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 | 2
# fs/ext2/file.c | 7
# fs/ext2/ialloc.c | 4
# fs/ext2/inode.c | 39 -
# fs/ext2/namei.c | 16
# fs/ext2/super.c | 21
# fs/ext2/symlink.c | 14
# fs/ext2/xattr.c | 1117 ++++++++++++++++++++++++++++++++++++++++++++++++
# fs/ext2/xattr.h | 135 +++++
# fs/ext2/xattr_user.c | 103 ++++
# include/linux/ext2_fs.h | 28 -
# 14 files changed, 1451 insertions(+), 49 deletions(-)
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/15 tytso@snap.thunk.org 1.853
# Port of (bugfixed) 0.8.50 xattr-ext2 to 2.5 (w/ hch cleanups)
#
# 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.
# --------------------------------------------
#
diff -Nru a/fs/Config.help b/fs/Config.help
--- a/fs/Config.help Tue Oct 15 16:58:31 2002
+++ b/fs/Config.help Tue Oct 15 16:58:31 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
+ <http://acl.bestbits.at/> 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 Tue Oct 15 16:58:31 2002
+++ b/fs/Config.in Tue Oct 15 16:58:31 2002
@@ -93,6 +93,7 @@
tristate 'ROM file system support' CONFIG_ROMFS_FS
tristate 'Second extended fs support' CONFIG_EXT2_FS
+dep_mbool ' Ext2 extended attributes' CONFIG_EXT2_FS_XATTR $CONFIG_EXT2_FS
tristate 'System V/Xenix/V7/Coherent file system support' CONFIG_SYSV_FS
diff -Nru a/fs/ext2/Makefile b/fs/ext2/Makefile
--- a/fs/ext2/Makefile Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/Makefile Tue Oct 15 16:58:31 2002
@@ -7,4 +7,10 @@
ext2-objs := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
ioctl.o namei.o super.o symlink.o
+export-objs += xattr.o
+
+ifeq ($(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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/ext2.h Tue Oct 15 16:58:31 2002
@@ -110,6 +110,8 @@
/* 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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/file.c Tue Oct 15 16:58:31 2002
@@ -18,8 +18,9 @@
* (jj@sunsite.ms.mff.cuni.cz)
*/
-#include "ext2.h"
#include <linux/time.h>
+#include "ext2.h"
+#include "xattr.h"
/*
* Called when an inode is released. Note that this is different
@@ -55,4 +56,8 @@
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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/ialloc.c Tue Oct 15 16:58:31 2002
@@ -13,11 +13,12 @@
*/
#include <linux/config.h>
-#include "ext2.h"
#include <linux/quotaops.h>
#include <linux/sched.h>
#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
+#include "ext2.h"
+#include "xattr.h"
/*
* ialloc.c contains the inodes allocation and deallocation routines
@@ -97,6 +98,7 @@
*/
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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/inode.c Tue Oct 15 16:58:31 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;
@@ -1025,9 +1036,7 @@
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;
@@ -1036,15 +1045,17 @@
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;
@@ -1076,12 +1087,6 @@
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",
- (unsigned long) 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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/namei.c Tue Oct 15 16:58:31 2002
@@ -29,8 +29,9 @@
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
-#include "ext2.h"
#include <linux/pagemap.h>
+#include "ext2.h"
+#include "xattr.h"
/*
* Couple of helper functions - make the code slightly cleaner.
@@ -162,7 +163,7 @@
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 +369,15 @@
.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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/super.c Tue Oct 15 16:58:31 2002
@@ -19,7 +19,6 @@
#include <linux/config.h>
#include <linux/module.h>
#include <linux/string.h>
-#include "ext2.h"
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
@@ -27,6 +26,8 @@
#include <linux/buffer_head.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
+#include "ext2.h"
+#include "xattr.h"
static void ext2_sync_super(struct super_block *sb,
@@ -131,6 +132,7 @@
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 +235,13 @@
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 +496,9 @@
*/
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 +895,10 @@
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 +908,7 @@
out:
destroy_inodecache();
out1:
+ exit_ext2_xattr();
return err;
}
@@ -900,6 +916,7 @@
{
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 Tue Oct 15 16:58:31 2002
+++ b/fs/ext2/symlink.c Tue Oct 15 16:58:31 2002
@@ -18,6 +18,7 @@
*/
#include "ext2.h"
+#include "xattr.h"
static int ext2_readlink(struct dentry *dentry, char *buffer, int buflen)
{
@@ -31,7 +32,20 @@
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 Tue Oct 15 16:58:31 2002
@@ -0,0 +1,1117 @@
+/*
+ * linux/fs/ext2/xattr.c
+ *
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Extended attributes for symlinks and special files added per
+ * suggestion of Luka Renko <luka.renko@hermes.si>.
+ */
+
+/*
+ * 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.
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mbcache.h>
+#include <linux/quotaops.h>
+#include <asm/semaphore.h>
+#include "ext2.h"
+#include "xattr.h"
+
+/* 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);
+
+#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.
+ */
+
+static DECLARE_MUTEX(ext2_xattr_sem);
+static struct ext2_xattr_handler *ext2_xattr_handlers[EXT2_XATTR_INDEX_MAX];
+static 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; i<EXT2_XATTR_INDEX_MAX; i++) {
+ if (ext2_xattr_handlers[i]) {
+ const char *n = strcmp_prefix(*name,
+ ext2_xattr_handlers[i]->prefix);
+ 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);
+ 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;
+ down(&ext2_xattr_sem);
+
+ if (EXT2_I(inode)->i_file_acl) {
+ /* The inode already has an extended attribute block. */
+ bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
+ 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,
+ EXT2_I(inode)->i_file_acl);
+ 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);
+ up(&ext2_xattr_sem);
+
+ 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 (DQUOT_ALLOC_BLOCK(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 block;
+ 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);
+ block = ext2_new_block(inode, goal, 0, 0, &error);
+ if (error)
+ goto cleanup;
+ ea_idebug(inode, "creating block %d", block);
+
+ new_bh = sb_getblk(sb, block);
+ if (!new_bh) {
+ ext2_free_blocks(inode, block, 1);
+ 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_free_blocks(inode, old_bh->b_blocknr, 1);
+ /* 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);
+ DQUOT_FREE_BLOCK(inode, 1);
+ 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;
+ down(&ext2_xattr_sem);
+
+ 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_free_blocks(inode, block, 1);
+ 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);
+ }
+ DQUOT_FREE_BLOCK(inode, 1);
+ }
+ EXT2_I(inode)->i_file_acl = 0;
+
+cleanup:
+ brelse(bh);
+ up(&ext2_xattr_sem);
+}
+
+/*
+ * 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.h b/fs/ext2/xattr.h
--- /dev/null Wed Dec 31 16:00:00 1969
+++ b/fs/ext2/xattr.h Tue Oct 15 16:58:31 2002
@@ -0,0 +1,135 @@
+/*
+ File: linux/ext2_xattr.h
+
+ On-disk format of extended attributes for the ext2 filesystem.
+
+ (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/xattr.h>
+
+/* 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<<EXT2_XATTR_PAD_BITS)
+#define EXT2_XATTR_ROUND (EXT2_XATTR_PAD-1)
+#define EXT2_XATTR_LEN(name_len) \
+ (((name_len) + EXT2_XATTR_ROUND + \
+ sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
+#define EXT2_XATTR_NEXT(entry) \
+ ( (struct ext2_xattr_entry *)( \
+ (char *)(entry) + EXT2_XATTR_LEN((entry)->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);
+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 -EOPNOTSUPP;
+}
+
+static inline int
+ext2_xattr_list(struct inode *inode, char *buffer, size_t size)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int
+ext2_xattr_set(struct inode *inode, int name_index, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return -EOPNOTSUPP;
+}
+
+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;
+
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 Tue Oct 15 16:58:31 2002
@@ -0,0 +1,103 @@
+/*
+ * linux/fs/ext2/xattr_user.c
+ * Handler for extended user attributes.
+ *
+ * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include "ext2.h"
+#include "xattr.h"
+
+
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+# include <linux/ext2_acl.h>
+#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 Tue Oct 15 16:58:31 2002
+++ b/include/linux/ext2_fs.h Tue Oct 15 16:58:31 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| \
-
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This archive was generated by hypermail 2b29 : Tue Oct 15 2002 - 22:00:58 EST