */
ret = PTR_ERR(inode);
goto iget_error;
}
/* apply the status report we've got for the new vnode */
vnode = AFS_FS_I(inode);
spin_lock(&vnode->lock);
vnode->update_cnt++;
spin_unlock(&vnode->lock);
afs_vnode_finalise_status_update(vnode, server);
afs_put_server(server);
d_instantiate(dentry, inode);
if (d_unhashed(dentry)) {
_debug("not hashed");
d_rehash(dentry);
}
key_put(key);
_leave(" = 0");
return 0;
iget_error:
afs_put_server(server);
create_error:
key_put(key);
error:
d_drop(dentry);
_leave(" = %d", ret);
return ret;
}
/*
* create a hard link between files in an AFS filesystem
*/
static int afs_link(struct dentry *from, struct inode *dir,
struct dentry *dentry)
{
struct afs_vnode *dvnode, *vnode;
struct key *key;
int ret;
vnode = AFS_FS_I(from->d_inode);
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%x:%u},{%s}",
vnode->fid.vid, vnode->fid.vnode,
dvnode->fid.vid, dvnode->fid.vnode,
dentry->d_name.name);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
if (ret < 0)
goto link_error;
atomic_inc(&vnode->vfs_inode.i_count);
d_instantiate(dentry, &vnode->vfs_inode);
key_put(key);
_leave(" = 0");
return 0;
link_error:
key_put(key);
error:
d_drop(dentry);
_leave(" = %d", ret);
return ret;
}
/*
* create a symlink in an AFS filesystem
*/
static int afs_symlink(struct inode *dir, struct dentry *dentry,
const char *content)
{
struct afs_file_status status;
struct afs_server *server;
struct afs_vnode *dvnode, *vnode;
struct afs_fid fid;
struct inode *inode;
struct key *key;
int ret;
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%s},%s",
dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
content);
ret = -ENAMETOOLONG;
if (dentry->d_name.len >= AFSNAMEMAX)
goto error;
ret = -EINVAL;
if (strlen(content) >= AFSPATHMAX)
goto error;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
&fid, &status, &server);
if (ret < 0)
goto create_error;
inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
if (IS_ERR(inode)) {
/* ENOMEM at a really inconvenient time - just abandon the new
* directory on the server */
ret = PTR_ERR(inode);
goto iget_error;
}
/* apply the status report we've got for the new vnode */
vnode = AFS_FS_I(inode);
spin_lock(&vnode->lock);
vnode->update_cnt++;
spin_unlock(&vnode->lock);
afs_vnode_finalise_status_update(vnode, server);
afs_put_server(server);
d_instantiate(dentry, inode);
if (d_unhashed(dentry)) {
_debug("not hashed");
d_rehash(dentry);
}
key_put(key);
_leave(" = 0");
return 0;
iget_error:
afs_put_server(server);
create_error:
key_put(key);
error:
d_drop(dentry);
_leave(" = %d", ret);
return ret;
}
/*
* rename a file in an AFS filesystem and/or move it between directories
*/
static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
struct key *key;
int ret;
vnode = AFS_FS_I(old_dentry->d_inode);
orig_dvnode = AFS_FS_I(old_dir);
new_dvnode = AFS_FS_I(new_dir);
_enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
vnode->fid.vid, vnode->fid.vnode,
new_dvnode->fid.vid, new_dvnode->fid.vnode,
new_dentry->d_name.name);
ret = -ENAMETOOLONG;
if (new_dentry->d_name.len >= AFSNAMEMAX)
goto error;
key = afs_request_key(orig_dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
old_dentry->d_name.name,
new_dentry->d_name.name);
if (ret < 0)
goto rename_error;
key_put(key);
_leave(" = 0");
return 0;
rename_error:
key_put(key);
error:
d_drop(new_dentry);
_leave(" = %d", ret);
return ret;
}