linux/fs/reiserfs/xattr.c

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/*
* linux/fs/reiserfs/xattr.c
*
* Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
*
*/
/*
* In order to implement EA/ACLs in a clean, backwards compatible manner,
* they are implemented as files in a "private" directory.
* Each EA is in it's own file, with the directory layout like so (/ is assumed
* to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
* directories named using the capital-hex form of the objectid and
* generation number are used. Inside each directory are individual files
* named with the name of the extended attribute.
*
* So, for objectid 12648430, we could have:
* /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
* /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
* /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
* .. or similar.
*
* The file contents are the text of the EA. The size is known based on the
* stat data describing the file.
*
* In the case of system.posix_acl_access and system.posix_acl_default, since
* these are special cases for filesystem ACLs, they are interpreted by the
* kernel, in addition, they are negatively and positively cached and attached
* to the inode so that unnecessary lookups are avoided.
*/
#include <linux/reiserfs_fs.h>
#include <linux/capability.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/xattr.h>
#include <linux/reiserfs_xattr.h>
#include <linux/reiserfs_acl.h>
#include <asm/uaccess.h>
#include <net/checksum.h>
#include <linux/smp_lock.h>
#include <linux/stat.h>
#define FL_READONLY 128
#define FL_DIR_SEM_HELD 256
#define PRIVROOT_NAME ".reiserfs_priv"
#define XAROOT_NAME "xattrs"
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
*prefix);
/* Returns the dentry referring to the root of the extended attribute
* directory tree. If it has already been retrieved, it is used. If it
* hasn't been created and the flags indicate creation is allowed, we
* attempt to create it. On error, we return a pointer-encoded error.
*/
static struct dentry *get_xa_root(struct super_block *sb, int flags)
{
struct dentry *privroot = dget(REISERFS_SB(sb)->priv_root);
struct dentry *xaroot;
/* This needs to be created at mount-time */
if (!privroot)
return ERR_PTR(-ENODATA);
mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
if (REISERFS_SB(sb)->xattr_root) {
xaroot = dget(REISERFS_SB(sb)->xattr_root);
goto out;
}
xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
if (IS_ERR(xaroot)) {
goto out;
} else if (!xaroot->d_inode) {
int err = -ENODATA;
if (flags == 0 || flags & XATTR_CREATE)
err = privroot->d_inode->i_op->mkdir(privroot->d_inode,
xaroot, 0700);
if (err) {
dput(xaroot);
xaroot = ERR_PTR(err);
goto out;
}
}
REISERFS_SB(sb)->xattr_root = dget(xaroot);
out:
mutex_unlock(&privroot->d_inode->i_mutex);
dput(privroot);
return xaroot;
}
/* Opens the directory corresponding to the inode's extended attribute store.
* If flags allow, the tree to the directory may be created. If creation is
* prohibited, -ENODATA is returned. */
static struct dentry *open_xa_dir(const struct inode *inode, int flags)
{
struct dentry *xaroot, *xadir;
char namebuf[17];
xaroot = get_xa_root(inode->i_sb, flags);
if (IS_ERR(xaroot))
return xaroot;
/* ok, we have xaroot open */
snprintf(namebuf, sizeof(namebuf), "%X.%X",
le32_to_cpu(INODE_PKEY(inode)->k_objectid),
inode->i_generation);
xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
if (IS_ERR(xadir)) {
dput(xaroot);
return xadir;
}
if (!xadir->d_inode) {
int err;
if (flags == 0 || flags & XATTR_CREATE) {
/* Although there is nothing else trying to create this directory,
* another directory with the same hash may be created, so we need
* to protect against that */
err =
xaroot->d_inode->i_op->mkdir(xaroot->d_inode, xadir,
0700);
if (err) {
dput(xaroot);
dput(xadir);
return ERR_PTR(err);
}
}
if (!xadir->d_inode) {
dput(xaroot);
dput(xadir);
return ERR_PTR(-ENODATA);
}
}
dput(xaroot);
return xadir;
}
/* Returns a dentry corresponding to a specific extended attribute file
* for the inode. If flags allow, the file is created. Otherwise, a
* valid or negative dentry, or an error is returned. */
static struct dentry *get_xa_file_dentry(const struct inode *inode,
const char *name, int flags)
{
struct dentry *xadir, *xafile;
int err = 0;
xadir = open_xa_dir(inode, flags);
if (IS_ERR(xadir)) {
return ERR_CAST(xadir);
} else if (!xadir->d_inode) {
dput(xadir);
return ERR_PTR(-ENODATA);
}
xafile = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(xafile)) {
dput(xadir);
return ERR_CAST(xafile);
}
if (xafile->d_inode) { /* file exists */
if (flags & XATTR_CREATE) {
err = -EEXIST;
dput(xafile);
goto out;
}
} else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
goto out;
} else {
/* inode->i_mutex is down, so nothing else can try to create
* the same xattr */
err = xadir->d_inode->i_op->create(xadir->d_inode, xafile,
0700 | S_IFREG, NULL);
if (err) {
dput(xafile);
goto out;
}
}
out:
dput(xadir);
if (err)
xafile = ERR_PTR(err);
else if (!xafile->d_inode) {
dput(xafile);
xafile = ERR_PTR(-ENODATA);
}
return xafile;
}
/*
* this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
* we need to drop the path before calling the filldir struct. That
* would be a big performance hit to the non-xattr case, so I've copied
* the whole thing for now. --clm
*
* the big difference is that I go backwards through the directory,
* and don't mess with f->f_pos, but the idea is the same. Do some
* action on each and every entry in the directory.
*
* we're called with i_mutex held, so there are no worries about the directory
* changing underneath us.
*/
static int __xattr_readdir(struct inode *inode, void *dirent, filldir_t filldir)
{
struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
INITIALIZE_PATH(path_to_entry);
struct buffer_head *bh;
int entry_num;
struct item_head *ih, tmp_ih;
int search_res;
char *local_buf;
loff_t next_pos;
char small_buf[32]; /* avoid kmalloc if we can */
struct reiserfs_de_head *deh;
int d_reclen;
char *d_name;
off_t d_off;
ino_t d_ino;
struct reiserfs_dir_entry de;
/* form key for search the next directory entry using f_pos field of
file structure */
next_pos = max_reiserfs_offset(inode);
while (1) {
research:
if (next_pos <= DOT_DOT_OFFSET)
break;
make_cpu_key(&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
search_res =
search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry,
&de);
if (search_res == IO_ERROR) {
// FIXME: we could just skip part of directory which could
// not be read
pathrelse(&path_to_entry);
return -EIO;
}
if (search_res == NAME_NOT_FOUND)
de.de_entry_num--;
set_de_name_and_namelen(&de);
entry_num = de.de_entry_num;
deh = &(de.de_deh[entry_num]);
bh = de.de_bh;
ih = de.de_ih;
if (!is_direntry_le_ih(ih)) {
reiserfs_warning(inode->i_sb, "not direntry %h", ih);
break;
}
copy_item_head(&tmp_ih, ih);
/* we must have found item, that is item of this directory, */
RFALSE(COMP_SHORT_KEYS(&(ih->ih_key), &pos_key),
"vs-9000: found item %h does not match to dir we readdir %K",
ih, &pos_key);
if (deh_offset(deh) <= DOT_DOT_OFFSET) {
break;
}
/* look for the previous entry in the directory */
next_pos = deh_offset(deh) - 1;
if (!de_visible(deh))
/* it is hidden entry */
continue;
d_reclen = entry_length(bh, ih, entry_num);
d_name = B_I_DEH_ENTRY_FILE_NAME(bh, ih, deh);
d_off = deh_offset(deh);
d_ino = deh_objectid(deh);
if (!d_name[d_reclen - 1])
d_reclen = strlen(d_name);
if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)) {
/* too big to send back to VFS */
continue;
}
/* Ignore the .reiserfs_priv entry */
if (reiserfs_xattrs(inode->i_sb) &&
!old_format_only(inode->i_sb) &&
deh_objectid(deh) ==
le32_to_cpu(INODE_PKEY
(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->
k_objectid))
continue;
if (d_reclen <= 32) {
local_buf = small_buf;
} else {
local_buf = kmalloc(d_reclen, GFP_NOFS);
if (!local_buf) {
pathrelse(&path_to_entry);
return -ENOMEM;
}
if (item_moved(&tmp_ih, &path_to_entry)) {
kfree(local_buf);
/* sigh, must retry. Do this same offset again */
next_pos = d_off;
goto research;
}
}
// Note, that we copy name to user space via temporary
// buffer (local_buf) because filldir will block if
// user space buffer is swapped out. At that time
// entry can move to somewhere else
memcpy(local_buf, d_name, d_reclen);
/* the filldir function might need to start transactions,
* or do who knows what. Release the path now that we've
* copied all the important stuff out of the deh
*/
pathrelse(&path_to_entry);
if (filldir(dirent, local_buf, d_reclen, d_off, d_ino,
DT_UNKNOWN) < 0) {
if (local_buf != small_buf) {
kfree(local_buf);
}
goto end;
}
if (local_buf != small_buf) {
kfree(local_buf);
}
} /* while */
end:
pathrelse(&path_to_entry);
return 0;
}
/*
* this could be done with dedicated readdir ops for the xattr files,
* but I want to get something working asap
* this is stolen from vfs_readdir
*
*/
static
int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
{
int res = -ENOENT;
mutex_lock_nested(&inode->i_mutex, I_MUTEX_XATTR);
if (!IS_DEADDIR(inode)) {
lock_kernel();
res = __xattr_readdir(inode, buf, filler);
unlock_kernel();
}
mutex_unlock(&inode->i_mutex);
return res;
}
/* Internal operations on file data */
static inline void reiserfs_put_page(struct page *page)
{
kunmap(page);
page_cache_release(page);
}
static struct page *reiserfs_get_page(struct inode *dir, unsigned long n)
{
struct address_space *mapping = dir->i_mapping;
struct page *page;
/* We can deadlock if we try to free dentries,
and an unlink/rmdir has just occured - GFP_NOFS avoids this */
mapping_set_gfp_mask(mapping, GFP_NOFS);
page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
kmap(page);
if (PageError(page))
goto fail;
}
return page;
fail:
reiserfs_put_page(page);
return ERR_PTR(-EIO);
}
static inline __u32 xattr_hash(const char *msg, int len)
{
return csum_partial(msg, len, 0);
}
int reiserfs_commit_write(struct file *f, struct page *page,
unsigned from, unsigned to);
int reiserfs_prepare_write(struct file *f, struct page *page,
unsigned from, unsigned to);
/* Generic extended attribute operations that can be used by xa plugins */
/*
* inode->i_mutex: down
*/
int
reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
size_t buffer_size, int flags)
{
int err = 0;
struct dentry *dentry;
struct page *page;
char *data;
struct address_space *mapping;
size_t file_pos = 0;
size_t buffer_pos = 0;
struct inode *xinode;
struct iattr newattrs;
__u32 xahash = 0;
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
/* Empty xattrs are ok, they're just empty files, no hash */
if (buffer && buffer_size)
xahash = xattr_hash(buffer, buffer_size);
open_file:
dentry = get_xa_file_dentry(inode, name, flags);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
xinode = dentry->d_inode;
REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
/* we need to copy it off.. */
if (xinode->i_nlink > 1) {
dput(dentry);
err = reiserfs_xattr_del(inode, name);
if (err < 0)
goto out;
/* We just killed the old one, we're not replacing anymore */
if (flags & XATTR_REPLACE)
flags &= ~XATTR_REPLACE;
goto open_file;
}
/* Resize it so we're ok to write there */
newattrs.ia_size = buffer_size;
newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
mutex_lock_nested(&xinode->i_mutex, I_MUTEX_XATTR);
err = notify_change(dentry, &newattrs);
if (err)
goto out_filp;
mapping = xinode->i_mapping;
while (buffer_pos < buffer_size || buffer_pos == 0) {
size_t chunk;
size_t skip = 0;
size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
chunk = PAGE_CACHE_SIZE;
else
chunk = buffer_size - buffer_pos;
page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
if (IS_ERR(page)) {
err = PTR_ERR(page);
goto out_filp;
}
lock_page(page);
data = page_address(page);
if (file_pos == 0) {
struct reiserfs_xattr_header *rxh;
skip = file_pos = sizeof(struct reiserfs_xattr_header);
if (chunk + skip > PAGE_CACHE_SIZE)
chunk = PAGE_CACHE_SIZE - skip;
rxh = (struct reiserfs_xattr_header *)data;
rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
rxh->h_hash = cpu_to_le32(xahash);
}
err = reiserfs_prepare_write(NULL, page, page_offset,
page_offset + chunk + skip);
if (!err) {
if (buffer)
memcpy(data + skip, buffer + buffer_pos, chunk);
err = reiserfs_commit_write(NULL, page, page_offset,
page_offset + chunk +
skip);
}
unlock_page(page);
reiserfs_put_page(page);
buffer_pos += chunk;
file_pos += chunk;
skip = 0;
if (err || buffer_size == 0 || !buffer)
break;
}
/* We can't mark the inode dirty if it's not hashed. This is the case
* when we're inheriting the default ACL. If we dirty it, the inode
* gets marked dirty, but won't (ever) make it onto the dirty list until
* it's synced explicitly to clear I_DIRTY. This is bad. */
if (!hlist_unhashed(&inode->i_hash)) {
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
}
out_filp:
mutex_unlock(&xinode->i_mutex);
dput(dentry);
out:
return err;
}
/*
* inode->i_mutex: down
*/
int
reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
size_t buffer_size)
{
ssize_t err = 0;
struct dentry *dentry;
size_t isize;
size_t file_pos = 0;
size_t buffer_pos = 0;
struct page *page;
struct inode *xinode;
__u32 hash = 0;
if (name == NULL)
return -EINVAL;
/* We can't have xattrs attached to v1 items since they don't have
* generation numbers */
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
dentry = get_xa_file_dentry(inode, name, FL_READONLY);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
xinode = dentry->d_inode;
isize = xinode->i_size;
REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
/* Just return the size needed */
if (buffer == NULL) {
err = isize - sizeof(struct reiserfs_xattr_header);
goto out_dput;
}
if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
err = -ERANGE;
goto out_dput;
}
while (file_pos < isize) {
size_t chunk;
char *data;
size_t skip = 0;
if (isize - file_pos > PAGE_CACHE_SIZE)
chunk = PAGE_CACHE_SIZE;
else
chunk = isize - file_pos;
page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
if (IS_ERR(page)) {
err = PTR_ERR(page);
goto out_dput;
}
lock_page(page);
data = page_address(page);
if (file_pos == 0) {
struct reiserfs_xattr_header *rxh =
(struct reiserfs_xattr_header *)data;
skip = file_pos = sizeof(struct reiserfs_xattr_header);
chunk -= skip;
/* Magic doesn't match up.. */
if (rxh->h_magic != cpu_to_le32(REISERFS_XATTR_MAGIC)) {
unlock_page(page);
reiserfs_put_page(page);
reiserfs_warning(inode->i_sb,
"Invalid magic for xattr (%s) "
"associated with %k", name,
INODE_PKEY(inode));
err = -EIO;
goto out_dput;
}
hash = le32_to_cpu(rxh->h_hash);
}
memcpy(buffer + buffer_pos, data + skip, chunk);
unlock_page(page);
reiserfs_put_page(page);
file_pos += chunk;
buffer_pos += chunk;
skip = 0;
}
err = isize - sizeof(struct reiserfs_xattr_header);
if (xattr_hash(buffer, isize - sizeof(struct reiserfs_xattr_header)) !=
hash) {
reiserfs_warning(inode->i_sb,
"Invalid hash for xattr (%s) associated "
"with %k", name, INODE_PKEY(inode));
err = -EIO;
}
out_dput:
dput(dentry);
out:
return err;
}
static int
__reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
{
struct dentry *dentry;
struct inode *dir = xadir->d_inode;
int err = 0;
dentry = lookup_one_len(name, xadir, namelen);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
} else if (!dentry->d_inode) {
err = -ENODATA;
goto out_file;
}
/* Skip directories.. */
if (S_ISDIR(dentry->d_inode->i_mode))
goto out_file;
if (!is_reiserfs_priv_object(dentry->d_inode)) {
reiserfs_warning(dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
"priv flag set [parent is %sset].",
le32_to_cpu(INODE_PKEY(dentry->d_inode)->
k_objectid), xadir->d_name.len,
xadir->d_name.name, namelen, name,
is_reiserfs_priv_object(xadir->
d_inode) ? "" :
"not ");
dput(dentry);
return -EIO;
}
err = dir->i_op->unlink(dir, dentry);
if (!err)
d_delete(dentry);
out_file:
dput(dentry);
out:
return err;
}
int reiserfs_xattr_del(struct inode *inode, const char *name)
{
struct dentry *dir;
int err;
dir = open_xa_dir(inode, FL_READONLY);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
goto out;
}
err = __reiserfs_xattr_del(dir, name, strlen(name));
dput(dir);
if (!err) {
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
}
out:
return err;
}
/* The following are side effects of other operations that aren't explicitly
* modifying extended attributes. This includes operations such as permissions
* or ownership changes, object deletions, etc. */
static int
reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers These patches make the kernel pass 64-bit inode numbers internally when communicating to userspace, even on a 32-bit system. They are required because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS for example. The 64-bit inode numbers are then propagated to userspace automatically where the arch supports it. Problems have been seen with userspace (eg: ld.so) using the 64-bit inode number returned by stat64() or getdents64() to differentiate files, and failing because the 64-bit inode number space was compressed to 32-bits, and so overlaps occur. This patch: Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit inode number so that 64-bit inode numbers can be passed back to userspace. The stat functions then returns the full 64-bit inode number where available and where possible. If it is not possible to represent the inode number supplied by the filesystem in the field provided by userspace, then error EOVERFLOW will be issued. Similarly, the getdents/readdir functions now pass the full 64-bit inode number to userspace where possible, returning EOVERFLOW instead when a directory entry is encountered that can't be properly represented. Note that this means that some inodes will not be stat'able on a 32-bit system with old libraries where they were before - but it does mean that there will be no ambiguity over what a 32-bit inode number refers to. Note similarly that directory scans may be cut short with an error on a 32-bit system with old libraries where the scan would work before for the same reasons. It is judged unlikely that this situation will occur because modern glibc uses 64-bit capable versions of stat and getdents class functions exclusively, and that older systems are unlikely to encounter unrepresentable inode numbers anyway. [akpm: alpha build fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:13:46 +00:00
loff_t offset, u64 ino, unsigned int d_type)
{
struct dentry *xadir = (struct dentry *)buf;
return __reiserfs_xattr_del(xadir, name, namelen);
}
/* This is called w/ inode->i_mutex downed */
int reiserfs_delete_xattrs(struct inode *inode)
{
struct dentry *dir, *root;
int err = 0;
/* Skip out, an xattr has no xattrs associated with it */
if (is_reiserfs_priv_object(inode) ||
get_inode_sd_version(inode) == STAT_DATA_V1 ||
!reiserfs_xattrs(inode->i_sb)) {
return 0;
}
reiserfs_read_lock_xattrs(inode->i_sb);
dir = open_xa_dir(inode, FL_READONLY);
reiserfs_read_unlock_xattrs(inode->i_sb);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
goto out;
} else if (!dir->d_inode) {
dput(dir);
return 0;
}
lock_kernel();
err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
if (err) {
unlock_kernel();
goto out_dir;
}
/* Leftovers besides . and .. -- that's not good. */
if (dir->d_inode->i_nlink <= 2) {
root = get_xa_root(inode->i_sb, XATTR_REPLACE);
reiserfs_write_lock_xattrs(inode->i_sb);
err = vfs_rmdir(root->d_inode, dir);
reiserfs_write_unlock_xattrs(inode->i_sb);
dput(root);
} else {
reiserfs_warning(inode->i_sb,
"Couldn't remove all entries in directory");
}
unlock_kernel();
out_dir:
dput(dir);
out:
if (!err)
REISERFS_I(inode)->i_flags =
REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
return err;
}
struct reiserfs_chown_buf {
struct inode *inode;
struct dentry *xadir;
struct iattr *attrs;
};
/* XXX: If there is a better way to do this, I'd love to hear about it */
static int
reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers These patches make the kernel pass 64-bit inode numbers internally when communicating to userspace, even on a 32-bit system. They are required because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS for example. The 64-bit inode numbers are then propagated to userspace automatically where the arch supports it. Problems have been seen with userspace (eg: ld.so) using the 64-bit inode number returned by stat64() or getdents64() to differentiate files, and failing because the 64-bit inode number space was compressed to 32-bits, and so overlaps occur. This patch: Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit inode number so that 64-bit inode numbers can be passed back to userspace. The stat functions then returns the full 64-bit inode number where available and where possible. If it is not possible to represent the inode number supplied by the filesystem in the field provided by userspace, then error EOVERFLOW will be issued. Similarly, the getdents/readdir functions now pass the full 64-bit inode number to userspace where possible, returning EOVERFLOW instead when a directory entry is encountered that can't be properly represented. Note that this means that some inodes will not be stat'able on a 32-bit system with old libraries where they were before - but it does mean that there will be no ambiguity over what a 32-bit inode number refers to. Note similarly that directory scans may be cut short with an error on a 32-bit system with old libraries where the scan would work before for the same reasons. It is judged unlikely that this situation will occur because modern glibc uses 64-bit capable versions of stat and getdents class functions exclusively, and that older systems are unlikely to encounter unrepresentable inode numbers anyway. [akpm: alpha build fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:13:46 +00:00
loff_t offset, u64 ino, unsigned int d_type)
{
struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
struct dentry *xafile, *xadir = chown_buf->xadir;
struct iattr *attrs = chown_buf->attrs;
int err = 0;
xafile = lookup_one_len(name, xadir, namelen);
if (IS_ERR(xafile))
return PTR_ERR(xafile);
else if (!xafile->d_inode) {
dput(xafile);
return -ENODATA;
}
if (!S_ISDIR(xafile->d_inode->i_mode))
err = notify_change(xafile, attrs);
dput(xafile);
return err;
}
int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
{
struct dentry *dir;
int err = 0;
struct reiserfs_chown_buf buf;
unsigned int ia_valid = attrs->ia_valid;
/* Skip out, an xattr has no xattrs associated with it */
if (is_reiserfs_priv_object(inode) ||
get_inode_sd_version(inode) == STAT_DATA_V1 ||
!reiserfs_xattrs(inode->i_sb)) {
return 0;
}
reiserfs_read_lock_xattrs(inode->i_sb);
dir = open_xa_dir(inode, FL_READONLY);
reiserfs_read_unlock_xattrs(inode->i_sb);
if (IS_ERR(dir)) {
if (PTR_ERR(dir) != -ENODATA)
err = PTR_ERR(dir);
goto out;
} else if (!dir->d_inode) {
dput(dir);
goto out;
}
lock_kernel();
attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
buf.xadir = dir;
buf.attrs = attrs;
buf.inode = inode;
err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
if (err) {
unlock_kernel();
goto out_dir;
}
err = notify_change(dir, attrs);
unlock_kernel();
out_dir:
dput(dir);
out:
attrs->ia_valid = ia_valid;
return err;
}
/* Actual operations that are exported to VFS-land */
/*
* Inode operation getxattr()
* Preliminary locking: we down dentry->d_inode->i_mutex
*/
ssize_t
reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
size_t size)
{
struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
int err;
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
reiserfs_read_lock_xattr_i(dentry->d_inode);
reiserfs_read_lock_xattrs(dentry->d_sb);
err = xah->get(dentry->d_inode, name, buffer, size);
reiserfs_read_unlock_xattrs(dentry->d_sb);
reiserfs_read_unlock_xattr_i(dentry->d_inode);
return err;
}
/*
* Inode operation setxattr()
*
* dentry->d_inode->i_mutex down
*/
int
reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
int err;
int lock;
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
reiserfs_write_lock_xattr_i(dentry->d_inode);
lock = !has_xattr_dir(dentry->d_inode);
if (lock)
reiserfs_write_lock_xattrs(dentry->d_sb);
else
reiserfs_read_lock_xattrs(dentry->d_sb);
err = xah->set(dentry->d_inode, name, value, size, flags);
if (lock)
reiserfs_write_unlock_xattrs(dentry->d_sb);
else
reiserfs_read_unlock_xattrs(dentry->d_sb);
reiserfs_write_unlock_xattr_i(dentry->d_inode);
return err;
}
/*
* Inode operation removexattr()
*
* dentry->d_inode->i_mutex down
*/
int reiserfs_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
reiserfs_write_lock_xattr_i(dentry->d_inode);
reiserfs_read_lock_xattrs(dentry->d_sb);
/* Deletion pre-operation */
if (xah->del) {
err = xah->del(dentry->d_inode, name);
if (err)
goto out;
}
err = reiserfs_xattr_del(dentry->d_inode, name);
dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dentry->d_inode);
out:
reiserfs_read_unlock_xattrs(dentry->d_sb);
reiserfs_write_unlock_xattr_i(dentry->d_inode);
return err;
}
/* This is what filldir will use:
* r_pos will always contain the amount of space required for the entire
* list. If r_pos becomes larger than r_size, we need more space and we
* return an error indicating this. If r_pos is less than r_size, then we've
* filled the buffer successfully and we return success */
struct reiserfs_listxattr_buf {
int r_pos;
int r_size;
char *r_buf;
struct inode *r_inode;
};
static int
reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers These patches make the kernel pass 64-bit inode numbers internally when communicating to userspace, even on a 32-bit system. They are required because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS for example. The 64-bit inode numbers are then propagated to userspace automatically where the arch supports it. Problems have been seen with userspace (eg: ld.so) using the 64-bit inode number returned by stat64() or getdents64() to differentiate files, and failing because the 64-bit inode number space was compressed to 32-bits, and so overlaps occur. This patch: Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit inode number so that 64-bit inode numbers can be passed back to userspace. The stat functions then returns the full 64-bit inode number where available and where possible. If it is not possible to represent the inode number supplied by the filesystem in the field provided by userspace, then error EOVERFLOW will be issued. Similarly, the getdents/readdir functions now pass the full 64-bit inode number to userspace where possible, returning EOVERFLOW instead when a directory entry is encountered that can't be properly represented. Note that this means that some inodes will not be stat'able on a 32-bit system with old libraries where they were before - but it does mean that there will be no ambiguity over what a 32-bit inode number refers to. Note similarly that directory scans may be cut short with an error on a 32-bit system with old libraries where the scan would work before for the same reasons. It is judged unlikely that this situation will occur because modern glibc uses 64-bit capable versions of stat and getdents class functions exclusively, and that older systems are unlikely to encounter unrepresentable inode numbers anyway. [akpm: alpha build fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-03 08:13:46 +00:00
loff_t offset, u64 ino, unsigned int d_type)
{
struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
int len = 0;
if (name[0] != '.'
|| (namelen != 1 && (name[1] != '.' || namelen != 2))) {
struct reiserfs_xattr_handler *xah =
find_xattr_handler_prefix(name);
if (!xah)
return 0; /* Unsupported xattr name, skip it */
/* We call ->list() twice because the operation isn't required to just
* return the name back - we want to make sure we have enough space */
len += xah->list(b->r_inode, name, namelen, NULL);
if (len) {
if (b->r_pos + len + 1 <= b->r_size) {
char *p = b->r_buf + b->r_pos;
p += xah->list(b->r_inode, name, namelen, p);
*p++ = '\0';
}
b->r_pos += len + 1;
}
}
return 0;
}
/*
* Inode operation listxattr()
*
* Preliminary locking: we down dentry->d_inode->i_mutex
*/
ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
{
struct dentry *dir;
int err = 0;
struct reiserfs_listxattr_buf buf;
if (!dentry->d_inode)
return -EINVAL;
if (!reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
reiserfs_read_lock_xattr_i(dentry->d_inode);
reiserfs_read_lock_xattrs(dentry->d_sb);
dir = open_xa_dir(dentry->d_inode, FL_READONLY);
reiserfs_read_unlock_xattrs(dentry->d_sb);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
if (err == -ENODATA)
err = 0; /* Not an error if there aren't any xattrs */
goto out;
}
buf.r_buf = buffer;
buf.r_size = buffer ? size : 0;
buf.r_pos = 0;
buf.r_inode = dentry->d_inode;
REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
if (err)
goto out_dir;
if (buf.r_pos > buf.r_size && buffer != NULL)
err = -ERANGE;
else
err = buf.r_pos;
out_dir:
dput(dir);
out:
reiserfs_read_unlock_xattr_i(dentry->d_inode);
return err;
}
/* This is the implementation for the xattr plugin infrastructure */
static LIST_HEAD(xattr_handlers);
static DEFINE_RWLOCK(handler_lock);
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
*prefix)
{
struct reiserfs_xattr_handler *xah = NULL;
struct list_head *p;
read_lock(&handler_lock);
list_for_each(p, &xattr_handlers) {
xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
if (strncmp(xah->prefix, prefix, strlen(xah->prefix)) == 0)
break;
xah = NULL;
}
read_unlock(&handler_lock);
return xah;
}
static void __unregister_handlers(void)
{
struct reiserfs_xattr_handler *xah;
struct list_head *p, *tmp;
list_for_each_safe(p, tmp, &xattr_handlers) {
xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
if (xah->exit)
xah->exit();
list_del_init(p);
}
INIT_LIST_HEAD(&xattr_handlers);
}
int __init reiserfs_xattr_register_handlers(void)
{
int err = 0;
struct reiserfs_xattr_handler *xah;
struct list_head *p;
write_lock(&handler_lock);
/* If we're already initialized, nothing to do */
if (!list_empty(&xattr_handlers)) {
write_unlock(&handler_lock);
return 0;
}
/* Add the handlers */
list_add_tail(&user_handler.handlers, &xattr_handlers);
list_add_tail(&trusted_handler.handlers, &xattr_handlers);
#ifdef CONFIG_REISERFS_FS_SECURITY
list_add_tail(&security_handler.handlers, &xattr_handlers);
#endif
#ifdef CONFIG_REISERFS_FS_POSIX_ACL
list_add_tail(&posix_acl_access_handler.handlers, &xattr_handlers);
list_add_tail(&posix_acl_default_handler.handlers, &xattr_handlers);
#endif
/* Run initializers, if available */
list_for_each(p, &xattr_handlers) {
xah = list_entry(p, struct reiserfs_xattr_handler, handlers);
if (xah->init) {
err = xah->init();
if (err) {
list_del_init(p);
break;
}
}
}
/* Clean up other handlers, if any failed */
if (err)
__unregister_handlers();
write_unlock(&handler_lock);
return err;
}
void reiserfs_xattr_unregister_handlers(void)
{
write_lock(&handler_lock);
__unregister_handlers();
write_unlock(&handler_lock);
}
/* This will catch lookups from the fs root to .reiserfs_priv */
static int
xattr_lookup_poison(struct dentry *dentry, struct qstr *q1, struct qstr *name)
{
struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
if (name->len == priv_root->d_name.len &&
name->hash == priv_root->d_name.hash &&
!memcmp(name->name, priv_root->d_name.name, name->len)) {
return -ENOENT;
} else if (q1->len == name->len &&
!memcmp(q1->name, name->name, name->len))
return 0;
return 1;
}
static struct dentry_operations xattr_lookup_poison_ops = {
.d_compare = xattr_lookup_poison,
};
/* We need to take a copy of the mount flags since things like
* MS_RDONLY don't get set until *after* we're called.
* mount_flags != mount_options */
int reiserfs_xattr_init(struct super_block *s, int mount_flags)
{
int err = 0;
/* We need generation numbers to ensure that the oid mapping is correct
* v3.5 filesystems don't have them. */
if (!old_format_only(s)) {
set_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
} else if (reiserfs_xattrs_optional(s)) {
/* Old format filesystem, but optional xattrs have been enabled
* at mount time. Error out. */
reiserfs_warning(s, "xattrs/ACLs not supported on pre v3.6 "
"format filesystem. Failing mount.");
err = -EOPNOTSUPP;
goto error;
} else {
/* Old format filesystem, but no optional xattrs have been enabled. This
* means we silently disable xattrs on the filesystem. */
clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
}
/* If we don't have the privroot located yet - go find it */
if (reiserfs_xattrs(s) && !REISERFS_SB(s)->priv_root) {
struct dentry *dentry;
dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
strlen(PRIVROOT_NAME));
if (!IS_ERR(dentry)) {
if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
struct inode *inode = dentry->d_parent->d_inode;
mutex_lock_nested(&inode->i_mutex,
I_MUTEX_XATTR);
err = inode->i_op->mkdir(inode, dentry, 0700);
mutex_unlock(&inode->i_mutex);
if (err) {
dput(dentry);
dentry = NULL;
}
if (dentry && dentry->d_inode)
reiserfs_warning(s,
"Created %s on %s - reserved for "
"xattr storage.",
PRIVROOT_NAME,
reiserfs_bdevname
(inode->i_sb));
} else if (!dentry->d_inode) {
dput(dentry);
dentry = NULL;
}
} else
err = PTR_ERR(dentry);
if (!err && dentry) {
s->s_root->d_op = &xattr_lookup_poison_ops;
reiserfs_mark_inode_private(dentry->d_inode);
REISERFS_SB(s)->priv_root = dentry;
} else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
/* If we're read-only it just means that the dir hasn't been
* created. Not an error -- just no xattrs on the fs. We'll
* check again if we go read-write */
reiserfs_warning(s, "xattrs/ACLs enabled and couldn't "
"find/create .reiserfs_priv. Failing mount.");
err = -EOPNOTSUPP;
}
}
error:
/* This is only nonzero if there was an error initializing the xattr
* directory or if there is a condition where we don't support them. */
if (err) {
clear_bit(REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
clear_bit(REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
clear_bit(REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
}
/* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
s->s_flags = s->s_flags & ~MS_POSIXACL;
if (reiserfs_posixacl(s))
s->s_flags |= MS_POSIXACL;
return err;
}
static int reiserfs_check_acl(struct inode *inode, int mask)
{
struct posix_acl *acl;
int error = -EAGAIN; /* do regular unix permission checks by default */
reiserfs_read_lock_xattr_i(inode);
reiserfs_read_lock_xattrs(inode->i_sb);
acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
reiserfs_read_unlock_xattrs(inode->i_sb);
reiserfs_read_unlock_xattr_i(inode);
if (acl) {
if (!IS_ERR(acl)) {
error = posix_acl_permission(inode, acl, mask);
posix_acl_release(acl);
} else if (PTR_ERR(acl) != -ENODATA)
error = PTR_ERR(acl);
}
return error;
}
int reiserfs_permission(struct inode *inode, int mask)
{
/*
* We don't do permission checks on the internal objects.
* Permissions are determined by the "owning" object.
*/
if (is_reiserfs_priv_object(inode))
return 0;
/*
* Stat data v1 doesn't support ACLs.
*/
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return generic_permission(inode, mask, NULL);
else
return generic_permission(inode, mask, reiserfs_check_acl);
}