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: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 8d7e5d9..d3ce274 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -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 @@
return error;
}
-
#define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
/* Returns and possibly creates the xattr dir. */
@@ -339,14 +337,17 @@
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 @@
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 @@
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 @@
}
#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_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 @@
* 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 @@
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 @@
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 @@
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 @@
* 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 @@
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 @@
return err;
}
-int reiserfs_xattr_del(struct inode *inode, const char *name)
+/* 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
+};
+
+/*
+ * 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)++)
+
+/* 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 dentry *dir;
- int err;
+ struct xattr_handler *xah;
- dir = open_xa_dir(inode, XATTR_REPLACE);
- if (IS_ERR(dir)) {
- err = PTR_ERR(dir);
- goto out;
+ if (!handlers)
+ return NULL;
+
+ for_each_xattr_handler(handlers, xah) {
+ if (strncmp(xah->prefix, name, strlen(xah->prefix)) == 0)
+ break;
}
- 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);
-
- if (!err) {
- inode->i_ctime = CURRENT_TIME_SEC;
- mark_inode_dirty(inode);
- }
-
- out:
- return err;
+ return xah;
}
-/* Actual operations that are exported to VFS-land */
+
/*
* Inode operation getxattr()
*/
@@ -870,15 +891,15 @@
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 @@
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 @@
*/
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 @@
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) {
- 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);
-}
-
static int reiserfs_check_acl(struct inode *inode, int mask)
{
struct posix_acl *acl;
@@ -1157,20 +1074,16 @@
{
/* 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, "jdm-20005",
- "xattrs/ACLs not supported on pre v3.6 "
- "format filesystem. Failing mount.");
- return -EOPNOTSUPP;
- } 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 (old_format_only(s)) {
+ if (reiserfs_xattrs_optional(s)) {
+ /* Old format filesystem, but optional xattrs have
+ * been enabled. Error out. */
+ reiserfs_warning(s, "jdm-2005",
+ "xattrs/ACLs not supported "
+ "on pre-v3.6 format filesystems. "
+ "Failing mount.");
+ return -EOPNOTSUPP;
+ }
}
return 0;
@@ -1251,9 +1164,11 @@
}
#ifdef CONFIG_REISERFS_FS_XATTR
+ if (!err)
+ s->s_xattr = reiserfs_xattr_handlers;
+
error:
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));
}