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linux/fs/afs/dir.c
Tim Schmielau cd354f1ae7 [PATCH] remove many unneeded #includes of sched.h 
After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-14 08:09:54 -08:00

664 lines
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/* 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/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/smp_lock.h>
#include "vnode.h"
#include "volume.h"
#include <rxrpc/call.h>
#include "super.h"
#include "internal.h"
static struct dentry *afs_dir_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd);
static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_dir_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 int afs_dir_lookup_filldir(void *_cookie, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype);
const struct file_operations afs_dir_file_operations = {
.open = afs_dir_open,
.readdir = afs_dir_readdir,
};
const struct inode_operations afs_dir_inode_operations = {
.lookup = afs_dir_lookup,
.getattr = afs_inode_getattr,
#if 0 /* TODO */
.create = afs_dir_create,
.link = afs_dir_link,
.unlink = afs_dir_unlink,
.symlink = afs_dir_symlink,
.mkdir = afs_dir_mkdir,
.rmdir = afs_dir_rmdir,
.mknod = afs_dir_mknod,
.rename = afs_dir_rename,
#endif
};
static struct dentry_operations afs_fs_dentry_operations = {
.d_revalidate = afs_d_revalidate,
.d_delete = afs_d_delete,
};
#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_dir_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",
__FUNCTION__,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",
__FUNCTION__, dir->i_ino, tmp, qty,
ntohs(dbuf->blocks[tmp].pagehdr.magic));
goto error;
}
}
SetPageChecked(page);
return;
error:
SetPageChecked(page);
SetPageError(page);
} /* end afs_dir_check_page() */
/*****************************************************************************/
/*
* discard a page cached in the pagecache
*/
static inline void afs_dir_put_page(struct page *page)
{
kunmap(page);
page_cache_release(page);
} /* end afs_dir_put_page() */
/*****************************************************************************/
/*
* get a page into the pagecache
*/
static struct page *afs_dir_get_page(struct inode *dir, unsigned long index)
{
struct page *page;
_enter("{%lu},%lu", dir->i_ino, index);
page = read_mapping_page(dir->i_mapping, index, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (!PageChecked(page))
afs_dir_check_page(dir, page);
if (PageError(page))
goto fail;
}
return page;
fail:
afs_dir_put_page(page);
return ERR_PTR(-EIO);
} /* end afs_dir_get_page() */
/*****************************************************************************/
/*
* 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 (AFS_FS_I(inode)->flags & AFS_VNODE_DELETED)
return -ENOENT;
_leave(" = 0");
return 0;
} /* end afs_dir_open() */
/*****************************************************************************/
/*
* 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\n",
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\"\n",
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)\n",
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)\n",
blkoff / sizeof(union afs_dir_block),
offset, next, tmp, nlen);
return -EIO;
}
_debug("ENT[%Zu.%u]: ext %u/%Zu\n",
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_dir_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;
} /* end afs_dir_iterate_block() */
/*****************************************************************************/
/*
* read an AFS directory
*/
static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
filldir_t filldir)
{
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 (AFS_FS_I(dir)->flags & AFS_VNODE_DELETED) {
_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);
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;
} /* end afs_dir_iterate() */
/*****************************************************************************/
/*
* read an AFS directory
*/
static int afs_dir_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);
fpos = file->f_pos;
ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos, cookie, filldir);
file->f_pos = fpos;
_leave(" = %d", ret);
return ret;
} /* end afs_dir_readdir() */
/*****************************************************************************/
/*
* 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_dir_lookup_filldir(void *_cookie, const char *name, int nlen,
loff_t fpos, u64 ino, unsigned dtype)
{
struct afs_dir_lookup_cookie *cookie = _cookie;
_enter("{%s,%Zu},%s,%u,,%lu,%u",
cookie->name, cookie->nlen, name, nlen, ino, dtype);
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;
} /* end afs_dir_lookup_filldir() */
/*****************************************************************************/
/*
* look up an entry in a directory
*/
static struct dentry *afs_dir_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct afs_dir_lookup_cookie cookie;
struct afs_super_info *as;
struct afs_vnode *vnode;
struct inode *inode;
unsigned fpos;
int ret;
_enter("{%lu},%p{%s}", dir->i_ino, dentry, dentry->d_name.name);
/* insanity checks first */
BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
if (dentry->d_name.len > 255) {
_leave(" = -ENAMETOOLONG");
return ERR_PTR(-ENAMETOOLONG);
}
vnode = AFS_FS_I(dir);
if (vnode->flags & AFS_VNODE_DELETED) {
_leave(" = -ESTALE");
return ERR_PTR(-ESTALE);
}
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_dir_lookup_filldir);
if (ret < 0) {
_leave(" = %d", ret);
return ERR_PTR(ret);
}
ret = -ENOENT;
if (!cookie.found) {
_leave(" = %d", ret);
return ERR_PTR(ret);
}
/* instantiate the dentry */
ret = afs_iget(dir->i_sb, &cookie.fid, &inode);
if (ret < 0) {
_leave(" = %d", ret);
return ERR_PTR(ret);
}
dentry->d_op = &afs_fs_dentry_operations;
dentry->d_fsdata = (void *) (unsigned long) vnode->status.version;
d_add(dentry, inode);
_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%lu }",
cookie.fid.vnode,
cookie.fid.unique,
dentry->d_inode->i_ino,
dentry->d_inode->i_version);
return NULL;
} /* end afs_dir_lookup() */
/*****************************************************************************/
/*
* 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
* (derived from nfs_lookup_revalidate)
*/
static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct afs_dir_lookup_cookie cookie;
struct dentry *parent;
struct inode *inode, *dir;
unsigned fpos;
int ret;
_enter("{sb=%p n=%s},", dentry->d_sb, dentry->d_name.name);
/* lock down the parent dentry so we can peer at it */
parent = dget_parent(dentry->d_parent);
dir = parent->d_inode;
inode = dentry->d_inode;
/* handle a negative dentry */
if (!inode)
goto out_bad;
/* handle a bad inode */
if (is_bad_inode(inode)) {
printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
dentry->d_parent->d_name.name, dentry->d_name.name);
goto out_bad;
}
/* force a full look up if the parent directory changed since last the
* server was consulted
* - otherwise this inode must still exist, even if the inode details
* themselves have changed
*/
if (AFS_FS_I(dir)->flags & AFS_VNODE_CHANGED)
afs_vnode_fetch_status(AFS_FS_I(dir));
if (AFS_FS_I(dir)->flags & AFS_VNODE_DELETED) {
_debug("%s: parent dir deleted", dentry->d_name.name);
goto out_bad;
}
if (AFS_FS_I(inode)->flags & AFS_VNODE_DELETED) {
_debug("%s: file already deleted", dentry->d_name.name);
goto out_bad;
}
if ((unsigned long) dentry->d_fsdata !=
(unsigned long) AFS_FS_I(dir)->status.version) {
_debug("%s: parent changed %lu -> %u",
dentry->d_name.name,
(unsigned long) dentry->d_fsdata,
(unsigned) AFS_FS_I(dir)->status.version);
/* search the directory for this vnode */
cookie.name = dentry->d_name.name;
cookie.nlen = dentry->d_name.len;
cookie.fid.vid = AFS_FS_I(inode)->volume->vid;
cookie.found = 0;
fpos = 0;
ret = afs_dir_iterate(dir, &fpos, &cookie,
afs_dir_lookup_filldir);
if (ret < 0) {
_debug("failed to iterate dir %s: %d",
parent->d_name.name, ret);
goto out_bad;
}
if (!cookie.found) {
_debug("%s: dirent not found", dentry->d_name.name);
goto not_found;
}
/* if the vnode ID has changed, then the dirent points to a
* different file */
if (cookie.fid.vnode != AFS_FS_I(inode)->fid.vnode) {
_debug("%s: dirent changed", dentry->d_name.name);
goto not_found;
}
/* if the vnode ID uniqifier has changed, then the file has
* been deleted */
if (cookie.fid.unique != AFS_FS_I(inode)->fid.unique) {
_debug("%s: file deleted (uq %u -> %u I:%lu)",
dentry->d_name.name,
cookie.fid.unique,
AFS_FS_I(inode)->fid.unique,
inode->i_version);
spin_lock(&AFS_FS_I(inode)->lock);
AFS_FS_I(inode)->flags |= AFS_VNODE_DELETED;
spin_unlock(&AFS_FS_I(inode)->lock);
invalidate_remote_inode(inode);
goto out_bad;
}
dentry->d_fsdata =
(void *) (unsigned long) AFS_FS_I(dir)->status.version;
}
out_valid:
dput(parent);
_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 (inode) {
/* don't unhash if we have submounts */
if (have_submounts(dentry))
goto out_valid;
}
shrink_dcache_parent(dentry);
_debug("dropping dentry %s/%s",
dentry->d_parent->d_name.name, dentry->d_name.name);
d_drop(dentry);
dput(parent);
_leave(" = 0 [bad]");
return 0;
} /* end afs_d_revalidate() */
/*****************************************************************************/
/*
* 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) {
if (AFS_FS_I(dentry->d_inode)->flags & AFS_VNODE_DELETED)
goto zap;
}
_leave(" = 0 [keep]");
return 0;
zap:
_leave(" = 1 [zap]");
return 1;
} /* end afs_d_delete() */
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