Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 14 Oct 2002 23:31:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 14 Oct 2002 23:31:03 -0400 Received: from SNAP.THUNK.ORG ([216.175.175.173]:14771 "EHLO snap.thunk.org") by vger.kernel.org with ESMTP id ; Mon, 14 Oct 2002 23:27:29 -0400 To: torvalds@transmeta.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH 4/4] Add extended attributes to ext2/3 From: tytso@mit.edu Message-Id: Date: Mon, 14 Oct 2002 23:33:18 -0400 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 52529 Lines: 1855 This patch adds extended attribute support to the ext2 filesystem. This uses the generic extended attribute patch which was developed by Andreas Gruenbacher and the XFS team. As a result, the user space utilities which work for XFS will also work with these patches. - Ted # This is a BitKeeper generated patch for the following project: # Project Name: Linux kernel tree # # fs/Config.help | 7 # fs/Config.in | 1 # fs/ext2/Makefile | 6 # fs/ext2/ext2.h | 3 # fs/ext2/file.c | 4 # fs/ext2/ialloc.c | 1 # fs/ext2/inode.c | 38 - # fs/ext2/namei.c | 13 # fs/ext2/super.c | 18 # fs/ext2/symlink.c | 13 # fs/ext2/xattr.c | 1208 ++++++++++++++++++++++++++++++++++++++++ # fs/ext2/xattr_user.c | 100 +++ # include/linux/ext2_fs.h | 28 - # include/linux/ext2_xattr.h | 135 +++++ # 14 files changed, 1531 insertions(+), 44 deletions(-) # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/10/14 tytso@snap.thunk.org 1.786 # Port of (bugfixed) 0.8.50 xattr-ext2 to 2.5 # # -------------------------------------------- # diff -Nru a/fs/Config.help b/fs/Config.help --- a/fs/Config.help Mon Oct 14 23:21:23 2002 +++ b/fs/Config.help Mon Oct 14 23:21:23 2002 @@ -123,6 +123,13 @@ be compiled as a module, and so this could be dangerous. Most everyone wants to say Y here. +CONFIG_EXT2_FS_XATTR + Extended attributes are name:value pairs associated with inodes by + the kernel or by users (see the attr(5) manual page, or visit + for details). + + If unsure, say N. + CONFIG_EXT3_FS This is the journaling version of the Second extended file system (often called ext3), the de facto standard Linux file system diff -Nru a/fs/Config.in b/fs/Config.in --- a/fs/Config.in Mon Oct 14 23:21:23 2002 +++ b/fs/Config.in Mon Oct 14 23:21:23 2002 @@ -93,6 +93,7 @@ tristate 'ROM file system support' CONFIG_ROMFS_FS tristate 'Second extended fs support' CONFIG_EXT2_FS +dep_bool ' Ext2 extended attributes' CONFIG_EXT2_FS_XATTR $CONFIG_EXT3_FS tristate 'System V/Xenix/V7/Coherent file system support' CONFIG_SYSV_FS diff -Nru a/fs/ext2/Makefile b/fs/ext2/Makefile --- a/fs/ext2/Makefile Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/Makefile Mon Oct 14 23:21:23 2002 @@ -7,4 +7,10 @@ ext2-objs := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ ioctl.o namei.o super.o symlink.o +export-objs += xattr.o + +ifeq ($(CONFIG_EXT2_FS_XATTR),y) +ext2-objs += xattr.o xattr_user.o +endif + include $(TOPDIR)/Rules.make diff -Nru a/fs/ext2/ext2.h b/fs/ext2/ext2.h --- a/fs/ext2/ext2.h Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/ext2.h Mon Oct 14 23:21:23 2002 @@ -1,5 +1,6 @@ #include #include +#include /* * second extended file system inode data in memory @@ -110,6 +111,8 @@ /* namei.c */ extern struct inode_operations ext2_dir_inode_operations; +extern struct inode_operations ext2_special_inode_operations; /* symlink.c */ extern struct inode_operations ext2_fast_symlink_inode_operations; +extern struct inode_operations ext2_symlink_inode_operations; diff -Nru a/fs/ext2/file.c b/fs/ext2/file.c --- a/fs/ext2/file.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/file.c Mon Oct 14 23:21:23 2002 @@ -55,4 +55,8 @@ struct inode_operations ext2_file_inode_operations = { .truncate = ext2_truncate, + .setxattr = ext2_setxattr, + .getxattr = ext2_getxattr, + .listxattr = ext2_listxattr, + .removexattr = ext2_removexattr, }; diff -Nru a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c --- a/fs/ext2/ialloc.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/ialloc.c Mon Oct 14 23:21:23 2002 @@ -97,6 +97,7 @@ */ if (!is_bad_inode(inode)) { /* Quota is already initialized in iput() */ + ext2_xattr_delete_inode(inode); DQUOT_FREE_INODE(inode); DQUOT_DROP(inode); } diff -Nru a/fs/ext2/inode.c b/fs/ext2/inode.c --- a/fs/ext2/inode.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/inode.c Mon Oct 14 23:21:23 2002 @@ -39,6 +39,18 @@ static int ext2_update_inode(struct inode * inode, int do_sync); /* + * Test whether an inode is a fast symlink. + */ +static inline int ext2_inode_is_fast_symlink(struct inode *inode) +{ + int ea_blocks = EXT2_I(inode)->i_file_acl ? + (inode->i_sb->s_blocksize >> 9) : 0; + + return (S_ISLNK(inode->i_mode) && + inode->i_blocks - ea_blocks == 0); +} + +/* * Called at each iput() */ void ext2_put_inode (struct inode * inode) @@ -51,9 +63,7 @@ */ void ext2_delete_inode (struct inode * inode) { - if (is_bad_inode(inode) || - inode->i_ino == EXT2_ACL_IDX_INO || - inode->i_ino == EXT2_ACL_DATA_INO) + if (is_bad_inode(inode)) goto no_delete; EXT2_I(inode)->i_dtime = CURRENT_TIME; mark_inode_dirty(inode); @@ -843,6 +853,8 @@ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) return; + if (ext2_inode_is_fast_symlink(inode)) + return; if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return; @@ -929,8 +941,7 @@ struct ext2_group_desc * gdp; *p = NULL; - if ((ino != EXT2_ROOT_INO && ino != EXT2_ACL_IDX_INO && - ino != EXT2_ACL_DATA_INO && ino < EXT2_FIRST_INO(sb)) || + if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) goto Einval; @@ -1024,9 +1035,7 @@ for (n = 0; n < EXT2_N_BLOCKS; n++) ei->i_data[n] = raw_inode->i_block[n]; - if (ino == EXT2_ACL_IDX_INO || ino == EXT2_ACL_DATA_INO) - /* Nothing to do */ ; - else if (S_ISREG(inode->i_mode)) { + if (S_ISREG(inode->i_mode)) { inode->i_op = &ext2_file_inode_operations; inode->i_fop = &ext2_file_operations; inode->i_mapping->a_ops = &ext2_aops; @@ -1035,15 +1044,17 @@ inode->i_fop = &ext2_dir_operations; inode->i_mapping->a_ops = &ext2_aops; } else if (S_ISLNK(inode->i_mode)) { - if (!inode->i_blocks) + if (ext2_inode_is_fast_symlink(inode)) inode->i_op = &ext2_fast_symlink_inode_operations; else { - inode->i_op = &page_symlink_inode_operations; + inode->i_op = &ext2_symlink_inode_operations; inode->i_mapping->a_ops = &ext2_aops; } - } else + } else { + inode->i_op = &ext2_special_inode_operations; init_special_inode(inode, inode->i_mode, le32_to_cpu(raw_inode->i_block[0])); + } brelse (bh); if (ei->i_flags & EXT2_SYNC_FL) inode->i_flags |= S_SYNC; @@ -1075,11 +1086,6 @@ if (IS_ERR(raw_inode)) return -EIO; - if (ino == EXT2_ACL_IDX_INO || ino == EXT2_ACL_DATA_INO) { - ext2_error (sb, "ext2_write_inode", "bad inode number: %lu", ino); - brelse(bh); - return -EIO; - } raw_inode->i_mode = cpu_to_le16(inode->i_mode); if (!(test_opt(sb, NO_UID32))) { raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); diff -Nru a/fs/ext2/namei.c b/fs/ext2/namei.c --- a/fs/ext2/namei.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/namei.c Mon Oct 14 23:21:23 2002 @@ -162,7 +162,7 @@ if (l > sizeof (EXT2_I(inode)->i_data)) { /* slow symlink */ - inode->i_op = &page_symlink_inode_operations; + inode->i_op = &ext2_symlink_inode_operations; inode->i_mapping->a_ops = &ext2_aops; err = page_symlink(inode, symname, l); if (err) @@ -368,4 +368,15 @@ .rmdir = ext2_rmdir, .mknod = ext2_mknod, .rename = ext2_rename, + .setxattr = ext2_setxattr, + .getxattr = ext2_getxattr, + .listxattr = ext2_listxattr, + .removexattr = ext2_removexattr, +}; + +struct inode_operations ext2_special_inode_operations = { + .setxattr = ext2_setxattr, + .getxattr = ext2_getxattr, + .listxattr = ext2_listxattr, + .removexattr = ext2_removexattr, }; diff -Nru a/fs/ext2/super.c b/fs/ext2/super.c --- a/fs/ext2/super.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/super.c Mon Oct 14 23:21:23 2002 @@ -131,6 +131,7 @@ int i; struct ext2_sb_info *sbi = EXT2_SB(sb); + ext2_xattr_put_super(sb); if (!(sb->s_flags & MS_RDONLY)) { struct ext2_super_block *es = sbi->s_es; @@ -233,6 +234,13 @@ continue; if ((value = strchr (this_char, '=')) != NULL) *value++ = 0; +#ifdef CONFIG_EXT2_FS_XATTR + if (!strcmp (this_char, "user_xattr")) + set_opt (*mount_options, XATTR_USER); + else if (!strcmp (this_char, "nouser_xattr")) + clear_opt (*mount_options, XATTR_USER); + else +#endif if (!strcmp (this_char, "bsddf")) clear_opt (*mount_options, MINIX_DF); else if (!strcmp (this_char, "nouid32")) { @@ -487,6 +495,9 @@ */ sbi->s_mount_opt = 0; +#ifdef CONFIG_EXT2_FS_XATTR + set_opt (EXT2_SB(sb)->s_mount_opt, XATTR_USER); +#endif if (!parse_options ((char *) data, &sb_block, &resuid, &resgid, &sbi->s_mount_opt)) goto failed_sbi; @@ -883,7 +894,10 @@ static int __init init_ext2_fs(void) { - int err = init_inodecache(); + int err = init_ext2_xattr(); + if (err) + return err; + err = init_inodecache(); if (err) goto out1; err = register_filesystem(&ext2_fs_type); @@ -893,6 +907,7 @@ out: destroy_inodecache(); out1: + exit_ext2_xattr(); return err; } @@ -900,6 +915,7 @@ { unregister_filesystem(&ext2_fs_type); destroy_inodecache(); + exit_ext2_xattr(); } module_init(init_ext2_fs) diff -Nru a/fs/ext2/symlink.c b/fs/ext2/symlink.c --- a/fs/ext2/symlink.c Mon Oct 14 23:21:23 2002 +++ b/fs/ext2/symlink.c Mon Oct 14 23:21:23 2002 @@ -31,7 +31,20 @@ return vfs_follow_link(nd, (char *)ei->i_data); } +struct inode_operations ext2_symlink_inode_operations = { + .readlink = page_readlink, + .follow_link = page_follow_link, + .setxattr = ext2_setxattr, + .getxattr = ext2_getxattr, + .listxattr = ext2_listxattr, + .removexattr = ext2_removexattr, +}; + struct inode_operations ext2_fast_symlink_inode_operations = { .readlink = ext2_readlink, .follow_link = ext2_follow_link, + .setxattr = ext2_setxattr, + .getxattr = ext2_getxattr, + .listxattr = ext2_listxattr, + .removexattr = ext2_removexattr, }; diff -Nru a/fs/ext2/xattr.c b/fs/ext2/xattr.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/fs/ext2/xattr.c Mon Oct 14 23:21:23 2002 @@ -0,0 +1,1208 @@ +/* + * linux/fs/ext2/xattr.c + * + * Copyright (C) 2001 by Andreas Gruenbacher, + * + * Fix by Harrison Xing . + * Extended attributes for symlinks and special files added per + * suggestion of Luka Renko . + */ + +/* + * Extended attributes are stored on disk blocks allocated outside of + * any inode. The i_file_acl field is then made to point to this allocated + * block. If all extended attributes of an inode are identical, these + * inodes may share the same extended attribute block. Such situations + * are automatically detected by keeping a cache of recent attribute block + * numbers and hashes over the block's contents in memory. + * + * + * Extended attribute block layout: + * + * +------------------+ + * | header | + * ? entry 1 | | + * | entry 2 | | growing downwards + * | entry 3 | v + * | four null bytes | + * | . . . | + * | value 1 | ^ + * | value 3 | | growing upwards + * | value 2 | | + * +------------------+ + * + * The block header is followed by multiple entry descriptors. These entry + * descriptors are variable in size, and alligned to EXT2_XATTR_PAD + * byte boundaries. The entry descriptors are sorted by attribute name, + * so that two extended attribute blocks can be compared efficiently. + * + * Attribute values are aligned to the end of the block, stored in + * no specific order. They are also padded to EXT2_XATTR_PAD byte + * boundaries. No additional gaps are left between them. + * + * Locking strategy + * ---------------- + * The VFS already holds the BKL and the inode->i_sem semaphore when any of + * the xattr inode operations are called, so we are guaranteed that only one + * processes accesses extended attributes of an inode at any time. + * + * For writing we also grab the ext2_xattr_sem semaphore. This ensures that + * only a single process is modifying an extended attribute block, even + * if the block is shared among inodes. + * + * Note for porting to 2.5 + * ----------------------- + * The BKL will no longer be held in the xattr inode operations. + */ + +#include "ext2.h" +#include +#include +#include +#include +#include +#include +#include + +/* These symbols may be needed by a module. */ +EXPORT_SYMBOL(ext2_xattr_register); +EXPORT_SYMBOL(ext2_xattr_unregister); +EXPORT_SYMBOL(ext2_xattr_get); +EXPORT_SYMBOL(ext2_xattr_list); +EXPORT_SYMBOL(ext2_xattr_set); + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,0) +# define mark_buffer_dirty(bh) mark_buffer_dirty(bh, 1) +#endif + +#define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data)) +#define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr)) +#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1) +#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) + +#ifdef EXT2_XATTR_DEBUG +# define ea_idebug(inode, f...) do { \ + printk(KERN_DEBUG "inode %s:%ld: ", \ + kdevname(inode->i_dev), inode->i_ino); \ + printk(f); \ + printk("\n"); \ + } while (0) +# define ea_bdebug(bh, f...) do { \ + printk(KERN_DEBUG "block %s:%ld: ", \ + kdevname(bh->b_dev), bh->b_blocknr); \ + printk(f); \ + printk("\n"); \ + } while (0) +#else +# define ea_idebug(f...) +# define ea_bdebug(f...) +#endif + +static int ext2_xattr_set2(struct inode *, struct buffer_head *, + struct ext2_xattr_header *); + +static int ext2_xattr_cache_insert(struct buffer_head *); +static struct buffer_head *ext2_xattr_cache_find(struct inode *, + struct ext2_xattr_header *); +static void ext2_xattr_cache_remove(struct buffer_head *); +static void ext2_xattr_rehash(struct ext2_xattr_header *, + struct ext2_xattr_entry *); + +static struct mb_cache *ext2_xattr_cache; + +/* + * If a file system does not share extended attributes among inodes, + * we should not need the ext2_xattr_sem semaphore. However, the + * filesystem may still contain shared blocks, so we always take + * the lock. + */ + +DECLARE_MUTEX(ext2_xattr_sem); + +static inline void +ext2_xattr_lock(void) +{ + down(&ext2_xattr_sem); +} + +static inline void +ext2_xattr_unlock(void) +{ + up(&ext2_xattr_sem); +} + +static inline int +ext2_xattr_new_block(struct inode *inode, int * errp, int force) +{ + struct super_block *sb = inode->i_sb; + int goal = le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block) + + EXT2_I(inode)->i_block_group * EXT2_BLOCKS_PER_GROUP(sb); + + /* How can we enforce the allocation? */ + int block = ext2_new_block(inode, goal, 0, 0, errp); +#ifdef OLD_QUOTAS + if (!*errp) + inode->i_blocks += inode->i_sb->s_blocksize >> 9; +#endif + return block; +} + +static inline int +ext2_xattr_quota_alloc(struct inode *inode, int force) +{ + /* How can we enforce the allocation? */ +#ifdef OLD_QUOTAS + int error = DQUOT_ALLOC_BLOCK(inode->i_sb, inode, 1); + if (!error) + inode->i_blocks += inode->i_sb->s_blocksize >> 9; +#else + int error = DQUOT_ALLOC_BLOCK(inode, 1); +#endif + return error; +} + +#ifdef OLD_QUOTAS + +static inline void +ext2_xattr_quota_free(struct inode *inode) +{ + DQUOT_FREE_BLOCK(inode->i_sb, inode, 1); + inode->i_blocks -= inode->i_sb->s_blocksize >> 9; +} + +static inline void +ext2_xattr_free_block(struct inode * inode, unsigned long block) +{ + ext2_free_blocks(inode, block, 1); + inode->i_blocks -= inode->i_sb->s_blocksize >> 9; +} + +#else +# define ext2_xattr_quota_free(inode) \ + DQUOT_FREE_BLOCK(inode, 1) +# define ext2_xattr_free_block(inode, block) \ + ext2_free_blocks(inode, block, 1) +#endif + +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,18) + +static inline struct buffer_head * +sb_bread(struct super_block *sb, int block) +{ + return bread(sb->s_dev, block, sb->s_blocksize); +} + +static inline struct buffer_head * +sb_getblk(struct super_block *sb, int block) +{ + return getblk(sb->s_dev, block, sb->s_blocksize); +} + +#endif + +struct ext2_xattr_handler *ext2_xattr_handlers[EXT2_XATTR_INDEX_MAX]; +rwlock_t ext2_handler_lock = RW_LOCK_UNLOCKED; + +int +ext2_xattr_register(int name_index, struct ext2_xattr_handler *handler) +{ + int error = -EINVAL; + + if (name_index > 0 && name_index <= EXT2_XATTR_INDEX_MAX) { + write_lock(&ext2_handler_lock); + if (!ext2_xattr_handlers[name_index-1]) { + ext2_xattr_handlers[name_index-1] = handler; + error = 0; + } + write_unlock(&ext2_handler_lock); + } + return error; +} + +void +ext2_xattr_unregister(int name_index, struct ext2_xattr_handler *handler) +{ + if (name_index > 0 || name_index <= EXT2_XATTR_INDEX_MAX) { + write_lock(&ext2_handler_lock); + ext2_xattr_handlers[name_index-1] = NULL; + write_unlock(&ext2_handler_lock); + } +} + +static inline const char * +strcmp_prefix(const char *a, const char *a_prefix) +{ + while (*a_prefix && *a == *a_prefix) { + a++; + a_prefix++; + } + return *a_prefix ? NULL : a; +} + +/* + * Decode the extended attribute name, and translate it into + * the name_index and name suffix. + */ +static struct ext2_xattr_handler * +ext2_xattr_resolve_name(const char **name) +{ + struct ext2_xattr_handler *handler = NULL; + int i; + + if (!*name) + return NULL; + read_lock(&ext2_handler_lock); + for (i=0; iprefix); + if (n) { + handler = ext2_xattr_handlers[i]; + *name = n; + break; + } + } + } + read_unlock(&ext2_handler_lock); + return handler; +} + +static inline struct ext2_xattr_handler * +ext2_xattr_handler(int name_index) +{ + struct ext2_xattr_handler *handler = NULL; + if (name_index > 0 && name_index <= EXT2_XATTR_INDEX_MAX) { + read_lock(&ext2_handler_lock); + handler = ext2_xattr_handlers[name_index-1]; + read_unlock(&ext2_handler_lock); + } + return handler; +} + +/* + * Inode operation getxattr() + * + * dentry->d_inode->i_sem down + * BKL held [before 2.5.x] + */ +ssize_t +ext2_getxattr(struct dentry *dentry, const char *name, + void *buffer, size_t size) +{ + struct ext2_xattr_handler *handler; + struct inode *inode = dentry->d_inode; + + handler = ext2_xattr_resolve_name(&name); + if (!handler) + return -EOPNOTSUPP; + return handler->get(inode, name, buffer, size); +} + +/* + * Inode operation listxattr() + * + * dentry->d_inode->i_sem down + * BKL held [before 2.5.x] + */ +ssize_t +ext2_listxattr(struct dentry *dentry, char *buffer, size_t size) +{ + return ext2_xattr_list(dentry->d_inode, buffer, size); +} + +/* + * Inode operation setxattr() + * + * dentry->d_inode->i_sem down + * BKL held [before 2.5.x] + */ +int +ext2_setxattr(struct dentry *dentry, const char *name, + void *value, size_t size, int flags) +{ + struct ext2_xattr_handler *handler; + struct inode *inode = dentry->d_inode; + + if (size == 0) + value = ""; /* empty EA, do not remove */ + handler = ext2_xattr_resolve_name(&name); + if (!handler) + return -EOPNOTSUPP; + return handler->set(inode, name, value, size, flags); +} + +/* + * Inode operation removexattr() + * + * dentry->d_inode->i_sem down + * BKL held [before 2.5.x] + */ +int +ext2_removexattr(struct dentry *dentry, const char *name) +{ + struct ext2_xattr_handler *handler; + struct inode *inode = dentry->d_inode; + + handler = ext2_xattr_resolve_name(&name); + if (!handler) + return -EOPNOTSUPP; + return handler->set(inode, name, NULL, 0, XATTR_REPLACE); +} + +/* + * ext2_xattr_get() + * + * Copy an extended attribute into the buffer + * provided, or compute the buffer size required. + * Buffer is NULL to compute the size of the buffer required. + * + * Returns a negative error number on failure, or the number of bytes + * used / required on success. + */ +int +ext2_xattr_get(struct inode *inode, int name_index, const char *name, + void *buffer, size_t buffer_size) +{ + struct buffer_head *bh = NULL; + struct ext2_xattr_entry *entry; + unsigned int block, size; + char *end; + int name_len, error; + + ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", + name_index, name, buffer, (long)buffer_size); + + if (name == NULL) + return -EINVAL; + if (!EXT2_I(inode)->i_file_acl) + return -ENODATA; + block = EXT2_I(inode)->i_file_acl; + ea_idebug(inode, "reading block %d", block); + bh = sb_bread(inode->i_sb, block); + if (!bh) + return -EIO; + ea_bdebug(bh, "b_count=%d, refcount=%d", + atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); + end = bh->b_data + bh->b_size; + if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || + HDR(bh)->h_blocks != cpu_to_le32(1)) { +bad_block: ext2_error(inode->i_sb, "ext2_xattr_get", + "inode %ld: bad block %d", inode->i_ino, block); + error = -EIO; + goto cleanup; + } + /* find named attribute */ + name_len = strlen(name); + + error = -ERANGE; + if (name_len > 255) + goto cleanup; + entry = FIRST_ENTRY(bh); + while (!IS_LAST_ENTRY(entry)) { + struct ext2_xattr_entry *next = + EXT2_XATTR_NEXT(entry); + if ((char *)next >= end) + goto bad_block; + if (name_index == entry->e_name_index && + name_len == entry->e_name_len && + memcmp(name, entry->e_name, name_len) == 0) + goto found; + entry = next; + } + /* Check the remaining name entries */ + while (!IS_LAST_ENTRY(entry)) { + struct ext2_xattr_entry *next = + EXT2_XATTR_NEXT(entry); + if ((char *)next >= end) + goto bad_block; + entry = next; + } + if (ext2_xattr_cache_insert(bh)) + ea_idebug(inode, "cache insert failed"); + error = -ENODATA; + goto cleanup; +found: + /* check the buffer size */ + if (entry->e_value_block != 0) + goto bad_block; + size = le32_to_cpu(entry->e_value_size); + if (size > inode->i_sb->s_blocksize || + le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize) + goto bad_block; + + if (ext2_xattr_cache_insert(bh)) + ea_idebug(inode, "cache insert failed"); + if (buffer) { + error = -ERANGE; + if (size > buffer_size) + goto cleanup; + /* return value of attribute */ + memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), + size); + } + error = size; + +cleanup: + brelse(bh); + + return error; +} + +/* + * ext2_xattr_list() + * + * Copy a list of attribute names into the buffer + * provided, or compute the buffer size required. + * Buffer is NULL to compute the size of the buffer required. + * + * Returns a negative error number on failure, or the number of bytes + * used / required on success. + */ +int +ext2_xattr_list(struct inode *inode, char *buffer, size_t buffer_size) +{ + struct buffer_head *bh = NULL; + struct ext2_xattr_entry *entry; + unsigned int block, size = 0; + char *buf, *end; + int error; + + ea_idebug(inode, "buffer=%p, buffer_size=%ld", + buffer, (long)buffer_size); + + if (!EXT2_I(inode)->i_file_acl) + return 0; + block = EXT2_I(inode)->i_file_acl; + ea_idebug(inode, "reading block %d", block); + bh = sb_bread(inode->i_sb, block); + if (!bh) + return -EIO; + ea_bdebug(bh, "b_count=%d, refcount=%d", + atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); + end = bh->b_data + bh->b_size; + if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || + HDR(bh)->h_blocks != cpu_to_le32(1)) { +bad_block: ext2_error(inode->i_sb, "ext2_xattr_list", + "inode %ld: bad block %d", inode->i_ino, block); + error = -EIO; + goto cleanup; + } + /* compute the size required for the list of attribute names */ + for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry); + entry = EXT2_XATTR_NEXT(entry)) { + struct ext2_xattr_handler *handler; + struct ext2_xattr_entry *next = + EXT2_XATTR_NEXT(entry); + if ((char *)next >= end) + goto bad_block; + + handler = ext2_xattr_handler(entry->e_name_index); + if (handler) { + size += handler->list(NULL, inode, entry->e_name, + entry->e_name_len) + 1; + } + } + + if (ext2_xattr_cache_insert(bh)) + ea_idebug(inode, "cache insert failed"); + if (!buffer) { + error = size; + goto cleanup; + } else { + error = -ERANGE; + if (size > buffer_size) + goto cleanup; + } + + /* list the attribute names */ + buf = buffer; + for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry); + entry = EXT2_XATTR_NEXT(entry)) { + struct ext2_xattr_handler *handler; + + handler = ext2_xattr_handler(entry->e_name_index); + if (handler) { + buf += handler->list(buf, inode, entry->e_name, + entry->e_name_len); + *buf++ = '\0'; + } + } + error = size; + +cleanup: + brelse(bh); + + return error; +} + +/* + * If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is + * not set, set it. + */ +static void ext2_xattr_update_super_block(struct super_block *sb) +{ + if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR)) + return; + + lock_super(sb); +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,4,0) + EXT2_SB(sb)->s_feature_compat |= EXT2_FEATURE_COMPAT_EXT_ATTR; +#endif + EXT2_SB(sb)->s_es->s_feature_compat |= + cpu_to_le32(EXT2_FEATURE_COMPAT_EXT_ATTR); + sb->s_dirt = 1; + mark_buffer_dirty(EXT2_SB(sb)->s_sbh); + unlock_super(sb); +} + +/* + * ext2_xattr_set() + * + * Create, replace or remove an extended attribute for this inode. Buffer + * is NULL to remove an existing extended attribute, and non-NULL to + * either replace an existing extended attribute, or create a new extended + * attribute. The flags XATTR_REPLACE and XATTR_CREATE + * specify that an extended attribute must exist and must not exist + * previous to the call, respectively. + * + * Returns 0, or a negative error number on failure. + */ +int +ext2_xattr_set(struct inode *inode, int name_index, const char *name, + const void *value, size_t value_len, int flags) +{ + struct super_block *sb = inode->i_sb; + struct buffer_head *bh = NULL; + struct ext2_xattr_header *header = NULL; + struct ext2_xattr_entry *here, *last; + unsigned int name_len; + int min_offs = sb->s_blocksize, not_found = 1, free, error; + char *end; + + /* + * header -- Points either into bh, or to a temporarily + * allocated buffer. + * here -- The named entry found, or the place for inserting, within + * the block pointed to by header. + * last -- Points right after the last named entry within the block + * pointed to by header. + * min_offs -- The offset of the first value (values are aligned + * towards the end of the block). + * end -- Points right after the block pointed to by header. + */ + + ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", + name_index, name, value, (long)value_len); + + if (IS_RDONLY(inode)) + return -EROFS; + if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) + return -EPERM; + if (value == NULL) + value_len = 0; + if (name == NULL) + return -EINVAL; + name_len = strlen(name); + if (name_len > 255 || value_len > sb->s_blocksize) + return -ERANGE; + ext2_xattr_lock(); + + if (EXT2_I(inode)->i_file_acl) { + /* The inode already has an extended attribute block. */ + int block = EXT2_I(inode)->i_file_acl; + + bh = sb_bread(sb, block); + error = -EIO; + if (!bh) + goto cleanup; + ea_bdebug(bh, "b_count=%d, refcount=%d", + atomic_read(&(bh->b_count)), + le32_to_cpu(HDR(bh)->h_refcount)); + header = HDR(bh); + end = bh->b_data + bh->b_size; + if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || + header->h_blocks != cpu_to_le32(1)) { +bad_block: ext2_error(sb, "ext2_xattr_set", + "inode %ld: bad block %d", inode->i_ino, block); + error = -EIO; + goto cleanup; + } + /* Find the named attribute. */ + here = FIRST_ENTRY(bh); + while (!IS_LAST_ENTRY(here)) { + struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here); + if ((char *)next >= end) + goto bad_block; + if (!here->e_value_block && here->e_value_size) { + int offs = le16_to_cpu(here->e_value_offs); + if (offs < min_offs) + min_offs = offs; + } + not_found = name_index - here->e_name_index; + if (!not_found) + not_found = name_len - here->e_name_len; + if (!not_found) + not_found = memcmp(name, here->e_name,name_len); + if (not_found <= 0) + break; + here = next; + } + last = here; + /* We still need to compute min_offs and last. */ + while (!IS_LAST_ENTRY(last)) { + struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last); + if ((char *)next >= end) + goto bad_block; + if (!last->e_value_block && last->e_value_size) { + int offs = le16_to_cpu(last->e_value_offs); + if (offs < min_offs) + min_offs = offs; + } + last = next; + } + + /* Check whether we have enough space left. */ + free = min_offs - ((char*)last - (char*)header) - sizeof(__u32); + } else { + /* We will use a new extended attribute block. */ + free = sb->s_blocksize - + sizeof(struct ext2_xattr_header) - sizeof(__u32); + here = last = NULL; /* avoid gcc uninitialized warning. */ + } + + if (not_found) { + /* Request to remove a nonexistent attribute? */ + error = -ENODATA; + if (flags & XATTR_REPLACE) + goto cleanup; + error = 0; + if (value == NULL) + goto cleanup; + else + free -= EXT2_XATTR_LEN(name_len); + } else { + /* Request to create an existing attribute? */ + error = -EEXIST; + if (flags & XATTR_CREATE) + goto cleanup; + if (!here->e_value_block && here->e_value_size) { + unsigned int size = le32_to_cpu(here->e_value_size); + + if (le16_to_cpu(here->e_value_offs) + size > + sb->s_blocksize || size > sb->s_blocksize) + goto bad_block; + free += EXT2_XATTR_SIZE(size); + } + } + free -= EXT2_XATTR_SIZE(value_len); + error = -ENOSPC; + if (free < 0) + goto cleanup; + + /* Here we know that we can set the new attribute. */ + + if (header) { + if (header->h_refcount == cpu_to_le32(1)) { + ea_bdebug(bh, "modifying in-place"); + ext2_xattr_cache_remove(bh); + } else { + int offset; + + ea_bdebug(bh, "cloning"); + header = kmalloc(bh->b_size, GFP_KERNEL); + error = -ENOMEM; + if (header == NULL) + goto cleanup; + memcpy(header, HDR(bh), bh->b_size); + header->h_refcount = cpu_to_le32(1); + offset = (char *)header - bh->b_data; + here = ENTRY((char *)here + offset); + last = ENTRY((char *)last + offset); + } + } else { + /* Allocate a buffer where we construct the new block. */ + header = kmalloc(sb->s_blocksize, GFP_KERNEL); + error = -ENOMEM; + if (header == NULL) + goto cleanup; + memset(header, 0, sb->s_blocksize); + end = (char *)header + sb->s_blocksize; + header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC); + header->h_blocks = header->h_refcount = cpu_to_le32(1); + last = here = ENTRY(header+1); + } + + if (not_found) { + /* Insert the new name. */ + int size = EXT2_XATTR_LEN(name_len); + int rest = (char *)last - (char *)here; + memmove((char *)here + size, here, rest); + memset(here, 0, size); + here->e_name_index = name_index; + here->e_name_len = name_len; + memcpy(here->e_name, name, name_len); + } else { + /* Remove the old value. */ + if (!here->e_value_block && here->e_value_size) { + char *first_val = (char *)header + min_offs; + int offs = le16_to_cpu(here->e_value_offs); + char *val = (char *)header + offs; + size_t size = EXT2_XATTR_SIZE( + le32_to_cpu(here->e_value_size)); + memmove(first_val + size, first_val, val - first_val); + memset(first_val, 0, size); + here->e_value_offs = 0; + min_offs += size; + + /* Adjust all value offsets. */ + last = ENTRY(header+1); + while (!IS_LAST_ENTRY(last)) { + int o = le16_to_cpu(last->e_value_offs); + if (!last->e_value_block && o < offs) + last->e_value_offs = + cpu_to_le16(o + size); + last = EXT2_XATTR_NEXT(last); + } + } + if (value == NULL) { + /* Remove this attribute. */ + if (EXT2_XATTR_NEXT(ENTRY(header+1)) == last) { + /* This block is now empty. */ + error = ext2_xattr_set2(inode, bh, NULL); + goto cleanup; + } else { + /* Remove the old name. */ + int size = EXT2_XATTR_LEN(name_len); + last = ENTRY((char *)last - size); + memmove(here, (char*)here + size, + (char*)last - (char*)here); + memset(last, 0, size); + } + } + } + + if (value != NULL) { + /* Insert the new value. */ + here->e_value_size = cpu_to_le32(value_len); + if (value_len) { + size_t size = EXT2_XATTR_SIZE(value_len); + char *val = (char *)header + min_offs - size; + here->e_value_offs = + cpu_to_le16((char *)val - (char *)header); + memset(val + size - EXT2_XATTR_PAD, 0, + EXT2_XATTR_PAD); /* Clear the pad bytes. */ + memcpy(val, value, value_len); + } + } + ext2_xattr_rehash(header, here); + + error = ext2_xattr_set2(inode, bh, header); + +cleanup: + brelse(bh); + if (!(bh && header == HDR(bh))) + kfree(header); + ext2_xattr_unlock(); + + return error; +} + +/* + * Second half of ext2_xattr_set(): Update the file system. + */ +static int +ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, + struct ext2_xattr_header *header) +{ + struct super_block *sb = inode->i_sb; + struct buffer_head *new_bh = NULL; + int error; + + if (header) { + new_bh = ext2_xattr_cache_find(inode, header); + if (new_bh) { + /* + * We found an identical block in the cache. + * The old block will be released after updating + * the inode. + */ + ea_bdebug(old_bh, "reusing block %ld", + new_bh->b_blocknr); + + error = -EDQUOT; + if (ext2_xattr_quota_alloc(inode, 1)) + goto cleanup; + + HDR(new_bh)->h_refcount = cpu_to_le32( + le32_to_cpu(HDR(new_bh)->h_refcount) + 1); + ea_bdebug(new_bh, "refcount now=%d", + le32_to_cpu(HDR(new_bh)->h_refcount)); + } else if (old_bh && header == HDR(old_bh)) { + /* Keep this block. */ + new_bh = old_bh; + ext2_xattr_cache_insert(new_bh); + } else { + /* We need to allocate a new block */ + int force = EXT2_I(inode)->i_file_acl != 0; + int block = ext2_xattr_new_block(inode, &error, force); + if (error) + goto cleanup; + ea_idebug(inode, "creating block %d", block); + + new_bh = sb_getblk(sb, block); + if (!new_bh) { + ext2_xattr_free_block(inode, block); + error = -EIO; + goto cleanup; + } + lock_buffer(new_bh); + memcpy(new_bh->b_data, header, new_bh->b_size); + set_buffer_uptodate(new_bh); + unlock_buffer(new_bh); + ext2_xattr_cache_insert(new_bh); + + ext2_xattr_update_super_block(sb); + } + mark_buffer_dirty(new_bh); + if (IS_SYNC(inode)) { + ll_rw_block(WRITE, 1, &new_bh); + wait_on_buffer(new_bh); + error = -EIO; + if (buffer_req(new_bh) && !buffer_uptodate(new_bh)) + goto cleanup; + } + } + + /* Update the inode. */ + EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; + inode->i_ctime = CURRENT_TIME; + if (IS_SYNC(inode)) { + error = ext2_sync_inode (inode); + if (error) + goto cleanup; + } else + mark_inode_dirty(inode); + + error = 0; + if (old_bh && old_bh != new_bh) { + /* + * If there was an old block, and we are not still using it, + * we now release the old block. + */ + unsigned int refcount = le32_to_cpu(HDR(old_bh)->h_refcount); + + if (refcount == 1) { + /* Free the old block. */ + ea_bdebug(old_bh, "freeing"); + ext2_xattr_free_block(inode, old_bh->b_blocknr); + /* We let our caller release old_bh, so we + * need to duplicate the buffer before. */ + get_bh(old_bh); + bforget(old_bh); + } else { + /* Decrement the refcount only. */ + refcount--; + HDR(old_bh)->h_refcount = cpu_to_le32(refcount); + ext2_xattr_quota_free(inode); + mark_buffer_dirty(old_bh); + ea_bdebug(old_bh, "refcount now=%d", refcount); + } + } + +cleanup: + if (old_bh != new_bh) + brelse(new_bh); + + return error; +} + +/* + * ext2_xattr_delete_inode() + * + * Free extended attribute resources associated with this inode. This + * is called immediately before an inode is freed. + */ +void +ext2_xattr_delete_inode(struct inode *inode) +{ + struct buffer_head *bh; + unsigned int block = EXT2_I(inode)->i_file_acl; + + if (!block) + return; + ext2_xattr_lock(); + + bh = sb_bread(inode->i_sb, block); + if (!bh) { + ext2_error(inode->i_sb, "ext2_xattr_delete_inode", + "inode %ld: block %d read error", inode->i_ino, block); + goto cleanup; + } + ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count))); + if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || + HDR(bh)->h_blocks != cpu_to_le32(1)) { + ext2_error(inode->i_sb, "ext2_xattr_delete_inode", + "inode %ld: bad block %d", inode->i_ino, block); + goto cleanup; + } + ea_bdebug(bh, "refcount now=%d", le32_to_cpu(HDR(bh)->h_refcount) - 1); + if (HDR(bh)->h_refcount == cpu_to_le32(1)) { + ext2_xattr_cache_remove(bh); + ext2_xattr_free_block(inode, block); + bforget(bh); + bh = NULL; + } else { + HDR(bh)->h_refcount = cpu_to_le32( + le32_to_cpu(HDR(bh)->h_refcount) - 1); + mark_buffer_dirty(bh); + if (IS_SYNC(inode)) { + ll_rw_block(WRITE, 1, &bh); + wait_on_buffer(bh); + } + ext2_xattr_quota_free(inode); + } + EXT2_I(inode)->i_file_acl = 0; + +cleanup: + brelse(bh); + ext2_xattr_unlock(); +} + +/* + * ext2_xattr_put_super() + * + * This is called when a file system is unmounted. + */ +void +ext2_xattr_put_super(struct super_block *sb) +{ + mb_cache_shrink(ext2_xattr_cache, sb->s_dev); +} + + +/* + * ext2_xattr_cache_insert() + * + * Create a new entry in the extended attribute cache, and insert + * it unless such an entry is already in the cache. + * + * Returns 0, or a negative error number on failure. + */ +static int +ext2_xattr_cache_insert(struct buffer_head *bh) +{ + __u32 hash = le32_to_cpu(HDR(bh)->h_hash); + struct mb_cache_entry *ce; + int error; + + ce = mb_cache_entry_alloc(ext2_xattr_cache); + if (!ce) + return -ENOMEM; + error = mb_cache_entry_insert(ce, bh->b_bdev->bd_dev, bh->b_blocknr, &hash); + if (error) { + mb_cache_entry_free(ce); + if (error == -EBUSY) { + ea_bdebug(bh, "already in cache (%d cache entries)", + atomic_read(&ext2_xattr_cache->c_entry_count)); + error = 0; + } + } else { + ea_bdebug(bh, "inserting [%x] (%d cache entries)", (int)hash, + atomic_read(&ext2_xattr_cache->c_entry_count)); + mb_cache_entry_release(ce); + } + return error; +} + +/* + * ext2_xattr_cmp() + * + * Compare two extended attribute blocks for equality. + * + * Returns 0 if the blocks are equal, 1 if they differ, and + * a negative error number on errors. + */ +static int +ext2_xattr_cmp(struct ext2_xattr_header *header1, + struct ext2_xattr_header *header2) +{ + struct ext2_xattr_entry *entry1, *entry2; + + entry1 = ENTRY(header1+1); + entry2 = ENTRY(header2+1); + while (!IS_LAST_ENTRY(entry1)) { + if (IS_LAST_ENTRY(entry2)) + return 1; + if (entry1->e_hash != entry2->e_hash || + entry1->e_name_len != entry2->e_name_len || + entry1->e_value_size != entry2->e_value_size || + memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) + return 1; + if (entry1->e_value_block != 0 || entry2->e_value_block != 0) + return -EIO; + if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), + (char *)header2 + le16_to_cpu(entry2->e_value_offs), + le32_to_cpu(entry1->e_value_size))) + return 1; + + entry1 = EXT2_XATTR_NEXT(entry1); + entry2 = EXT2_XATTR_NEXT(entry2); + } + if (!IS_LAST_ENTRY(entry2)) + return 1; + return 0; +} + +/* + * ext2_xattr_cache_find() + * + * Find an identical extended attribute block. + * + * Returns a pointer to the block found, or NULL if such a block was + * not found or an error occurred. + */ +static struct buffer_head * +ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header) +{ + __u32 hash = le32_to_cpu(header->h_hash); + struct mb_cache_entry *ce; + + if (!header->h_hash) + return NULL; /* never share */ + ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); + ce = mb_cache_entry_find_first(ext2_xattr_cache, 0, inode->i_dev, hash); + while (ce) { + struct buffer_head *bh = sb_bread(inode->i_sb, ce->e_block); + + if (!bh) { + ext2_error(inode->i_sb, "ext2_xattr_cache_find", + "inode %ld: block %ld read error", + inode->i_ino, ce->e_block); + } else if (le32_to_cpu(HDR(bh)->h_refcount) > + EXT2_XATTR_REFCOUNT_MAX) { + ea_idebug(inode, "block %ld refcount %d>%d",ce->e_block, + le32_to_cpu(HDR(bh)->h_refcount), + EXT2_XATTR_REFCOUNT_MAX); + } else if (!ext2_xattr_cmp(header, HDR(bh))) { + ea_bdebug(bh, "b_count=%d",atomic_read(&(bh->b_count))); + mb_cache_entry_release(ce); + return bh; + } + brelse(bh); + ce = mb_cache_entry_find_next(ce, 0, inode->i_dev, hash); + } + return NULL; +} + +/* + * ext2_xattr_cache_remove() + * + * Remove the cache entry of a block from the cache. Called when a + * block becomes invalid. + */ +static void +ext2_xattr_cache_remove(struct buffer_head *bh) +{ + struct mb_cache_entry *ce; + + ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev->bd_dev, bh->b_blocknr); + if (ce) { + ea_bdebug(bh, "removing (%d cache entries remaining)", + atomic_read(&ext2_xattr_cache->c_entry_count)-1); + mb_cache_entry_free(ce); + } else + ea_bdebug(bh, "no cache entry"); +} + +#define NAME_HASH_SHIFT 5 +#define VALUE_HASH_SHIFT 16 + +/* + * ext2_xattr_hash_entry() + * + * Compute the hash of an extended attribute. + */ +static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header, + struct ext2_xattr_entry *entry) +{ + __u32 hash = 0; + char *name = entry->e_name; + int n; + + for (n=0; n < entry->e_name_len; n++) { + hash = (hash << NAME_HASH_SHIFT) ^ + (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ + *name++; + } + + if (entry->e_value_block == 0 && entry->e_value_size != 0) { + __u32 *value = (__u32 *)((char *)header + + le16_to_cpu(entry->e_value_offs)); + for (n = (le32_to_cpu(entry->e_value_size) + + EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) { + hash = (hash << VALUE_HASH_SHIFT) ^ + (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ + le32_to_cpu(*value++); + } + } + entry->e_hash = cpu_to_le32(hash); +} + +#undef NAME_HASH_SHIFT +#undef VALUE_HASH_SHIFT + +#define BLOCK_HASH_SHIFT 16 + +/* + * ext2_xattr_rehash() + * + * Re-compute the extended attribute hash value after an entry has changed. + */ +static void ext2_xattr_rehash(struct ext2_xattr_header *header, + struct ext2_xattr_entry *entry) +{ + struct ext2_xattr_entry *here; + __u32 hash = 0; + + ext2_xattr_hash_entry(header, entry); + here = ENTRY(header+1); + while (!IS_LAST_ENTRY(here)) { + if (!here->e_hash) { + /* Block is not shared if an entry's hash value == 0 */ + hash = 0; + break; + } + hash = (hash << BLOCK_HASH_SHIFT) ^ + (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ + le32_to_cpu(here->e_hash); + here = EXT2_XATTR_NEXT(here); + } + header->h_hash = cpu_to_le32(hash); +} + +#undef BLOCK_HASH_SHIFT + +int __init +init_ext2_xattr(void) +{ + int err; + + err = ext2_xattr_register(EXT2_XATTR_INDEX_USER, &ext2_xattr_user_handler); + if (err) + return err; + ext2_xattr_cache = mb_cache_create("ext2_xattr", NULL, + sizeof(struct mb_cache_entry) + + sizeof(struct mb_cache_entry_index), 1, 61); + if (!ext2_xattr_cache) { + ext2_xattr_unregister(EXT2_XATTR_INDEX_USER, &ext2_xattr_user_handler); + return -ENOMEM; + } + return 0; +} + +void +exit_ext2_xattr(void) +{ + mb_cache_destroy(ext2_xattr_cache); + ext2_xattr_unregister(EXT2_XATTR_INDEX_USER, &ext2_xattr_user_handler); +} diff -Nru a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/fs/ext2/xattr_user.c Mon Oct 14 23:21:23 2002 @@ -0,0 +1,100 @@ +/* + * linux/fs/ext2/xattr_user.c + * Handler for extended user attributes. + * + * Copyright (C) 2001 by Andreas Gruenbacher, + */ + +#include "ext2.h" +#include +#include + +#ifdef CONFIG_EXT2_FS_POSIX_ACL +# include +#endif + +#define XATTR_USER_PREFIX "user." + +static size_t +ext2_xattr_user_list(char *list, struct inode *inode, + const char *name, int name_len) +{ + const int prefix_len = sizeof(XATTR_USER_PREFIX)-1; + + if (!test_opt(inode->i_sb, XATTR_USER)) + return 0; + + if (list) { + memcpy(list, XATTR_USER_PREFIX, prefix_len); + memcpy(list+prefix_len, name, name_len); + } + return prefix_len + name_len; +} + +static int +ext2_xattr_user_get(struct inode *inode, const char *name, + void *buffer, size_t size) +{ + int error; + + if (strcmp(name, "") == 0) + return -EINVAL; + if (!test_opt(inode->i_sb, XATTR_USER)) + return -EOPNOTSUPP; +#ifdef CONFIG_EXT2_FS_POSIX_ACL + error = ext2_permission_locked(inode, MAY_READ); +#else + error = permission(inode, MAY_READ); +#endif + if (error) + return error; + + return ext2_xattr_get(inode, EXT2_XATTR_INDEX_USER, name, + buffer, size); +} + +static int +ext2_xattr_user_set(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + int error; + + if (strcmp(name, "") == 0) + return -EINVAL; + if (!test_opt(inode->i_sb, XATTR_USER)) + return -EOPNOTSUPP; + if ( !S_ISREG(inode->i_mode) && + (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX)) + return -EPERM; +#ifdef CONFIG_EXT2_FS_POSIX_ACL + error = ext2_permission_locked(inode, MAY_WRITE); +#else + error = permission(inode, MAY_WRITE); +#endif + if (error) + return error; + + return ext2_xattr_set(inode, EXT2_XATTR_INDEX_USER, name, + value, size, flags); +} + +struct ext2_xattr_handler ext2_xattr_user_handler = { + prefix: XATTR_USER_PREFIX, + list: ext2_xattr_user_list, + get: ext2_xattr_user_get, + set: ext2_xattr_user_set, +}; + +int __init +init_ext2_xattr_user(void) +{ + return ext2_xattr_register(EXT2_XATTR_INDEX_USER, + &ext2_xattr_user_handler); +} + +void +exit_ext2_xattr_user(void) +{ + ext2_xattr_unregister(EXT2_XATTR_INDEX_USER, + &ext2_xattr_user_handler); +} diff -Nru a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h --- a/include/linux/ext2_fs.h Mon Oct 14 23:21:23 2002 +++ b/include/linux/ext2_fs.h Mon Oct 14 23:21:23 2002 @@ -58,8 +58,6 @@ */ #define EXT2_BAD_INO 1 /* Bad blocks inode */ #define EXT2_ROOT_INO 2 /* Root inode */ -#define EXT2_ACL_IDX_INO 3 /* ACL inode */ -#define EXT2_ACL_DATA_INO 4 /* ACL inode */ #define EXT2_BOOT_LOADER_INO 5 /* Boot loader inode */ #define EXT2_UNDEL_DIR_INO 6 /* Undelete directory inode */ @@ -99,7 +97,6 @@ #else # define EXT2_BLOCK_SIZE(s) (EXT2_MIN_BLOCK_SIZE << (s)->s_log_block_size) #endif -#define EXT2_ACLE_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_acl_entry)) #define EXT2_ADDR_PER_BLOCK(s) (EXT2_BLOCK_SIZE(s) / sizeof (__u32)) #ifdef __KERNEL__ # define EXT2_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits) @@ -134,28 +131,6 @@ #endif /* - * ACL structures - */ -struct ext2_acl_header /* Header of Access Control Lists */ -{ - __u32 aclh_size; - __u32 aclh_file_count; - __u32 aclh_acle_count; - __u32 aclh_first_acle; -}; - -struct ext2_acl_entry /* Access Control List Entry */ -{ - __u32 acle_size; - __u16 acle_perms; /* Access permissions */ - __u16 acle_type; /* Type of entry */ - __u16 acle_tag; /* User or group identity */ - __u16 acle_pad1; - __u32 acle_next; /* Pointer on next entry for the */ - /* same inode or on next free entry */ -}; - -/* * Structure of a blocks group descriptor */ struct ext2_group_desc @@ -332,6 +307,7 @@ #define EXT2_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */ #define EXT2_MOUNT_MINIX_DF 0x0080 /* Mimics the Minix statfs */ #define EXT2_MOUNT_NO_UID32 0x0200 /* Disable 32-bit UIDs */ +#define EXT2_MOUNT_XATTR_USER 0x4000 /* Extended user attributes */ #define clear_opt(o, opt) o &= ~EXT2_MOUNT_##opt #define set_opt(o, opt) o |= EXT2_MOUNT_##opt @@ -475,7 +451,7 @@ #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 #define EXT2_FEATURE_INCOMPAT_ANY 0xffffffff -#define EXT2_FEATURE_COMPAT_SUPP 0 +#define EXT2_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR #define EXT2_FEATURE_INCOMPAT_SUPP EXT2_FEATURE_INCOMPAT_FILETYPE #define EXT2_FEATURE_RO_COMPAT_SUPP (EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER| \ EXT2_FEATURE_RO_COMPAT_LARGE_FILE| \ diff -Nru a/include/linux/ext2_xattr.h b/include/linux/ext2_xattr.h --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/include/linux/ext2_xattr.h Mon Oct 14 23:21:23 2002 @@ -0,0 +1,135 @@ +/* + File: linux/ext2_xattr.h + + On-disk format of extended attributes for the ext2 filesystem. + + (C) 2001 Andreas Gruenbacher, +*/ + +#include +#include +#include + +/* Magic value in attribute blocks */ +#define EXT2_XATTR_MAGIC 0xEA020000 + +/* Maximum number of references to one attribute block */ +#define EXT2_XATTR_REFCOUNT_MAX 1024 + +/* Name indexes */ +#define EXT2_XATTR_INDEX_MAX 10 +#define EXT2_XATTR_INDEX_USER 1 +#define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS 2 +#define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT 3 + +struct ext2_xattr_header { + __u32 h_magic; /* magic number for identification */ + __u32 h_refcount; /* reference count */ + __u32 h_blocks; /* number of disk blocks used */ + __u32 h_hash; /* hash value of all attributes */ + __u32 h_reserved[4]; /* zero right now */ +}; + +struct ext2_xattr_entry { + __u8 e_name_len; /* length of name */ + __u8 e_name_index; /* attribute name index */ + __u16 e_value_offs; /* offset in disk block of value */ + __u32 e_value_block; /* disk block attribute is stored on (n/i) */ + __u32 e_value_size; /* size of attribute value */ + __u32 e_hash; /* hash value of name and value */ + char e_name[0]; /* attribute name */ +}; + +#define EXT2_XATTR_PAD_BITS 2 +#define EXT2_XATTR_PAD (1<e_name_len)) ) +#define EXT2_XATTR_SIZE(size) \ + (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND) + +# ifdef CONFIG_EXT2_FS_XATTR + +struct ext2_xattr_handler { + char *prefix; + size_t (*list)(char *list, struct inode *inode, const char *name, + int name_len); + int (*get)(struct inode *inode, const char *name, void *buffer, + size_t size); + int (*set)(struct inode *inode, const char *name, const void *buffer, + size_t size, int flags); +}; + +extern int ext2_xattr_register(int, struct ext2_xattr_handler *); +extern void ext2_xattr_unregister(int, struct ext2_xattr_handler *); + +extern int ext2_setxattr(struct dentry *, const char *, void *, size_t, int); +extern ssize_t ext2_getxattr(struct dentry *, const char *, void *, size_t); +extern ssize_t ext2_listxattr(struct dentry *, char *, size_t); +extern int ext2_removexattr(struct dentry *, const char *); + +extern int ext2_xattr_get(struct inode *, int, const char *, void *, size_t); +extern int ext2_xattr_list(struct inode *, char *, size_t); +extern int ext2_xattr_set(struct inode *, int, const char *, const void *, size_t, int); + +extern void ext2_xattr_delete_inode(struct inode *); +extern void ext2_xattr_put_super(struct super_block *); + +extern int init_ext2_xattr(void) __init; +extern void exit_ext2_xattr(void); + +# else /* CONFIG_EXT2_FS_XATTR */ +# define ext2_setxattr NULL +# define ext2_getxattr NULL +# define ext2_listxattr NULL +# define ext2_removexattr NULL + +static inline int +ext2_xattr_get(struct inode *inode, int name_index, + const char *name, void *buffer, size_t size) +{ + return -ENOTSUP; +} + +static inline int +ext2_xattr_list(struct inode *inode, char *buffer, size_t size) +{ + return -ENOTSUP; +} + +static inline int +ext2_xattr_set(struct inode *inode, int name_index, const char *name, + const void *value, size_t size, int flags) +{ + return -ENOTSUP; +} + +static inline void +ext2_xattr_delete_inode(struct inode *inode) +{ +} + +static inline void +ext2_xattr_put_super(struct super_block *sb) +{ +} + +static inline int +init_ext2_xattr(void) +{ + return 0; +} + +static inline void +exit_ext2_xattr(void) +{ +} + +# endif /* CONFIG_EXT2_FS_XATTR */ + +extern struct ext2_xattr_handler ext2_xattr_user_handler; + - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/