Commit 48b32a35 authored by Jeff Mahoney's avatar Jeff Mahoney Committed by Linus Torvalds
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reiserfs: use generic xattr handlers



Christoph Hellwig had asked me quite some time ago to port the reiserfs
xattrs to the generic xattr interface.

This patch replaces the reiserfs-specific xattr handling code with the
generic struct xattr_handler.

However, since reiserfs doesn't split the prefix and name when accessing
xattrs, it can't leverage generic_{set,get,list,remove}xattr without
needlessly reconstructing the name on the back end.

Update 7/26/07: Added missing dput() to deletion path.
Update 8/30/07: Added missing mark_inode_dirty when i_mode is used to
                represent an ACL and no previous ACL existed.
Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8ecbe550
......@@ -2263,9 +2263,6 @@ static int __init init_reiserfs_fs(void)
return ret;
}
if ((ret = reiserfs_xattr_register_handlers()))
goto failed_reiserfs_xattr_register_handlers;
reiserfs_proc_info_global_init();
reiserfs_proc_register_global("version",
reiserfs_global_version_in_proc);
......@@ -2276,9 +2273,6 @@ static int __init init_reiserfs_fs(void)
return 0;
}
reiserfs_xattr_unregister_handlers();
failed_reiserfs_xattr_register_handlers:
reiserfs_proc_unregister_global("version");
reiserfs_proc_info_global_done();
destroy_inodecache();
......@@ -2288,7 +2282,6 @@ static int __init init_reiserfs_fs(void)
static void __exit exit_reiserfs_fs(void)
{
reiserfs_xattr_unregister_handlers();
reiserfs_proc_unregister_global("version");
reiserfs_proc_info_global_done();
unregister_filesystem(&reiserfs_fs_type);
......
......@@ -53,7 +53,6 @@
#define PRIVROOT_NAME ".reiserfs_priv"
#define XAROOT_NAME "xattrs"
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char *);
/* Helpers for inode ops. We do this so that we don't have all the VFS
* overhead and also for proper i_mutex annotation.
......@@ -110,7 +109,6 @@ static int xattr_rmdir(struct inode *dir, struct dentry *dentry)
return error;
}
#define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
/* Returns and possibly creates the xattr dir. */
......@@ -339,14 +337,17 @@ int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
return res;
}
/* expects xadir->d_inode->i_mutex to be locked */
/* 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_xattr_del(struct dentry *xadir, const char *name, int namelen)
reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
loff_t offset, u64 ino, unsigned int d_type)
{
struct dentry *xadir = (struct dentry *)buf;
struct dentry *dentry;
struct inode *dir = xadir->d_inode;
int err = 0;
struct reiserfs_xattr_handler *xah;
dentry = lookup_one_len(name, xadir, namelen);
if (IS_ERR(dentry)) {
......@@ -361,28 +362,7 @@ __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
if (S_ISDIR(dentry->d_inode->i_mode))
goto out_file;
if (!IS_PRIVATE(dentry->d_inode)) {
reiserfs_error(dir->i_sb, "jdm-20003",
"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_PRIVATE(xadir->d_inode) ? "" :
"not ");
dput(dentry);
return -EIO;
}
/* Deletion pre-operation */
xah = find_xattr_handler_prefix(name);
if (xah && xah->del) {
err = xah->del(dentry->d_inode, name);
if (err)
goto out;
}
err = xattr_unlink(dir, dentry);
err = xattr_unlink(xadir->d_inode, dentry);
out_file:
dput(dentry);
......@@ -391,20 +371,6 @@ __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
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,
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)
{
......@@ -541,14 +507,11 @@ int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
}
#ifdef CONFIG_REISERFS_FS_XATTR
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
*prefix);
/* 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)
static struct dentry *xattr_lookup(struct inode *inode, const char *name,
int flags)
{
struct dentry *xadir, *xafile;
int err = 0;
......@@ -623,6 +586,45 @@ int reiserfs_commit_write(struct file *f, struct page *page,
int reiserfs_prepare_write(struct file *f, struct page *page,
unsigned from, unsigned to);
static void update_ctime(struct inode *inode)
{
struct timespec now = current_fs_time(inode->i_sb);
if (hlist_unhashed(&inode->i_hash) || !inode->i_nlink ||
timespec_equal(&inode->i_ctime, &now))
return;
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
}
static int lookup_and_delete_xattr(struct inode *inode, const char *name)
{
int err = 0;
struct dentry *dentry, *xadir;
xadir = open_xa_dir(inode, XATTR_REPLACE);
if (IS_ERR(xadir))
return PTR_ERR(xadir);
dentry = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_dput;
}
if (dentry->d_inode) {
mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
err = xattr_unlink(xadir->d_inode, dentry);
mutex_unlock(&xadir->d_inode->i_mutex);
update_ctime(inode);
}
dput(dentry);
out_dput:
dput(xadir);
return err;
}
/* Generic extended attribute operations that can be used by xa plugins */
......@@ -630,8 +632,8 @@ int reiserfs_prepare_write(struct file *f, struct page *page,
* inode->i_mutex: down
*/
int
reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
size_t buffer_size, int flags)
__reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
size_t buffer_size, int flags)
{
int err = 0;
struct dentry *dentry;
......@@ -639,37 +641,22 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
char *data;
size_t file_pos = 0;
size_t buffer_pos = 0;
struct iattr newattrs;
size_t new_size;
__u32 xahash = 0;
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
if (!buffer)
return reiserfs_xattr_del(inode, name);
return lookup_and_delete_xattr(inode, name);
dentry = get_xa_file_dentry(inode, name, flags);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
dentry = xattr_lookup(inode, name, flags);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
down_write(&REISERFS_I(inode)->i_xattr_sem);
xahash = xattr_hash(buffer, buffer_size);
/* Resize it so we're ok to write there */
newattrs.ia_size = buffer_size;
newattrs.ia_ctime = current_fs_time(inode->i_sb);
newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
down_write(&dentry->d_inode->i_alloc_sem);
err = reiserfs_setattr(dentry, &newattrs);
up_write(&dentry->d_inode->i_alloc_sem);
mutex_unlock(&dentry->d_inode->i_mutex);
if (err)
goto out_filp;
while (buffer_pos < buffer_size || buffer_pos == 0) {
size_t chunk;
size_t skip = 0;
......@@ -682,7 +669,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
page = reiserfs_get_page(dentry->d_inode, file_pos);
if (IS_ERR(page)) {
err = PTR_ERR(page);
goto out_filp;
goto out_unlock;
}
lock_page(page);
......@@ -716,20 +703,33 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *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:
new_size = buffer_size + sizeof(struct reiserfs_xattr_header);
if (!err && new_size < i_size_read(dentry->d_inode)) {
struct iattr newattrs = {
.ia_ctime = current_fs_time(inode->i_sb),
.ia_size = buffer_size,
.ia_valid = ATTR_SIZE | ATTR_CTIME,
};
mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
down_write(&dentry->d_inode->i_alloc_sem);
err = reiserfs_setattr(dentry, &newattrs);
up_write(&dentry->d_inode->i_alloc_sem);
mutex_unlock(&dentry->d_inode->i_mutex);
} else
update_ctime(inode);
out_unlock:
up_write(&REISERFS_I(inode)->i_xattr_sem);
dput(dentry);
return err;
}
out:
int
reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
size_t buffer_size, int flags)
{
int err = __reiserfs_xattr_set(inode, name, buffer, buffer_size, flags);
if (err == -ENODATA)
err = 0;
return err;
}
......@@ -737,7 +737,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
* inode->i_mutex: down
*/
int
reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
reiserfs_xattr_get(struct inode *inode, const char *name, void *buffer,
size_t buffer_size)
{
ssize_t err = 0;
......@@ -756,7 +756,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
dentry = get_xa_file_dentry(inode, name, XATTR_REPLACE);
dentry = xattr_lookup(inode, name, XATTR_REPLACE);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
......@@ -837,32 +837,53 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
return err;
}
int reiserfs_xattr_del(struct inode *inode, const char *name)
{
struct dentry *dir;
int err;
/* Actual operations that are exported to VFS-land */
struct xattr_handler *reiserfs_xattr_handlers[] = {
&reiserfs_xattr_user_handler,
&reiserfs_xattr_trusted_handler,
#ifdef CONFIG_REISERFS_FS_SECURITY
&reiserfs_xattr_security_handler,
#endif
#ifdef CONFIG_REISERFS_FS_POSIX_ACL
&reiserfs_posix_acl_access_handler,
&reiserfs_posix_acl_default_handler,
#endif
NULL
};
dir = open_xa_dir(inode, XATTR_REPLACE);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
goto out;
}
/*
* In order to implement different sets of xattr operations for each xattr
* prefix with the generic xattr API, a filesystem should create a
* null-terminated array of struct xattr_handler (one for each prefix) and
* hang a pointer to it off of the s_xattr field of the superblock.
*
* The generic_fooxattr() functions will use this list to dispatch xattr
* operations to the correct xattr_handler.
*/
#define for_each_xattr_handler(handlers, handler) \
for ((handler) = *(handlers)++; \
(handler) != NULL; \
(handler) = *(handlers)++)
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
err = __reiserfs_xattr_del(dir, name, strlen(name));
mutex_unlock(&dir->d_inode->i_mutex);
dput(dir);
/* This is the implementation for the xattr plugin infrastructure */
static inline struct xattr_handler *
find_xattr_handler_prefix(struct xattr_handler **handlers,
const char *name)
{
struct xattr_handler *xah;
if (!err) {
inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
if (!handlers)
return NULL;
for_each_xattr_handler(handlers, xah) {
if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
break;
}
out:
return err;
return xah;
}
/* Actual operations that are exported to VFS-land */
/*
* Inode operation getxattr()
*/
......@@ -870,15 +891,15 @@ 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;
struct inode *inode = dentry->d_inode;
struct xattr_handler *handler;
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
err = xah->get(dentry->d_inode, name, buffer, size);
return err;
return handler->get(inode, name, buffer, size);
}
/*
......@@ -890,15 +911,15 @@ 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;
struct inode *inode = dentry->d_inode;
struct xattr_handler *handler;
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
err = xah->set(dentry->d_inode, name, value, size, flags);
return err;
return handler->set(inode, name, value, size, flags);
}
/*
......@@ -908,71 +929,65 @@ reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
*/
int reiserfs_removexattr(struct dentry *dentry, const char *name)
{
int err;
struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix(name);
struct inode *inode = dentry->d_inode;
struct xattr_handler *handler;
handler = find_xattr_handler_prefix(inode->i_sb->s_xattr, name);
if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
if (!handler || get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
err = reiserfs_xattr_del(dentry->d_inode, name);
dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dentry->d_inode);
return err;
return handler->set(inode, name, NULL, 0, XATTR_REPLACE);
}
/* 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;
struct listxattr_buf {
size_t size;
size_t pos;
char *buf;
struct inode *inode;
};
static int
reiserfs_listxattr_filler(void *buf, const char *name, int namelen,
loff_t offset, u64 ino, unsigned int d_type)
static int listxattr_filler(void *buf, const char *name, int namelen,
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;
struct listxattr_buf *b = (struct listxattr_buf *)buf;
size_t size;
if (name[0] != '.' ||
(namelen != 1 && (name[1] != '.' || namelen != 2))) {
struct xattr_handler *handler;
handler = find_xattr_handler_prefix(b->inode->i_sb->s_xattr,
name);
if (!handler) /* Unsupported xattr name */
return 0;
if (b->buf) {
size = handler->list(b->inode, b->buf + b->pos,
b->size, name, namelen);
if (size > b->size)
return -ERANGE;
} else {
size = handler->list(b->inode, NULL, 0, name, namelen);
}
}
b->pos += size;
}
return 0;
}
/*
* Inode operation listxattr()
*
* We totally ignore the generic listxattr here because it would be stupid
* not to. Since the xattrs are organized in a directory, we can just
* readdir to find them.
*/
ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
{
struct dentry *dir;
int err = 0;
struct reiserfs_listxattr_buf buf;
struct listxattr_buf buf = {
.inode = dentry->d_inode,
.buf = buffer,
.size = buffer ? size : 0,
};
if (!dentry->d_inode)
return -EINVAL;
......@@ -985,120 +1000,22 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
if (err == -ENODATA)
err = 0; /* Not an error if there aren't any xattrs */
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;
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
err = xattr_readdir(dir->d_inode, listxattr_filler, &buf);
mutex_unlock(&dir->d_inode->i_mutex);
if (!err) {
if (buf.r_pos > buf.r_size && buffer != NULL)
err = -ERANGE;
else
err = buf.r_pos;
}
if (!err)
err = buf.pos;
dput(dir);
out:
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) {