1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/fs/ext2/xattr.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de> 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Fix by Harrison Xing <harrison@mountainviewdata.com>. 81da177e4SLinus Torvalds * Extended attributes for symlinks and special files added per 91da177e4SLinus Torvalds * suggestion of Luka Renko <luka.renko@hermes.si>. 101da177e4SLinus Torvalds * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, 111da177e4SLinus Torvalds * Red Hat Inc. 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds */ 141da177e4SLinus Torvalds 151da177e4SLinus Torvalds /* 161da177e4SLinus Torvalds * Extended attributes are stored on disk blocks allocated outside of 171da177e4SLinus Torvalds * any inode. The i_file_acl field is then made to point to this allocated 181da177e4SLinus Torvalds * block. If all extended attributes of an inode are identical, these 191da177e4SLinus Torvalds * inodes may share the same extended attribute block. Such situations 201da177e4SLinus Torvalds * are automatically detected by keeping a cache of recent attribute block 211da177e4SLinus Torvalds * numbers and hashes over the block's contents in memory. 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds * 241da177e4SLinus Torvalds * Extended attribute block layout: 251da177e4SLinus Torvalds * 261da177e4SLinus Torvalds * +------------------+ 271da177e4SLinus Torvalds * | header | 281da177e4SLinus Torvalds * | entry 1 | | 291da177e4SLinus Torvalds * | entry 2 | | growing downwards 301da177e4SLinus Torvalds * | entry 3 | v 311da177e4SLinus Torvalds * | four null bytes | 321da177e4SLinus Torvalds * | . . . | 331da177e4SLinus Torvalds * | value 1 | ^ 341da177e4SLinus Torvalds * | value 3 | | growing upwards 351da177e4SLinus Torvalds * | value 2 | | 361da177e4SLinus Torvalds * +------------------+ 371da177e4SLinus Torvalds * 381da177e4SLinus Torvalds * The block header is followed by multiple entry descriptors. These entry 3925985edcSLucas De Marchi * descriptors are variable in size, and aligned to EXT2_XATTR_PAD 401da177e4SLinus Torvalds * byte boundaries. The entry descriptors are sorted by attribute name, 411da177e4SLinus Torvalds * so that two extended attribute blocks can be compared efficiently. 421da177e4SLinus Torvalds * 431da177e4SLinus Torvalds * Attribute values are aligned to the end of the block, stored in 441da177e4SLinus Torvalds * no specific order. They are also padded to EXT2_XATTR_PAD byte 451da177e4SLinus Torvalds * boundaries. No additional gaps are left between them. 461da177e4SLinus Torvalds * 471da177e4SLinus Torvalds * Locking strategy 481da177e4SLinus Torvalds * ---------------- 491da177e4SLinus Torvalds * EXT2_I(inode)->i_file_acl is protected by EXT2_I(inode)->xattr_sem. 501da177e4SLinus Torvalds * EA blocks are only changed if they are exclusive to an inode, so 511da177e4SLinus Torvalds * holding xattr_sem also means that nothing but the EA block's reference 521da177e4SLinus Torvalds * count will change. Multiple writers to an EA block are synchronized 531da177e4SLinus Torvalds * by the bh lock. No more than a single bh lock is held at any time 541da177e4SLinus Torvalds * to avoid deadlocks. 551da177e4SLinus Torvalds */ 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds #include <linux/buffer_head.h> 581da177e4SLinus Torvalds #include <linux/init.h> 591da177e4SLinus Torvalds #include <linux/slab.h> 607a2508e1SJan Kara #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 { \ 81a1c6f057SDmitry Monakhov printk(KERN_DEBUG "block %pg:%lu: ", \ 82a1c6f057SDmitry Monakhov bh->b_bdev, (unsigned long) bh->b_blocknr); \ 831da177e4SLinus Torvalds printk(f); \ 841da177e4SLinus Torvalds printk("\n"); \ 851da177e4SLinus Torvalds } while (0) 861da177e4SLinus Torvalds #else 871da177e4SLinus Torvalds # define ea_idebug(f...) 881da177e4SLinus Torvalds # define ea_bdebug(f...) 891da177e4SLinus Torvalds #endif 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds static int ext2_xattr_set2(struct inode *, struct buffer_head *, 921da177e4SLinus Torvalds struct ext2_xattr_header *); 931da177e4SLinus Torvalds 947a2508e1SJan Kara static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *); 951da177e4SLinus Torvalds static struct buffer_head *ext2_xattr_cache_find(struct inode *, 961da177e4SLinus Torvalds struct ext2_xattr_header *); 971da177e4SLinus Torvalds static void ext2_xattr_rehash(struct ext2_xattr_header *, 981da177e4SLinus Torvalds struct ext2_xattr_entry *); 991da177e4SLinus Torvalds 100749c72efSStephen Hemminger static const struct xattr_handler *ext2_xattr_handler_map[] = { 1011da177e4SLinus Torvalds [EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler, 1021da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_POSIX_ACL 10364e178a7SChristoph Hellwig [EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 10464e178a7SChristoph Hellwig [EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 1051da177e4SLinus Torvalds #endif 1061da177e4SLinus Torvalds [EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler, 1071da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_SECURITY 1081da177e4SLinus Torvalds [EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler, 1091da177e4SLinus Torvalds #endif 1101da177e4SLinus Torvalds }; 1111da177e4SLinus Torvalds 112749c72efSStephen Hemminger const struct xattr_handler *ext2_xattr_handlers[] = { 1131da177e4SLinus Torvalds &ext2_xattr_user_handler, 1141da177e4SLinus Torvalds &ext2_xattr_trusted_handler, 1151da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_POSIX_ACL 11664e178a7SChristoph Hellwig &posix_acl_access_xattr_handler, 11764e178a7SChristoph Hellwig &posix_acl_default_xattr_handler, 1181da177e4SLinus Torvalds #endif 1191da177e4SLinus Torvalds #ifdef CONFIG_EXT2_FS_SECURITY 1201da177e4SLinus Torvalds &ext2_xattr_security_handler, 1211da177e4SLinus Torvalds #endif 1221da177e4SLinus Torvalds NULL 1231da177e4SLinus Torvalds }; 1241da177e4SLinus Torvalds 12547387409STahsin Erdogan #define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache) 12647387409STahsin Erdogan 127749c72efSStephen Hemminger static inline const struct xattr_handler * 1281da177e4SLinus Torvalds ext2_xattr_handler(int name_index) 1291da177e4SLinus Torvalds { 130749c72efSStephen Hemminger const struct xattr_handler *handler = NULL; 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map)) 1331da177e4SLinus Torvalds handler = ext2_xattr_handler_map[name_index]; 1341da177e4SLinus Torvalds return handler; 1351da177e4SLinus Torvalds } 1361da177e4SLinus Torvalds 13702475de9SChengguang Xu static bool 13802475de9SChengguang Xu ext2_xattr_header_valid(struct ext2_xattr_header *header) 13902475de9SChengguang Xu { 14002475de9SChengguang Xu if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) || 14102475de9SChengguang Xu header->h_blocks != cpu_to_le32(1)) 14202475de9SChengguang Xu return false; 14302475de9SChengguang Xu 14402475de9SChengguang Xu return true; 14502475de9SChengguang Xu } 14602475de9SChengguang Xu 1471da177e4SLinus Torvalds /* 1481da177e4SLinus Torvalds * ext2_xattr_get() 1491da177e4SLinus Torvalds * 1501da177e4SLinus Torvalds * Copy an extended attribute into the buffer 1511da177e4SLinus Torvalds * provided, or compute the buffer size required. 1521da177e4SLinus Torvalds * Buffer is NULL to compute the size of the buffer required. 1531da177e4SLinus Torvalds * 1541da177e4SLinus Torvalds * Returns a negative error number on failure, or the number of bytes 1551da177e4SLinus Torvalds * used / required on success. 1561da177e4SLinus Torvalds */ 1571da177e4SLinus Torvalds int 1581da177e4SLinus Torvalds ext2_xattr_get(struct inode *inode, int name_index, const char *name, 1591da177e4SLinus Torvalds void *buffer, size_t buffer_size) 1601da177e4SLinus Torvalds { 1611da177e4SLinus Torvalds struct buffer_head *bh = NULL; 1621da177e4SLinus Torvalds struct ext2_xattr_entry *entry; 1631da177e4SLinus Torvalds size_t name_len, size; 1641da177e4SLinus Torvalds char *end; 1651da177e4SLinus Torvalds int error; 16647387409STahsin Erdogan struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", 1691da177e4SLinus Torvalds name_index, name, buffer, (long)buffer_size); 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds if (name == NULL) 1721da177e4SLinus Torvalds return -EINVAL; 17303b5bb34SWang Sheng-Hui name_len = strlen(name); 17403b5bb34SWang Sheng-Hui if (name_len > 255) 17503b5bb34SWang Sheng-Hui return -ERANGE; 17603b5bb34SWang Sheng-Hui 1771da177e4SLinus Torvalds down_read(&EXT2_I(inode)->xattr_sem); 1781da177e4SLinus Torvalds error = -ENODATA; 1791da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 1801da177e4SLinus Torvalds goto cleanup; 1811da177e4SLinus Torvalds ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl); 1821da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 1831da177e4SLinus Torvalds error = -EIO; 1841da177e4SLinus Torvalds if (!bh) 1851da177e4SLinus Torvalds goto cleanup; 1861da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 1871da177e4SLinus Torvalds atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); 1881da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 18902475de9SChengguang Xu if (!ext2_xattr_header_valid(HDR(bh))) { 19002475de9SChengguang Xu bad_block: 19102475de9SChengguang Xu ext2_error(inode->i_sb, "ext2_xattr_get", 1921da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 1931da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 1941da177e4SLinus Torvalds error = -EIO; 1951da177e4SLinus Torvalds goto cleanup; 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds 19803b5bb34SWang Sheng-Hui /* find named attribute */ 1991da177e4SLinus Torvalds entry = FIRST_ENTRY(bh); 2001da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry)) { 2011da177e4SLinus Torvalds struct ext2_xattr_entry *next = 2021da177e4SLinus Torvalds EXT2_XATTR_NEXT(entry); 2031da177e4SLinus Torvalds if ((char *)next >= end) 2041da177e4SLinus Torvalds goto bad_block; 2051da177e4SLinus Torvalds if (name_index == entry->e_name_index && 2061da177e4SLinus Torvalds name_len == entry->e_name_len && 2071da177e4SLinus Torvalds memcmp(name, entry->e_name, name_len) == 0) 2081da177e4SLinus Torvalds goto found; 2091da177e4SLinus Torvalds entry = next; 2101da177e4SLinus Torvalds } 21147387409STahsin Erdogan if (ext2_xattr_cache_insert(ea_block_cache, bh)) 2121da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2131da177e4SLinus Torvalds error = -ENODATA; 2141da177e4SLinus Torvalds goto cleanup; 2151da177e4SLinus Torvalds found: 2161da177e4SLinus Torvalds /* check the buffer size */ 2171da177e4SLinus Torvalds if (entry->e_value_block != 0) 2181da177e4SLinus Torvalds goto bad_block; 2191da177e4SLinus Torvalds size = le32_to_cpu(entry->e_value_size); 2201da177e4SLinus Torvalds if (size > inode->i_sb->s_blocksize || 2211da177e4SLinus Torvalds le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize) 2221da177e4SLinus Torvalds goto bad_block; 2231da177e4SLinus Torvalds 22447387409STahsin Erdogan if (ext2_xattr_cache_insert(ea_block_cache, bh)) 2251da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2261da177e4SLinus Torvalds if (buffer) { 2271da177e4SLinus Torvalds error = -ERANGE; 2281da177e4SLinus Torvalds if (size > buffer_size) 2291da177e4SLinus Torvalds goto cleanup; 2301da177e4SLinus Torvalds /* return value of attribute */ 2311da177e4SLinus Torvalds memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), 2321da177e4SLinus Torvalds size); 2331da177e4SLinus Torvalds } 2341da177e4SLinus Torvalds error = size; 2351da177e4SLinus Torvalds 2361da177e4SLinus Torvalds cleanup: 2371da177e4SLinus Torvalds brelse(bh); 2381da177e4SLinus Torvalds up_read(&EXT2_I(inode)->xattr_sem); 2391da177e4SLinus Torvalds 2401da177e4SLinus Torvalds return error; 2411da177e4SLinus Torvalds } 2421da177e4SLinus Torvalds 2431da177e4SLinus Torvalds /* 2441da177e4SLinus Torvalds * ext2_xattr_list() 2451da177e4SLinus Torvalds * 2461da177e4SLinus Torvalds * Copy a list of attribute names into the buffer 2471da177e4SLinus Torvalds * provided, or compute the buffer size required. 2481da177e4SLinus Torvalds * Buffer is NULL to compute the size of the buffer required. 2491da177e4SLinus Torvalds * 2501da177e4SLinus Torvalds * Returns a negative error number on failure, or the number of bytes 2511da177e4SLinus Torvalds * used / required on success. 2521da177e4SLinus Torvalds */ 2531da177e4SLinus Torvalds static int 254431547b3SChristoph Hellwig ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) 2551da177e4SLinus Torvalds { 2562b0143b5SDavid Howells struct inode *inode = d_inode(dentry); 2571da177e4SLinus Torvalds struct buffer_head *bh = NULL; 2581da177e4SLinus Torvalds struct ext2_xattr_entry *entry; 2591da177e4SLinus Torvalds char *end; 2601da177e4SLinus Torvalds size_t rest = buffer_size; 2611da177e4SLinus Torvalds int error; 26247387409STahsin Erdogan struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds ea_idebug(inode, "buffer=%p, buffer_size=%ld", 2651da177e4SLinus Torvalds buffer, (long)buffer_size); 2661da177e4SLinus Torvalds 2671da177e4SLinus Torvalds down_read(&EXT2_I(inode)->xattr_sem); 2681da177e4SLinus Torvalds error = 0; 2691da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 2701da177e4SLinus Torvalds goto cleanup; 2711da177e4SLinus Torvalds ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl); 2721da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 2731da177e4SLinus Torvalds error = -EIO; 2741da177e4SLinus Torvalds if (!bh) 2751da177e4SLinus Torvalds goto cleanup; 2761da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 2771da177e4SLinus Torvalds atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount)); 2781da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 27902475de9SChengguang Xu if (!ext2_xattr_header_valid(HDR(bh))) { 28002475de9SChengguang Xu bad_block: 28102475de9SChengguang Xu ext2_error(inode->i_sb, "ext2_xattr_list", 2821da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 2831da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 2841da177e4SLinus Torvalds error = -EIO; 2851da177e4SLinus Torvalds goto cleanup; 2861da177e4SLinus Torvalds } 2871da177e4SLinus Torvalds 2881da177e4SLinus Torvalds /* check the on-disk data structure */ 2891da177e4SLinus Torvalds entry = FIRST_ENTRY(bh); 2901da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry)) { 2911da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry); 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds if ((char *)next >= end) 2941da177e4SLinus Torvalds goto bad_block; 2951da177e4SLinus Torvalds entry = next; 2961da177e4SLinus Torvalds } 29747387409STahsin Erdogan if (ext2_xattr_cache_insert(ea_block_cache, bh)) 2981da177e4SLinus Torvalds ea_idebug(inode, "cache insert failed"); 2991da177e4SLinus Torvalds 3001da177e4SLinus Torvalds /* list the attribute names */ 3011da177e4SLinus Torvalds for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry); 3021da177e4SLinus Torvalds entry = EXT2_XATTR_NEXT(entry)) { 303749c72efSStephen Hemminger const struct xattr_handler *handler = 3041da177e4SLinus Torvalds ext2_xattr_handler(entry->e_name_index); 3051da177e4SLinus Torvalds 306764a5c6bSAndreas Gruenbacher if (handler && (!handler->list || handler->list(dentry))) { 307764a5c6bSAndreas Gruenbacher const char *prefix = handler->prefix ?: handler->name; 308764a5c6bSAndreas Gruenbacher size_t prefix_len = strlen(prefix); 309764a5c6bSAndreas Gruenbacher size_t size = prefix_len + entry->e_name_len + 1; 310764a5c6bSAndreas Gruenbacher 3111da177e4SLinus Torvalds if (buffer) { 3121da177e4SLinus Torvalds if (size > rest) { 3131da177e4SLinus Torvalds error = -ERANGE; 3141da177e4SLinus Torvalds goto cleanup; 3151da177e4SLinus Torvalds } 316764a5c6bSAndreas Gruenbacher memcpy(buffer, prefix, prefix_len); 317764a5c6bSAndreas Gruenbacher buffer += prefix_len; 318764a5c6bSAndreas Gruenbacher memcpy(buffer, entry->e_name, entry->e_name_len); 319764a5c6bSAndreas Gruenbacher buffer += entry->e_name_len; 320764a5c6bSAndreas Gruenbacher *buffer++ = 0; 3211da177e4SLinus Torvalds } 3221da177e4SLinus Torvalds rest -= size; 3231da177e4SLinus Torvalds } 3241da177e4SLinus Torvalds } 3251da177e4SLinus Torvalds error = buffer_size - rest; /* total size */ 3261da177e4SLinus Torvalds 3271da177e4SLinus Torvalds cleanup: 3281da177e4SLinus Torvalds brelse(bh); 3291da177e4SLinus Torvalds up_read(&EXT2_I(inode)->xattr_sem); 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds return error; 3321da177e4SLinus Torvalds } 3331da177e4SLinus Torvalds 3341da177e4SLinus Torvalds /* 3351da177e4SLinus Torvalds * Inode operation listxattr() 3361da177e4SLinus Torvalds * 3372b0143b5SDavid Howells * d_inode(dentry)->i_mutex: don't care 3381da177e4SLinus Torvalds */ 3391da177e4SLinus Torvalds ssize_t 3401da177e4SLinus Torvalds ext2_listxattr(struct dentry *dentry, char *buffer, size_t size) 3411da177e4SLinus Torvalds { 342431547b3SChristoph Hellwig return ext2_xattr_list(dentry, buffer, size); 3431da177e4SLinus Torvalds } 3441da177e4SLinus Torvalds 3451da177e4SLinus Torvalds /* 3461da177e4SLinus Torvalds * If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is 3471da177e4SLinus Torvalds * not set, set it. 3481da177e4SLinus Torvalds */ 3491da177e4SLinus Torvalds static void ext2_xattr_update_super_block(struct super_block *sb) 3501da177e4SLinus Torvalds { 3511da177e4SLinus Torvalds if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR)) 3521da177e4SLinus Torvalds return; 3531da177e4SLinus Torvalds 354c15271f4SJan Blunck spin_lock(&EXT2_SB(sb)->s_lock); 355032cdc39SJan Kara ext2_update_dynamic_rev(sb); 356ed2908f3SAndreas Gruenbacher EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR); 357c15271f4SJan Blunck spin_unlock(&EXT2_SB(sb)->s_lock); 3581da177e4SLinus Torvalds mark_buffer_dirty(EXT2_SB(sb)->s_sbh); 3591da177e4SLinus Torvalds } 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds /* 3621da177e4SLinus Torvalds * ext2_xattr_set() 3631da177e4SLinus Torvalds * 3646e9510b0SWang Sheng-Hui * Create, replace or remove an extended attribute for this inode. Value 3651da177e4SLinus Torvalds * is NULL to remove an existing extended attribute, and non-NULL to 3661da177e4SLinus Torvalds * either replace an existing extended attribute, or create a new extended 3671da177e4SLinus Torvalds * attribute. The flags XATTR_REPLACE and XATTR_CREATE 3681da177e4SLinus Torvalds * specify that an extended attribute must exist and must not exist 3691da177e4SLinus Torvalds * previous to the call, respectively. 3701da177e4SLinus Torvalds * 3711da177e4SLinus Torvalds * Returns 0, or a negative error number on failure. 3721da177e4SLinus Torvalds */ 3731da177e4SLinus Torvalds int 3741da177e4SLinus Torvalds ext2_xattr_set(struct inode *inode, int name_index, const char *name, 3751da177e4SLinus Torvalds const void *value, size_t value_len, int flags) 3761da177e4SLinus Torvalds { 3771da177e4SLinus Torvalds struct super_block *sb = inode->i_sb; 3781da177e4SLinus Torvalds struct buffer_head *bh = NULL; 3791da177e4SLinus Torvalds struct ext2_xattr_header *header = NULL; 3801da177e4SLinus Torvalds struct ext2_xattr_entry *here, *last; 3811da177e4SLinus Torvalds size_t name_len, free, min_offs = sb->s_blocksize; 3821da177e4SLinus Torvalds int not_found = 1, error; 3831da177e4SLinus Torvalds char *end; 3841da177e4SLinus Torvalds 3851da177e4SLinus Torvalds /* 3861da177e4SLinus Torvalds * header -- Points either into bh, or to a temporarily 3871da177e4SLinus Torvalds * allocated buffer. 3881da177e4SLinus Torvalds * here -- The named entry found, or the place for inserting, within 3891da177e4SLinus Torvalds * the block pointed to by header. 3901da177e4SLinus Torvalds * last -- Points right after the last named entry within the block 3911da177e4SLinus Torvalds * pointed to by header. 3921da177e4SLinus Torvalds * min_offs -- The offset of the first value (values are aligned 3931da177e4SLinus Torvalds * towards the end of the block). 3941da177e4SLinus Torvalds * end -- Points right after the block pointed to by header. 3951da177e4SLinus Torvalds */ 3961da177e4SLinus Torvalds 3971da177e4SLinus Torvalds ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", 3981da177e4SLinus Torvalds name_index, name, value, (long)value_len); 3991da177e4SLinus Torvalds 4001da177e4SLinus Torvalds if (value == NULL) 4011da177e4SLinus Torvalds value_len = 0; 4021da177e4SLinus Torvalds if (name == NULL) 4031da177e4SLinus Torvalds return -EINVAL; 4041da177e4SLinus Torvalds name_len = strlen(name); 4051da177e4SLinus Torvalds if (name_len > 255 || value_len > sb->s_blocksize) 4061da177e4SLinus Torvalds return -ERANGE; 4071da177e4SLinus Torvalds down_write(&EXT2_I(inode)->xattr_sem); 4081da177e4SLinus Torvalds if (EXT2_I(inode)->i_file_acl) { 4091da177e4SLinus Torvalds /* The inode already has an extended attribute block. */ 4101da177e4SLinus Torvalds bh = sb_bread(sb, EXT2_I(inode)->i_file_acl); 4111da177e4SLinus Torvalds error = -EIO; 4121da177e4SLinus Torvalds if (!bh) 4131da177e4SLinus Torvalds goto cleanup; 4141da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d, refcount=%d", 4151da177e4SLinus Torvalds atomic_read(&(bh->b_count)), 4161da177e4SLinus Torvalds le32_to_cpu(HDR(bh)->h_refcount)); 4171da177e4SLinus Torvalds header = HDR(bh); 4181da177e4SLinus Torvalds end = bh->b_data + bh->b_size; 41902475de9SChengguang Xu if (!ext2_xattr_header_valid(header)) { 42002475de9SChengguang Xu bad_block: 42102475de9SChengguang Xu ext2_error(sb, "ext2_xattr_set", 4221da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 4231da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 4241da177e4SLinus Torvalds error = -EIO; 4251da177e4SLinus Torvalds goto cleanup; 4261da177e4SLinus Torvalds } 4271da177e4SLinus Torvalds /* Find the named attribute. */ 4281da177e4SLinus Torvalds here = FIRST_ENTRY(bh); 4291da177e4SLinus Torvalds while (!IS_LAST_ENTRY(here)) { 4301da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here); 4311da177e4SLinus Torvalds if ((char *)next >= end) 4321da177e4SLinus Torvalds goto bad_block; 4331da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 4341da177e4SLinus Torvalds size_t offs = le16_to_cpu(here->e_value_offs); 4351da177e4SLinus Torvalds if (offs < min_offs) 4361da177e4SLinus Torvalds min_offs = offs; 4371da177e4SLinus Torvalds } 4381da177e4SLinus Torvalds not_found = name_index - here->e_name_index; 4391da177e4SLinus Torvalds if (!not_found) 4401da177e4SLinus Torvalds not_found = name_len - here->e_name_len; 4411da177e4SLinus Torvalds if (!not_found) 4421da177e4SLinus Torvalds not_found = memcmp(name, here->e_name,name_len); 4431da177e4SLinus Torvalds if (not_found <= 0) 4441da177e4SLinus Torvalds break; 4451da177e4SLinus Torvalds here = next; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds last = here; 4481da177e4SLinus Torvalds /* We still need to compute min_offs and last. */ 4491da177e4SLinus Torvalds while (!IS_LAST_ENTRY(last)) { 4501da177e4SLinus Torvalds struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last); 4511da177e4SLinus Torvalds if ((char *)next >= end) 4521da177e4SLinus Torvalds goto bad_block; 4531da177e4SLinus Torvalds if (!last->e_value_block && last->e_value_size) { 4541da177e4SLinus Torvalds size_t offs = le16_to_cpu(last->e_value_offs); 4551da177e4SLinus Torvalds if (offs < min_offs) 4561da177e4SLinus Torvalds min_offs = offs; 4571da177e4SLinus Torvalds } 4581da177e4SLinus Torvalds last = next; 4591da177e4SLinus Torvalds } 4601da177e4SLinus Torvalds 4611da177e4SLinus Torvalds /* Check whether we have enough space left. */ 4621da177e4SLinus Torvalds free = min_offs - ((char*)last - (char*)header) - sizeof(__u32); 4631da177e4SLinus Torvalds } else { 4641da177e4SLinus Torvalds /* We will use a new extended attribute block. */ 4651da177e4SLinus Torvalds free = sb->s_blocksize - 4661da177e4SLinus Torvalds sizeof(struct ext2_xattr_header) - sizeof(__u32); 4671da177e4SLinus Torvalds here = last = NULL; /* avoid gcc uninitialized warning. */ 4681da177e4SLinus Torvalds } 4691da177e4SLinus Torvalds 4701da177e4SLinus Torvalds if (not_found) { 4711da177e4SLinus Torvalds /* Request to remove a nonexistent attribute? */ 4721da177e4SLinus Torvalds error = -ENODATA; 4731da177e4SLinus Torvalds if (flags & XATTR_REPLACE) 4741da177e4SLinus Torvalds goto cleanup; 4751da177e4SLinus Torvalds error = 0; 4761da177e4SLinus Torvalds if (value == NULL) 4771da177e4SLinus Torvalds goto cleanup; 4781da177e4SLinus Torvalds } else { 4791da177e4SLinus Torvalds /* Request to create an existing attribute? */ 4801da177e4SLinus Torvalds error = -EEXIST; 4811da177e4SLinus Torvalds if (flags & XATTR_CREATE) 4821da177e4SLinus Torvalds goto cleanup; 4831da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 4841da177e4SLinus Torvalds size_t size = le32_to_cpu(here->e_value_size); 4851da177e4SLinus Torvalds 4861da177e4SLinus Torvalds if (le16_to_cpu(here->e_value_offs) + size > 4871da177e4SLinus Torvalds sb->s_blocksize || size > sb->s_blocksize) 4881da177e4SLinus Torvalds goto bad_block; 4891da177e4SLinus Torvalds free += EXT2_XATTR_SIZE(size); 4901da177e4SLinus Torvalds } 4911da177e4SLinus Torvalds free += EXT2_XATTR_LEN(name_len); 4921da177e4SLinus Torvalds } 4931da177e4SLinus Torvalds error = -ENOSPC; 4941da177e4SLinus Torvalds if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len)) 4951da177e4SLinus Torvalds goto cleanup; 4961da177e4SLinus Torvalds 4971da177e4SLinus Torvalds /* Here we know that we can set the new attribute. */ 4981da177e4SLinus Torvalds 4991da177e4SLinus Torvalds if (header) { 5001da177e4SLinus Torvalds /* assert(header == HDR(bh)); */ 5011da177e4SLinus Torvalds lock_buffer(bh); 5021da177e4SLinus Torvalds if (header->h_refcount == cpu_to_le32(1)) { 503be0726d3SJan Kara __u32 hash = le32_to_cpu(header->h_hash); 504be0726d3SJan Kara 5051da177e4SLinus Torvalds ea_bdebug(bh, "modifying in-place"); 506be0726d3SJan Kara /* 507be0726d3SJan Kara * This must happen under buffer lock for 508be0726d3SJan Kara * ext2_xattr_set2() to reliably detect modified block 509be0726d3SJan Kara */ 51047387409STahsin Erdogan mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash, 511c07dfcb4STahsin Erdogan bh->b_blocknr); 512be0726d3SJan Kara 5131da177e4SLinus Torvalds /* keep the buffer locked while modifying it. */ 5141da177e4SLinus Torvalds } else { 5151da177e4SLinus Torvalds int offset; 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds unlock_buffer(bh); 5181da177e4SLinus Torvalds ea_bdebug(bh, "cloning"); 5191da177e4SLinus Torvalds header = kmalloc(bh->b_size, GFP_KERNEL); 5201da177e4SLinus Torvalds error = -ENOMEM; 5211da177e4SLinus Torvalds if (header == NULL) 5221da177e4SLinus Torvalds goto cleanup; 5231da177e4SLinus Torvalds memcpy(header, HDR(bh), bh->b_size); 5241da177e4SLinus Torvalds header->h_refcount = cpu_to_le32(1); 5251da177e4SLinus Torvalds 5261da177e4SLinus Torvalds offset = (char *)here - bh->b_data; 5271da177e4SLinus Torvalds here = ENTRY((char *)header + offset); 5281da177e4SLinus Torvalds offset = (char *)last - bh->b_data; 5291da177e4SLinus Torvalds last = ENTRY((char *)header + offset); 5301da177e4SLinus Torvalds } 5311da177e4SLinus Torvalds } else { 5321da177e4SLinus Torvalds /* Allocate a buffer where we construct the new block. */ 533f8314dc6SPanagiotis Issaris header = kzalloc(sb->s_blocksize, GFP_KERNEL); 5341da177e4SLinus Torvalds error = -ENOMEM; 5351da177e4SLinus Torvalds if (header == NULL) 5361da177e4SLinus Torvalds goto cleanup; 5371da177e4SLinus Torvalds end = (char *)header + sb->s_blocksize; 5381da177e4SLinus Torvalds header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC); 5391da177e4SLinus Torvalds header->h_blocks = header->h_refcount = cpu_to_le32(1); 5401da177e4SLinus Torvalds last = here = ENTRY(header+1); 5411da177e4SLinus Torvalds } 5421da177e4SLinus Torvalds 5431da177e4SLinus Torvalds /* Iff we are modifying the block in-place, bh is locked here. */ 5441da177e4SLinus Torvalds 5451da177e4SLinus Torvalds if (not_found) { 5461da177e4SLinus Torvalds /* Insert the new name. */ 5471da177e4SLinus Torvalds size_t size = EXT2_XATTR_LEN(name_len); 5481da177e4SLinus Torvalds size_t rest = (char *)last - (char *)here; 5491da177e4SLinus Torvalds memmove((char *)here + size, here, rest); 5501da177e4SLinus Torvalds memset(here, 0, size); 5511da177e4SLinus Torvalds here->e_name_index = name_index; 5521da177e4SLinus Torvalds here->e_name_len = name_len; 5531da177e4SLinus Torvalds memcpy(here->e_name, name, name_len); 5541da177e4SLinus Torvalds } else { 5551da177e4SLinus Torvalds if (!here->e_value_block && here->e_value_size) { 5561da177e4SLinus Torvalds char *first_val = (char *)header + min_offs; 5571da177e4SLinus Torvalds size_t offs = le16_to_cpu(here->e_value_offs); 5581da177e4SLinus Torvalds char *val = (char *)header + offs; 5591da177e4SLinus Torvalds size_t size = EXT2_XATTR_SIZE( 5601da177e4SLinus Torvalds le32_to_cpu(here->e_value_size)); 5611da177e4SLinus Torvalds 5621da177e4SLinus Torvalds if (size == EXT2_XATTR_SIZE(value_len)) { 5631da177e4SLinus Torvalds /* The old and the new value have the same 5641da177e4SLinus Torvalds size. Just replace. */ 5651da177e4SLinus Torvalds here->e_value_size = cpu_to_le32(value_len); 5661da177e4SLinus Torvalds memset(val + size - EXT2_XATTR_PAD, 0, 5671da177e4SLinus Torvalds EXT2_XATTR_PAD); /* Clear pad bytes. */ 5681da177e4SLinus Torvalds memcpy(val, value, value_len); 5691da177e4SLinus Torvalds goto skip_replace; 5701da177e4SLinus Torvalds } 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds /* Remove the old value. */ 5731da177e4SLinus Torvalds memmove(first_val + size, first_val, val - first_val); 5741da177e4SLinus Torvalds memset(first_val, 0, size); 5751da177e4SLinus Torvalds here->e_value_offs = 0; 5761da177e4SLinus Torvalds min_offs += size; 5771da177e4SLinus Torvalds 5781da177e4SLinus Torvalds /* Adjust all value offsets. */ 5791da177e4SLinus Torvalds last = ENTRY(header+1); 5801da177e4SLinus Torvalds while (!IS_LAST_ENTRY(last)) { 5811da177e4SLinus Torvalds size_t o = le16_to_cpu(last->e_value_offs); 5821da177e4SLinus Torvalds if (!last->e_value_block && o < offs) 5831da177e4SLinus Torvalds last->e_value_offs = 5841da177e4SLinus Torvalds cpu_to_le16(o + size); 5851da177e4SLinus Torvalds last = EXT2_XATTR_NEXT(last); 5861da177e4SLinus Torvalds } 5871da177e4SLinus Torvalds } 5881da177e4SLinus Torvalds if (value == NULL) { 5891da177e4SLinus Torvalds /* Remove the old name. */ 5901da177e4SLinus Torvalds size_t size = EXT2_XATTR_LEN(name_len); 5911da177e4SLinus Torvalds last = ENTRY((char *)last - size); 5921da177e4SLinus Torvalds memmove(here, (char*)here + size, 5931da177e4SLinus Torvalds (char*)last - (char*)here); 5941da177e4SLinus Torvalds memset(last, 0, size); 5951da177e4SLinus Torvalds } 5961da177e4SLinus Torvalds } 5971da177e4SLinus Torvalds 5981da177e4SLinus Torvalds if (value != NULL) { 5991da177e4SLinus Torvalds /* Insert the new value. */ 6001da177e4SLinus Torvalds here->e_value_size = cpu_to_le32(value_len); 6011da177e4SLinus Torvalds if (value_len) { 6021da177e4SLinus Torvalds size_t size = EXT2_XATTR_SIZE(value_len); 6031da177e4SLinus Torvalds char *val = (char *)header + min_offs - size; 6041da177e4SLinus Torvalds here->e_value_offs = 6051da177e4SLinus Torvalds cpu_to_le16((char *)val - (char *)header); 6061da177e4SLinus Torvalds memset(val + size - EXT2_XATTR_PAD, 0, 6071da177e4SLinus Torvalds EXT2_XATTR_PAD); /* Clear the pad bytes. */ 6081da177e4SLinus Torvalds memcpy(val, value, value_len); 6091da177e4SLinus Torvalds } 6101da177e4SLinus Torvalds } 6111da177e4SLinus Torvalds 6121da177e4SLinus Torvalds skip_replace: 6131da177e4SLinus Torvalds if (IS_LAST_ENTRY(ENTRY(header+1))) { 6141da177e4SLinus Torvalds /* This block is now empty. */ 6151da177e4SLinus Torvalds if (bh && header == HDR(bh)) 6161da177e4SLinus Torvalds unlock_buffer(bh); /* we were modifying in-place. */ 6171da177e4SLinus Torvalds error = ext2_xattr_set2(inode, bh, NULL); 6181da177e4SLinus Torvalds } else { 6191da177e4SLinus Torvalds ext2_xattr_rehash(header, here); 6201da177e4SLinus Torvalds if (bh && header == HDR(bh)) 6211da177e4SLinus Torvalds unlock_buffer(bh); /* we were modifying in-place. */ 6221da177e4SLinus Torvalds error = ext2_xattr_set2(inode, bh, header); 6231da177e4SLinus Torvalds } 6241da177e4SLinus Torvalds 6251da177e4SLinus Torvalds cleanup: 6261da177e4SLinus Torvalds if (!(bh && header == HDR(bh))) 6271da177e4SLinus Torvalds kfree(header); 628ecebf55dSPan Bian brelse(bh); 6291da177e4SLinus Torvalds up_write(&EXT2_I(inode)->xattr_sem); 6301da177e4SLinus Torvalds 6311da177e4SLinus Torvalds return error; 6321da177e4SLinus Torvalds } 6331da177e4SLinus Torvalds 6341da177e4SLinus Torvalds /* 6351da177e4SLinus Torvalds * Second half of ext2_xattr_set(): Update the file system. 6361da177e4SLinus Torvalds */ 6371da177e4SLinus Torvalds static int 6381da177e4SLinus Torvalds ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, 6391da177e4SLinus Torvalds struct ext2_xattr_header *header) 6401da177e4SLinus Torvalds { 6411da177e4SLinus Torvalds struct super_block *sb = inode->i_sb; 6421da177e4SLinus Torvalds struct buffer_head *new_bh = NULL; 6431da177e4SLinus Torvalds int error; 64447387409STahsin Erdogan struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 6451da177e4SLinus Torvalds 6461da177e4SLinus Torvalds if (header) { 6471da177e4SLinus Torvalds new_bh = ext2_xattr_cache_find(inode, header); 6481da177e4SLinus Torvalds if (new_bh) { 6491da177e4SLinus Torvalds /* We found an identical block in the cache. */ 6501da177e4SLinus Torvalds if (new_bh == old_bh) { 6511da177e4SLinus Torvalds ea_bdebug(new_bh, "keeping this block"); 6521da177e4SLinus Torvalds } else { 6531da177e4SLinus Torvalds /* The old block is released after updating 6541da177e4SLinus Torvalds the inode. */ 6551da177e4SLinus Torvalds ea_bdebug(new_bh, "reusing block"); 6561da177e4SLinus Torvalds 6575dd4056dSChristoph Hellwig error = dquot_alloc_block(inode, 1); 6585dd4056dSChristoph Hellwig if (error) { 6591da177e4SLinus Torvalds unlock_buffer(new_bh); 6601da177e4SLinus Torvalds goto cleanup; 6611da177e4SLinus Torvalds } 662fba4d399SMarcin Slusarz le32_add_cpu(&HDR(new_bh)->h_refcount, 1); 6631da177e4SLinus Torvalds ea_bdebug(new_bh, "refcount now=%d", 6641da177e4SLinus Torvalds le32_to_cpu(HDR(new_bh)->h_refcount)); 6651da177e4SLinus Torvalds } 6661da177e4SLinus Torvalds unlock_buffer(new_bh); 6671da177e4SLinus Torvalds } else if (old_bh && header == HDR(old_bh)) { 6681da177e4SLinus Torvalds /* Keep this block. No need to lock the block as we 6691da177e4SLinus Torvalds don't need to change the reference count. */ 6701da177e4SLinus Torvalds new_bh = old_bh; 6711da177e4SLinus Torvalds get_bh(new_bh); 67247387409STahsin Erdogan ext2_xattr_cache_insert(ea_block_cache, new_bh); 6731da177e4SLinus Torvalds } else { 6741da177e4SLinus Torvalds /* We need to allocate a new block */ 67524097d12SAkinobu Mita ext2_fsblk_t goal = ext2_group_first_block_no(sb, 67624097d12SAkinobu Mita EXT2_I(inode)->i_block_group); 677a686cd89SMartin J. Bligh int block = ext2_new_block(inode, goal, &error); 6781da177e4SLinus Torvalds if (error) 6791da177e4SLinus Torvalds goto cleanup; 6801da177e4SLinus Torvalds ea_idebug(inode, "creating block %d", block); 6811da177e4SLinus Torvalds 6821da177e4SLinus Torvalds new_bh = sb_getblk(sb, block); 6832b0542a4SWang Shilong if (unlikely(!new_bh)) { 6841da177e4SLinus Torvalds ext2_free_blocks(inode, block, 1); 685addacc7dSAl Viro mark_inode_dirty(inode); 686ab6a773dSWang Shilong error = -ENOMEM; 6871da177e4SLinus Torvalds goto cleanup; 6881da177e4SLinus Torvalds } 6891da177e4SLinus Torvalds lock_buffer(new_bh); 6901da177e4SLinus Torvalds memcpy(new_bh->b_data, header, new_bh->b_size); 6911da177e4SLinus Torvalds set_buffer_uptodate(new_bh); 6921da177e4SLinus Torvalds unlock_buffer(new_bh); 69347387409STahsin Erdogan ext2_xattr_cache_insert(ea_block_cache, new_bh); 6941da177e4SLinus Torvalds 6951da177e4SLinus Torvalds ext2_xattr_update_super_block(sb); 6961da177e4SLinus Torvalds } 6971da177e4SLinus Torvalds mark_buffer_dirty(new_bh); 6981da177e4SLinus Torvalds if (IS_SYNC(inode)) { 6991da177e4SLinus Torvalds sync_dirty_buffer(new_bh); 7001da177e4SLinus Torvalds error = -EIO; 7011da177e4SLinus Torvalds if (buffer_req(new_bh) && !buffer_uptodate(new_bh)) 7021da177e4SLinus Torvalds goto cleanup; 7031da177e4SLinus Torvalds } 7041da177e4SLinus Torvalds } 7051da177e4SLinus Torvalds 7061da177e4SLinus Torvalds /* Update the inode. */ 7071da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; 70802027d42SDeepa Dinamani inode->i_ctime = current_time(inode); 7091da177e4SLinus Torvalds if (IS_SYNC(inode)) { 710c3765016SChristoph Hellwig error = sync_inode_metadata(inode, 1); 7111da177e4SLinus Torvalds /* In case sync failed due to ENOSPC the inode was actually 7121da177e4SLinus Torvalds * written (only some dirty data were not) so we just proceed 7131da177e4SLinus Torvalds * as if nothing happened and cleanup the unused block */ 7141da177e4SLinus Torvalds if (error && error != -ENOSPC) { 7153889717dSAl Viro if (new_bh && new_bh != old_bh) { 7163889717dSAl Viro dquot_free_block_nodirty(inode, 1); 7173889717dSAl Viro mark_inode_dirty(inode); 7183889717dSAl Viro } 7191da177e4SLinus Torvalds goto cleanup; 7201da177e4SLinus Torvalds } 7211da177e4SLinus Torvalds } else 7221da177e4SLinus Torvalds mark_inode_dirty(inode); 7231da177e4SLinus Torvalds 7241da177e4SLinus Torvalds error = 0; 7251da177e4SLinus Torvalds if (old_bh && old_bh != new_bh) { 7261da177e4SLinus Torvalds /* 7271da177e4SLinus Torvalds * If there was an old block and we are no longer using it, 7281da177e4SLinus Torvalds * release the old block. 7291da177e4SLinus Torvalds */ 7301da177e4SLinus Torvalds lock_buffer(old_bh); 7311da177e4SLinus Torvalds if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) { 732be0726d3SJan Kara __u32 hash = le32_to_cpu(HDR(old_bh)->h_hash); 733be0726d3SJan Kara 734be0726d3SJan Kara /* 735be0726d3SJan Kara * This must happen under buffer lock for 736be0726d3SJan Kara * ext2_xattr_set2() to reliably detect freed block 737be0726d3SJan Kara */ 73847387409STahsin Erdogan mb_cache_entry_delete(ea_block_cache, hash, 739c07dfcb4STahsin Erdogan old_bh->b_blocknr); 7401da177e4SLinus Torvalds /* Free the old block. */ 7411da177e4SLinus Torvalds ea_bdebug(old_bh, "freeing"); 7421da177e4SLinus Torvalds ext2_free_blocks(inode, old_bh->b_blocknr, 1); 743addacc7dSAl Viro mark_inode_dirty(inode); 7441da177e4SLinus Torvalds /* We let our caller release old_bh, so we 7451da177e4SLinus Torvalds * need to duplicate the buffer before. */ 7461da177e4SLinus Torvalds get_bh(old_bh); 7471da177e4SLinus Torvalds bforget(old_bh); 7481da177e4SLinus Torvalds } else { 7491da177e4SLinus Torvalds /* Decrement the refcount only. */ 750fba4d399SMarcin Slusarz le32_add_cpu(&HDR(old_bh)->h_refcount, -1); 7513889717dSAl Viro dquot_free_block_nodirty(inode, 1); 7523889717dSAl Viro mark_inode_dirty(inode); 7531da177e4SLinus Torvalds mark_buffer_dirty(old_bh); 7541da177e4SLinus Torvalds ea_bdebug(old_bh, "refcount now=%d", 7551da177e4SLinus Torvalds le32_to_cpu(HDR(old_bh)->h_refcount)); 7561da177e4SLinus Torvalds } 7571da177e4SLinus Torvalds unlock_buffer(old_bh); 7581da177e4SLinus Torvalds } 7591da177e4SLinus Torvalds 7601da177e4SLinus Torvalds cleanup: 7611da177e4SLinus Torvalds brelse(new_bh); 7621da177e4SLinus Torvalds 7631da177e4SLinus Torvalds return error; 7641da177e4SLinus Torvalds } 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds /* 7671da177e4SLinus Torvalds * ext2_xattr_delete_inode() 7681da177e4SLinus Torvalds * 7691da177e4SLinus Torvalds * Free extended attribute resources associated with this inode. This 7701da177e4SLinus Torvalds * is called immediately before an inode is freed. 7711da177e4SLinus Torvalds */ 7721da177e4SLinus Torvalds void 7731da177e4SLinus Torvalds ext2_xattr_delete_inode(struct inode *inode) 7741da177e4SLinus Torvalds { 7751da177e4SLinus Torvalds struct buffer_head *bh = NULL; 776ff0031d8SCarlos Maiolino struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); 7771da177e4SLinus Torvalds 7781da177e4SLinus Torvalds down_write(&EXT2_I(inode)->xattr_sem); 7791da177e4SLinus Torvalds if (!EXT2_I(inode)->i_file_acl) 7801da177e4SLinus Torvalds goto cleanup; 781ff0031d8SCarlos Maiolino 782ff0031d8SCarlos Maiolino if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 0)) { 783ff0031d8SCarlos Maiolino ext2_error(inode->i_sb, "ext2_xattr_delete_inode", 784ff0031d8SCarlos Maiolino "inode %ld: xattr block %d is out of data blocks range", 785ff0031d8SCarlos Maiolino inode->i_ino, EXT2_I(inode)->i_file_acl); 786ff0031d8SCarlos Maiolino goto cleanup; 787ff0031d8SCarlos Maiolino } 788ff0031d8SCarlos Maiolino 7891da177e4SLinus Torvalds bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl); 7901da177e4SLinus Torvalds if (!bh) { 7911da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_delete_inode", 7921da177e4SLinus Torvalds "inode %ld: block %d read error", inode->i_ino, 7931da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 7941da177e4SLinus Torvalds goto cleanup; 7951da177e4SLinus Torvalds } 7961da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count))); 79702475de9SChengguang Xu if (!ext2_xattr_header_valid(HDR(bh))) { 7981da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_delete_inode", 7991da177e4SLinus Torvalds "inode %ld: bad block %d", inode->i_ino, 8001da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl); 8011da177e4SLinus Torvalds goto cleanup; 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds lock_buffer(bh); 8041da177e4SLinus Torvalds if (HDR(bh)->h_refcount == cpu_to_le32(1)) { 805be0726d3SJan Kara __u32 hash = le32_to_cpu(HDR(bh)->h_hash); 806be0726d3SJan Kara 807be0726d3SJan Kara /* 808be0726d3SJan Kara * This must happen under buffer lock for ext2_xattr_set2() to 809be0726d3SJan Kara * reliably detect freed block 810be0726d3SJan Kara */ 81147387409STahsin Erdogan mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash, 812c07dfcb4STahsin Erdogan bh->b_blocknr); 8131da177e4SLinus Torvalds ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1); 8141da177e4SLinus Torvalds get_bh(bh); 8151da177e4SLinus Torvalds bforget(bh); 816b2f49033SPeter Staubach unlock_buffer(bh); 8171da177e4SLinus Torvalds } else { 818fba4d399SMarcin Slusarz le32_add_cpu(&HDR(bh)->h_refcount, -1); 819b2f49033SPeter Staubach ea_bdebug(bh, "refcount now=%d", 820b2f49033SPeter Staubach le32_to_cpu(HDR(bh)->h_refcount)); 821b2f49033SPeter Staubach unlock_buffer(bh); 8221da177e4SLinus Torvalds mark_buffer_dirty(bh); 8231da177e4SLinus Torvalds if (IS_SYNC(inode)) 8241da177e4SLinus Torvalds sync_dirty_buffer(bh); 8253889717dSAl Viro dquot_free_block_nodirty(inode, 1); 8261da177e4SLinus Torvalds } 8271da177e4SLinus Torvalds EXT2_I(inode)->i_file_acl = 0; 8281da177e4SLinus Torvalds 8291da177e4SLinus Torvalds cleanup: 8301da177e4SLinus Torvalds brelse(bh); 8311da177e4SLinus Torvalds up_write(&EXT2_I(inode)->xattr_sem); 8321da177e4SLinus Torvalds } 8331da177e4SLinus Torvalds 8341da177e4SLinus Torvalds /* 8351da177e4SLinus Torvalds * ext2_xattr_cache_insert() 8361da177e4SLinus Torvalds * 8371da177e4SLinus Torvalds * Create a new entry in the extended attribute cache, and insert 8381da177e4SLinus Torvalds * it unless such an entry is already in the cache. 8391da177e4SLinus Torvalds * 8401da177e4SLinus Torvalds * Returns 0, or a negative error number on failure. 8411da177e4SLinus Torvalds */ 8421da177e4SLinus Torvalds static int 8437a2508e1SJan Kara ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh) 8441da177e4SLinus Torvalds { 8451da177e4SLinus Torvalds __u32 hash = le32_to_cpu(HDR(bh)->h_hash); 8461da177e4SLinus Torvalds int error; 8471da177e4SLinus Torvalds 8483e159b95SChengguang Xu error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 8493e159b95SChengguang Xu true); 8501da177e4SLinus Torvalds if (error) { 8511da177e4SLinus Torvalds if (error == -EBUSY) { 8521da177e4SLinus Torvalds ea_bdebug(bh, "already in cache (%d cache entries)", 8531da177e4SLinus Torvalds atomic_read(&ext2_xattr_cache->c_entry_count)); 8541da177e4SLinus Torvalds error = 0; 8551da177e4SLinus Torvalds } 856be0726d3SJan Kara } else 857be0726d3SJan Kara ea_bdebug(bh, "inserting [%x]", (int)hash); 8581da177e4SLinus Torvalds return error; 8591da177e4SLinus Torvalds } 8601da177e4SLinus Torvalds 8611da177e4SLinus Torvalds /* 8621da177e4SLinus Torvalds * ext2_xattr_cmp() 8631da177e4SLinus Torvalds * 8641da177e4SLinus Torvalds * Compare two extended attribute blocks for equality. 8651da177e4SLinus Torvalds * 8661da177e4SLinus Torvalds * Returns 0 if the blocks are equal, 1 if they differ, and 8671da177e4SLinus Torvalds * a negative error number on errors. 8681da177e4SLinus Torvalds */ 8691da177e4SLinus Torvalds static int 8701da177e4SLinus Torvalds ext2_xattr_cmp(struct ext2_xattr_header *header1, 8711da177e4SLinus Torvalds struct ext2_xattr_header *header2) 8721da177e4SLinus Torvalds { 8731da177e4SLinus Torvalds struct ext2_xattr_entry *entry1, *entry2; 8741da177e4SLinus Torvalds 8751da177e4SLinus Torvalds entry1 = ENTRY(header1+1); 8761da177e4SLinus Torvalds entry2 = ENTRY(header2+1); 8771da177e4SLinus Torvalds while (!IS_LAST_ENTRY(entry1)) { 8781da177e4SLinus Torvalds if (IS_LAST_ENTRY(entry2)) 8791da177e4SLinus Torvalds return 1; 8801da177e4SLinus Torvalds if (entry1->e_hash != entry2->e_hash || 8811da177e4SLinus Torvalds entry1->e_name_index != entry2->e_name_index || 8821da177e4SLinus Torvalds entry1->e_name_len != entry2->e_name_len || 8831da177e4SLinus Torvalds entry1->e_value_size != entry2->e_value_size || 8841da177e4SLinus Torvalds memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) 8851da177e4SLinus Torvalds return 1; 8861da177e4SLinus Torvalds if (entry1->e_value_block != 0 || entry2->e_value_block != 0) 8871da177e4SLinus Torvalds return -EIO; 8881da177e4SLinus Torvalds if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), 8891da177e4SLinus Torvalds (char *)header2 + le16_to_cpu(entry2->e_value_offs), 8901da177e4SLinus Torvalds le32_to_cpu(entry1->e_value_size))) 8911da177e4SLinus Torvalds return 1; 8921da177e4SLinus Torvalds 8931da177e4SLinus Torvalds entry1 = EXT2_XATTR_NEXT(entry1); 8941da177e4SLinus Torvalds entry2 = EXT2_XATTR_NEXT(entry2); 8951da177e4SLinus Torvalds } 8961da177e4SLinus Torvalds if (!IS_LAST_ENTRY(entry2)) 8971da177e4SLinus Torvalds return 1; 8981da177e4SLinus Torvalds return 0; 8991da177e4SLinus Torvalds } 9001da177e4SLinus Torvalds 9011da177e4SLinus Torvalds /* 9021da177e4SLinus Torvalds * ext2_xattr_cache_find() 9031da177e4SLinus Torvalds * 9041da177e4SLinus Torvalds * Find an identical extended attribute block. 9051da177e4SLinus Torvalds * 9061da177e4SLinus Torvalds * Returns a locked buffer head to the block found, or NULL if such 9071da177e4SLinus Torvalds * a block was not found or an error occurred. 9081da177e4SLinus Torvalds */ 9091da177e4SLinus Torvalds static struct buffer_head * 9101da177e4SLinus Torvalds ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header) 9111da177e4SLinus Torvalds { 9121da177e4SLinus Torvalds __u32 hash = le32_to_cpu(header->h_hash); 9137a2508e1SJan Kara struct mb_cache_entry *ce; 91447387409STahsin Erdogan struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); 9151da177e4SLinus Torvalds 9161da177e4SLinus Torvalds if (!header->h_hash) 9171da177e4SLinus Torvalds return NULL; /* never share */ 9181da177e4SLinus Torvalds ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); 9191da177e4SLinus Torvalds again: 92047387409STahsin Erdogan ce = mb_cache_entry_find_first(ea_block_cache, hash); 9211da177e4SLinus Torvalds while (ce) { 9221da177e4SLinus Torvalds struct buffer_head *bh; 9231da177e4SLinus Torvalds 924c07dfcb4STahsin Erdogan bh = sb_bread(inode->i_sb, ce->e_value); 9251da177e4SLinus Torvalds if (!bh) { 9261da177e4SLinus Torvalds ext2_error(inode->i_sb, "ext2_xattr_cache_find", 9271da177e4SLinus Torvalds "inode %ld: block %ld read error", 928c07dfcb4STahsin Erdogan inode->i_ino, (unsigned long) ce->e_value); 9291da177e4SLinus Torvalds } else { 9301da177e4SLinus Torvalds lock_buffer(bh); 931be0726d3SJan Kara /* 932be0726d3SJan Kara * We have to be careful about races with freeing or 933be0726d3SJan Kara * rehashing of xattr block. Once we hold buffer lock 934be0726d3SJan Kara * xattr block's state is stable so we can check 935be0726d3SJan Kara * whether the block got freed / rehashed or not. 936be0726d3SJan Kara * Since we unhash mbcache entry under buffer lock when 937be0726d3SJan Kara * freeing / rehashing xattr block, checking whether 938be0726d3SJan Kara * entry is still hashed is reliable. 939be0726d3SJan Kara */ 940be0726d3SJan Kara if (hlist_bl_unhashed(&ce->e_hash_list)) { 94147387409STahsin Erdogan mb_cache_entry_put(ea_block_cache, ce); 942be0726d3SJan Kara unlock_buffer(bh); 943be0726d3SJan Kara brelse(bh); 944be0726d3SJan Kara goto again; 945be0726d3SJan Kara } else if (le32_to_cpu(HDR(bh)->h_refcount) > 9461da177e4SLinus Torvalds EXT2_XATTR_REFCOUNT_MAX) { 9471da177e4SLinus Torvalds ea_idebug(inode, "block %ld refcount %d>%d", 948c07dfcb4STahsin Erdogan (unsigned long) ce->e_value, 9491da177e4SLinus Torvalds le32_to_cpu(HDR(bh)->h_refcount), 9501da177e4SLinus Torvalds EXT2_XATTR_REFCOUNT_MAX); 9511da177e4SLinus Torvalds } else if (!ext2_xattr_cmp(header, HDR(bh))) { 9521da177e4SLinus Torvalds ea_bdebug(bh, "b_count=%d", 9531da177e4SLinus Torvalds atomic_read(&(bh->b_count))); 95447387409STahsin Erdogan mb_cache_entry_touch(ea_block_cache, ce); 95547387409STahsin Erdogan mb_cache_entry_put(ea_block_cache, ce); 9561da177e4SLinus Torvalds return bh; 9571da177e4SLinus Torvalds } 9581da177e4SLinus Torvalds unlock_buffer(bh); 9591da177e4SLinus Torvalds brelse(bh); 9601da177e4SLinus Torvalds } 96147387409STahsin Erdogan ce = mb_cache_entry_find_next(ea_block_cache, ce); 9621da177e4SLinus Torvalds } 9631da177e4SLinus Torvalds return NULL; 9641da177e4SLinus Torvalds } 9651da177e4SLinus Torvalds 9661da177e4SLinus Torvalds #define NAME_HASH_SHIFT 5 9671da177e4SLinus Torvalds #define VALUE_HASH_SHIFT 16 9681da177e4SLinus Torvalds 9691da177e4SLinus Torvalds /* 9701da177e4SLinus Torvalds * ext2_xattr_hash_entry() 9711da177e4SLinus Torvalds * 9721da177e4SLinus Torvalds * Compute the hash of an extended attribute. 9731da177e4SLinus Torvalds */ 9741da177e4SLinus Torvalds static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header, 9751da177e4SLinus Torvalds struct ext2_xattr_entry *entry) 9761da177e4SLinus Torvalds { 9771da177e4SLinus Torvalds __u32 hash = 0; 9781da177e4SLinus Torvalds char *name = entry->e_name; 9791da177e4SLinus Torvalds int n; 9801da177e4SLinus Torvalds 9811da177e4SLinus Torvalds for (n=0; n < entry->e_name_len; n++) { 9821da177e4SLinus Torvalds hash = (hash << NAME_HASH_SHIFT) ^ 9831da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ 9841da177e4SLinus Torvalds *name++; 9851da177e4SLinus Torvalds } 9861da177e4SLinus Torvalds 9871da177e4SLinus Torvalds if (entry->e_value_block == 0 && entry->e_value_size != 0) { 9881da177e4SLinus Torvalds __le32 *value = (__le32 *)((char *)header + 9891da177e4SLinus Torvalds le16_to_cpu(entry->e_value_offs)); 9901da177e4SLinus Torvalds for (n = (le32_to_cpu(entry->e_value_size) + 9911da177e4SLinus Torvalds EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) { 9921da177e4SLinus Torvalds hash = (hash << VALUE_HASH_SHIFT) ^ 9931da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ 9941da177e4SLinus Torvalds le32_to_cpu(*value++); 9951da177e4SLinus Torvalds } 9961da177e4SLinus Torvalds } 9971da177e4SLinus Torvalds entry->e_hash = cpu_to_le32(hash); 9981da177e4SLinus Torvalds } 9991da177e4SLinus Torvalds 10001da177e4SLinus Torvalds #undef NAME_HASH_SHIFT 10011da177e4SLinus Torvalds #undef VALUE_HASH_SHIFT 10021da177e4SLinus Torvalds 10031da177e4SLinus Torvalds #define BLOCK_HASH_SHIFT 16 10041da177e4SLinus Torvalds 10051da177e4SLinus Torvalds /* 10061da177e4SLinus Torvalds * ext2_xattr_rehash() 10071da177e4SLinus Torvalds * 10081da177e4SLinus Torvalds * Re-compute the extended attribute hash value after an entry has changed. 10091da177e4SLinus Torvalds */ 10101da177e4SLinus Torvalds static void ext2_xattr_rehash(struct ext2_xattr_header *header, 10111da177e4SLinus Torvalds struct ext2_xattr_entry *entry) 10121da177e4SLinus Torvalds { 10131da177e4SLinus Torvalds struct ext2_xattr_entry *here; 10141da177e4SLinus Torvalds __u32 hash = 0; 10151da177e4SLinus Torvalds 10161da177e4SLinus Torvalds ext2_xattr_hash_entry(header, entry); 10171da177e4SLinus Torvalds here = ENTRY(header+1); 10181da177e4SLinus Torvalds while (!IS_LAST_ENTRY(here)) { 10191da177e4SLinus Torvalds if (!here->e_hash) { 10201da177e4SLinus Torvalds /* Block is not shared if an entry's hash value == 0 */ 10211da177e4SLinus Torvalds hash = 0; 10221da177e4SLinus Torvalds break; 10231da177e4SLinus Torvalds } 10241da177e4SLinus Torvalds hash = (hash << BLOCK_HASH_SHIFT) ^ 10251da177e4SLinus Torvalds (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ 10261da177e4SLinus Torvalds le32_to_cpu(here->e_hash); 10271da177e4SLinus Torvalds here = EXT2_XATTR_NEXT(here); 10281da177e4SLinus Torvalds } 10291da177e4SLinus Torvalds header->h_hash = cpu_to_le32(hash); 10301da177e4SLinus Torvalds } 10311da177e4SLinus Torvalds 10321da177e4SLinus Torvalds #undef BLOCK_HASH_SHIFT 10331da177e4SLinus Torvalds 1034be0726d3SJan Kara #define HASH_BUCKET_BITS 10 1035be0726d3SJan Kara 10367a2508e1SJan Kara struct mb_cache *ext2_xattr_create_cache(void) 10371da177e4SLinus Torvalds { 10387a2508e1SJan Kara return mb_cache_create(HASH_BUCKET_BITS); 10391da177e4SLinus Torvalds } 10401da177e4SLinus Torvalds 10417a2508e1SJan Kara void ext2_xattr_destroy_cache(struct mb_cache *cache) 10421da177e4SLinus Torvalds { 1043be0726d3SJan Kara if (cache) 10447a2508e1SJan Kara mb_cache_destroy(cache); 10451da177e4SLinus Torvalds } 1046