![Tahsin Erdogan](/assets/img/avatar_default.png)
ext4_xattr_block_set() calls dquot_alloc_block() to charge for an xattr block when new references are made. However if dquot_initialize() hasn't been called on an inode, request for charging is effectively ignored because ext4_inode_info->i_dquot is not initialized yet. Add dquot_initialize() to call paths that lead to ext4_xattr_block_set(). Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
1794 lines
48 KiB
C
1794 lines
48 KiB
C
/*
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* linux/fs/ext4/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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* Ext4 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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* EXT4_I(inode)->i_file_acl is protected by EXT4_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/mbcache.h>
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#include <linux/quotaops.h>
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#include "ext4_jbd2.h"
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#include "ext4.h"
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#include "xattr.h"
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#include "acl.h"
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#ifdef EXT4_XATTR_DEBUG
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# define ea_idebug(inode, fmt, ...) \
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printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \
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inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__)
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# define ea_bdebug(bh, fmt, ...) \
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printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \
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bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__)
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#else
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# define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
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# define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
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#endif
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static void ext4_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
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static struct buffer_head *ext4_xattr_cache_find(struct inode *,
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struct ext4_xattr_header *,
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struct mb_cache_entry **);
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static void ext4_xattr_rehash(struct ext4_xattr_header *,
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struct ext4_xattr_entry *);
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static const struct xattr_handler * const ext4_xattr_handler_map[] = {
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[EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
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#ifdef CONFIG_EXT4_FS_POSIX_ACL
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[EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
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[EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
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#endif
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[EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
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#ifdef CONFIG_EXT4_FS_SECURITY
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[EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
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#endif
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};
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const struct xattr_handler *ext4_xattr_handlers[] = {
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&ext4_xattr_user_handler,
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&ext4_xattr_trusted_handler,
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#ifdef CONFIG_EXT4_FS_POSIX_ACL
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&posix_acl_access_xattr_handler,
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&posix_acl_default_xattr_handler,
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#endif
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#ifdef CONFIG_EXT4_FS_SECURITY
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&ext4_xattr_security_handler,
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#endif
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NULL
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};
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#define EXT4_GET_MB_CACHE(inode) (((struct ext4_sb_info *) \
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inode->i_sb->s_fs_info)->s_mb_cache)
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static __le32 ext4_xattr_block_csum(struct inode *inode,
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sector_t block_nr,
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struct ext4_xattr_header *hdr)
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{
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struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
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__u32 csum;
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__le64 dsk_block_nr = cpu_to_le64(block_nr);
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__u32 dummy_csum = 0;
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int offset = offsetof(struct ext4_xattr_header, h_checksum);
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csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
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sizeof(dsk_block_nr));
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csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
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csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
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offset += sizeof(dummy_csum);
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csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
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EXT4_BLOCK_SIZE(inode->i_sb) - offset);
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return cpu_to_le32(csum);
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}
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static int ext4_xattr_block_csum_verify(struct inode *inode,
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struct buffer_head *bh)
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{
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struct ext4_xattr_header *hdr = BHDR(bh);
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int ret = 1;
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if (ext4_has_metadata_csum(inode->i_sb)) {
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lock_buffer(bh);
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ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
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bh->b_blocknr, hdr));
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unlock_buffer(bh);
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}
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return ret;
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}
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static void ext4_xattr_block_csum_set(struct inode *inode,
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struct buffer_head *bh)
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{
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if (ext4_has_metadata_csum(inode->i_sb))
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BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
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bh->b_blocknr, BHDR(bh));
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}
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static inline const struct xattr_handler *
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ext4_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(ext4_xattr_handler_map))
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handler = ext4_xattr_handler_map[name_index];
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return handler;
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}
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static int
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ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
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void *value_start)
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{
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struct ext4_xattr_entry *e = entry;
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/* Find the end of the names list */
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while (!IS_LAST_ENTRY(e)) {
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struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
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if ((void *)next >= end)
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return -EFSCORRUPTED;
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e = next;
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}
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/* Check the values */
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while (!IS_LAST_ENTRY(entry)) {
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if (entry->e_value_block != 0)
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return -EFSCORRUPTED;
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if (entry->e_value_size != 0) {
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u16 offs = le16_to_cpu(entry->e_value_offs);
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u32 size = le32_to_cpu(entry->e_value_size);
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void *value;
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/*
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* The value cannot overlap the names, and the value
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* with padding cannot extend beyond 'end'. Check both
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* the padded and unpadded sizes, since the size may
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* overflow to 0 when adding padding.
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*/
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if (offs > end - value_start)
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return -EFSCORRUPTED;
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value = value_start + offs;
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if (value < (void *)e + sizeof(u32) ||
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size > end - value ||
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EXT4_XATTR_SIZE(size) > end - value)
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return -EFSCORRUPTED;
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}
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entry = EXT4_XATTR_NEXT(entry);
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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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ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
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{
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int error;
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if (buffer_verified(bh))
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return 0;
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if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
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BHDR(bh)->h_blocks != cpu_to_le32(1))
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return -EFSCORRUPTED;
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if (!ext4_xattr_block_csum_verify(inode, bh))
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return -EFSBADCRC;
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error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
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bh->b_data);
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if (!error)
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set_buffer_verified(bh);
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return error;
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}
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static int
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__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
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void *end, const char *function, unsigned int line)
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{
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int error = -EFSCORRUPTED;
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if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
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(header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
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goto errout;
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error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
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errout:
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if (error)
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__ext4_error_inode(inode, function, line, 0,
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"corrupted in-inode xattr");
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return error;
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}
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#define xattr_check_inode(inode, header, end) \
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__xattr_check_inode((inode), (header), (end), __func__, __LINE__)
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static int
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ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
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const char *name, int sorted)
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{
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struct ext4_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 = EXT4_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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return cmp ? -ENODATA : 0;
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}
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static int
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ext4_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 ext4_xattr_entry *entry;
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size_t size;
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int error;
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struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
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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 (!EXT4_I(inode)->i_file_acl)
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goto cleanup;
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ea_idebug(inode, "reading block %llu",
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(unsigned long long)EXT4_I(inode)->i_file_acl);
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bh = sb_bread(inode->i_sb, EXT4_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 (ext4_xattr_check_block(inode, bh)) {
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EXT4_ERROR_INODE(inode, "bad block %llu",
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EXT4_I(inode)->i_file_acl);
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error = -EFSCORRUPTED;
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goto cleanup;
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}
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ext4_xattr_cache_insert(ext4_mb_cache, bh);
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entry = BFIRST(bh);
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error = ext4_xattr_find_entry(&entry, name_index, name, 1);
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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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int
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ext4_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 ext4_xattr_ibody_header *header;
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struct ext4_xattr_entry *entry;
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struct ext4_inode *raw_inode;
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struct ext4_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 (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
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return -ENODATA;
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error = ext4_get_inode_loc(inode, &iloc);
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if (error)
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return error;
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raw_inode = ext4_raw_inode(&iloc);
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header = IHDR(inode, raw_inode);
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end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
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error = xattr_check_inode(inode, header, end);
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if (error)
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goto cleanup;
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entry = IFIRST(header);
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error = ext4_xattr_find_entry(&entry, name_index, name, 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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* ext4_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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ext4_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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|
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if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
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return -EIO;
|
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|
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if (strlen(name) > 255)
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return -ERANGE;
|
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|
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down_read(&EXT4_I(inode)->xattr_sem);
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error = ext4_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 = ext4_xattr_block_get(inode, name_index, name, buffer,
|
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buffer_size);
|
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up_read(&EXT4_I(inode)->xattr_sem);
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return error;
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}
|
|
|
|
static int
|
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ext4_xattr_list_entries(struct dentry *dentry, struct ext4_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 = EXT4_XATTR_NEXT(entry)) {
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const struct xattr_handler *handler =
|
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ext4_xattr_handler(entry->e_name_index);
|
|
|
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if (handler && (!handler->list || handler->list(dentry))) {
|
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const char *prefix = handler->prefix ?: handler->name;
|
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size_t prefix_len = strlen(prefix);
|
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size_t size = prefix_len + entry->e_name_len + 1;
|
|
|
|
if (buffer) {
|
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if (size > rest)
|
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return -ERANGE;
|
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memcpy(buffer, prefix, prefix_len);
|
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buffer += prefix_len;
|
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memcpy(buffer, entry->e_name, entry->e_name_len);
|
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buffer += entry->e_name_len;
|
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*buffer++ = 0;
|
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}
|
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rest -= size;
|
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}
|
|
}
|
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return buffer_size - rest; /* total size */
|
|
}
|
|
|
|
static int
|
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ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct buffer_head *bh = NULL;
|
|
int error;
|
|
struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
|
|
|
|
ea_idebug(inode, "buffer=%p, buffer_size=%ld",
|
|
buffer, (long)buffer_size);
|
|
|
|
error = 0;
|
|
if (!EXT4_I(inode)->i_file_acl)
|
|
goto cleanup;
|
|
ea_idebug(inode, "reading block %llu",
|
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(unsigned long long)EXT4_I(inode)->i_file_acl);
|
|
bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
|
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error = -EIO;
|
|
if (!bh)
|
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goto cleanup;
|
|
ea_bdebug(bh, "b_count=%d, refcount=%d",
|
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atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
|
|
if (ext4_xattr_check_block(inode, bh)) {
|
|
EXT4_ERROR_INODE(inode, "bad block %llu",
|
|
EXT4_I(inode)->i_file_acl);
|
|
error = -EFSCORRUPTED;
|
|
goto cleanup;
|
|
}
|
|
ext4_xattr_cache_insert(ext4_mb_cache, bh);
|
|
error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
|
|
{
|
|
struct inode *inode = d_inode(dentry);
|
|
struct ext4_xattr_ibody_header *header;
|
|
struct ext4_inode *raw_inode;
|
|
struct ext4_iloc iloc;
|
|
void *end;
|
|
int error;
|
|
|
|
if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
|
|
return 0;
|
|
error = ext4_get_inode_loc(inode, &iloc);
|
|
if (error)
|
|
return error;
|
|
raw_inode = ext4_raw_inode(&iloc);
|
|
header = IHDR(inode, raw_inode);
|
|
end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
|
|
error = xattr_check_inode(inode, header, end);
|
|
if (error)
|
|
goto cleanup;
|
|
error = ext4_xattr_list_entries(dentry, IFIRST(header),
|
|
buffer, buffer_size);
|
|
|
|
cleanup:
|
|
brelse(iloc.bh);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Inode operation listxattr()
|
|
*
|
|
* d_inode(dentry)->i_rwsem: don't care
|
|
*
|
|
* 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.
|
|
*/
|
|
ssize_t
|
|
ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
|
|
{
|
|
int ret, ret2;
|
|
|
|
down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
|
|
ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
|
|
if (ret < 0)
|
|
goto errout;
|
|
if (buffer) {
|
|
buffer += ret;
|
|
buffer_size -= ret;
|
|
}
|
|
ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
|
|
if (ret < 0)
|
|
goto errout;
|
|
ret += ret2;
|
|
errout:
|
|
up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
|
|
* not set, set it.
|
|
*/
|
|
static void ext4_xattr_update_super_block(handle_t *handle,
|
|
struct super_block *sb)
|
|
{
|
|
if (ext4_has_feature_xattr(sb))
|
|
return;
|
|
|
|
BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
|
|
if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
|
|
ext4_set_feature_xattr(sb);
|
|
ext4_handle_dirty_super(handle, sb);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Release the xattr block BH: If the reference count is > 1, decrement it;
|
|
* otherwise free the block.
|
|
*/
|
|
static void
|
|
ext4_xattr_release_block(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *bh)
|
|
{
|
|
struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
|
|
u32 hash, ref;
|
|
int error = 0;
|
|
|
|
BUFFER_TRACE(bh, "get_write_access");
|
|
error = ext4_journal_get_write_access(handle, bh);
|
|
if (error)
|
|
goto out;
|
|
|
|
lock_buffer(bh);
|
|
hash = le32_to_cpu(BHDR(bh)->h_hash);
|
|
ref = le32_to_cpu(BHDR(bh)->h_refcount);
|
|
if (ref == 1) {
|
|
ea_bdebug(bh, "refcount now=0; freeing");
|
|
/*
|
|
* This must happen under buffer lock for
|
|
* ext4_xattr_block_set() to reliably detect freed block
|
|
*/
|
|
mb_cache_entry_delete_block(ext4_mb_cache, hash, bh->b_blocknr);
|
|
get_bh(bh);
|
|
unlock_buffer(bh);
|
|
ext4_free_blocks(handle, inode, bh, 0, 1,
|
|
EXT4_FREE_BLOCKS_METADATA |
|
|
EXT4_FREE_BLOCKS_FORGET);
|
|
} else {
|
|
ref--;
|
|
BHDR(bh)->h_refcount = cpu_to_le32(ref);
|
|
if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
|
|
struct mb_cache_entry *ce;
|
|
|
|
ce = mb_cache_entry_get(ext4_mb_cache, hash,
|
|
bh->b_blocknr);
|
|
if (ce) {
|
|
ce->e_reusable = 1;
|
|
mb_cache_entry_put(ext4_mb_cache, ce);
|
|
}
|
|
}
|
|
|
|
ext4_xattr_block_csum_set(inode, bh);
|
|
/*
|
|
* Beware of this ugliness: Releasing of xattr block references
|
|
* from different inodes can race and so we have to protect
|
|
* from a race where someone else frees the block (and releases
|
|
* its journal_head) before we are done dirtying the buffer. In
|
|
* nojournal mode this race is harmless and we actually cannot
|
|
* call ext4_handle_dirty_metadata() with locked buffer as
|
|
* that function can call sync_dirty_buffer() so for that case
|
|
* we handle the dirtying after unlocking the buffer.
|
|
*/
|
|
if (ext4_handle_valid(handle))
|
|
error = ext4_handle_dirty_metadata(handle, inode, bh);
|
|
unlock_buffer(bh);
|
|
if (!ext4_handle_valid(handle))
|
|
error = ext4_handle_dirty_metadata(handle, inode, bh);
|
|
if (IS_SYNC(inode))
|
|
ext4_handle_sync(handle);
|
|
dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
|
|
ea_bdebug(bh, "refcount now=%d; releasing",
|
|
le32_to_cpu(BHDR(bh)->h_refcount));
|
|
}
|
|
out:
|
|
ext4_std_error(inode->i_sb, error);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Find the available free space for EAs. This also returns the total number of
|
|
* bytes used by EA entries.
|
|
*/
|
|
static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
|
|
size_t *min_offs, void *base, int *total)
|
|
{
|
|
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
|
|
if (last->e_value_size) {
|
|
size_t offs = le16_to_cpu(last->e_value_offs);
|
|
if (offs < *min_offs)
|
|
*min_offs = offs;
|
|
}
|
|
if (total)
|
|
*total += EXT4_XATTR_LEN(last->e_name_len);
|
|
}
|
|
return (*min_offs - ((void *)last - base) - sizeof(__u32));
|
|
}
|
|
|
|
static int
|
|
ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
|
|
{
|
|
struct ext4_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 = EXT4_XATTR_NEXT(last)) {
|
|
if (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_size) {
|
|
size_t size = le32_to_cpu(s->here->e_value_size);
|
|
free += EXT4_XATTR_SIZE(size);
|
|
}
|
|
free += EXT4_XATTR_LEN(name_len);
|
|
}
|
|
if (i->value) {
|
|
if (free < EXT4_XATTR_LEN(name_len) +
|
|
EXT4_XATTR_SIZE(i->value_len))
|
|
return -ENOSPC;
|
|
}
|
|
|
|
if (i->value && s->not_found) {
|
|
/* Insert the new name. */
|
|
size_t size = EXT4_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_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 = EXT4_XATTR_SIZE(
|
|
le32_to_cpu(s->here->e_value_size));
|
|
|
|
if (i->value && size == EXT4_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);
|
|
if (i->value == EXT4_ZERO_XATTR_VALUE) {
|
|
memset(val, 0, size);
|
|
} else {
|
|
/* Clear pad bytes first. */
|
|
memset(val + size - EXT4_XATTR_PAD, 0,
|
|
EXT4_XATTR_PAD);
|
|
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_size && o < offs)
|
|
last->e_value_offs =
|
|
cpu_to_le16(o + size);
|
|
last = EXT4_XATTR_NEXT(last);
|
|
}
|
|
}
|
|
if (!i->value) {
|
|
/* Remove the old name. */
|
|
size_t size = EXT4_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 = EXT4_XATTR_SIZE(i->value_len);
|
|
void *val = s->base + min_offs - size;
|
|
s->here->e_value_offs = cpu_to_le16(min_offs - size);
|
|
if (i->value == EXT4_ZERO_XATTR_VALUE) {
|
|
memset(val, 0, size);
|
|
} else {
|
|
/* Clear the pad bytes first. */
|
|
memset(val + size - EXT4_XATTR_PAD, 0,
|
|
EXT4_XATTR_PAD);
|
|
memcpy(val, i->value, i->value_len);
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
struct ext4_xattr_block_find {
|
|
struct ext4_xattr_search s;
|
|
struct buffer_head *bh;
|
|
};
|
|
|
|
static int
|
|
ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
|
|
struct ext4_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 (EXT4_I(inode)->i_file_acl) {
|
|
/* The inode already has an extended attribute block. */
|
|
bs->bh = sb_bread(sb, EXT4_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 (ext4_xattr_check_block(inode, bs->bh)) {
|
|
EXT4_ERROR_INODE(inode, "bad block %llu",
|
|
EXT4_I(inode)->i_file_acl);
|
|
error = -EFSCORRUPTED;
|
|
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 = ext4_xattr_find_entry(&bs->s.here, i->name_index,
|
|
i->name, 1);
|
|
if (error && error != -ENODATA)
|
|
goto cleanup;
|
|
bs->s.not_found = error;
|
|
}
|
|
error = 0;
|
|
|
|
cleanup:
|
|
return error;
|
|
}
|
|
|
|
static int
|
|
ext4_xattr_block_set(handle_t *handle, struct inode *inode,
|
|
struct ext4_xattr_info *i,
|
|
struct ext4_xattr_block_find *bs)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
struct buffer_head *new_bh = NULL;
|
|
struct ext4_xattr_search *s = &bs->s;
|
|
struct mb_cache_entry *ce = NULL;
|
|
int error = 0;
|
|
struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
|
|
|
|
#define header(x) ((struct ext4_xattr_header *)(x))
|
|
|
|
if (i->value && i->value_len > sb->s_blocksize)
|
|
return -ENOSPC;
|
|
if (s->base) {
|
|
BUFFER_TRACE(bs->bh, "get_write_access");
|
|
error = ext4_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)) {
|
|
__u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
|
|
|
|
/*
|
|
* This must happen under buffer lock for
|
|
* ext4_xattr_block_set() to reliably detect modified
|
|
* block
|
|
*/
|
|
mb_cache_entry_delete_block(ext4_mb_cache, hash,
|
|
bs->bh->b_blocknr);
|
|
ea_bdebug(bs->bh, "modifying in-place");
|
|
error = ext4_xattr_set_entry(i, s);
|
|
if (!error) {
|
|
if (!IS_LAST_ENTRY(s->first))
|
|
ext4_xattr_rehash(header(s->base),
|
|
s->here);
|
|
ext4_xattr_cache_insert(ext4_mb_cache,
|
|
bs->bh);
|
|
}
|
|
ext4_xattr_block_csum_set(inode, bs->bh);
|
|
unlock_buffer(bs->bh);
|
|
if (error == -EFSCORRUPTED)
|
|
goto bad_block;
|
|
if (!error)
|
|
error = ext4_handle_dirty_metadata(handle,
|
|
inode,
|
|
bs->bh);
|
|
if (error)
|
|
goto cleanup;
|
|
goto inserted;
|
|
} else {
|
|
int offset = (char *)s->here - bs->bh->b_data;
|
|
|
|
unlock_buffer(bs->bh);
|
|
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(EXT4_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 = ext4_xattr_set_entry(i, s);
|
|
if (error == -EFSCORRUPTED)
|
|
goto bad_block;
|
|
if (error)
|
|
goto cleanup;
|
|
if (!IS_LAST_ENTRY(s->first))
|
|
ext4_xattr_rehash(header(s->base), s->here);
|
|
|
|
inserted:
|
|
if (!IS_LAST_ENTRY(s->first)) {
|
|
new_bh = ext4_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 {
|
|
u32 ref;
|
|
|
|
WARN_ON_ONCE(dquot_initialize_needed(inode));
|
|
|
|
/* The old block is released after updating
|
|
the inode. */
|
|
error = dquot_alloc_block(inode,
|
|
EXT4_C2B(EXT4_SB(sb), 1));
|
|
if (error)
|
|
goto cleanup;
|
|
BUFFER_TRACE(new_bh, "get_write_access");
|
|
error = ext4_journal_get_write_access(handle,
|
|
new_bh);
|
|
if (error)
|
|
goto cleanup_dquot;
|
|
lock_buffer(new_bh);
|
|
/*
|
|
* We have to be careful about races with
|
|
* freeing, rehashing or adding references to
|
|
* xattr block. Once we hold buffer lock xattr
|
|
* block's state is stable so we can check
|
|
* whether the block got freed / rehashed or
|
|
* not. Since we unhash mbcache entry under
|
|
* buffer lock when freeing / rehashing xattr
|
|
* block, checking whether entry is still
|
|
* hashed is reliable. Same rules hold for
|
|
* e_reusable handling.
|
|
*/
|
|
if (hlist_bl_unhashed(&ce->e_hash_list) ||
|
|
!ce->e_reusable) {
|
|
/*
|
|
* Undo everything and check mbcache
|
|
* again.
|
|
*/
|
|
unlock_buffer(new_bh);
|
|
dquot_free_block(inode,
|
|
EXT4_C2B(EXT4_SB(sb),
|
|
1));
|
|
brelse(new_bh);
|
|
mb_cache_entry_put(ext4_mb_cache, ce);
|
|
ce = NULL;
|
|
new_bh = NULL;
|
|
goto inserted;
|
|
}
|
|
ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
|
|
BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
|
|
if (ref >= EXT4_XATTR_REFCOUNT_MAX)
|
|
ce->e_reusable = 0;
|
|
ea_bdebug(new_bh, "reusing; refcount now=%d",
|
|
ref);
|
|
ext4_xattr_block_csum_set(inode, new_bh);
|
|
unlock_buffer(new_bh);
|
|
error = ext4_handle_dirty_metadata(handle,
|
|
inode,
|
|
new_bh);
|
|
if (error)
|
|
goto cleanup_dquot;
|
|
}
|
|
mb_cache_entry_touch(ext4_mb_cache, ce);
|
|
mb_cache_entry_put(ext4_mb_cache, 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 */
|
|
ext4_fsblk_t goal, block;
|
|
|
|
WARN_ON_ONCE(dquot_initialize_needed(inode));
|
|
|
|
goal = ext4_group_first_block_no(sb,
|
|
EXT4_I(inode)->i_block_group);
|
|
|
|
/* non-extent files can't have physical blocks past 2^32 */
|
|
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
|
|
goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
|
|
|
|
block = ext4_new_meta_blocks(handle, inode, goal, 0,
|
|
NULL, &error);
|
|
if (error)
|
|
goto cleanup;
|
|
|
|
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
|
|
BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
|
|
|
|
ea_idebug(inode, "creating block %llu",
|
|
(unsigned long long)block);
|
|
|
|
new_bh = sb_getblk(sb, block);
|
|
if (unlikely(!new_bh)) {
|
|
error = -ENOMEM;
|
|
getblk_failed:
|
|
ext4_free_blocks(handle, inode, NULL, block, 1,
|
|
EXT4_FREE_BLOCKS_METADATA);
|
|
goto cleanup;
|
|
}
|
|
lock_buffer(new_bh);
|
|
error = ext4_journal_get_create_access(handle, new_bh);
|
|
if (error) {
|
|
unlock_buffer(new_bh);
|
|
error = -EIO;
|
|
goto getblk_failed;
|
|
}
|
|
memcpy(new_bh->b_data, s->base, new_bh->b_size);
|
|
ext4_xattr_block_csum_set(inode, new_bh);
|
|
set_buffer_uptodate(new_bh);
|
|
unlock_buffer(new_bh);
|
|
ext4_xattr_cache_insert(ext4_mb_cache, new_bh);
|
|
error = ext4_handle_dirty_metadata(handle, inode,
|
|
new_bh);
|
|
if (error)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
/* Update the inode. */
|
|
EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
|
|
|
|
/* Drop the previous xattr block. */
|
|
if (bs->bh && bs->bh != new_bh)
|
|
ext4_xattr_release_block(handle, inode, bs->bh);
|
|
error = 0;
|
|
|
|
cleanup:
|
|
if (ce)
|
|
mb_cache_entry_put(ext4_mb_cache, ce);
|
|
brelse(new_bh);
|
|
if (!(bs->bh && s->base == bs->bh->b_data))
|
|
kfree(s->base);
|
|
|
|
return error;
|
|
|
|
cleanup_dquot:
|
|
dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
|
|
goto cleanup;
|
|
|
|
bad_block:
|
|
EXT4_ERROR_INODE(inode, "bad block %llu",
|
|
EXT4_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
|
|
#undef header
|
|
}
|
|
|
|
int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
|
|
struct ext4_xattr_ibody_find *is)
|
|
{
|
|
struct ext4_xattr_ibody_header *header;
|
|
struct ext4_inode *raw_inode;
|
|
int error;
|
|
|
|
if (EXT4_I(inode)->i_extra_isize == 0)
|
|
return 0;
|
|
raw_inode = ext4_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 + EXT4_SB(inode->i_sb)->s_inode_size;
|
|
if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
|
|
error = xattr_check_inode(inode, header, is->s.end);
|
|
if (error)
|
|
return error;
|
|
/* Find the named attribute. */
|
|
error = ext4_xattr_find_entry(&is->s.here, i->name_index,
|
|
i->name, 0);
|
|
if (error && error != -ENODATA)
|
|
return error;
|
|
is->s.not_found = error;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
|
|
struct ext4_xattr_info *i,
|
|
struct ext4_xattr_ibody_find *is)
|
|
{
|
|
struct ext4_xattr_ibody_header *header;
|
|
struct ext4_xattr_search *s = &is->s;
|
|
int error;
|
|
|
|
if (EXT4_I(inode)->i_extra_isize == 0)
|
|
return -ENOSPC;
|
|
error = ext4_xattr_set_entry(i, s);
|
|
if (error) {
|
|
if (error == -ENOSPC &&
|
|
ext4_has_inline_data(inode)) {
|
|
error = ext4_try_to_evict_inline_data(handle, inode,
|
|
EXT4_XATTR_LEN(strlen(i->name) +
|
|
EXT4_XATTR_SIZE(i->value_len)));
|
|
if (error)
|
|
return error;
|
|
error = ext4_xattr_ibody_find(inode, i, is);
|
|
if (error)
|
|
return error;
|
|
error = ext4_xattr_set_entry(i, s);
|
|
}
|
|
if (error)
|
|
return error;
|
|
}
|
|
header = IHDR(inode, ext4_raw_inode(&is->iloc));
|
|
if (!IS_LAST_ENTRY(s->first)) {
|
|
header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
|
|
ext4_set_inode_state(inode, EXT4_STATE_XATTR);
|
|
} else {
|
|
header->h_magic = cpu_to_le32(0);
|
|
ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_xattr_ibody_set(struct inode *inode,
|
|
struct ext4_xattr_info *i,
|
|
struct ext4_xattr_ibody_find *is)
|
|
{
|
|
struct ext4_xattr_ibody_header *header;
|
|
struct ext4_xattr_search *s = &is->s;
|
|
int error;
|
|
|
|
if (EXT4_I(inode)->i_extra_isize == 0)
|
|
return -ENOSPC;
|
|
error = ext4_xattr_set_entry(i, s);
|
|
if (error)
|
|
return error;
|
|
header = IHDR(inode, ext4_raw_inode(&is->iloc));
|
|
if (!IS_LAST_ENTRY(s->first)) {
|
|
header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
|
|
ext4_set_inode_state(inode, EXT4_STATE_XATTR);
|
|
} else {
|
|
header->h_magic = cpu_to_le32(0);
|
|
ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_xattr_value_same(struct ext4_xattr_search *s,
|
|
struct ext4_xattr_info *i)
|
|
{
|
|
void *value;
|
|
|
|
if (le32_to_cpu(s->here->e_value_size) != i->value_len)
|
|
return 0;
|
|
value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
|
|
return !memcmp(value, i->value, i->value_len);
|
|
}
|
|
|
|
/*
|
|
* ext4_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
|
|
ext4_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 ext4_xattr_info i = {
|
|
.name_index = name_index,
|
|
.name = name,
|
|
.value = value,
|
|
.value_len = value_len,
|
|
|
|
};
|
|
struct ext4_xattr_ibody_find is = {
|
|
.s = { .not_found = -ENODATA, },
|
|
};
|
|
struct ext4_xattr_block_find bs = {
|
|
.s = { .not_found = -ENODATA, },
|
|
};
|
|
int no_expand;
|
|
int error;
|
|
|
|
if (!name)
|
|
return -EINVAL;
|
|
if (strlen(name) > 255)
|
|
return -ERANGE;
|
|
|
|
ext4_write_lock_xattr(inode, &no_expand);
|
|
|
|
error = ext4_reserve_inode_write(handle, inode, &is.iloc);
|
|
if (error)
|
|
goto cleanup;
|
|
|
|
if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
|
|
struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
|
|
memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
|
|
ext4_clear_inode_state(inode, EXT4_STATE_NEW);
|
|
}
|
|
|
|
error = ext4_xattr_ibody_find(inode, &i, &is);
|
|
if (error)
|
|
goto cleanup;
|
|
if (is.s.not_found)
|
|
error = ext4_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 = ext4_xattr_ibody_set(inode, &i, &is);
|
|
else if (!bs.s.not_found)
|
|
error = ext4_xattr_block_set(handle, inode, &i, &bs);
|
|
} else {
|
|
error = 0;
|
|
/* Xattr value did not change? Save us some work and bail out */
|
|
if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
|
|
goto cleanup;
|
|
if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
|
|
goto cleanup;
|
|
|
|
error = ext4_xattr_ibody_set(inode, &i, &is);
|
|
if (!error && !bs.s.not_found) {
|
|
i.value = NULL;
|
|
error = ext4_xattr_block_set(handle, inode, &i, &bs);
|
|
} else if (error == -ENOSPC) {
|
|
if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
|
|
error = ext4_xattr_block_find(inode, &i, &bs);
|
|
if (error)
|
|
goto cleanup;
|
|
}
|
|
error = ext4_xattr_block_set(handle, inode, &i, &bs);
|
|
if (error)
|
|
goto cleanup;
|
|
if (!is.s.not_found) {
|
|
i.value = NULL;
|
|
error = ext4_xattr_ibody_set(inode, &i, &is);
|
|
}
|
|
}
|
|
}
|
|
if (!error) {
|
|
ext4_xattr_update_super_block(handle, inode->i_sb);
|
|
inode->i_ctime = current_time(inode);
|
|
if (!value)
|
|
no_expand = 0;
|
|
error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
|
|
/*
|
|
* The bh is consumed by ext4_mark_iloc_dirty, even with
|
|
* error != 0.
|
|
*/
|
|
is.iloc.bh = NULL;
|
|
if (IS_SYNC(inode))
|
|
ext4_handle_sync(handle);
|
|
}
|
|
|
|
cleanup:
|
|
brelse(is.iloc.bh);
|
|
brelse(bs.bh);
|
|
ext4_write_unlock_xattr(inode, &no_expand);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext4_xattr_set()
|
|
*
|
|
* Like ext4_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
|
|
ext4_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;
|
|
int credits = ext4_jbd2_credits_xattr(inode);
|
|
|
|
error = dquot_initialize(inode);
|
|
if (error)
|
|
return error;
|
|
retry:
|
|
handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
|
|
if (IS_ERR(handle)) {
|
|
error = PTR_ERR(handle);
|
|
} else {
|
|
int error2;
|
|
|
|
error = ext4_xattr_set_handle(handle, inode, name_index, name,
|
|
value, value_len, flags);
|
|
error2 = ext4_journal_stop(handle);
|
|
if (error == -ENOSPC &&
|
|
ext4_should_retry_alloc(inode->i_sb, &retries))
|
|
goto retry;
|
|
if (error == 0)
|
|
error = error2;
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Shift the EA entries in the inode to create space for the increased
|
|
* i_extra_isize.
|
|
*/
|
|
static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
|
|
int value_offs_shift, void *to,
|
|
void *from, size_t n)
|
|
{
|
|
struct ext4_xattr_entry *last = entry;
|
|
int new_offs;
|
|
|
|
/* We always shift xattr headers further thus offsets get lower */
|
|
BUG_ON(value_offs_shift > 0);
|
|
|
|
/* Adjust the value offsets of the entries */
|
|
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
|
|
if (last->e_value_size) {
|
|
new_offs = le16_to_cpu(last->e_value_offs) +
|
|
value_offs_shift;
|
|
last->e_value_offs = cpu_to_le16(new_offs);
|
|
}
|
|
}
|
|
/* Shift the entries by n bytes */
|
|
memmove(to, from, n);
|
|
}
|
|
|
|
/*
|
|
* Move xattr pointed to by 'entry' from inode into external xattr block
|
|
*/
|
|
static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
|
|
struct ext4_inode *raw_inode,
|
|
struct ext4_xattr_entry *entry)
|
|
{
|
|
struct ext4_xattr_ibody_find *is = NULL;
|
|
struct ext4_xattr_block_find *bs = NULL;
|
|
char *buffer = NULL, *b_entry_name = NULL;
|
|
size_t value_offs, value_size;
|
|
struct ext4_xattr_info i = {
|
|
.value = NULL,
|
|
.value_len = 0,
|
|
.name_index = entry->e_name_index,
|
|
};
|
|
struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
|
|
int error;
|
|
|
|
value_offs = le16_to_cpu(entry->e_value_offs);
|
|
value_size = le32_to_cpu(entry->e_value_size);
|
|
|
|
is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
|
|
bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
|
|
buffer = kmalloc(value_size, GFP_NOFS);
|
|
b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
|
|
if (!is || !bs || !buffer || !b_entry_name) {
|
|
error = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
is->s.not_found = -ENODATA;
|
|
bs->s.not_found = -ENODATA;
|
|
is->iloc.bh = NULL;
|
|
bs->bh = NULL;
|
|
|
|
/* Save the entry name and the entry value */
|
|
memcpy(buffer, (void *)IFIRST(header) + value_offs, value_size);
|
|
memcpy(b_entry_name, entry->e_name, entry->e_name_len);
|
|
b_entry_name[entry->e_name_len] = '\0';
|
|
i.name = b_entry_name;
|
|
|
|
error = ext4_get_inode_loc(inode, &is->iloc);
|
|
if (error)
|
|
goto out;
|
|
|
|
error = ext4_xattr_ibody_find(inode, &i, is);
|
|
if (error)
|
|
goto out;
|
|
|
|
/* Remove the chosen entry from the inode */
|
|
error = ext4_xattr_ibody_set(inode, &i, is);
|
|
if (error)
|
|
goto out;
|
|
|
|
i.name = b_entry_name;
|
|
i.value = buffer;
|
|
i.value_len = value_size;
|
|
error = ext4_xattr_block_find(inode, &i, bs);
|
|
if (error)
|
|
goto out;
|
|
|
|
/* Add entry which was removed from the inode into the block */
|
|
error = ext4_xattr_block_set(handle, inode, &i, bs);
|
|
if (error)
|
|
goto out;
|
|
error = 0;
|
|
out:
|
|
kfree(b_entry_name);
|
|
kfree(buffer);
|
|
if (is)
|
|
brelse(is->iloc.bh);
|
|
kfree(is);
|
|
kfree(bs);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
|
|
struct ext4_inode *raw_inode,
|
|
int isize_diff, size_t ifree,
|
|
size_t bfree, int *total_ino)
|
|
{
|
|
struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
|
|
struct ext4_xattr_entry *small_entry;
|
|
struct ext4_xattr_entry *entry;
|
|
struct ext4_xattr_entry *last;
|
|
unsigned int entry_size; /* EA entry size */
|
|
unsigned int total_size; /* EA entry size + value size */
|
|
unsigned int min_total_size;
|
|
int error;
|
|
|
|
while (isize_diff > ifree) {
|
|
entry = NULL;
|
|
small_entry = NULL;
|
|
min_total_size = ~0U;
|
|
last = IFIRST(header);
|
|
/* Find the entry best suited to be pushed into EA block */
|
|
for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
|
|
total_size =
|
|
EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
|
|
EXT4_XATTR_LEN(last->e_name_len);
|
|
if (total_size <= bfree &&
|
|
total_size < min_total_size) {
|
|
if (total_size + ifree < isize_diff) {
|
|
small_entry = last;
|
|
} else {
|
|
entry = last;
|
|
min_total_size = total_size;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (entry == NULL) {
|
|
if (small_entry == NULL)
|
|
return -ENOSPC;
|
|
entry = small_entry;
|
|
}
|
|
|
|
entry_size = EXT4_XATTR_LEN(entry->e_name_len);
|
|
total_size = entry_size +
|
|
EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size));
|
|
error = ext4_xattr_move_to_block(handle, inode, raw_inode,
|
|
entry);
|
|
if (error)
|
|
return error;
|
|
|
|
*total_ino -= entry_size;
|
|
ifree += total_size;
|
|
bfree -= total_size;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Expand an inode by new_extra_isize bytes when EAs are present.
|
|
* Returns 0 on success or negative error number on failure.
|
|
*/
|
|
int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
|
|
struct ext4_inode *raw_inode, handle_t *handle)
|
|
{
|
|
struct ext4_xattr_ibody_header *header;
|
|
struct buffer_head *bh = NULL;
|
|
size_t min_offs;
|
|
size_t ifree, bfree;
|
|
int total_ino;
|
|
void *base, *end;
|
|
int error = 0, tried_min_extra_isize = 0;
|
|
int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
|
|
int isize_diff; /* How much do we need to grow i_extra_isize */
|
|
int no_expand;
|
|
|
|
if (ext4_write_trylock_xattr(inode, &no_expand) == 0)
|
|
return 0;
|
|
|
|
retry:
|
|
isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
|
|
if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
|
|
goto out;
|
|
|
|
header = IHDR(inode, raw_inode);
|
|
|
|
/*
|
|
* Check if enough free space is available in the inode to shift the
|
|
* entries ahead by new_extra_isize.
|
|
*/
|
|
|
|
base = IFIRST(header);
|
|
end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
|
|
min_offs = end - base;
|
|
total_ino = sizeof(struct ext4_xattr_ibody_header);
|
|
|
|
error = xattr_check_inode(inode, header, end);
|
|
if (error)
|
|
goto cleanup;
|
|
|
|
ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
|
|
if (ifree >= isize_diff)
|
|
goto shift;
|
|
|
|
/*
|
|
* Enough free space isn't available in the inode, check if
|
|
* EA block can hold new_extra_isize bytes.
|
|
*/
|
|
if (EXT4_I(inode)->i_file_acl) {
|
|
bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
|
|
error = -EIO;
|
|
if (!bh)
|
|
goto cleanup;
|
|
if (ext4_xattr_check_block(inode, bh)) {
|
|
EXT4_ERROR_INODE(inode, "bad block %llu",
|
|
EXT4_I(inode)->i_file_acl);
|
|
error = -EFSCORRUPTED;
|
|
goto cleanup;
|
|
}
|
|
base = BHDR(bh);
|
|
end = bh->b_data + bh->b_size;
|
|
min_offs = end - base;
|
|
bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
|
|
NULL);
|
|
if (bfree + ifree < isize_diff) {
|
|
if (!tried_min_extra_isize && s_min_extra_isize) {
|
|
tried_min_extra_isize++;
|
|
new_extra_isize = s_min_extra_isize;
|
|
brelse(bh);
|
|
goto retry;
|
|
}
|
|
error = -ENOSPC;
|
|
goto cleanup;
|
|
}
|
|
} else {
|
|
bfree = inode->i_sb->s_blocksize;
|
|
}
|
|
|
|
error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
|
|
isize_diff, ifree, bfree,
|
|
&total_ino);
|
|
if (error) {
|
|
if (error == -ENOSPC && !tried_min_extra_isize &&
|
|
s_min_extra_isize) {
|
|
tried_min_extra_isize++;
|
|
new_extra_isize = s_min_extra_isize;
|
|
brelse(bh);
|
|
goto retry;
|
|
}
|
|
goto cleanup;
|
|
}
|
|
shift:
|
|
/* Adjust the offsets and shift the remaining entries ahead */
|
|
ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
|
|
- new_extra_isize, (void *)raw_inode +
|
|
EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
|
|
(void *)header, total_ino);
|
|
EXT4_I(inode)->i_extra_isize = new_extra_isize;
|
|
brelse(bh);
|
|
out:
|
|
ext4_write_unlock_xattr(inode, &no_expand);
|
|
return 0;
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
/*
|
|
* Inode size expansion failed; don't try again
|
|
*/
|
|
no_expand = 1;
|
|
ext4_write_unlock_xattr(inode, &no_expand);
|
|
return error;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* ext4_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
|
|
ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
|
|
{
|
|
struct buffer_head *bh = NULL;
|
|
|
|
if (!EXT4_I(inode)->i_file_acl)
|
|
goto cleanup;
|
|
bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
|
|
if (!bh) {
|
|
EXT4_ERROR_INODE(inode, "block %llu read error",
|
|
EXT4_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
|
|
BHDR(bh)->h_blocks != cpu_to_le32(1)) {
|
|
EXT4_ERROR_INODE(inode, "bad block %llu",
|
|
EXT4_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
ext4_xattr_release_block(handle, inode, bh);
|
|
EXT4_I(inode)->i_file_acl = 0;
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
}
|
|
|
|
/*
|
|
* ext4_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
|
|
ext4_xattr_cache_insert(struct mb_cache *ext4_mb_cache, struct buffer_head *bh)
|
|
{
|
|
struct ext4_xattr_header *header = BHDR(bh);
|
|
__u32 hash = le32_to_cpu(header->h_hash);
|
|
int reusable = le32_to_cpu(header->h_refcount) <
|
|
EXT4_XATTR_REFCOUNT_MAX;
|
|
int error;
|
|
|
|
error = mb_cache_entry_create(ext4_mb_cache, GFP_NOFS, hash,
|
|
bh->b_blocknr, reusable);
|
|
if (error) {
|
|
if (error == -EBUSY)
|
|
ea_bdebug(bh, "already in cache");
|
|
} else
|
|
ea_bdebug(bh, "inserting [%x]", (int)hash);
|
|
}
|
|
|
|
/*
|
|
* ext4_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
|
|
ext4_xattr_cmp(struct ext4_xattr_header *header1,
|
|
struct ext4_xattr_header *header2)
|
|
{
|
|
struct ext4_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 -EFSCORRUPTED;
|
|
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 = EXT4_XATTR_NEXT(entry1);
|
|
entry2 = EXT4_XATTR_NEXT(entry2);
|
|
}
|
|
if (!IS_LAST_ENTRY(entry2))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ext4_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 *
|
|
ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
|
|
struct mb_cache_entry **pce)
|
|
{
|
|
__u32 hash = le32_to_cpu(header->h_hash);
|
|
struct mb_cache_entry *ce;
|
|
struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode);
|
|
|
|
if (!header->h_hash)
|
|
return NULL; /* never share */
|
|
ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
|
|
ce = mb_cache_entry_find_first(ext4_mb_cache, hash);
|
|
while (ce) {
|
|
struct buffer_head *bh;
|
|
|
|
bh = sb_bread(inode->i_sb, ce->e_block);
|
|
if (!bh) {
|
|
EXT4_ERROR_INODE(inode, "block %lu read error",
|
|
(unsigned long) ce->e_block);
|
|
} else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
|
|
*pce = ce;
|
|
return bh;
|
|
}
|
|
brelse(bh);
|
|
ce = mb_cache_entry_find_next(ext4_mb_cache, ce);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#define NAME_HASH_SHIFT 5
|
|
#define VALUE_HASH_SHIFT 16
|
|
|
|
/*
|
|
* ext4_xattr_hash_entry()
|
|
*
|
|
* Compute the hash of an extended attribute.
|
|
*/
|
|
static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
|
|
struct ext4_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_size != 0) {
|
|
__le32 *value = (__le32 *)((char *)header +
|
|
le16_to_cpu(entry->e_value_offs));
|
|
for (n = (le32_to_cpu(entry->e_value_size) +
|
|
EXT4_XATTR_ROUND) >> EXT4_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
|
|
|
|
/*
|
|
* ext4_xattr_rehash()
|
|
*
|
|
* Re-compute the extended attribute hash value after an entry has changed.
|
|
*/
|
|
static void ext4_xattr_rehash(struct ext4_xattr_header *header,
|
|
struct ext4_xattr_entry *entry)
|
|
{
|
|
struct ext4_xattr_entry *here;
|
|
__u32 hash = 0;
|
|
|
|
ext4_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 = EXT4_XATTR_NEXT(here);
|
|
}
|
|
header->h_hash = cpu_to_le32(hash);
|
|
}
|
|
|
|
#undef BLOCK_HASH_SHIFT
|
|
|
|
#define HASH_BUCKET_BITS 10
|
|
|
|
struct mb_cache *
|
|
ext4_xattr_create_cache(void)
|
|
{
|
|
return mb_cache_create(HASH_BUCKET_BITS);
|
|
}
|
|
|
|
void ext4_xattr_destroy_cache(struct mb_cache *cache)
|
|
{
|
|
if (cache)
|
|
mb_cache_destroy(cache);
|
|
}
|
|
|