linux-sg2042/fs/afs/dir.c

1331 lines
31 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/namei.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
#include <linux/dns_resolver.h>
#include "internal.h"
static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_readdir(struct file *file, struct dir_context *ctx);
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
static int afs_d_delete(const struct dentry *dentry);
static void afs_d_release(struct dentry *dentry);
static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl);
static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t 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,
unsigned int flags);
const struct file_operations afs_dir_file_operations = {
.open = afs_dir_open,
.release = afs_release,
.iterate_shared = 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,
.listxattr = afs_listxattr,
};
const struct file_operations afs_dynroot_file_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
.iterate_shared = dcache_readdir,
.llseek = dcache_dir_lseek,
};
const struct inode_operations afs_dynroot_inode_operations = {
.lookup = afs_dynroot_lookup,
};
const struct dentry_operations afs_fs_dentry_operations = {
.d_revalidate = afs_d_revalidate,
.d_delete = afs_d_delete,
.d_release = afs_d_release,
.d_automount = afs_d_automount,
};
#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 dir_context ctx;
struct afs_fid fid;
struct qstr name;
int found;
};
/*
* check that a directory page is valid
*/
bool afs_dir_check_page(struct inode *dir, struct page *page)
{
struct afs_dir_page *dbuf;
struct afs_vnode *vnode = AFS_FS_I(dir);
loff_t latter, i_size, off;
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, but
* we must take care because the directory may change size under us.
*/
off = page_offset(page);
i_size = i_size_read(dir);
if (i_size <= off)
goto checked;
latter = i_size - off;
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(%lx): bad magic %d/%d is %04hx\n",
__func__, dir->i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].pagehdr.magic));
trace_afs_dir_check_failed(vnode, off, i_size);
goto error;
}
}
checked:
SetPageChecked(page);
return true;
error:
SetPageError(page);
return false;
}
/*
* discard a page cached in the pagecache
*/
static inline void afs_dir_put_page(struct page *page)
{
kunmap(page);
unlock_page(page);
put_page(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)) {
lock_page(page);
kmap(page);
if (unlikely(!PageChecked(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(struct dir_context *ctx,
union afs_dir_block *block,
unsigned blkoff)
{
union afs_dirent *dire;
unsigned offset, next, curr;
size_t nlen;
int tmp;
_enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block);
curr = (ctx->pos - 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)
ctx->pos = 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 */
if (!dir_emit(ctx, dire->u.name, nlen,
ntohl(dire->u.vnode),
ctx->actor == afs_lookup_filldir ?
ntohl(dire->u.unique) : DT_UNKNOWN)) {
_leave(" = 0 [full]");
return 0;
}
ctx->pos = 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, struct dir_context *ctx,
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, (unsigned)ctx->pos);
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 */
ctx->pos += sizeof(union afs_dirent) - 1;
ctx->pos &= ~(sizeof(union afs_dirent) - 1);
/* walk through the blocks in sequence */
ret = 0;
while (ctx->pos < dir->i_size) {
blkoff = ctx->pos & ~(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(ctx, dblock, blkoff);
if (ret != 1) {
afs_dir_put_page(page);
goto out;
}
blkoff += sizeof(union afs_dir_block);
} while (ctx->pos < 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, struct dir_context *ctx)
{
return afs_dir_iterate(file_inode(file), ctx, afs_file_key(file));
}
/*
* 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(struct dir_context *ctx, const char *name,
int nlen, loff_t fpos, u64 ino, unsigned dtype)
{
struct afs_lookup_cookie *cookie =
container_of(ctx, struct afs_lookup_cookie, ctx);
_enter("{%s,%u},%s,%u,,%llu,%u",
cookie->name.name, cookie->name.len, 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->name.len != nlen ||
memcmp(cookie->name.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_super_info *as = dir->i_sb->s_fs_info;
struct afs_lookup_cookie cookie = {
.ctx.actor = afs_lookup_filldir,
.name = dentry->d_name,
.fid.vid = as->volume->vid
};
int ret;
_enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry);
/* search the directory */
ret = afs_dir_iterate(dir, &cookie.ctx, 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;
}
/*
* Probe to see if a cell may exist. This prevents positive dentries from
* being created unnecessarily.
*/
static int afs_probe_cell_name(struct dentry *dentry)
{
struct afs_cell *cell;
const char *name = dentry->d_name.name;
size_t len = dentry->d_name.len;
int ret;
/* Names prefixed with a dot are R/W mounts. */
if (name[0] == '.') {
if (len == 1)
return -EINVAL;
name++;
len--;
}
cell = afs_lookup_cell_rcu(afs_d2net(dentry), name, len);
if (!IS_ERR(cell)) {
afs_put_cell(afs_d2net(dentry), cell);
return 0;
}
ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL);
if (ret == -ENODATA)
ret = -EDESTADDRREQ;
return ret;
}
/*
* Try to auto mount the mountpoint with pseudo directory, if the autocell
* operation is setted.
*/
static struct inode *afs_try_auto_mntpt(struct dentry *dentry,
struct inode *dir, struct afs_fid *fid)
{
struct afs_vnode *vnode = AFS_FS_I(dir);
struct inode *inode;
int ret = -ENOENT;
_enter("%p{%pd}, {%x:%u}",
dentry, dentry, vnode->fid.vid, vnode->fid.vnode);
if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
goto out;
ret = afs_probe_cell_name(dentry);
if (ret < 0)
goto out;
inode = afs_iget_pseudo_dir(dir->i_sb, false);
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,
unsigned int flags)
{
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{%pd},",
vnode->fid.vid, vnode->fid.vnode, dentry, dentry);
ASSERTCMP(d_inode(dentry), ==, 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) {
if (ret == -ENOENT) {
inode = afs_try_auto_mntpt(dentry, dir, &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, NULL);
key_put(key);
if (IS_ERR(inode)) {
_leave(" = %ld", PTR_ERR(inode));
return ERR_CAST(inode);
}
success:
d_add(dentry, inode);
_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
fid.vnode,
fid.unique,
d_inode(dentry)->i_ino,
d_inode(dentry)->i_generation);
return NULL;
}
/*
* Look up an entry in a dynroot directory.
*/
static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct afs_vnode *vnode;
struct afs_fid fid;
struct inode *inode;
int ret;
vnode = AFS_FS_I(dir);
_enter("%pd", dentry);
ASSERTCMP(d_inode(dentry), ==, NULL);
if (dentry->d_name.len >= AFSNAMEMAX) {
_leave(" = -ENAMETOOLONG");
return ERR_PTR(-ENAMETOOLONG);
}
inode = afs_try_auto_mntpt(dentry, dir, &fid);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
if (ret == -ENOENT) {
d_add(dentry, NULL);
_leave(" = NULL [negative]");
return NULL;
}
_leave(" = %d [do]", ret);
return ERR_PTR(ret);
}
d_add(dentry, inode);
_leave(" = 0 { ino=%lu v=%u }",
d_inode(dentry)->i_ino, d_inode(dentry)->i_generation);
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, unsigned int flags)
{
struct afs_super_info *as = dentry->d_sb->s_fs_info;
struct afs_vnode *vnode, *dir;
struct afs_fid uninitialized_var(fid);
struct dentry *parent;
struct inode *inode;
struct key *key;
void *dir_version;
int ret;
if (flags & LOOKUP_RCU)
return -ECHILD;
if (as->dyn_root)
return 1;
if (d_really_is_positive(dentry)) {
vnode = AFS_FS_I(d_inode(dentry));
_enter("{v={%x:%u} n=%pd fl=%lx},",
vnode->fid.vid, vnode->fid.vnode, dentry,
vnode->flags);
} else {
_enter("{neg n=%pd}", dentry);
}
key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
if (IS_ERR(key))
key = NULL;
if (d_really_is_positive(dentry)) {
inode = d_inode(dentry);
if (inode) {
vnode = AFS_FS_I(inode);
afs_validate(vnode, key);
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
goto out_bad;
}
}
/* lock down the parent dentry so we can peer at it */
parent = dget_parent(dentry);
dir = AFS_FS_I(d_inode(parent));
/* validate the parent directory */
afs_validate(dir, key);
if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
_debug("%pd: parent dir deleted", dentry);
goto out_bad_parent;
}
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 (d_really_is_negative(dentry))
goto out_bad_parent;
inode = d_inode(dentry);
if (is_bad_inode(inode)) {
printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n",
dentry);
goto out_bad_parent;
}
vnode = AFS_FS_I(inode);
/* if the vnode ID has changed, then the dirent points to a
* different file */
if (fid.vnode != vnode->fid.vnode) {
_debug("%pd: dirent changed [%u != %u]",
dentry, 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("%pd: file deleted (uq %u -> %u I:%u)",
dentry, fid.unique,
vnode->fid.unique,
vnode->vfs_inode.i_generation);
write_seqlock(&vnode->cb_lock);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
write_sequnlock(&vnode->cb_lock);
goto not_found;
}
goto out_valid;
case -ENOENT:
/* the filename is unknown */
_debug("%pd: dirent not found", dentry);
if (d_really_is_positive(dentry))
goto not_found;
goto out_valid;
default:
_debug("failed to iterate dir %pd: %d",
parent, ret);
goto out_bad_parent;
}
out_valid:
dentry->d_fsdata = dir_version;
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_parent:
_debug("dropping dentry %pd2", dentry);
dput(parent);
out_bad:
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(const struct dentry *dentry)
{
_enter("%pd", dentry);
if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
goto zap;
if (d_really_is_positive(dentry) &&
(test_bit(AFS_VNODE_DELETED, &AFS_FS_I(d_inode(dentry))->flags) ||
test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->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("%pd", dentry);
}
/*
* Create a new inode for create/mkdir/symlink
*/
static void afs_vnode_new_inode(struct afs_fs_cursor *fc,
struct dentry *new_dentry,
struct afs_fid *newfid,
struct afs_file_status *newstatus,
struct afs_callback *newcb)
{
struct inode *inode;
if (fc->ac.error < 0)
return;
d_drop(new_dentry);
inode = afs_iget(fc->vnode->vfs_inode.i_sb, fc->key,
newfid, newstatus, newcb, fc->cbi);
if (IS_ERR(inode)) {
/* ENOMEM or EINTR at a really inconvenient time - just abandon
* the new directory on the server.
*/
fc->ac.error = PTR_ERR(inode);
return;
}
d_add(new_dentry, inode);
}
/*
* create a directory on an AFS filesystem
*/
static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct afs_file_status newstatus;
struct afs_fs_cursor fc;
struct afs_callback newcb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
int ret;
mode |= S_IFDIR;
_enter("{%x:%u},{%pd},%ho",
dvnode->fid.vid, dvnode->fid.vnode, dentry, mode);
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
afs_fs_create(&fc, dentry->d_name.name, mode,
&newfid, &newstatus, &newcb);
}
afs_check_for_remote_deletion(&fc, fc.vnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
key_put(key);
_leave(" = 0");
return 0;
error_key:
key_put(key);
error:
d_drop(dentry);
_leave(" = %d", ret);
return ret;
}
/*
* Remove a subdir from a directory.
*/
static void afs_dir_remove_subdir(struct dentry *dentry)
{
if (d_really_is_positive(dentry)) {
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
clear_nlink(&vnode->vfs_inode);
set_bit(AFS_VNODE_DELETED, &vnode->flags);
clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
}
}
/*
* remove a directory from an AFS filesystem
*/
static int afs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct afs_fs_cursor fc;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct key *key;
int ret;
_enter("{%x:%u},{%pd}",
dvnode->fid.vid, dvnode->fid.vnode, dentry);
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
afs_fs_remove(&fc, dentry->d_name.name, true);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
ret = afs_end_vnode_operation(&fc);
if (ret == 0)
afs_dir_remove_subdir(dentry);
}
key_put(key);
error:
return ret;
}
/*
* Remove a link to a file or symlink from a directory.
*
* If the file was not 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...
*/
static int afs_dir_remove_link(struct dentry *dentry, struct key *key,
unsigned long d_version_before,
unsigned long d_version_after)
{
bool dir_valid;
int ret = 0;
/* There were no intervening changes on the server if the version
* number we got back was incremented by exactly 1.
*/
dir_valid = (d_version_after == d_version_before + 1);
if (d_really_is_positive(dentry)) {
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
if (dir_valid) {
drop_nlink(&vnode->vfs_inode);
if (vnode->vfs_inode.i_nlink == 0) {
set_bit(AFS_VNODE_DELETED, &vnode->flags);
clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
}
ret = 0;
} else {
clear_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
kdebug("AFS_VNODE_DELETED");
ret = afs_validate(vnode, key);
if (ret == -ESTALE)
ret = 0;
}
_debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
}
return ret;
}
/*
* Remove a file or symlink from an AFS filesystem.
*/
static int afs_unlink(struct inode *dir, struct dentry *dentry)
{
struct afs_fs_cursor fc;
struct afs_vnode *dvnode = AFS_FS_I(dir), *vnode;
struct key *key;
unsigned long d_version = (unsigned long)dentry->d_fsdata;
int ret;
_enter("{%x:%u},{%pd}",
dvnode->fid.vid, dvnode->fid.vnode, dentry);
if (dentry->d_name.len >= AFSNAMEMAX)
return -ENAMETOOLONG;
key = afs_request_key(dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
/* Try to make sure we have a callback promise on the victim. */
if (d_really_is_positive(dentry)) {
vnode = AFS_FS_I(d_inode(dentry));
ret = afs_validate(vnode, key);
if (ret < 0)
goto error_key;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
afs_fs_remove(&fc, dentry->d_name.name, false);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
ret = afs_end_vnode_operation(&fc);
if (ret == 0)
ret = afs_dir_remove_link(
dentry, key, d_version,
(unsigned long)dvnode->status.data_version);
}
error_key:
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, umode_t mode,
bool excl)
{
struct afs_fs_cursor fc;
struct afs_file_status newstatus;
struct afs_callback newcb;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
int ret;
mode |= S_IFREG;
_enter("{%x:%u},{%pd},%ho,",
dvnode->fid.vid, dvnode->fid.vnode, dentry, 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;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
afs_fs_create(&fc, dentry->d_name.name, mode,
&newfid, &newstatus, &newcb);
}
afs_check_for_remote_deletion(&fc, fc.vnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, &newcb);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
key_put(key);
_leave(" = 0");
return 0;
error_key:
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_fs_cursor fc;
struct afs_vnode *dvnode, *vnode;
struct key *key;
int ret;
vnode = AFS_FS_I(d_inode(from));
dvnode = AFS_FS_I(dir);
_enter("{%x:%u},{%x:%u},{%pd}",
vnode->fid.vid, vnode->fid.vnode,
dvnode->fid.vid, dvnode->fid.vnode,
dentry);
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 = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
if (mutex_lock_interruptible_nested(&vnode->io_lock, 1) < 0) {
afs_end_vnode_operation(&fc);
goto error_key;
}
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
fc.cb_break_2 = vnode->cb_break + vnode->cb_s_break;
afs_fs_link(&fc, vnode, dentry->d_name.name);
}
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
afs_vnode_commit_status(&fc, vnode, fc.cb_break_2);
ihold(&vnode->vfs_inode);
d_instantiate(dentry, &vnode->vfs_inode);
mutex_unlock(&vnode->io_lock);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
key_put(key);
_leave(" = 0");
return 0;
error_key:
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_fs_cursor fc;
struct afs_file_status newstatus;
struct afs_vnode *dvnode = AFS_FS_I(dir);
struct afs_fid newfid;
struct key *key;
int ret;
_enter("{%x:%u},{%pd},%s",
dvnode->fid.vid, dvnode->fid.vnode, dentry,
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 = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, dvnode, key)) {
while (afs_select_fileserver(&fc)) {
fc.cb_break = dvnode->cb_break + dvnode->cb_s_break;
afs_fs_symlink(&fc, dentry->d_name.name, content,
&newfid, &newstatus);
}
afs_check_for_remote_deletion(&fc, fc.vnode);
afs_vnode_commit_status(&fc, dvnode, fc.cb_break);
afs_vnode_new_inode(&fc, dentry, &newfid, &newstatus, NULL);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
} else {
goto error_key;
}
key_put(key);
_leave(" = 0");
return 0;
error_key:
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,
unsigned int flags)
{
struct afs_fs_cursor fc;
struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
struct key *key;
int ret;
if (flags)
return -EINVAL;
vnode = AFS_FS_I(d_inode(old_dentry));
orig_dvnode = AFS_FS_I(old_dir);
new_dvnode = AFS_FS_I(new_dir);
_enter("{%x:%u},{%x:%u},{%x:%u},{%pd}",
orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
vnode->fid.vid, vnode->fid.vnode,
new_dvnode->fid.vid, new_dvnode->fid.vnode,
new_dentry);
key = afs_request_key(orig_dvnode->volume->cell);
if (IS_ERR(key)) {
ret = PTR_ERR(key);
goto error;
}
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, orig_dvnode, key)) {
if (orig_dvnode != new_dvnode) {
if (mutex_lock_interruptible_nested(&new_dvnode->io_lock, 1) < 0) {
afs_end_vnode_operation(&fc);
goto error_key;
}
}
while (afs_select_fileserver(&fc)) {
fc.cb_break = orig_dvnode->cb_break + orig_dvnode->cb_s_break;
fc.cb_break_2 = new_dvnode->cb_break + new_dvnode->cb_s_break;
afs_fs_rename(&fc, old_dentry->d_name.name,
new_dvnode, new_dentry->d_name.name);
}
afs_vnode_commit_status(&fc, orig_dvnode, fc.cb_break);
afs_vnode_commit_status(&fc, new_dvnode, fc.cb_break_2);
if (orig_dvnode != new_dvnode)
mutex_unlock(&new_dvnode->io_lock);
ret = afs_end_vnode_operation(&fc);
if (ret < 0)
goto error_key;
}
error_key:
key_put(key);
error:
_leave(" = %d", ret);
return ret;
}