11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/fs/ext2/xattr.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de> 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Fix by Harrison Xing <harrison@mountainviewdata.com>. 71da177e4SLinus Torvalds * Extended attributes for symlinks and special files added per 81da177e4SLinus Torvalds * suggestion of Luka Renko <luka.renko@hermes.si>. 91da177e4SLinus Torvalds * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 101da177e4SLinus Torvalds * Red Hat Inc. 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds */ 131da177e4SLinus Torvalds 141da177e4SLinus Torvalds /* 151da177e4SLinus Torvalds * Extended attributes are stored on disk blocks allocated outside of 161da177e4SLinus Torvalds * any inode. The i_file_acl field is then made to point to this allocated 171da177e4SLinus Torvalds * block. If all extended attributes of an inode are identical, these 181da177e4SLinus Torvalds * inodes may share the same extended attribute block. Such situations 191da177e4SLinus Torvalds * are automatically detected by keeping a cache of recent attribute block 201da177e4SLinus Torvalds * numbers and hashes over the block's contents in memory. 211da177e4SLinus Torvalds * 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds * Extended attribute block layout: 241da177e4SLinus Torvalds * 251da177e4SLinus Torvalds * +------------------+ 261da177e4SLinus Torvalds * | header | 271da177e4SLinus Torvalds * | entry 1 | | 281da177e4SLinus Torvalds * | entry 2 | | growing downwards 291da177e4SLinus Torvalds * | entry 3 | v 301da177e4SLinus Torvalds * | four null bytes | 311da177e4SLinus Torvalds * | . . . | 321da177e4SLinus Torvalds * | value 1 | ^ 331da177e4SLinus Torvalds * | value 3 | | growing upwards 341da177e4SLinus Torvalds * | value 2 | | 351da177e4SLinus Torvalds * +------------------+ 361da177e4SLinus Torvalds * 371da177e4SLinus Torvalds * The block header is followed by multiple entry descriptors. These entry 3825985edcSLucas De Marchi * descriptors are variable in size, and aligned to EXT2_XATTR_PAD 391da177e4SLinus Torvalds * byte boundaries. The entry descriptors are sorted by attribute name, 401da177e4SLinus Torvalds * so that two extended attribute blocks can be compared efficiently. 411da177e4SLinus Torvalds * 421da177e4SLinus Torvalds * Attribute values are aligned to the end of the block, stored in 431da177e4SLinus Torvalds * no specific order. They are also padded to EXT2_XATTR_PAD byte 441da177e4SLinus Torvalds * boundaries. No additional gaps are left between them. 451da177e4SLinus Torvalds * 461da177e4SLinus Torvalds * Locking strategy 471da177e4SLinus Torvalds * ---------------- 481da177e4SLinus Torvalds * EXT2_I(inode)->i_file_acl is protected by EXT2_I(inode)->xattr_sem. 491da177e4SLinus Torvalds * EA blocks are only changed if they are exclusive to an inode, so 501da177e4SLinus Torvalds * holding xattr_sem also means that nothing but the EA block's reference 511da177e4SLinus Torvalds * count will change. Multiple writers to an EA block are synchronized 521da177e4SLinus Torvalds * by the bh lock. No more than a single bh lock is held at any time 531da177e4SLinus Torvalds * to avoid deadlocks. 541da177e4SLinus Torvalds */ 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds #include <linux/buffer_head.h> 571da177e4SLinus Torvalds #include <linux/module.h> 581da177e4SLinus Torvalds #include <linux/init.h> 591da177e4SLinus Torvalds #include <linux/slab.h> 601da177e4SLinus Torvalds #include <linux/mbcache.h> 611da177e4SLinus Torvalds #include <linux/quotaops.h> 621da177e4SLinus Torvalds #include <linux/rwsem.h> 63431547b3SChristoph Hellwig #include <linux/security.h> 641da177e4SLinus Torvalds #include "ext2.h" 651da177e4SLinus Torvalds #include "xattr.h" 661da177e4SLinus Torvalds #include "acl.h" 671da177e4SLinus Torvalds 681da177e4SLinus Torvalds #define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data)) 691da177e4SLinus Torvalds #define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr)) 701da177e4SLinus Torvalds #define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1) 711da177e4SLinus Torvalds #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds #ifdef EXT2_XATTR_DEBUG 741da177e4SLinus Torvalds # define ea_idebug(inode, f...) do { \ 751da177e4SLinus Torvalds printk(KERN_DEBUG "inode %s:%ld: ", \ 761da177e4SLinus Torvalds inode->i_sb->s_id, inode->i_ino); \ 771da177e4SLinus Torvalds printk(f); \ 781da177e4SLinus Torvalds printk("\n"); \ 791da177e4SLinus Torvalds } while (0) 801da177e4SLinus Torvalds # define ea_bdebug(bh, f...) do { \ 811da177e4SLinus Torvalds char b[BDEVNAME_SIZE]; \ 821da177e4SLinus Torvalds printk(KERN_DEBUG "block %s:%lu: ", \ 831da177e4SLinus Torvalds bdevname(bh->b_bdev, b), \ 841da177e4SLinus Torvalds (unsigned long) bh->b_blocknr); \ 851da177e4SLinus Torvalds printk(f); \ 861da177e4SLinus Torvalds printk("\n"); \ 871da177e4SLinus Torvalds } while (0) 881da177e4SLinus Torvalds #else 891da177e4SLinus Torvalds # define ea_idebug(f...) 901da177e4SLinus Torvalds # define ea_bdebug(f...) 911da177e4SLinus Torvalds #endif 921da177e4SLinus Torvalds 931da177e4SLinus Torvalds static int ext2_xattr_set2(struct inode *, struct buffer_head *, 941da177e4SLinus Torvalds struct ext2_xattr_header *); 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds static int ext2_xattr_cache_insert(struct buffer_head *); 971da177e4SLinus Torvalds static struct buffer_head *ext2_xattr_cache_find(struct inode *, 981da177e4SLinus Torvalds struct ext2_xattr_header *); 991da177e4SLinus Torvalds static void ext2_xattr_rehash(struct ext2_xattr_header *, 1001da177e4SLinus Torvalds struct ext2_xattr_entry *); 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds static struct mb_cache *ext2_xattr_cache; 1031da177e4SLinus Torvalds 104749c72efSStephen Hemminger static const struct xattr_handler *ext2_xattr_handler_map[] = { 1051da177e4SLinus Torvalds [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler, 1061da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_POSIX_ACL 1071da177e4SLinus Torvalds [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext2_xattr_acl_access_handler, 1081da177e4SLinus Torvalds [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext2_xattr_acl_default_handler, 1091da177e4SLinus Torvalds #endif 1101da177e4SLinus Torvalds [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler, 1111da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_SECURITY 1121da177e4SLinus Torvalds [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler, 1131da177e4SLinus Torvalds #endif 1141da177e4SLinus Torvalds }; 1151da177e4SLinus Torvalds 116749c72efSStephen Hemminger const struct xattr_handler *ext2_xattr_handlers[] = { 1171da177e4SLinus Torvalds &ext2_xattr_user_handler, 1181da177e4SLinus Torvalds &ext2_xattr_trusted_handler, 1191da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_POSIX_ACL 1201da177e4SLinus Torvalds &ext2_xattr_acl_access_handler, 1211da177e4SLinus Torvalds &ext2_xattr_acl_default_handler, 1221da177e4SLinus Torvalds #endif 1231da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_SECURITY 1241da177e4SLinus Torvalds &ext2_xattr_security_handler, 1251da177e4SLinus Torvalds #endif 1261da177e4SLinus Torvalds NULL 1271da177e4SLinus Torvalds }; 1281da177e4SLinus Torvalds 129749c72efSStephen Hemminger static inline const struct xattr_handler * 1301da177e4SLinus Torvalds ext2_xattr_handler(int name_index) 1311da177e4SLinus Torvalds { 132749c72efSStephen Hemminger const struct xattr_handler *handler = NULL; 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map)) 1351da177e4SLinus Torvalds handler = ext2_xattr_handler_map[name_index]; 1361da177e4SLinus Torvalds return handler; 1371da177e4SLinus Torvalds } 1381da177e4SLinus Torvalds 1391da177e4SLinus Torvalds /* 1401da177e4SLinus Torvalds * ext2_xattr_get() 1411da177e4SLinus Torvalds * 1421da177e4SLinus Torvalds * Copy an extended attribute into the buffer 1431da177e4SLinus Torvalds * provided, or compute the buffer size required. 1441da177e4SLinus Torvalds * Buffer is NULL to compute the size of the buffer required. 1451da177e4SLinus Torvalds * 1461da177e4SLinus Torvalds * Returns a negative error number on failure, or the number of bytes 1471da177e4SLinus Torvalds * used / required on success. 1481da177e4SLinus Torvalds */ 1491da177e4SLinus Torvalds int 1501da177e4SLinus Torvalds ext2_xattr_get(struct inode *inode, int name_index, const char *name, 1511da177e4SLinus Torvalds void *buffer, size_t buffer_size) 1521da177e4SLinus Torvalds { 1531da177e4SLinus Torvalds struct buffer_head *bh = NULL; 1541da177e4SLinus Torvalds struct ext2_xattr_entry *entry; 1551da177e4SLinus Torvalds size_t name_len, size; 1561da177e4SLinus Torvalds char *end; 1571da177e4SLinus Torvalds int error; 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 1601da177e4SLinus Torvalds name_index, name, buffer, (long)buffer_size); 1611da177e4SLinus Torvalds 1621da177e4SLinus Torvalds if (name == NULL) 1631da177e4SLinus Torvalds return -EINVAL; 1641da177e4SLinus Torvalds down_read(&EXT2_I(inode)->xattr_sem); 1651da177e4SLinus Torvalds error = -ENODATA; 1661da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 1671da177e4SLinus Torvalds goto cleanup; 1681da177e4SLinus Torvalds ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl); 1691da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 1701da177e4SLinus Torvalds error = -EIO; 1711da177e4SLinus Torvalds if (!bh) 1721da177e4SLinus Torvalds goto cleanup; 1731da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 1741da177e4SLinus Torvalds atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); 1751da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 1761da177e4SLinus Torvalds if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || 1771da177e4SLinus Torvalds HDR(bh)->h_blocks != cpu_to_le32(1)) { 1781da177e4SLinus Torvalds bad_block: ext2_error(inode->i_sb, "ext2_xattr_get", 1791da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 1801da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 1811da177e4SLinus Torvalds error = -EIO; 1821da177e4SLinus Torvalds goto cleanup; 1831da177e4SLinus Torvalds } 1841da177e4SLinus Torvalds /* find named attribute */ 1851da177e4SLinus Torvalds name_len = strlen(name); 1861da177e4SLinus Torvalds 1871da177e4SLinus Torvalds error = -ERANGE; 1881da177e4SLinus Torvalds if (name_len > 255) 1891da177e4SLinus Torvalds goto cleanup; 1901da177e4SLinus Torvalds entry = FIRST_ENTRY(bh); 1911da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry)) { 1921da177e4SLinus Torvalds struct ext2_xattr_entry *next = 1931da177e4SLinus Torvalds EXT2_XATTR_NEXT(entry); 1941da177e4SLinus Torvalds if ((char *)next >= end) 1951da177e4SLinus Torvalds goto bad_block; 1961da177e4SLinus Torvalds if (name_index == entry->e_name_index && 1971da177e4SLinus Torvalds name_len == entry->e_name_len && 1981da177e4SLinus Torvalds memcmp(name, entry->e_name, name_len) == 0) 1991da177e4SLinus Torvalds goto found; 2001da177e4SLinus Torvalds entry = next; 2011da177e4SLinus Torvalds } 2021da177e4SLinus Torvalds if (ext2_xattr_cache_insert(bh)) 2031da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2041da177e4SLinus Torvalds error = -ENODATA; 2051da177e4SLinus Torvalds goto cleanup; 2061da177e4SLinus Torvalds found: 2071da177e4SLinus Torvalds /* check the buffer size */ 2081da177e4SLinus Torvalds if (entry->e_value_block != 0) 2091da177e4SLinus Torvalds goto bad_block; 2101da177e4SLinus Torvalds size = le32_to_cpu(entry->e_value_size); 2111da177e4SLinus Torvalds if (size > inode->i_sb->s_blocksize || 2121da177e4SLinus Torvalds le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize) 2131da177e4SLinus Torvalds goto bad_block; 2141da177e4SLinus Torvalds 2151da177e4SLinus Torvalds if (ext2_xattr_cache_insert(bh)) 2161da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2171da177e4SLinus Torvalds if (buffer) { 2181da177e4SLinus Torvalds error = -ERANGE; 2191da177e4SLinus Torvalds if (size > buffer_size) 2201da177e4SLinus Torvalds goto cleanup; 2211da177e4SLinus Torvalds /* return value of attribute */ 2221da177e4SLinus Torvalds memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), 2231da177e4SLinus Torvalds size); 2241da177e4SLinus Torvalds } 2251da177e4SLinus Torvalds error = size; 2261da177e4SLinus Torvalds 2271da177e4SLinus Torvalds cleanup: 2281da177e4SLinus Torvalds brelse(bh); 2291da177e4SLinus Torvalds up_read(&EXT2_I(inode)->xattr_sem); 2301da177e4SLinus Torvalds 2311da177e4SLinus Torvalds return error; 2321da177e4SLinus Torvalds } 2331da177e4SLinus Torvalds 2341da177e4SLinus Torvalds /* 2351da177e4SLinus Torvalds * ext2_xattr_list() 2361da177e4SLinus Torvalds * 2371da177e4SLinus Torvalds * Copy a list of attribute names into the buffer 2381da177e4SLinus Torvalds * provided, or compute the buffer size required. 2391da177e4SLinus Torvalds * Buffer is NULL to compute the size of the buffer required. 2401da177e4SLinus Torvalds * 2411da177e4SLinus Torvalds * Returns a negative error number on failure, or the number of bytes 2421da177e4SLinus Torvalds * used / required on success. 2431da177e4SLinus Torvalds */ 2441da177e4SLinus Torvalds static int 245431547b3SChristoph Hellwig ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) 2461da177e4SLinus Torvalds { 247431547b3SChristoph Hellwig struct inode *inode = dentry->d_inode; 2481da177e4SLinus Torvalds struct buffer_head *bh = NULL; 2491da177e4SLinus Torvalds struct ext2_xattr_entry *entry; 2501da177e4SLinus Torvalds char *end; 2511da177e4SLinus Torvalds size_t rest = buffer_size; 2521da177e4SLinus Torvalds int error; 2531da177e4SLinus Torvalds 2541da177e4SLinus Torvalds ea_idebug(inode, "buffer=%p, buffer_size=%ld", 2551da177e4SLinus Torvalds buffer, (long)buffer_size); 2561da177e4SLinus Torvalds 2571da177e4SLinus Torvalds down_read(&EXT2_I(inode)->xattr_sem); 2581da177e4SLinus Torvalds error = 0; 2591da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 2601da177e4SLinus Torvalds goto cleanup; 2611da177e4SLinus Torvalds ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl); 2621da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 2631da177e4SLinus Torvalds error = -EIO; 2641da177e4SLinus Torvalds if (!bh) 2651da177e4SLinus Torvalds goto cleanup; 2661da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 2671da177e4SLinus Torvalds atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); 2681da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 2691da177e4SLinus Torvalds if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || 2701da177e4SLinus Torvalds HDR(bh)->h_blocks != cpu_to_le32(1)) { 2711da177e4SLinus Torvalds bad_block: ext2_error(inode->i_sb, "ext2_xattr_list", 2721da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 2731da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 2741da177e4SLinus Torvalds error = -EIO; 2751da177e4SLinus Torvalds goto cleanup; 2761da177e4SLinus Torvalds } 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds /* check the on-disk data structure */ 2791da177e4SLinus Torvalds entry = FIRST_ENTRY(bh); 2801da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry)) { 2811da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry); 2821da177e4SLinus Torvalds 2831da177e4SLinus Torvalds if ((char *)next >= end) 2841da177e4SLinus Torvalds goto bad_block; 2851da177e4SLinus Torvalds entry = next; 2861da177e4SLinus Torvalds } 2871da177e4SLinus Torvalds if (ext2_xattr_cache_insert(bh)) 2881da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2891da177e4SLinus Torvalds 2901da177e4SLinus Torvalds /* list the attribute names */ 2911da177e4SLinus Torvalds for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry); 2921da177e4SLinus Torvalds entry = EXT2_XATTR_NEXT(entry)) { 293749c72efSStephen Hemminger const struct xattr_handler *handler = 2941da177e4SLinus Torvalds ext2_xattr_handler(entry->e_name_index); 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds if (handler) { 297431547b3SChristoph Hellwig size_t size = handler->list(dentry, buffer, rest, 2981da177e4SLinus Torvalds entry->e_name, 299431547b3SChristoph Hellwig entry->e_name_len, 300431547b3SChristoph Hellwig handler->flags); 3011da177e4SLinus Torvalds if (buffer) { 3021da177e4SLinus Torvalds if (size > rest) { 3031da177e4SLinus Torvalds error = -ERANGE; 3041da177e4SLinus Torvalds goto cleanup; 3051da177e4SLinus Torvalds } 3061da177e4SLinus Torvalds buffer += size; 3071da177e4SLinus Torvalds } 3081da177e4SLinus Torvalds rest -= size; 3091da177e4SLinus Torvalds } 3101da177e4SLinus Torvalds } 3111da177e4SLinus Torvalds error = buffer_size - rest; /* total size */ 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds cleanup: 3141da177e4SLinus Torvalds brelse(bh); 3151da177e4SLinus Torvalds up_read(&EXT2_I(inode)->xattr_sem); 3161da177e4SLinus Torvalds 3171da177e4SLinus Torvalds return error; 3181da177e4SLinus Torvalds } 3191da177e4SLinus Torvalds 3201da177e4SLinus Torvalds /* 3211da177e4SLinus Torvalds * Inode operation listxattr() 3221da177e4SLinus Torvalds * 3231b1dcc1bSJes Sorensen * dentry->d_inode->i_mutex: don't care 3241da177e4SLinus Torvalds */ 3251da177e4SLinus Torvalds ssize_t 3261da177e4SLinus Torvalds ext2_listxattr(struct dentry *dentry, char *buffer, size_t size) 3271da177e4SLinus Torvalds { 328431547b3SChristoph Hellwig return ext2_xattr_list(dentry, buffer, size); 3291da177e4SLinus Torvalds } 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds /* 3321da177e4SLinus Torvalds * If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is 3331da177e4SLinus Torvalds * not set, set it. 3341da177e4SLinus Torvalds */ 3351da177e4SLinus Torvalds static void ext2_xattr_update_super_block(struct super_block *sb) 3361da177e4SLinus Torvalds { 3371da177e4SLinus Torvalds if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR)) 3381da177e4SLinus Torvalds return; 3391da177e4SLinus Torvalds 340c15271f4SJan Blunck spin_lock(&EXT2_SB(sb)->s_lock); 341ed2908f3SAndreas Gruenbacher EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR); 342c15271f4SJan Blunck spin_unlock(&EXT2_SB(sb)->s_lock); 3431da177e4SLinus Torvalds sb->s_dirt = 1; 3441da177e4SLinus Torvalds mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 3451da177e4SLinus Torvalds } 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds /* 3481da177e4SLinus Torvalds * ext2_xattr_set() 3491da177e4SLinus Torvalds * 3506e9510b0SWang Sheng-Hui * Create, replace or remove an extended attribute for this inode. Value 3511da177e4SLinus Torvalds * is NULL to remove an existing extended attribute, and non-NULL to 3521da177e4SLinus Torvalds * either replace an existing extended attribute, or create a new extended 3531da177e4SLinus Torvalds * attribute. The flags XATTR_REPLACE and XATTR_CREATE 3541da177e4SLinus Torvalds * specify that an extended attribute must exist and must not exist 3551da177e4SLinus Torvalds * previous to the call, respectively. 3561da177e4SLinus Torvalds * 3571da177e4SLinus Torvalds * Returns 0, or a negative error number on failure. 3581da177e4SLinus Torvalds */ 3591da177e4SLinus Torvalds int 3601da177e4SLinus Torvalds ext2_xattr_set(struct inode *inode, int name_index, const char *name, 3611da177e4SLinus Torvalds const void *value, size_t value_len, int flags) 3621da177e4SLinus Torvalds { 3631da177e4SLinus Torvalds struct super_block *sb = inode->i_sb; 3641da177e4SLinus Torvalds struct buffer_head *bh = NULL; 3651da177e4SLinus Torvalds struct ext2_xattr_header *header = NULL; 3661da177e4SLinus Torvalds struct ext2_xattr_entry *here, *last; 3671da177e4SLinus Torvalds size_t name_len, free, min_offs = sb->s_blocksize; 3681da177e4SLinus Torvalds int not_found = 1, error; 3691da177e4SLinus Torvalds char *end; 3701da177e4SLinus Torvalds 3711da177e4SLinus Torvalds /* 3721da177e4SLinus Torvalds * header -- Points either into bh, or to a temporarily 3731da177e4SLinus Torvalds * allocated buffer. 3741da177e4SLinus Torvalds * here -- The named entry found, or the place for inserting, within 3751da177e4SLinus Torvalds * the block pointed to by header. 3761da177e4SLinus Torvalds * last -- Points right after the last named entry within the block 3771da177e4SLinus Torvalds * pointed to by header. 3781da177e4SLinus Torvalds * min_offs -- The offset of the first value (values are aligned 3791da177e4SLinus Torvalds * towards the end of the block). 3801da177e4SLinus Torvalds * end -- Points right after the block pointed to by header. 3811da177e4SLinus Torvalds */ 3821da177e4SLinus Torvalds 3831da177e4SLinus Torvalds ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 3841da177e4SLinus Torvalds name_index, name, value, (long)value_len); 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds if (value == NULL) 3871da177e4SLinus Torvalds value_len = 0; 3881da177e4SLinus Torvalds if (name == NULL) 3891da177e4SLinus Torvalds return -EINVAL; 3901da177e4SLinus Torvalds name_len = strlen(name); 3911da177e4SLinus Torvalds if (name_len > 255 || value_len > sb->s_blocksize) 3921da177e4SLinus Torvalds return -ERANGE; 3931da177e4SLinus Torvalds down_write(&EXT2_I(inode)->xattr_sem); 3941da177e4SLinus Torvalds if (EXT2_I(inode)->i_file_acl) { 3951da177e4SLinus Torvalds /* The inode already has an extended attribute block. */ 3961da177e4SLinus Torvalds bh = sb_bread(sb, EXT2_I(inode)->i_file_acl); 3971da177e4SLinus Torvalds error = -EIO; 3981da177e4SLinus Torvalds if (!bh) 3991da177e4SLinus Torvalds goto cleanup; 4001da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 4011da177e4SLinus Torvalds atomic_read(&(bh->b_count)), 4021da177e4SLinus Torvalds le32_to_cpu(HDR(bh)->h_refcount)); 4031da177e4SLinus Torvalds header = HDR(bh); 4041da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 4051da177e4SLinus Torvalds if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || 4061da177e4SLinus Torvalds header->h_blocks != cpu_to_le32(1)) { 4071da177e4SLinus Torvalds bad_block: ext2_error(sb, "ext2_xattr_set", 4081da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 4091da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 4101da177e4SLinus Torvalds error = -EIO; 4111da177e4SLinus Torvalds goto cleanup; 4121da177e4SLinus Torvalds } 4131da177e4SLinus Torvalds /* Find the named attribute. */ 4141da177e4SLinus Torvalds here = FIRST_ENTRY(bh); 4151da177e4SLinus Torvalds while (!IS_LAST_ENTRY(here)) { 4161da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here); 4171da177e4SLinus Torvalds if ((char *)next >= end) 4181da177e4SLinus Torvalds goto bad_block; 4191da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 4201da177e4SLinus Torvalds size_t offs = le16_to_cpu(here->e_value_offs); 4211da177e4SLinus Torvalds if (offs < min_offs) 4221da177e4SLinus Torvalds min_offs = offs; 4231da177e4SLinus Torvalds } 4241da177e4SLinus Torvalds not_found = name_index - here->e_name_index; 4251da177e4SLinus Torvalds if (!not_found) 4261da177e4SLinus Torvalds not_found = name_len - here->e_name_len; 4271da177e4SLinus Torvalds if (!not_found) 4281da177e4SLinus Torvalds not_found = memcmp(name, here->e_name,name_len); 4291da177e4SLinus Torvalds if (not_found <= 0) 4301da177e4SLinus Torvalds break; 4311da177e4SLinus Torvalds here = next; 4321da177e4SLinus Torvalds } 4331da177e4SLinus Torvalds last = here; 4341da177e4SLinus Torvalds /* We still need to compute min_offs and last. */ 4351da177e4SLinus Torvalds while (!IS_LAST_ENTRY(last)) { 4361da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last); 4371da177e4SLinus Torvalds if ((char *)next >= end) 4381da177e4SLinus Torvalds goto bad_block; 4391da177e4SLinus Torvalds if (!last->e_value_block && last->e_value_size) { 4401da177e4SLinus Torvalds size_t offs = le16_to_cpu(last->e_value_offs); 4411da177e4SLinus Torvalds if (offs < min_offs) 4421da177e4SLinus Torvalds min_offs = offs; 4431da177e4SLinus Torvalds } 4441da177e4SLinus Torvalds last = next; 4451da177e4SLinus Torvalds } 4461da177e4SLinus Torvalds 4471da177e4SLinus Torvalds /* Check whether we have enough space left. */ 4481da177e4SLinus Torvalds free = min_offs - ((char*)last - (char*)header) - sizeof(__u32); 4491da177e4SLinus Torvalds } else { 4501da177e4SLinus Torvalds /* We will use a new extended attribute block. */ 4511da177e4SLinus Torvalds free = sb->s_blocksize - 4521da177e4SLinus Torvalds sizeof(struct ext2_xattr_header) - sizeof(__u32); 4531da177e4SLinus Torvalds here = last = NULL; /* avoid gcc uninitialized warning. */ 4541da177e4SLinus Torvalds } 4551da177e4SLinus Torvalds 4561da177e4SLinus Torvalds if (not_found) { 4571da177e4SLinus Torvalds /* Request to remove a nonexistent attribute? */ 4581da177e4SLinus Torvalds error = -ENODATA; 4591da177e4SLinus Torvalds if (flags & XATTR_REPLACE) 4601da177e4SLinus Torvalds goto cleanup; 4611da177e4SLinus Torvalds error = 0; 4621da177e4SLinus Torvalds if (value == NULL) 4631da177e4SLinus Torvalds goto cleanup; 4641da177e4SLinus Torvalds } else { 4651da177e4SLinus Torvalds /* Request to create an existing attribute? */ 4661da177e4SLinus Torvalds error = -EEXIST; 4671da177e4SLinus Torvalds if (flags & XATTR_CREATE) 4681da177e4SLinus Torvalds goto cleanup; 4691da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 4701da177e4SLinus Torvalds size_t size = le32_to_cpu(here->e_value_size); 4711da177e4SLinus Torvalds 4721da177e4SLinus Torvalds if (le16_to_cpu(here->e_value_offs) + size > 4731da177e4SLinus Torvalds sb->s_blocksize || size > sb->s_blocksize) 4741da177e4SLinus Torvalds goto bad_block; 4751da177e4SLinus Torvalds free += EXT2_XATTR_SIZE(size); 4761da177e4SLinus Torvalds } 4771da177e4SLinus Torvalds free += EXT2_XATTR_LEN(name_len); 4781da177e4SLinus Torvalds } 4791da177e4SLinus Torvalds error = -ENOSPC; 4801da177e4SLinus Torvalds if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len)) 4811da177e4SLinus Torvalds goto cleanup; 4821da177e4SLinus Torvalds 4831da177e4SLinus Torvalds /* Here we know that we can set the new attribute. */ 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds if (header) { 4861da177e4SLinus Torvalds struct mb_cache_entry *ce; 4871da177e4SLinus Torvalds 4881da177e4SLinus Torvalds /* assert(header == HDR(bh)); */ 4891da177e4SLinus Torvalds ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev, 4901da177e4SLinus Torvalds bh->b_blocknr); 4911da177e4SLinus Torvalds lock_buffer(bh); 4921da177e4SLinus Torvalds if (header->h_refcount == cpu_to_le32(1)) { 4931da177e4SLinus Torvalds ea_bdebug(bh, "modifying in-place"); 4941da177e4SLinus Torvalds if (ce) 4951da177e4SLinus Torvalds mb_cache_entry_free(ce); 4961da177e4SLinus Torvalds /* keep the buffer locked while modifying it. */ 4971da177e4SLinus Torvalds } else { 4981da177e4SLinus Torvalds int offset; 4991da177e4SLinus Torvalds 5001da177e4SLinus Torvalds if (ce) 5011da177e4SLinus Torvalds mb_cache_entry_release(ce); 5021da177e4SLinus Torvalds unlock_buffer(bh); 5031da177e4SLinus Torvalds ea_bdebug(bh, "cloning"); 5041da177e4SLinus Torvalds header = kmalloc(bh->b_size, GFP_KERNEL); 5051da177e4SLinus Torvalds error = -ENOMEM; 5061da177e4SLinus Torvalds if (header == NULL) 5071da177e4SLinus Torvalds goto cleanup; 5081da177e4SLinus Torvalds memcpy(header, HDR(bh), bh->b_size); 5091da177e4SLinus Torvalds header->h_refcount = cpu_to_le32(1); 5101da177e4SLinus Torvalds 5111da177e4SLinus Torvalds offset = (char *)here - bh->b_data; 5121da177e4SLinus Torvalds here = ENTRY((char *)header + offset); 5131da177e4SLinus Torvalds offset = (char *)last - bh->b_data; 5141da177e4SLinus Torvalds last = ENTRY((char *)header + offset); 5151da177e4SLinus Torvalds } 5161da177e4SLinus Torvalds } else { 5171da177e4SLinus Torvalds /* Allocate a buffer where we construct the new block. */ 518f8314dc6SPanagiotis Issaris header = kzalloc(sb->s_blocksize, GFP_KERNEL); 5191da177e4SLinus Torvalds error = -ENOMEM; 5201da177e4SLinus Torvalds if (header == NULL) 5211da177e4SLinus Torvalds goto cleanup; 5221da177e4SLinus Torvalds end = (char *)header + sb->s_blocksize; 5231da177e4SLinus Torvalds header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC); 5241da177e4SLinus Torvalds header->h_blocks = header->h_refcount = cpu_to_le32(1); 5251da177e4SLinus Torvalds last = here = ENTRY(header+1); 5261da177e4SLinus Torvalds } 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds /* Iff we are modifying the block in-place, bh is locked here. */ 5291da177e4SLinus Torvalds 5301da177e4SLinus Torvalds if (not_found) { 5311da177e4SLinus Torvalds /* Insert the new name. */ 5321da177e4SLinus Torvalds size_t size = EXT2_XATTR_LEN(name_len); 5331da177e4SLinus Torvalds size_t rest = (char *)last - (char *)here; 5341da177e4SLinus Torvalds memmove((char *)here + size, here, rest); 5351da177e4SLinus Torvalds memset(here, 0, size); 5361da177e4SLinus Torvalds here->e_name_index = name_index; 5371da177e4SLinus Torvalds here->e_name_len = name_len; 5381da177e4SLinus Torvalds memcpy(here->e_name, name, name_len); 5391da177e4SLinus Torvalds } else { 5401da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 5411da177e4SLinus Torvalds char *first_val = (char *)header + min_offs; 5421da177e4SLinus Torvalds size_t offs = le16_to_cpu(here->e_value_offs); 5431da177e4SLinus Torvalds char *val = (char *)header + offs; 5441da177e4SLinus Torvalds size_t size = EXT2_XATTR_SIZE( 5451da177e4SLinus Torvalds le32_to_cpu(here->e_value_size)); 5461da177e4SLinus Torvalds 5471da177e4SLinus Torvalds if (size == EXT2_XATTR_SIZE(value_len)) { 5481da177e4SLinus Torvalds /* The old and the new value have the same 5491da177e4SLinus Torvalds size. Just replace. */ 5501da177e4SLinus Torvalds here->e_value_size = cpu_to_le32(value_len); 5511da177e4SLinus Torvalds memset(val + size - EXT2_XATTR_PAD, 0, 5521da177e4SLinus Torvalds EXT2_XATTR_PAD); /* Clear pad bytes. */ 5531da177e4SLinus Torvalds memcpy(val, value, value_len); 5541da177e4SLinus Torvalds goto skip_replace; 5551da177e4SLinus Torvalds } 5561da177e4SLinus Torvalds 5571da177e4SLinus Torvalds /* Remove the old value. */ 5581da177e4SLinus Torvalds memmove(first_val + size, first_val, val - first_val); 5591da177e4SLinus Torvalds memset(first_val, 0, size); 5601da177e4SLinus Torvalds here->e_value_offs = 0; 5611da177e4SLinus Torvalds min_offs += size; 5621da177e4SLinus Torvalds 5631da177e4SLinus Torvalds /* Adjust all value offsets. */ 5641da177e4SLinus Torvalds last = ENTRY(header+1); 5651da177e4SLinus Torvalds while (!IS_LAST_ENTRY(last)) { 5661da177e4SLinus Torvalds size_t o = le16_to_cpu(last->e_value_offs); 5671da177e4SLinus Torvalds if (!last->e_value_block && o < offs) 5681da177e4SLinus Torvalds last->e_value_offs = 5691da177e4SLinus Torvalds cpu_to_le16(o + size); 5701da177e4SLinus Torvalds last = EXT2_XATTR_NEXT(last); 5711da177e4SLinus Torvalds } 5721da177e4SLinus Torvalds } 5731da177e4SLinus Torvalds if (value == NULL) { 5741da177e4SLinus Torvalds /* Remove the old name. */ 5751da177e4SLinus Torvalds size_t size = EXT2_XATTR_LEN(name_len); 5761da177e4SLinus Torvalds last = ENTRY((char *)last - size); 5771da177e4SLinus Torvalds memmove(here, (char*)here + size, 5781da177e4SLinus Torvalds (char*)last - (char*)here); 5791da177e4SLinus Torvalds memset(last, 0, size); 5801da177e4SLinus Torvalds } 5811da177e4SLinus Torvalds } 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds if (value != NULL) { 5841da177e4SLinus Torvalds /* Insert the new value. */ 5851da177e4SLinus Torvalds here->e_value_size = cpu_to_le32(value_len); 5861da177e4SLinus Torvalds if (value_len) { 5871da177e4SLinus Torvalds size_t size = EXT2_XATTR_SIZE(value_len); 5881da177e4SLinus Torvalds char *val = (char *)header + min_offs - size; 5891da177e4SLinus Torvalds here->e_value_offs = 5901da177e4SLinus Torvalds cpu_to_le16((char *)val - (char *)header); 5911da177e4SLinus Torvalds memset(val + size - EXT2_XATTR_PAD, 0, 5921da177e4SLinus Torvalds EXT2_XATTR_PAD); /* Clear the pad bytes. */ 5931da177e4SLinus Torvalds memcpy(val, value, value_len); 5941da177e4SLinus Torvalds } 5951da177e4SLinus Torvalds } 5961da177e4SLinus Torvalds 5971da177e4SLinus Torvalds skip_replace: 5981da177e4SLinus Torvalds if (IS_LAST_ENTRY(ENTRY(header+1))) { 5991da177e4SLinus Torvalds /* This block is now empty. */ 6001da177e4SLinus Torvalds if (bh && header == HDR(bh)) 6011da177e4SLinus Torvalds unlock_buffer(bh); /* we were modifying in-place. */ 6021da177e4SLinus Torvalds error = ext2_xattr_set2(inode, bh, NULL); 6031da177e4SLinus Torvalds } else { 6041da177e4SLinus Torvalds ext2_xattr_rehash(header, here); 6051da177e4SLinus Torvalds if (bh && header == HDR(bh)) 6061da177e4SLinus Torvalds unlock_buffer(bh); /* we were modifying in-place. */ 6071da177e4SLinus Torvalds error = ext2_xattr_set2(inode, bh, header); 6081da177e4SLinus Torvalds } 6091da177e4SLinus Torvalds 6101da177e4SLinus Torvalds cleanup: 6111da177e4SLinus Torvalds brelse(bh); 6121da177e4SLinus Torvalds if (!(bh && header == HDR(bh))) 6131da177e4SLinus Torvalds kfree(header); 6141da177e4SLinus Torvalds up_write(&EXT2_I(inode)->xattr_sem); 6151da177e4SLinus Torvalds 6161da177e4SLinus Torvalds return error; 6171da177e4SLinus Torvalds } 6181da177e4SLinus Torvalds 6191da177e4SLinus Torvalds /* 6201da177e4SLinus Torvalds * Second half of ext2_xattr_set(): Update the file system. 6211da177e4SLinus Torvalds */ 6221da177e4SLinus Torvalds static int 6231da177e4SLinus Torvalds ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, 6241da177e4SLinus Torvalds struct ext2_xattr_header *header) 6251da177e4SLinus Torvalds { 6261da177e4SLinus Torvalds struct super_block *sb = inode->i_sb; 6271da177e4SLinus Torvalds struct buffer_head *new_bh = NULL; 6281da177e4SLinus Torvalds int error; 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds if (header) { 6311da177e4SLinus Torvalds new_bh = ext2_xattr_cache_find(inode, header); 6321da177e4SLinus Torvalds if (new_bh) { 6331da177e4SLinus Torvalds /* We found an identical block in the cache. */ 6341da177e4SLinus Torvalds if (new_bh == old_bh) { 6351da177e4SLinus Torvalds ea_bdebug(new_bh, "keeping this block"); 6361da177e4SLinus Torvalds } else { 6371da177e4SLinus Torvalds /* The old block is released after updating 6381da177e4SLinus Torvalds the inode. */ 6391da177e4SLinus Torvalds ea_bdebug(new_bh, "reusing block"); 6401da177e4SLinus Torvalds 6415dd4056dSChristoph Hellwig error = dquot_alloc_block(inode, 1); 6425dd4056dSChristoph Hellwig if (error) { 6431da177e4SLinus Torvalds unlock_buffer(new_bh); 6441da177e4SLinus Torvalds goto cleanup; 6451da177e4SLinus Torvalds } 646fba4d399SMarcin Slusarz le32_add_cpu(&HDR(new_bh)->h_refcount, 1); 6471da177e4SLinus Torvalds ea_bdebug(new_bh, "refcount now=%d", 6481da177e4SLinus Torvalds le32_to_cpu(HDR(new_bh)->h_refcount)); 6491da177e4SLinus Torvalds } 6501da177e4SLinus Torvalds unlock_buffer(new_bh); 6511da177e4SLinus Torvalds } else if (old_bh && header == HDR(old_bh)) { 6521da177e4SLinus Torvalds /* Keep this block. No need to lock the block as we 6531da177e4SLinus Torvalds don't need to change the reference count. */ 6541da177e4SLinus Torvalds new_bh = old_bh; 6551da177e4SLinus Torvalds get_bh(new_bh); 6561da177e4SLinus Torvalds ext2_xattr_cache_insert(new_bh); 6571da177e4SLinus Torvalds } else { 6581da177e4SLinus Torvalds /* We need to allocate a new block */ 65924097d12SAkinobu Mita ext2_fsblk_t goal = ext2_group_first_block_no(sb, 66024097d12SAkinobu Mita EXT2_I(inode)->i_block_group); 661a686cd89SMartin J. Bligh int block = ext2_new_block(inode, goal, &error); 6621da177e4SLinus Torvalds if (error) 6631da177e4SLinus Torvalds goto cleanup; 6641da177e4SLinus Torvalds ea_idebug(inode, "creating block %d", block); 6651da177e4SLinus Torvalds 6661da177e4SLinus Torvalds new_bh = sb_getblk(sb, block); 6671da177e4SLinus Torvalds if (!new_bh) { 6681da177e4SLinus Torvalds ext2_free_blocks(inode, block, 1); 669addacc7dSAl Viro mark_inode_dirty(inode); 6701da177e4SLinus Torvalds error = -EIO; 6711da177e4SLinus Torvalds goto cleanup; 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds lock_buffer(new_bh); 6741da177e4SLinus Torvalds memcpy(new_bh->b_data, header, new_bh->b_size); 6751da177e4SLinus Torvalds set_buffer_uptodate(new_bh); 6761da177e4SLinus Torvalds unlock_buffer(new_bh); 6771da177e4SLinus Torvalds ext2_xattr_cache_insert(new_bh); 6781da177e4SLinus Torvalds 6791da177e4SLinus Torvalds ext2_xattr_update_super_block(sb); 6801da177e4SLinus Torvalds } 6811da177e4SLinus Torvalds mark_buffer_dirty(new_bh); 6821da177e4SLinus Torvalds if (IS_SYNC(inode)) { 6831da177e4SLinus Torvalds sync_dirty_buffer(new_bh); 6841da177e4SLinus Torvalds error = -EIO; 6851da177e4SLinus Torvalds if (buffer_req(new_bh) && !buffer_uptodate(new_bh)) 6861da177e4SLinus Torvalds goto cleanup; 6871da177e4SLinus Torvalds } 6881da177e4SLinus Torvalds } 6891da177e4SLinus Torvalds 6901da177e4SLinus Torvalds /* Update the inode. */ 6911da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 6921da177e4SLinus Torvalds inode->i_ctime = CURRENT_TIME_SEC; 6931da177e4SLinus Torvalds if (IS_SYNC(inode)) { 694c3765016SChristoph Hellwig error = sync_inode_metadata(inode, 1); 6951da177e4SLinus Torvalds /* In case sync failed due to ENOSPC the inode was actually 6961da177e4SLinus Torvalds * written (only some dirty data were not) so we just proceed 6971da177e4SLinus Torvalds * as if nothing happened and cleanup the unused block */ 6981da177e4SLinus Torvalds if (error && error != -ENOSPC) { 6993889717dSAl Viro if (new_bh && new_bh != old_bh) { 7003889717dSAl Viro dquot_free_block_nodirty(inode, 1); 7013889717dSAl Viro mark_inode_dirty(inode); 7023889717dSAl Viro } 7031da177e4SLinus Torvalds goto cleanup; 7041da177e4SLinus Torvalds } 7051da177e4SLinus Torvalds } else 7061da177e4SLinus Torvalds mark_inode_dirty(inode); 7071da177e4SLinus Torvalds 7081da177e4SLinus Torvalds error = 0; 7091da177e4SLinus Torvalds if (old_bh && old_bh != new_bh) { 7101da177e4SLinus Torvalds struct mb_cache_entry *ce; 7111da177e4SLinus Torvalds 7121da177e4SLinus Torvalds /* 7131da177e4SLinus Torvalds * If there was an old block and we are no longer using it, 7141da177e4SLinus Torvalds * release the old block. 7151da177e4SLinus Torvalds */ 7161da177e4SLinus Torvalds ce = mb_cache_entry_get(ext2_xattr_cache, old_bh->b_bdev, 7171da177e4SLinus Torvalds old_bh->b_blocknr); 7181da177e4SLinus Torvalds lock_buffer(old_bh); 7191da177e4SLinus Torvalds if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) { 7201da177e4SLinus Torvalds /* Free the old block. */ 7211da177e4SLinus Torvalds if (ce) 7221da177e4SLinus Torvalds mb_cache_entry_free(ce); 7231da177e4SLinus Torvalds ea_bdebug(old_bh, "freeing"); 7241da177e4SLinus Torvalds ext2_free_blocks(inode, old_bh->b_blocknr, 1); 725addacc7dSAl Viro mark_inode_dirty(inode); 7261da177e4SLinus Torvalds /* We let our caller release old_bh, so we 7271da177e4SLinus Torvalds * need to duplicate the buffer before. */ 7281da177e4SLinus Torvalds get_bh(old_bh); 7291da177e4SLinus Torvalds bforget(old_bh); 7301da177e4SLinus Torvalds } else { 7311da177e4SLinus Torvalds /* Decrement the refcount only. */ 732fba4d399SMarcin Slusarz le32_add_cpu(&HDR(old_bh)->h_refcount, -1); 7331da177e4SLinus Torvalds if (ce) 7341da177e4SLinus Torvalds mb_cache_entry_release(ce); 7353889717dSAl Viro dquot_free_block_nodirty(inode, 1); 7363889717dSAl Viro mark_inode_dirty(inode); 7371da177e4SLinus Torvalds mark_buffer_dirty(old_bh); 7381da177e4SLinus Torvalds ea_bdebug(old_bh, "refcount now=%d", 7391da177e4SLinus Torvalds le32_to_cpu(HDR(old_bh)->h_refcount)); 7401da177e4SLinus Torvalds } 7411da177e4SLinus Torvalds unlock_buffer(old_bh); 7421da177e4SLinus Torvalds } 7431da177e4SLinus Torvalds 7441da177e4SLinus Torvalds cleanup: 7451da177e4SLinus Torvalds brelse(new_bh); 7461da177e4SLinus Torvalds 7471da177e4SLinus Torvalds return error; 7481da177e4SLinus Torvalds } 7491da177e4SLinus Torvalds 7501da177e4SLinus Torvalds /* 7511da177e4SLinus Torvalds * ext2_xattr_delete_inode() 7521da177e4SLinus Torvalds * 7531da177e4SLinus Torvalds * Free extended attribute resources associated with this inode. This 7541da177e4SLinus Torvalds * is called immediately before an inode is freed. 7551da177e4SLinus Torvalds */ 7561da177e4SLinus Torvalds void 7571da177e4SLinus Torvalds ext2_xattr_delete_inode(struct inode *inode) 7581da177e4SLinus Torvalds { 7591da177e4SLinus Torvalds struct buffer_head *bh = NULL; 7601da177e4SLinus Torvalds struct mb_cache_entry *ce; 7611da177e4SLinus Torvalds 7621da177e4SLinus Torvalds down_write(&EXT2_I(inode)->xattr_sem); 7631da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 7641da177e4SLinus Torvalds goto cleanup; 7651da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 7661da177e4SLinus Torvalds if (!bh) { 7671da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_delete_inode", 7681da177e4SLinus Torvalds "inode %ld: block %d read error", inode->i_ino, 7691da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 7701da177e4SLinus Torvalds goto cleanup; 7711da177e4SLinus Torvalds } 7721da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count))); 7731da177e4SLinus Torvalds if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || 7741da177e4SLinus Torvalds HDR(bh)->h_blocks != cpu_to_le32(1)) { 7751da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_delete_inode", 7761da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 7771da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 7781da177e4SLinus Torvalds goto cleanup; 7791da177e4SLinus Torvalds } 7801da177e4SLinus Torvalds ce = mb_cache_entry_get(ext2_xattr_cache, bh->b_bdev, bh->b_blocknr); 7811da177e4SLinus Torvalds lock_buffer(bh); 7821da177e4SLinus Torvalds if (HDR(bh)->h_refcount == cpu_to_le32(1)) { 7831da177e4SLinus Torvalds if (ce) 7841da177e4SLinus Torvalds mb_cache_entry_free(ce); 7851da177e4SLinus Torvalds ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1); 7861da177e4SLinus Torvalds get_bh(bh); 7871da177e4SLinus Torvalds bforget(bh); 788b2f49033SPeter Staubach unlock_buffer(bh); 7891da177e4SLinus Torvalds } else { 790fba4d399SMarcin Slusarz le32_add_cpu(&HDR(bh)->h_refcount, -1); 7911da177e4SLinus Torvalds if (ce) 7921da177e4SLinus Torvalds mb_cache_entry_release(ce); 793b2f49033SPeter Staubach ea_bdebug(bh, "refcount now=%d", 794b2f49033SPeter Staubach le32_to_cpu(HDR(bh)->h_refcount)); 795b2f49033SPeter Staubach unlock_buffer(bh); 7961da177e4SLinus Torvalds mark_buffer_dirty(bh); 7971da177e4SLinus Torvalds if (IS_SYNC(inode)) 7981da177e4SLinus Torvalds sync_dirty_buffer(bh); 7993889717dSAl Viro dquot_free_block_nodirty(inode, 1); 8001da177e4SLinus Torvalds } 8011da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl = 0; 8021da177e4SLinus Torvalds 8031da177e4SLinus Torvalds cleanup: 8041da177e4SLinus Torvalds brelse(bh); 8051da177e4SLinus Torvalds up_write(&EXT2_I(inode)->xattr_sem); 8061da177e4SLinus Torvalds } 8071da177e4SLinus Torvalds 8081da177e4SLinus Torvalds /* 8091da177e4SLinus Torvalds * ext2_xattr_put_super() 8101da177e4SLinus Torvalds * 8111da177e4SLinus Torvalds * This is called when a file system is unmounted. 8121da177e4SLinus Torvalds */ 8131da177e4SLinus Torvalds void 8141da177e4SLinus Torvalds ext2_xattr_put_super(struct super_block *sb) 8151da177e4SLinus Torvalds { 8168c52ab42SAndreas Gruenbacher mb_cache_shrink(sb->s_bdev); 8171da177e4SLinus Torvalds } 8181da177e4SLinus Torvalds 8191da177e4SLinus Torvalds 8201da177e4SLinus Torvalds /* 8211da177e4SLinus Torvalds * ext2_xattr_cache_insert() 8221da177e4SLinus Torvalds * 8231da177e4SLinus Torvalds * Create a new entry in the extended attribute cache, and insert 8241da177e4SLinus Torvalds * it unless such an entry is already in the cache. 8251da177e4SLinus Torvalds * 8261da177e4SLinus Torvalds * Returns 0, or a negative error number on failure. 8271da177e4SLinus Torvalds */ 8281da177e4SLinus Torvalds static int 8291da177e4SLinus Torvalds ext2_xattr_cache_insert(struct buffer_head *bh) 8301da177e4SLinus Torvalds { 8311da177e4SLinus Torvalds __u32 hash = le32_to_cpu(HDR(bh)->h_hash); 8321da177e4SLinus Torvalds struct mb_cache_entry *ce; 8331da177e4SLinus Torvalds int error; 8341da177e4SLinus Torvalds 835335e92e8SJan Kara ce = mb_cache_entry_alloc(ext2_xattr_cache, GFP_NOFS); 8361da177e4SLinus Torvalds if (!ce) 8371da177e4SLinus Torvalds return -ENOMEM; 8382aec7c52SAndreas Gruenbacher error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash); 8391da177e4SLinus Torvalds if (error) { 8401da177e4SLinus Torvalds mb_cache_entry_free(ce); 8411da177e4SLinus Torvalds if (error == -EBUSY) { 8421da177e4SLinus Torvalds ea_bdebug(bh, "already in cache (%d cache entries)", 8431da177e4SLinus Torvalds atomic_read(&ext2_xattr_cache->c_entry_count)); 8441da177e4SLinus Torvalds error = 0; 8451da177e4SLinus Torvalds } 8461da177e4SLinus Torvalds } else { 8471da177e4SLinus Torvalds ea_bdebug(bh, "inserting [%x] (%d cache entries)", (int)hash, 8481da177e4SLinus Torvalds atomic_read(&ext2_xattr_cache->c_entry_count)); 8491da177e4SLinus Torvalds mb_cache_entry_release(ce); 8501da177e4SLinus Torvalds } 8511da177e4SLinus Torvalds return error; 8521da177e4SLinus Torvalds } 8531da177e4SLinus Torvalds 8541da177e4SLinus Torvalds /* 8551da177e4SLinus Torvalds * ext2_xattr_cmp() 8561da177e4SLinus Torvalds * 8571da177e4SLinus Torvalds * Compare two extended attribute blocks for equality. 8581da177e4SLinus Torvalds * 8591da177e4SLinus Torvalds * Returns 0 if the blocks are equal, 1 if they differ, and 8601da177e4SLinus Torvalds * a negative error number on errors. 8611da177e4SLinus Torvalds */ 8621da177e4SLinus Torvalds static int 8631da177e4SLinus Torvalds ext2_xattr_cmp(struct ext2_xattr_header *header1, 8641da177e4SLinus Torvalds struct ext2_xattr_header *header2) 8651da177e4SLinus Torvalds { 8661da177e4SLinus Torvalds struct ext2_xattr_entry *entry1, *entry2; 8671da177e4SLinus Torvalds 8681da177e4SLinus Torvalds entry1 = ENTRY(header1+1); 8691da177e4SLinus Torvalds entry2 = ENTRY(header2+1); 8701da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry1)) { 8711da177e4SLinus Torvalds if (IS_LAST_ENTRY(entry2)) 8721da177e4SLinus Torvalds return 1; 8731da177e4SLinus Torvalds if (entry1->e_hash != entry2->e_hash || 8741da177e4SLinus Torvalds entry1->e_name_index != entry2->e_name_index || 8751da177e4SLinus Torvalds entry1->e_name_len != entry2->e_name_len || 8761da177e4SLinus Torvalds entry1->e_value_size != entry2->e_value_size || 8771da177e4SLinus Torvalds memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 8781da177e4SLinus Torvalds return 1; 8791da177e4SLinus Torvalds if (entry1->e_value_block != 0 || entry2->e_value_block != 0) 8801da177e4SLinus Torvalds return -EIO; 8811da177e4SLinus Torvalds if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 8821da177e4SLinus Torvalds (char *)header2 + le16_to_cpu(entry2->e_value_offs), 8831da177e4SLinus Torvalds le32_to_cpu(entry1->e_value_size))) 8841da177e4SLinus Torvalds return 1; 8851da177e4SLinus Torvalds 8861da177e4SLinus Torvalds entry1 = EXT2_XATTR_NEXT(entry1); 8871da177e4SLinus Torvalds entry2 = EXT2_XATTR_NEXT(entry2); 8881da177e4SLinus Torvalds } 8891da177e4SLinus Torvalds if (!IS_LAST_ENTRY(entry2)) 8901da177e4SLinus Torvalds return 1; 8911da177e4SLinus Torvalds return 0; 8921da177e4SLinus Torvalds } 8931da177e4SLinus Torvalds 8941da177e4SLinus Torvalds /* 8951da177e4SLinus Torvalds * ext2_xattr_cache_find() 8961da177e4SLinus Torvalds * 8971da177e4SLinus Torvalds * Find an identical extended attribute block. 8981da177e4SLinus Torvalds * 8991da177e4SLinus Torvalds * Returns a locked buffer head to the block found, or NULL if such 9001da177e4SLinus Torvalds * a block was not found or an error occurred. 9011da177e4SLinus Torvalds */ 9021da177e4SLinus Torvalds static struct buffer_head * 9031da177e4SLinus Torvalds ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header) 9041da177e4SLinus Torvalds { 9051da177e4SLinus Torvalds __u32 hash = le32_to_cpu(header->h_hash); 9061da177e4SLinus Torvalds struct mb_cache_entry *ce; 9071da177e4SLinus Torvalds 9081da177e4SLinus Torvalds if (!header->h_hash) 9091da177e4SLinus Torvalds return NULL; /* never share */ 9101da177e4SLinus Torvalds ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 9111da177e4SLinus Torvalds again: 9122aec7c52SAndreas Gruenbacher ce = mb_cache_entry_find_first(ext2_xattr_cache, inode->i_sb->s_bdev, 9132aec7c52SAndreas Gruenbacher hash); 9141da177e4SLinus Torvalds while (ce) { 9151da177e4SLinus Torvalds struct buffer_head *bh; 9161da177e4SLinus Torvalds 9171da177e4SLinus Torvalds if (IS_ERR(ce)) { 9181da177e4SLinus Torvalds if (PTR_ERR(ce) == -EAGAIN) 9191da177e4SLinus Torvalds goto again; 9201da177e4SLinus Torvalds break; 9211da177e4SLinus Torvalds } 9221da177e4SLinus Torvalds 9231da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, ce->e_block); 9241da177e4SLinus Torvalds if (!bh) { 9251da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_cache_find", 9261da177e4SLinus Torvalds "inode %ld: block %ld read error", 9271da177e4SLinus Torvalds inode->i_ino, (unsigned long) ce->e_block); 9281da177e4SLinus Torvalds } else { 9291da177e4SLinus Torvalds lock_buffer(bh); 9301da177e4SLinus Torvalds if (le32_to_cpu(HDR(bh)->h_refcount) > 9311da177e4SLinus Torvalds EXT2_XATTR_REFCOUNT_MAX) { 9321da177e4SLinus Torvalds ea_idebug(inode, "block %ld refcount %d>%d", 9331da177e4SLinus Torvalds (unsigned long) ce->e_block, 9341da177e4SLinus Torvalds le32_to_cpu(HDR(bh)->h_refcount), 9351da177e4SLinus Torvalds EXT2_XATTR_REFCOUNT_MAX); 9361da177e4SLinus Torvalds } else if (!ext2_xattr_cmp(header, HDR(bh))) { 9371da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d", 9381da177e4SLinus Torvalds atomic_read(&(bh->b_count))); 9391da177e4SLinus Torvalds mb_cache_entry_release(ce); 9401da177e4SLinus Torvalds return bh; 9411da177e4SLinus Torvalds } 9421da177e4SLinus Torvalds unlock_buffer(bh); 9431da177e4SLinus Torvalds brelse(bh); 9441da177e4SLinus Torvalds } 9452aec7c52SAndreas Gruenbacher ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash); 9461da177e4SLinus Torvalds } 9471da177e4SLinus Torvalds return NULL; 9481da177e4SLinus Torvalds } 9491da177e4SLinus Torvalds 9501da177e4SLinus Torvalds #define NAME_HASH_SHIFT 5 9511da177e4SLinus Torvalds #define VALUE_HASH_SHIFT 16 9521da177e4SLinus Torvalds 9531da177e4SLinus Torvalds /* 9541da177e4SLinus Torvalds * ext2_xattr_hash_entry() 9551da177e4SLinus Torvalds * 9561da177e4SLinus Torvalds * Compute the hash of an extended attribute. 9571da177e4SLinus Torvalds */ 9581da177e4SLinus Torvalds static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header, 9591da177e4SLinus Torvalds struct ext2_xattr_entry *entry) 9601da177e4SLinus Torvalds { 9611da177e4SLinus Torvalds __u32 hash = 0; 9621da177e4SLinus Torvalds char *name = entry->e_name; 9631da177e4SLinus Torvalds int n; 9641da177e4SLinus Torvalds 9651da177e4SLinus Torvalds for (n=0; n < entry->e_name_len; n++) { 9661da177e4SLinus Torvalds hash = (hash << NAME_HASH_SHIFT) ^ 9671da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 9681da177e4SLinus Torvalds *name++; 9691da177e4SLinus Torvalds } 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds if (entry->e_value_block == 0 && entry->e_value_size != 0) { 9721da177e4SLinus Torvalds __le32 *value = (__le32 *)((char *)header + 9731da177e4SLinus Torvalds le16_to_cpu(entry->e_value_offs)); 9741da177e4SLinus Torvalds for (n = (le32_to_cpu(entry->e_value_size) + 9751da177e4SLinus Torvalds EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) { 9761da177e4SLinus Torvalds hash = (hash << VALUE_HASH_SHIFT) ^ 9771da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 9781da177e4SLinus Torvalds le32_to_cpu(*value++); 9791da177e4SLinus Torvalds } 9801da177e4SLinus Torvalds } 9811da177e4SLinus Torvalds entry->e_hash = cpu_to_le32(hash); 9821da177e4SLinus Torvalds } 9831da177e4SLinus Torvalds 9841da177e4SLinus Torvalds #undef NAME_HASH_SHIFT 9851da177e4SLinus Torvalds #undef VALUE_HASH_SHIFT 9861da177e4SLinus Torvalds 9871da177e4SLinus Torvalds #define BLOCK_HASH_SHIFT 16 9881da177e4SLinus Torvalds 9891da177e4SLinus Torvalds /* 9901da177e4SLinus Torvalds * ext2_xattr_rehash() 9911da177e4SLinus Torvalds * 9921da177e4SLinus Torvalds * Re-compute the extended attribute hash value after an entry has changed. 9931da177e4SLinus Torvalds */ 9941da177e4SLinus Torvalds static void ext2_xattr_rehash(struct ext2_xattr_header *header, 9951da177e4SLinus Torvalds struct ext2_xattr_entry *entry) 9961da177e4SLinus Torvalds { 9971da177e4SLinus Torvalds struct ext2_xattr_entry *here; 9981da177e4SLinus Torvalds __u32 hash = 0; 9991da177e4SLinus Torvalds 10001da177e4SLinus Torvalds ext2_xattr_hash_entry(header, entry); 10011da177e4SLinus Torvalds here = ENTRY(header+1); 10021da177e4SLinus Torvalds while (!IS_LAST_ENTRY(here)) { 10031da177e4SLinus Torvalds if (!here->e_hash) { 10041da177e4SLinus Torvalds /* Block is not shared if an entry's hash value == 0 */ 10051da177e4SLinus Torvalds hash = 0; 10061da177e4SLinus Torvalds break; 10071da177e4SLinus Torvalds } 10081da177e4SLinus Torvalds hash = (hash << BLOCK_HASH_SHIFT) ^ 10091da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 10101da177e4SLinus Torvalds le32_to_cpu(here->e_hash); 10111da177e4SLinus Torvalds here = EXT2_XATTR_NEXT(here); 10121da177e4SLinus Torvalds } 10131da177e4SLinus Torvalds header->h_hash = cpu_to_le32(hash); 10141da177e4SLinus Torvalds } 10151da177e4SLinus Torvalds 10161da177e4SLinus Torvalds #undef BLOCK_HASH_SHIFT 10171da177e4SLinus Torvalds 10181da177e4SLinus Torvalds int __init 10191da177e4SLinus Torvalds init_ext2_xattr(void) 10201da177e4SLinus Torvalds { 10212aec7c52SAndreas Gruenbacher ext2_xattr_cache = mb_cache_create("ext2_xattr", 6); 10221da177e4SLinus Torvalds if (!ext2_xattr_cache) 10231da177e4SLinus Torvalds return -ENOMEM; 10241da177e4SLinus Torvalds return 0; 10251da177e4SLinus Torvalds } 10261da177e4SLinus Torvalds 10271da177e4SLinus Torvalds void 10281da177e4SLinus Torvalds exit_ext2_xattr(void) 10291da177e4SLinus Torvalds { 10301da177e4SLinus Torvalds mb_cache_destroy(ext2_xattr_cache); 10311da177e4SLinus Torvalds } 1032