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https://github.com/edk2-porting/linux-next.git
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6e9510b0e0
Signed-off-by: Wang Sheng-Hui <crosslonelyover@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
1329 lines
34 KiB
C
1329 lines
34 KiB
C
/*
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* linux/fs/ext3/xattr.c
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*
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* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
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*
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* Fix by Harrison Xing <harrison@mountainviewdata.com>.
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* Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
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* Extended attributes for symlinks and special files added per
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* suggestion of Luka Renko <luka.renko@hermes.si>.
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* xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
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* Red Hat Inc.
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* ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
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* and Andreas Gruenbacher <agruen@suse.de>.
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*/
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/*
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* Extended attributes are stored directly in inodes (on file systems with
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* inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
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* field contains the block number if an inode uses an additional block. All
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* attributes must fit in the inode and one additional block. Blocks that
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* contain the identical set of attributes may be shared among several inodes.
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* Identical blocks are detected by keeping a cache of blocks that have
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* recently been accessed.
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*
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* The attributes in inodes and on blocks have a different header; the entries
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* are stored in the same format:
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*
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* +------------------+
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* | header |
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* | entry 1 | |
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* | entry 2 | | growing downwards
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* | entry 3 | v
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* | four null bytes |
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* | . . . |
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* | value 1 | ^
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* | value 3 | | growing upwards
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* | value 2 | |
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* +------------------+
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*
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* The header is followed by multiple entry descriptors. In disk blocks, the
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* entry descriptors are kept sorted. In inodes, they are unsorted. The
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* attribute values are aligned to the end of the block in no specific order.
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*
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* Locking strategy
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* ----------------
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* EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
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* EA blocks are only changed if they are exclusive to an inode, so
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* holding xattr_sem also means that nothing but the EA block's reference
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* count can change. Multiple writers to the same block are synchronized
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* by the buffer lock.
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*/
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/ext3_jbd.h>
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#include <linux/ext3_fs.h>
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#include <linux/mbcache.h>
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#include <linux/quotaops.h>
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#include <linux/rwsem.h>
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#include "xattr.h"
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#include "acl.h"
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#define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
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#define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
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#define BFIRST(bh) ENTRY(BHDR(bh)+1)
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#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
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#define IHDR(inode, raw_inode) \
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((struct ext3_xattr_ibody_header *) \
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((void *)raw_inode + \
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EXT3_GOOD_OLD_INODE_SIZE + \
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EXT3_I(inode)->i_extra_isize))
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#define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
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#ifdef EXT3_XATTR_DEBUG
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# define ea_idebug(inode, f...) do { \
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printk(KERN_DEBUG "inode %s:%lu: ", \
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inode->i_sb->s_id, inode->i_ino); \
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printk(f); \
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printk("\n"); \
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} while (0)
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# define ea_bdebug(bh, f...) do { \
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char b[BDEVNAME_SIZE]; \
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printk(KERN_DEBUG "block %s:%lu: ", \
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bdevname(bh->b_bdev, b), \
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(unsigned long) bh->b_blocknr); \
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printk(f); \
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printk("\n"); \
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} while (0)
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#else
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# define ea_idebug(f...)
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# define ea_bdebug(f...)
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#endif
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static void ext3_xattr_cache_insert(struct buffer_head *);
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static struct buffer_head *ext3_xattr_cache_find(struct inode *,
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struct ext3_xattr_header *,
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struct mb_cache_entry **);
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static void ext3_xattr_rehash(struct ext3_xattr_header *,
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struct ext3_xattr_entry *);
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static int ext3_xattr_list(struct dentry *dentry, char *buffer,
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size_t buffer_size);
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static struct mb_cache *ext3_xattr_cache;
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static const struct xattr_handler *ext3_xattr_handler_map[] = {
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[EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler,
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#ifdef CONFIG_EXT3_FS_POSIX_ACL
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[EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext3_xattr_acl_access_handler,
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[EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext3_xattr_acl_default_handler,
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#endif
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[EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler,
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#ifdef CONFIG_EXT3_FS_SECURITY
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[EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler,
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#endif
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};
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const struct xattr_handler *ext3_xattr_handlers[] = {
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&ext3_xattr_user_handler,
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&ext3_xattr_trusted_handler,
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#ifdef CONFIG_EXT3_FS_POSIX_ACL
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&ext3_xattr_acl_access_handler,
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&ext3_xattr_acl_default_handler,
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#endif
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#ifdef CONFIG_EXT3_FS_SECURITY
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&ext3_xattr_security_handler,
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#endif
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NULL
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};
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static inline const struct xattr_handler *
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ext3_xattr_handler(int name_index)
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{
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const struct xattr_handler *handler = NULL;
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if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map))
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handler = ext3_xattr_handler_map[name_index];
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return handler;
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}
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/*
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* Inode operation listxattr()
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*
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* dentry->d_inode->i_mutex: don't care
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*/
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ssize_t
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ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
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{
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return ext3_xattr_list(dentry, buffer, size);
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}
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static int
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ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end)
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{
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while (!IS_LAST_ENTRY(entry)) {
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struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry);
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if ((void *)next >= end)
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return -EIO;
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entry = next;
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}
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return 0;
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}
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static inline int
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ext3_xattr_check_block(struct buffer_head *bh)
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{
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int error;
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if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
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BHDR(bh)->h_blocks != cpu_to_le32(1))
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return -EIO;
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error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
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return error;
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}
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static inline int
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ext3_xattr_check_entry(struct ext3_xattr_entry *entry, size_t size)
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{
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size_t value_size = le32_to_cpu(entry->e_value_size);
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if (entry->e_value_block != 0 || value_size > size ||
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le16_to_cpu(entry->e_value_offs) + value_size > size)
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return -EIO;
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return 0;
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}
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static int
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ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index,
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const char *name, size_t size, int sorted)
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{
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struct ext3_xattr_entry *entry;
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size_t name_len;
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int cmp = 1;
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if (name == NULL)
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return -EINVAL;
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name_len = strlen(name);
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entry = *pentry;
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for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
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cmp = name_index - entry->e_name_index;
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if (!cmp)
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cmp = name_len - entry->e_name_len;
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if (!cmp)
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cmp = memcmp(name, entry->e_name, name_len);
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if (cmp <= 0 && (sorted || cmp == 0))
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break;
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}
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*pentry = entry;
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if (!cmp && ext3_xattr_check_entry(entry, size))
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return -EIO;
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return cmp ? -ENODATA : 0;
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}
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static int
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ext3_xattr_block_get(struct inode *inode, int name_index, const char *name,
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void *buffer, size_t buffer_size)
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{
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struct buffer_head *bh = NULL;
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struct ext3_xattr_entry *entry;
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size_t size;
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int error;
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ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
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name_index, name, buffer, (long)buffer_size);
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error = -ENODATA;
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if (!EXT3_I(inode)->i_file_acl)
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goto cleanup;
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ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
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bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
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if (!bh)
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goto cleanup;
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ea_bdebug(bh, "b_count=%d, refcount=%d",
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atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
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if (ext3_xattr_check_block(bh)) {
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bad_block: ext3_error(inode->i_sb, __func__,
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"inode %lu: bad block "E3FSBLK, inode->i_ino,
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EXT3_I(inode)->i_file_acl);
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error = -EIO;
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goto cleanup;
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}
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ext3_xattr_cache_insert(bh);
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entry = BFIRST(bh);
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error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
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if (error == -EIO)
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goto bad_block;
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if (error)
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goto cleanup;
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size = le32_to_cpu(entry->e_value_size);
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if (buffer) {
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error = -ERANGE;
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if (size > buffer_size)
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goto cleanup;
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memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
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size);
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}
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error = size;
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cleanup:
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brelse(bh);
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return error;
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}
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static int
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ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
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void *buffer, size_t buffer_size)
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{
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struct ext3_xattr_ibody_header *header;
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struct ext3_xattr_entry *entry;
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struct ext3_inode *raw_inode;
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struct ext3_iloc iloc;
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size_t size;
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void *end;
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int error;
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if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
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return -ENODATA;
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error = ext3_get_inode_loc(inode, &iloc);
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if (error)
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return error;
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raw_inode = ext3_raw_inode(&iloc);
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header = IHDR(inode, raw_inode);
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entry = IFIRST(header);
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end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
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error = ext3_xattr_check_names(entry, end);
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if (error)
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goto cleanup;
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error = ext3_xattr_find_entry(&entry, name_index, name,
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end - (void *)entry, 0);
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if (error)
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goto cleanup;
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size = le32_to_cpu(entry->e_value_size);
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if (buffer) {
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error = -ERANGE;
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if (size > buffer_size)
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goto cleanup;
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memcpy(buffer, (void *)IFIRST(header) +
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le16_to_cpu(entry->e_value_offs), size);
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}
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error = size;
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cleanup:
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brelse(iloc.bh);
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return error;
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}
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|
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/*
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* ext3_xattr_get()
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*
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* Copy an extended attribute into the buffer
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* provided, or compute the buffer size required.
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* Buffer is NULL to compute the size of the buffer required.
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*
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* Returns a negative error number on failure, or the number of bytes
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* used / required on success.
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*/
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int
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ext3_xattr_get(struct inode *inode, int name_index, const char *name,
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void *buffer, size_t buffer_size)
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{
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int error;
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down_read(&EXT3_I(inode)->xattr_sem);
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error = ext3_xattr_ibody_get(inode, name_index, name, buffer,
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buffer_size);
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if (error == -ENODATA)
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error = ext3_xattr_block_get(inode, name_index, name, buffer,
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buffer_size);
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up_read(&EXT3_I(inode)->xattr_sem);
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return error;
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}
|
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|
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static int
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ext3_xattr_list_entries(struct dentry *dentry, struct ext3_xattr_entry *entry,
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char *buffer, size_t buffer_size)
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{
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size_t rest = buffer_size;
|
|
|
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for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
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const struct xattr_handler *handler =
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ext3_xattr_handler(entry->e_name_index);
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|
|
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if (handler) {
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size_t size = handler->list(dentry, buffer, rest,
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entry->e_name,
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entry->e_name_len,
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handler->flags);
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if (buffer) {
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if (size > rest)
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return -ERANGE;
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buffer += size;
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}
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rest -= size;
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}
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}
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return buffer_size - rest;
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}
|
|
|
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static int
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ext3_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
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{
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struct inode *inode = dentry->d_inode;
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struct buffer_head *bh = NULL;
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int error;
|
|
|
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ea_idebug(inode, "buffer=%p, buffer_size=%ld",
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buffer, (long)buffer_size);
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|
|
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error = 0;
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if (!EXT3_I(inode)->i_file_acl)
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goto cleanup;
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ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
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bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
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error = -EIO;
|
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if (!bh)
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goto cleanup;
|
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ea_bdebug(bh, "b_count=%d, refcount=%d",
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atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
|
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if (ext3_xattr_check_block(bh)) {
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ext3_error(inode->i_sb, __func__,
|
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"inode %lu: bad block "E3FSBLK, inode->i_ino,
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EXT3_I(inode)->i_file_acl);
|
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error = -EIO;
|
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goto cleanup;
|
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}
|
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ext3_xattr_cache_insert(bh);
|
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error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
|
|
|
|
cleanup:
|
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brelse(bh);
|
|
|
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return error;
|
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}
|
|
|
|
static int
|
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ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
struct ext3_xattr_ibody_header *header;
|
|
struct ext3_inode *raw_inode;
|
|
struct ext3_iloc iloc;
|
|
void *end;
|
|
int error;
|
|
|
|
if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
|
|
return 0;
|
|
error = ext3_get_inode_loc(inode, &iloc);
|
|
if (error)
|
|
return error;
|
|
raw_inode = ext3_raw_inode(&iloc);
|
|
header = IHDR(inode, raw_inode);
|
|
end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
|
|
error = ext3_xattr_check_names(IFIRST(header), end);
|
|
if (error)
|
|
goto cleanup;
|
|
error = ext3_xattr_list_entries(dentry, IFIRST(header),
|
|
buffer, buffer_size);
|
|
|
|
cleanup:
|
|
brelse(iloc.bh);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext3_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.
|
|
*/
|
|
static int
|
|
ext3_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
|
|
{
|
|
int i_error, b_error;
|
|
|
|
down_read(&EXT3_I(dentry->d_inode)->xattr_sem);
|
|
i_error = ext3_xattr_ibody_list(dentry, buffer, buffer_size);
|
|
if (i_error < 0) {
|
|
b_error = 0;
|
|
} else {
|
|
if (buffer) {
|
|
buffer += i_error;
|
|
buffer_size -= i_error;
|
|
}
|
|
b_error = ext3_xattr_block_list(dentry, buffer, buffer_size);
|
|
if (b_error < 0)
|
|
i_error = 0;
|
|
}
|
|
up_read(&EXT3_I(dentry->d_inode)->xattr_sem);
|
|
return i_error + b_error;
|
|
}
|
|
|
|
/*
|
|
* If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
|
|
* not set, set it.
|
|
*/
|
|
static void ext3_xattr_update_super_block(handle_t *handle,
|
|
struct super_block *sb)
|
|
{
|
|
if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
|
|
return;
|
|
|
|
if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
|
|
EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR);
|
|
ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Release the xattr block BH: If the reference count is > 1, decrement
|
|
* it; otherwise free the block.
|
|
*/
|
|
static void
|
|
ext3_xattr_release_block(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *bh)
|
|
{
|
|
struct mb_cache_entry *ce = NULL;
|
|
int error = 0;
|
|
|
|
ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
|
|
error = ext3_journal_get_write_access(handle, bh);
|
|
if (error)
|
|
goto out;
|
|
|
|
lock_buffer(bh);
|
|
|
|
if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
|
|
ea_bdebug(bh, "refcount now=0; freeing");
|
|
if (ce)
|
|
mb_cache_entry_free(ce);
|
|
ext3_free_blocks(handle, inode, bh->b_blocknr, 1);
|
|
get_bh(bh);
|
|
ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
|
|
} else {
|
|
le32_add_cpu(&BHDR(bh)->h_refcount, -1);
|
|
error = ext3_journal_dirty_metadata(handle, bh);
|
|
if (IS_SYNC(inode))
|
|
handle->h_sync = 1;
|
|
dquot_free_block(inode, 1);
|
|
ea_bdebug(bh, "refcount now=%d; releasing",
|
|
le32_to_cpu(BHDR(bh)->h_refcount));
|
|
if (ce)
|
|
mb_cache_entry_release(ce);
|
|
}
|
|
unlock_buffer(bh);
|
|
out:
|
|
ext3_std_error(inode->i_sb, error);
|
|
return;
|
|
}
|
|
|
|
struct ext3_xattr_info {
|
|
int name_index;
|
|
const char *name;
|
|
const void *value;
|
|
size_t value_len;
|
|
};
|
|
|
|
struct ext3_xattr_search {
|
|
struct ext3_xattr_entry *first;
|
|
void *base;
|
|
void *end;
|
|
struct ext3_xattr_entry *here;
|
|
int not_found;
|
|
};
|
|
|
|
static int
|
|
ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s)
|
|
{
|
|
struct ext3_xattr_entry *last;
|
|
size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
|
|
|
|
/* Compute min_offs and last. */
|
|
last = s->first;
|
|
for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) {
|
|
if (!last->e_value_block && last->e_value_size) {
|
|
size_t offs = le16_to_cpu(last->e_value_offs);
|
|
if (offs < min_offs)
|
|
min_offs = offs;
|
|
}
|
|
}
|
|
free = min_offs - ((void *)last - s->base) - sizeof(__u32);
|
|
if (!s->not_found) {
|
|
if (!s->here->e_value_block && s->here->e_value_size) {
|
|
size_t size = le32_to_cpu(s->here->e_value_size);
|
|
free += EXT3_XATTR_SIZE(size);
|
|
}
|
|
free += EXT3_XATTR_LEN(name_len);
|
|
}
|
|
if (i->value) {
|
|
if (free < EXT3_XATTR_SIZE(i->value_len) ||
|
|
free < EXT3_XATTR_LEN(name_len) +
|
|
EXT3_XATTR_SIZE(i->value_len))
|
|
return -ENOSPC;
|
|
}
|
|
|
|
if (i->value && s->not_found) {
|
|
/* Insert the new name. */
|
|
size_t size = EXT3_XATTR_LEN(name_len);
|
|
size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
|
|
memmove((void *)s->here + size, s->here, rest);
|
|
memset(s->here, 0, size);
|
|
s->here->e_name_index = i->name_index;
|
|
s->here->e_name_len = name_len;
|
|
memcpy(s->here->e_name, i->name, name_len);
|
|
} else {
|
|
if (!s->here->e_value_block && s->here->e_value_size) {
|
|
void *first_val = s->base + min_offs;
|
|
size_t offs = le16_to_cpu(s->here->e_value_offs);
|
|
void *val = s->base + offs;
|
|
size_t size = EXT3_XATTR_SIZE(
|
|
le32_to_cpu(s->here->e_value_size));
|
|
|
|
if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) {
|
|
/* The old and the new value have the same
|
|
size. Just replace. */
|
|
s->here->e_value_size =
|
|
cpu_to_le32(i->value_len);
|
|
memset(val + size - EXT3_XATTR_PAD, 0,
|
|
EXT3_XATTR_PAD); /* Clear pad bytes. */
|
|
memcpy(val, i->value, i->value_len);
|
|
return 0;
|
|
}
|
|
|
|
/* Remove the old value. */
|
|
memmove(first_val + size, first_val, val - first_val);
|
|
memset(first_val, 0, size);
|
|
s->here->e_value_size = 0;
|
|
s->here->e_value_offs = 0;
|
|
min_offs += size;
|
|
|
|
/* Adjust all value offsets. */
|
|
last = s->first;
|
|
while (!IS_LAST_ENTRY(last)) {
|
|
size_t o = le16_to_cpu(last->e_value_offs);
|
|
if (!last->e_value_block &&
|
|
last->e_value_size && o < offs)
|
|
last->e_value_offs =
|
|
cpu_to_le16(o + size);
|
|
last = EXT3_XATTR_NEXT(last);
|
|
}
|
|
}
|
|
if (!i->value) {
|
|
/* Remove the old name. */
|
|
size_t size = EXT3_XATTR_LEN(name_len);
|
|
last = ENTRY((void *)last - size);
|
|
memmove(s->here, (void *)s->here + size,
|
|
(void *)last - (void *)s->here + sizeof(__u32));
|
|
memset(last, 0, size);
|
|
}
|
|
}
|
|
|
|
if (i->value) {
|
|
/* Insert the new value. */
|
|
s->here->e_value_size = cpu_to_le32(i->value_len);
|
|
if (i->value_len) {
|
|
size_t size = EXT3_XATTR_SIZE(i->value_len);
|
|
void *val = s->base + min_offs - size;
|
|
s->here->e_value_offs = cpu_to_le16(min_offs - size);
|
|
memset(val + size - EXT3_XATTR_PAD, 0,
|
|
EXT3_XATTR_PAD); /* Clear the pad bytes. */
|
|
memcpy(val, i->value, i->value_len);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct ext3_xattr_block_find {
|
|
struct ext3_xattr_search s;
|
|
struct buffer_head *bh;
|
|
};
|
|
|
|
static int
|
|
ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i,
|
|
struct ext3_xattr_block_find *bs)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
int error;
|
|
|
|
ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
|
|
i->name_index, i->name, i->value, (long)i->value_len);
|
|
|
|
if (EXT3_I(inode)->i_file_acl) {
|
|
/* The inode already has an extended attribute block. */
|
|
bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
|
|
error = -EIO;
|
|
if (!bs->bh)
|
|
goto cleanup;
|
|
ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
|
|
atomic_read(&(bs->bh->b_count)),
|
|
le32_to_cpu(BHDR(bs->bh)->h_refcount));
|
|
if (ext3_xattr_check_block(bs->bh)) {
|
|
ext3_error(sb, __func__,
|
|
"inode %lu: bad block "E3FSBLK, inode->i_ino,
|
|
EXT3_I(inode)->i_file_acl);
|
|
error = -EIO;
|
|
goto cleanup;
|
|
}
|
|
/* Find the named attribute. */
|
|
bs->s.base = BHDR(bs->bh);
|
|
bs->s.first = BFIRST(bs->bh);
|
|
bs->s.end = bs->bh->b_data + bs->bh->b_size;
|
|
bs->s.here = bs->s.first;
|
|
error = ext3_xattr_find_entry(&bs->s.here, i->name_index,
|
|
i->name, bs->bh->b_size, 1);
|
|
if (error && error != -ENODATA)
|
|
goto cleanup;
|
|
bs->s.not_found = error;
|
|
}
|
|
error = 0;
|
|
|
|
cleanup:
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
ext3_xattr_block_set(handle_t *handle, struct inode *inode,
|
|
struct ext3_xattr_info *i,
|
|
struct ext3_xattr_block_find *bs)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
struct buffer_head *new_bh = NULL;
|
|
struct ext3_xattr_search *s = &bs->s;
|
|
struct mb_cache_entry *ce = NULL;
|
|
int error = 0;
|
|
|
|
#define header(x) ((struct ext3_xattr_header *)(x))
|
|
|
|
if (i->value && i->value_len > sb->s_blocksize)
|
|
return -ENOSPC;
|
|
if (s->base) {
|
|
ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
|
|
bs->bh->b_blocknr);
|
|
error = ext3_journal_get_write_access(handle, bs->bh);
|
|
if (error)
|
|
goto cleanup;
|
|
lock_buffer(bs->bh);
|
|
|
|
if (header(s->base)->h_refcount == cpu_to_le32(1)) {
|
|
if (ce) {
|
|
mb_cache_entry_free(ce);
|
|
ce = NULL;
|
|
}
|
|
ea_bdebug(bs->bh, "modifying in-place");
|
|
error = ext3_xattr_set_entry(i, s);
|
|
if (!error) {
|
|
if (!IS_LAST_ENTRY(s->first))
|
|
ext3_xattr_rehash(header(s->base),
|
|
s->here);
|
|
ext3_xattr_cache_insert(bs->bh);
|
|
}
|
|
unlock_buffer(bs->bh);
|
|
if (error == -EIO)
|
|
goto bad_block;
|
|
if (!error)
|
|
error = ext3_journal_dirty_metadata(handle,
|
|
bs->bh);
|
|
if (error)
|
|
goto cleanup;
|
|
goto inserted;
|
|
} else {
|
|
int offset = (char *)s->here - bs->bh->b_data;
|
|
|
|
unlock_buffer(bs->bh);
|
|
journal_release_buffer(handle, bs->bh);
|
|
|
|
if (ce) {
|
|
mb_cache_entry_release(ce);
|
|
ce = NULL;
|
|
}
|
|
ea_bdebug(bs->bh, "cloning");
|
|
s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
|
|
error = -ENOMEM;
|
|
if (s->base == NULL)
|
|
goto cleanup;
|
|
memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
|
|
s->first = ENTRY(header(s->base)+1);
|
|
header(s->base)->h_refcount = cpu_to_le32(1);
|
|
s->here = ENTRY(s->base + offset);
|
|
s->end = s->base + bs->bh->b_size;
|
|
}
|
|
} else {
|
|
/* Allocate a buffer where we construct the new block. */
|
|
s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
|
|
/* assert(header == s->base) */
|
|
error = -ENOMEM;
|
|
if (s->base == NULL)
|
|
goto cleanup;
|
|
header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
|
|
header(s->base)->h_blocks = cpu_to_le32(1);
|
|
header(s->base)->h_refcount = cpu_to_le32(1);
|
|
s->first = ENTRY(header(s->base)+1);
|
|
s->here = ENTRY(header(s->base)+1);
|
|
s->end = s->base + sb->s_blocksize;
|
|
}
|
|
|
|
error = ext3_xattr_set_entry(i, s);
|
|
if (error == -EIO)
|
|
goto bad_block;
|
|
if (error)
|
|
goto cleanup;
|
|
if (!IS_LAST_ENTRY(s->first))
|
|
ext3_xattr_rehash(header(s->base), s->here);
|
|
|
|
inserted:
|
|
if (!IS_LAST_ENTRY(s->first)) {
|
|
new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce);
|
|
if (new_bh) {
|
|
/* We found an identical block in the cache. */
|
|
if (new_bh == bs->bh)
|
|
ea_bdebug(new_bh, "keeping");
|
|
else {
|
|
/* The old block is released after updating
|
|
the inode. */
|
|
error = dquot_alloc_block(inode, 1);
|
|
if (error)
|
|
goto cleanup;
|
|
error = ext3_journal_get_write_access(handle,
|
|
new_bh);
|
|
if (error)
|
|
goto cleanup_dquot;
|
|
lock_buffer(new_bh);
|
|
le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
|
|
ea_bdebug(new_bh, "reusing; refcount now=%d",
|
|
le32_to_cpu(BHDR(new_bh)->h_refcount));
|
|
unlock_buffer(new_bh);
|
|
error = ext3_journal_dirty_metadata(handle,
|
|
new_bh);
|
|
if (error)
|
|
goto cleanup_dquot;
|
|
}
|
|
mb_cache_entry_release(ce);
|
|
ce = NULL;
|
|
} else if (bs->bh && s->base == bs->bh->b_data) {
|
|
/* We were modifying this block in-place. */
|
|
ea_bdebug(bs->bh, "keeping this block");
|
|
new_bh = bs->bh;
|
|
get_bh(new_bh);
|
|
} else {
|
|
/* We need to allocate a new block */
|
|
ext3_fsblk_t goal = ext3_group_first_block_no(sb,
|
|
EXT3_I(inode)->i_block_group);
|
|
ext3_fsblk_t block = ext3_new_block(handle, inode,
|
|
goal, &error);
|
|
if (error)
|
|
goto cleanup;
|
|
ea_idebug(inode, "creating block %d", block);
|
|
|
|
new_bh = sb_getblk(sb, block);
|
|
if (!new_bh) {
|
|
getblk_failed:
|
|
ext3_free_blocks(handle, inode, block, 1);
|
|
error = -EIO;
|
|
goto cleanup;
|
|
}
|
|
lock_buffer(new_bh);
|
|
error = ext3_journal_get_create_access(handle, new_bh);
|
|
if (error) {
|
|
unlock_buffer(new_bh);
|
|
goto getblk_failed;
|
|
}
|
|
memcpy(new_bh->b_data, s->base, new_bh->b_size);
|
|
set_buffer_uptodate(new_bh);
|
|
unlock_buffer(new_bh);
|
|
ext3_xattr_cache_insert(new_bh);
|
|
error = ext3_journal_dirty_metadata(handle, new_bh);
|
|
if (error)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
/* Update the inode. */
|
|
EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
|
|
|
|
/* Drop the previous xattr block. */
|
|
if (bs->bh && bs->bh != new_bh)
|
|
ext3_xattr_release_block(handle, inode, bs->bh);
|
|
error = 0;
|
|
|
|
cleanup:
|
|
if (ce)
|
|
mb_cache_entry_release(ce);
|
|
brelse(new_bh);
|
|
if (!(bs->bh && s->base == bs->bh->b_data))
|
|
kfree(s->base);
|
|
|
|
return error;
|
|
|
|
cleanup_dquot:
|
|
dquot_free_block(inode, 1);
|
|
goto cleanup;
|
|
|
|
bad_block:
|
|
ext3_error(inode->i_sb, __func__,
|
|
"inode %lu: bad block "E3FSBLK, inode->i_ino,
|
|
EXT3_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
|
|
#undef header
|
|
}
|
|
|
|
struct ext3_xattr_ibody_find {
|
|
struct ext3_xattr_search s;
|
|
struct ext3_iloc iloc;
|
|
};
|
|
|
|
static int
|
|
ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i,
|
|
struct ext3_xattr_ibody_find *is)
|
|
{
|
|
struct ext3_xattr_ibody_header *header;
|
|
struct ext3_inode *raw_inode;
|
|
int error;
|
|
|
|
if (EXT3_I(inode)->i_extra_isize == 0)
|
|
return 0;
|
|
raw_inode = ext3_raw_inode(&is->iloc);
|
|
header = IHDR(inode, raw_inode);
|
|
is->s.base = is->s.first = IFIRST(header);
|
|
is->s.here = is->s.first;
|
|
is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
|
|
if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) {
|
|
error = ext3_xattr_check_names(IFIRST(header), is->s.end);
|
|
if (error)
|
|
return error;
|
|
/* Find the named attribute. */
|
|
error = ext3_xattr_find_entry(&is->s.here, i->name_index,
|
|
i->name, is->s.end -
|
|
(void *)is->s.base, 0);
|
|
if (error && error != -ENODATA)
|
|
return error;
|
|
is->s.not_found = error;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
ext3_xattr_ibody_set(handle_t *handle, struct inode *inode,
|
|
struct ext3_xattr_info *i,
|
|
struct ext3_xattr_ibody_find *is)
|
|
{
|
|
struct ext3_xattr_ibody_header *header;
|
|
struct ext3_xattr_search *s = &is->s;
|
|
int error;
|
|
|
|
if (EXT3_I(inode)->i_extra_isize == 0)
|
|
return -ENOSPC;
|
|
error = ext3_xattr_set_entry(i, s);
|
|
if (error)
|
|
return error;
|
|
header = IHDR(inode, ext3_raw_inode(&is->iloc));
|
|
if (!IS_LAST_ENTRY(s->first)) {
|
|
header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
|
|
ext3_set_inode_state(inode, EXT3_STATE_XATTR);
|
|
} else {
|
|
header->h_magic = cpu_to_le32(0);
|
|
ext3_clear_inode_state(inode, EXT3_STATE_XATTR);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ext3_xattr_set_handle()
|
|
*
|
|
* Create, replace or remove an extended attribute for this inode. Value
|
|
* 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
|
|
ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
|
|
const char *name, const void *value, size_t value_len,
|
|
int flags)
|
|
{
|
|
struct ext3_xattr_info i = {
|
|
.name_index = name_index,
|
|
.name = name,
|
|
.value = value,
|
|
.value_len = value_len,
|
|
|
|
};
|
|
struct ext3_xattr_ibody_find is = {
|
|
.s = { .not_found = -ENODATA, },
|
|
};
|
|
struct ext3_xattr_block_find bs = {
|
|
.s = { .not_found = -ENODATA, },
|
|
};
|
|
int error;
|
|
|
|
if (!name)
|
|
return -EINVAL;
|
|
if (strlen(name) > 255)
|
|
return -ERANGE;
|
|
down_write(&EXT3_I(inode)->xattr_sem);
|
|
error = ext3_get_inode_loc(inode, &is.iloc);
|
|
if (error)
|
|
goto cleanup;
|
|
|
|
error = ext3_journal_get_write_access(handle, is.iloc.bh);
|
|
if (error)
|
|
goto cleanup;
|
|
|
|
if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) {
|
|
struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);
|
|
memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
|
|
ext3_clear_inode_state(inode, EXT3_STATE_NEW);
|
|
}
|
|
|
|
error = ext3_xattr_ibody_find(inode, &i, &is);
|
|
if (error)
|
|
goto cleanup;
|
|
if (is.s.not_found)
|
|
error = ext3_xattr_block_find(inode, &i, &bs);
|
|
if (error)
|
|
goto cleanup;
|
|
if (is.s.not_found && bs.s.not_found) {
|
|
error = -ENODATA;
|
|
if (flags & XATTR_REPLACE)
|
|
goto cleanup;
|
|
error = 0;
|
|
if (!value)
|
|
goto cleanup;
|
|
} else {
|
|
error = -EEXIST;
|
|
if (flags & XATTR_CREATE)
|
|
goto cleanup;
|
|
}
|
|
if (!value) {
|
|
if (!is.s.not_found)
|
|
error = ext3_xattr_ibody_set(handle, inode, &i, &is);
|
|
else if (!bs.s.not_found)
|
|
error = ext3_xattr_block_set(handle, inode, &i, &bs);
|
|
} else {
|
|
error = ext3_xattr_ibody_set(handle, inode, &i, &is);
|
|
if (!error && !bs.s.not_found) {
|
|
i.value = NULL;
|
|
error = ext3_xattr_block_set(handle, inode, &i, &bs);
|
|
} else if (error == -ENOSPC) {
|
|
if (EXT3_I(inode)->i_file_acl && !bs.s.base) {
|
|
error = ext3_xattr_block_find(inode, &i, &bs);
|
|
if (error)
|
|
goto cleanup;
|
|
}
|
|
error = ext3_xattr_block_set(handle, inode, &i, &bs);
|
|
if (error)
|
|
goto cleanup;
|
|
if (!is.s.not_found) {
|
|
i.value = NULL;
|
|
error = ext3_xattr_ibody_set(handle, inode, &i,
|
|
&is);
|
|
}
|
|
}
|
|
}
|
|
if (!error) {
|
|
ext3_xattr_update_super_block(handle, inode->i_sb);
|
|
inode->i_ctime = CURRENT_TIME_SEC;
|
|
error = ext3_mark_iloc_dirty(handle, inode, &is.iloc);
|
|
/*
|
|
* The bh is consumed by ext3_mark_iloc_dirty, even with
|
|
* error != 0.
|
|
*/
|
|
is.iloc.bh = NULL;
|
|
if (IS_SYNC(inode))
|
|
handle->h_sync = 1;
|
|
}
|
|
|
|
cleanup:
|
|
brelse(is.iloc.bh);
|
|
brelse(bs.bh);
|
|
up_write(&EXT3_I(inode)->xattr_sem);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext3_xattr_set()
|
|
*
|
|
* Like ext3_xattr_set_handle, but start from an inode. This extended
|
|
* attribute modification is a filesystem transaction by itself.
|
|
*
|
|
* Returns 0, or a negative error number on failure.
|
|
*/
|
|
int
|
|
ext3_xattr_set(struct inode *inode, int name_index, const char *name,
|
|
const void *value, size_t value_len, int flags)
|
|
{
|
|
handle_t *handle;
|
|
int error, retries = 0;
|
|
|
|
retry:
|
|
handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
|
|
if (IS_ERR(handle)) {
|
|
error = PTR_ERR(handle);
|
|
} else {
|
|
int error2;
|
|
|
|
error = ext3_xattr_set_handle(handle, inode, name_index, name,
|
|
value, value_len, flags);
|
|
error2 = ext3_journal_stop(handle);
|
|
if (error == -ENOSPC &&
|
|
ext3_should_retry_alloc(inode->i_sb, &retries))
|
|
goto retry;
|
|
if (error == 0)
|
|
error = error2;
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext3_xattr_delete_inode()
|
|
*
|
|
* Free extended attribute resources associated with this inode. This
|
|
* is called immediately before an inode is freed. We have exclusive
|
|
* access to the inode.
|
|
*/
|
|
void
|
|
ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
|
|
{
|
|
struct buffer_head *bh = NULL;
|
|
|
|
if (!EXT3_I(inode)->i_file_acl)
|
|
goto cleanup;
|
|
bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
|
|
if (!bh) {
|
|
ext3_error(inode->i_sb, __func__,
|
|
"inode %lu: block "E3FSBLK" read error", inode->i_ino,
|
|
EXT3_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
|
|
BHDR(bh)->h_blocks != cpu_to_le32(1)) {
|
|
ext3_error(inode->i_sb, __func__,
|
|
"inode %lu: bad block "E3FSBLK, inode->i_ino,
|
|
EXT3_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
ext3_xattr_release_block(handle, inode, bh);
|
|
EXT3_I(inode)->i_file_acl = 0;
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
}
|
|
|
|
/*
|
|
* ext3_xattr_put_super()
|
|
*
|
|
* This is called when a file system is unmounted.
|
|
*/
|
|
void
|
|
ext3_xattr_put_super(struct super_block *sb)
|
|
{
|
|
mb_cache_shrink(sb->s_bdev);
|
|
}
|
|
|
|
/*
|
|
* ext3_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 void
|
|
ext3_xattr_cache_insert(struct buffer_head *bh)
|
|
{
|
|
__u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
|
|
struct mb_cache_entry *ce;
|
|
int error;
|
|
|
|
ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS);
|
|
if (!ce) {
|
|
ea_bdebug(bh, "out of memory");
|
|
return;
|
|
}
|
|
error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
|
|
if (error) {
|
|
mb_cache_entry_free(ce);
|
|
if (error == -EBUSY) {
|
|
ea_bdebug(bh, "already in cache");
|
|
error = 0;
|
|
}
|
|
} else {
|
|
ea_bdebug(bh, "inserting [%x]", (int)hash);
|
|
mb_cache_entry_release(ce);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ext3_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
|
|
ext3_xattr_cmp(struct ext3_xattr_header *header1,
|
|
struct ext3_xattr_header *header2)
|
|
{
|
|
struct ext3_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_index != entry2->e_name_index ||
|
|
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 = EXT3_XATTR_NEXT(entry1);
|
|
entry2 = EXT3_XATTR_NEXT(entry2);
|
|
}
|
|
if (!IS_LAST_ENTRY(entry2))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ext3_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 *
|
|
ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header,
|
|
struct mb_cache_entry **pce)
|
|
{
|
|
__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);
|
|
again:
|
|
ce = mb_cache_entry_find_first(ext3_xattr_cache, inode->i_sb->s_bdev,
|
|
hash);
|
|
while (ce) {
|
|
struct buffer_head *bh;
|
|
|
|
if (IS_ERR(ce)) {
|
|
if (PTR_ERR(ce) == -EAGAIN)
|
|
goto again;
|
|
break;
|
|
}
|
|
bh = sb_bread(inode->i_sb, ce->e_block);
|
|
if (!bh) {
|
|
ext3_error(inode->i_sb, __func__,
|
|
"inode %lu: block %lu read error",
|
|
inode->i_ino, (unsigned long) ce->e_block);
|
|
} else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
|
|
EXT3_XATTR_REFCOUNT_MAX) {
|
|
ea_idebug(inode, "block %lu refcount %d>=%d",
|
|
(unsigned long) ce->e_block,
|
|
le32_to_cpu(BHDR(bh)->h_refcount),
|
|
EXT3_XATTR_REFCOUNT_MAX);
|
|
} else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) {
|
|
*pce = ce;
|
|
return bh;
|
|
}
|
|
brelse(bh);
|
|
ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#define NAME_HASH_SHIFT 5
|
|
#define VALUE_HASH_SHIFT 16
|
|
|
|
/*
|
|
* ext3_xattr_hash_entry()
|
|
*
|
|
* Compute the hash of an extended attribute.
|
|
*/
|
|
static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
|
|
struct ext3_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) {
|
|
__le32 *value = (__le32 *)((char *)header +
|
|
le16_to_cpu(entry->e_value_offs));
|
|
for (n = (le32_to_cpu(entry->e_value_size) +
|
|
EXT3_XATTR_ROUND) >> EXT3_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
|
|
|
|
/*
|
|
* ext3_xattr_rehash()
|
|
*
|
|
* Re-compute the extended attribute hash value after an entry has changed.
|
|
*/
|
|
static void ext3_xattr_rehash(struct ext3_xattr_header *header,
|
|
struct ext3_xattr_entry *entry)
|
|
{
|
|
struct ext3_xattr_entry *here;
|
|
__u32 hash = 0;
|
|
|
|
ext3_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 = EXT3_XATTR_NEXT(here);
|
|
}
|
|
header->h_hash = cpu_to_le32(hash);
|
|
}
|
|
|
|
#undef BLOCK_HASH_SHIFT
|
|
|
|
int __init
|
|
init_ext3_xattr(void)
|
|
{
|
|
ext3_xattr_cache = mb_cache_create("ext3_xattr", 6);
|
|
if (!ext3_xattr_cache)
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
exit_ext3_xattr(void)
|
|
{
|
|
if (ext3_xattr_cache)
|
|
mb_cache_destroy(ext3_xattr_cache);
|
|
ext3_xattr_cache = NULL;
|
|
}
|