From eaa47d8612783807ef9703ebc9bf0d0f0455bf62 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 28 Aug 2008 06:21:16 -0400 Subject: btrfs: optmize listxattr The ->list handler is really not useful at all, because we always call btrfs_xattr_generic_list anyway. After this is done find_btrfs_xattr_handler becomes unused, and it becomes obvious that the temporary name buffer allocation isn't needed but we can directly copy into the supplied buffer. Tested with various getfattr -d calls on varying xattr lists. Signed-off-by: Christoph Hellwig Signed-off-by: Chris Mason --- fs/btrfs/xattr.c | 82 ++++++++------------------------------------------------ 1 file changed, 11 insertions(+), 71 deletions(-) (limited to 'fs/btrfs/xattr.c') diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c index 121c9550314f..fdfece41dd16 100644 --- a/fs/btrfs/xattr.c +++ b/fs/btrfs/xattr.c @@ -50,35 +50,6 @@ struct xattr_handler *btrfs_xattr_handlers[] = { NULL, }; -/* - * @param name - the xattr name - * @return - the xattr_handler for the xattr, NULL if its not found - * - * use this with listxattr where we don't already know the type of xattr we - * have - */ -static struct xattr_handler *find_btrfs_xattr_handler(struct extent_buffer *l, - unsigned long name_ptr, - u16 name_len) -{ - struct xattr_handler *handler = NULL; - int i = 0; - - for (handler = btrfs_xattr_handlers[i]; handler != NULL; i++, - handler = btrfs_xattr_handlers[i]) { - u16 prefix_len = strlen(handler->prefix); - - if (name_len < prefix_len) - continue; - - if (memcmp_extent_buffer(l, handler->prefix, name_ptr, - prefix_len) == 0) - break; - } - - return handler; -} - /* * @param name_index - the index for the xattr handler * @return the xattr_handler if we found it, NULL otherwise @@ -118,19 +89,6 @@ static inline char *get_name(const char *name, int name_index) return ret; } -size_t btrfs_xattr_generic_list(struct inode *inode, char *list, - size_t list_size, const char *name, - size_t name_len) -{ - if (list && (name_len+1) <= list_size) { - memcpy(list, name, name_len); - list[name_len] = '\0'; - } else - return -ERANGE; - - return name_len+1; -} - ssize_t btrfs_xattr_get(struct inode *inode, int name_index, const char *attr_name, void *buffer, size_t size) { @@ -278,11 +236,10 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size) struct btrfs_item *item; struct extent_buffer *leaf; struct btrfs_dir_item *di; - struct xattr_handler *handler; int ret = 0, slot, advance; - size_t total_size = 0, size_left = size, written; + size_t total_size = 0, size_left = size; unsigned long name_ptr; - char *name; + size_t name_len; u32 nritems; /* @@ -344,37 +301,24 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size) di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); - total_size += btrfs_dir_name_len(leaf, di)+1; + name_len = btrfs_dir_name_len(leaf, di); + total_size += name_len + 1; /* we are just looking for how big our buffer needs to be */ if (!size) continue; - /* find our handler for this xattr */ - name_ptr = (unsigned long)(di + 1); - handler = find_btrfs_xattr_handler(leaf, name_ptr, - btrfs_dir_name_len(leaf, di)); - if (!handler) { - printk(KERN_ERR "btrfs: unsupported xattr found\n"); - continue; - } - - name = kmalloc(btrfs_dir_name_len(leaf, di), GFP_KERNEL); - read_extent_buffer(leaf, name, name_ptr, - btrfs_dir_name_len(leaf, di)); - - /* call the list function associated with this xattr */ - written = handler->list(inode, buffer, size_left, name, - btrfs_dir_name_len(leaf, di)); - kfree(name); - - if (written < 0) { + if (!buffer || (name_len + 1) > size_left) { ret = -ERANGE; break; } - size_left -= written; - buffer += written; + name_ptr = (unsigned long)(di + 1); + read_extent_buffer(leaf, buffer, name_ptr, name_len); + buffer[name_len] = '\0'; + + size_left -= name_len + 1; + buffer += name_len + 1; } ret = total_size; @@ -412,28 +356,24 @@ BTRFS_XATTR_SETGET_FUNCS(trusted, BTRFS_XATTR_INDEX_TRUSTED); struct xattr_handler btrfs_xattr_security_handler = { .prefix = XATTR_SECURITY_PREFIX, - .list = btrfs_xattr_generic_list, .get = btrfs_xattr_security_get, .set = btrfs_xattr_security_set, }; struct xattr_handler btrfs_xattr_system_handler = { .prefix = XATTR_SYSTEM_PREFIX, - .list = btrfs_xattr_generic_list, .get = btrfs_xattr_system_get, .set = btrfs_xattr_system_set, }; struct xattr_handler btrfs_xattr_user_handler = { .prefix = XATTR_USER_PREFIX, - .list = btrfs_xattr_generic_list, .get = btrfs_xattr_user_get, .set = btrfs_xattr_user_set, }; struct xattr_handler btrfs_xattr_trusted_handler = { .prefix = XATTR_TRUSTED_PREFIX, - .list = btrfs_xattr_generic_list, .get = btrfs_xattr_trusted_get, .set = btrfs_xattr_trusted_set, }; -- cgit v1.2.3