diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ext4/xattr.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ext4/xattr.c | 1608 |
1 files changed, 0 insertions, 1608 deletions
diff --git a/ANDROID_3.4.5/fs/ext4/xattr.c b/ANDROID_3.4.5/fs/ext4/xattr.c deleted file mode 100644 index e88748e5..00000000 --- a/ANDROID_3.4.5/fs/ext4/xattr.c +++ /dev/null @@ -1,1608 +0,0 @@ -/* - * linux/fs/ext4/xattr.c - * - * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de> - * - * Fix by Harrison Xing <harrison@mountainviewdata.com>. - * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>. - * Extended attributes for symlinks and special files added per - * suggestion of Luka Renko <luka.renko@hermes.si>. - * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>, - * Red Hat Inc. - * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz - * and Andreas Gruenbacher <agruen@suse.de>. - */ - -/* - * Extended attributes are stored directly in inodes (on file systems with - * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl - * field contains the block number if an inode uses an additional block. All - * attributes must fit in the inode and one additional block. Blocks that - * contain the identical set of attributes may be shared among several inodes. - * Identical blocks are detected by keeping a cache of blocks that have - * recently been accessed. - * - * The attributes in inodes and on blocks have a different header; the entries - * are stored in the same format: - * - * +------------------+ - * | header | - * | entry 1 | | - * | entry 2 | | growing downwards - * | entry 3 | v - * | four null bytes | - * | . . . | - * | value 1 | ^ - * | value 3 | | growing upwards - * | value 2 | | - * +------------------+ - * - * The header is followed by multiple entry descriptors. In disk blocks, the - * entry descriptors are kept sorted. In inodes, they are unsorted. The - * attribute values are aligned to the end of the block in no specific order. - * - * Locking strategy - * ---------------- - * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem. - * EA blocks are only changed if they are exclusive to an inode, so - * holding xattr_sem also means that nothing but the EA block's reference - * count can change. Multiple writers to the same block are synchronized - * by the buffer lock. - */ - -#include <linux/init.h> -#include <linux/fs.h> -#include <linux/slab.h> -#include <linux/mbcache.h> -#include <linux/quotaops.h> -#include <linux/rwsem.h> -#include "ext4_jbd2.h" -#include "ext4.h" -#include "xattr.h" -#include "acl.h" - -#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data)) -#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr)) -#define BFIRST(bh) ENTRY(BHDR(bh)+1) -#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0) - -#ifdef EXT4_XATTR_DEBUG -# define ea_idebug(inode, f...) do { \ - printk(KERN_DEBUG "inode %s:%lu: ", \ - inode->i_sb->s_id, inode->i_ino); \ - printk(f); \ - printk("\n"); \ - } while (0) -# define ea_bdebug(bh, f...) do { \ - char b[BDEVNAME_SIZE]; \ - printk(KERN_DEBUG "block %s:%lu: ", \ - bdevname(bh->b_bdev, b), \ - (unsigned long) bh->b_blocknr); \ - printk(f); \ - printk("\n"); \ - } while (0) -#else -# define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__) -# define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__) -#endif - -static void ext4_xattr_cache_insert(struct buffer_head *); -static struct buffer_head *ext4_xattr_cache_find(struct inode *, - struct ext4_xattr_header *, - struct mb_cache_entry **); -static void ext4_xattr_rehash(struct ext4_xattr_header *, - struct ext4_xattr_entry *); -static int ext4_xattr_list(struct dentry *dentry, char *buffer, - size_t buffer_size); - -static struct mb_cache *ext4_xattr_cache; - -static const struct xattr_handler *ext4_xattr_handler_map[] = { - [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler, -#ifdef CONFIG_EXT4_FS_POSIX_ACL - [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler, - [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler, -#endif - [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler, -#ifdef CONFIG_EXT4_FS_SECURITY - [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler, -#endif -}; - -const struct xattr_handler *ext4_xattr_handlers[] = { - &ext4_xattr_user_handler, - &ext4_xattr_trusted_handler, -#ifdef CONFIG_EXT4_FS_POSIX_ACL - &ext4_xattr_acl_access_handler, - &ext4_xattr_acl_default_handler, -#endif -#ifdef CONFIG_EXT4_FS_SECURITY - &ext4_xattr_security_handler, -#endif - NULL -}; - -static inline const struct xattr_handler * -ext4_xattr_handler(int name_index) -{ - const struct xattr_handler *handler = NULL; - - if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map)) - handler = ext4_xattr_handler_map[name_index]; - return handler; -} - -/* - * Inode operation listxattr() - * - * dentry->d_inode->i_mutex: don't care - */ -ssize_t -ext4_listxattr(struct dentry *dentry, char *buffer, size_t size) -{ - return ext4_xattr_list(dentry, buffer, size); -} - -static int -ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end) -{ - while (!IS_LAST_ENTRY(entry)) { - struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry); - if ((void *)next >= end) - return -EIO; - entry = next; - } - return 0; -} - -static inline int -ext4_xattr_check_block(struct buffer_head *bh) -{ - if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || - BHDR(bh)->h_blocks != cpu_to_le32(1)) - return -EIO; - return ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size); -} - -static inline int -ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size) -{ - size_t value_size = le32_to_cpu(entry->e_value_size); - - if (entry->e_value_block != 0 || value_size > size || - le16_to_cpu(entry->e_value_offs) + value_size > size) - return -EIO; - return 0; -} - -static int -ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, - const char *name, size_t size, int sorted) -{ - struct ext4_xattr_entry *entry; - size_t name_len; - int cmp = 1; - - if (name == NULL) - return -EINVAL; - name_len = strlen(name); - entry = *pentry; - for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { - cmp = name_index - entry->e_name_index; - if (!cmp) - cmp = name_len - entry->e_name_len; - if (!cmp) - cmp = memcmp(name, entry->e_name, name_len); - if (cmp <= 0 && (sorted || cmp == 0)) - break; - } - *pentry = entry; - if (!cmp && ext4_xattr_check_entry(entry, size)) - return -EIO; - return cmp ? -ENODATA : 0; -} - -static int -ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, - void *buffer, size_t buffer_size) -{ - struct buffer_head *bh = NULL; - struct ext4_xattr_entry *entry; - size_t size; - int error; - - ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld", - name_index, name, buffer, (long)buffer_size); - - error = -ENODATA; - if (!EXT4_I(inode)->i_file_acl) - goto cleanup; - ea_idebug(inode, "reading block %llu", - (unsigned long long)EXT4_I(inode)->i_file_acl); - bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); - if (!bh) - goto cleanup; - ea_bdebug(bh, "b_count=%d, refcount=%d", - atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(bh)) { -bad_block: - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EIO; - goto cleanup; - } - ext4_xattr_cache_insert(bh); - entry = BFIRST(bh); - error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1); - if (error == -EIO) - goto bad_block; - if (error) - goto cleanup; - size = le32_to_cpu(entry->e_value_size); - if (buffer) { - error = -ERANGE; - if (size > buffer_size) - goto cleanup; - memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs), - size); - } - error = size; - -cleanup: - brelse(bh); - return error; -} - -static int -ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, - void *buffer, size_t buffer_size) -{ - struct ext4_xattr_ibody_header *header; - struct ext4_xattr_entry *entry; - struct ext4_inode *raw_inode; - struct ext4_iloc iloc; - size_t size; - void *end; - int error; - - if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) - return -ENODATA; - error = ext4_get_inode_loc(inode, &iloc); - if (error) - return error; - raw_inode = ext4_raw_inode(&iloc); - header = IHDR(inode, raw_inode); - entry = IFIRST(header); - end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(entry, end); - if (error) - goto cleanup; - error = ext4_xattr_find_entry(&entry, name_index, name, - end - (void *)entry, 0); - if (error) - goto cleanup; - size = le32_to_cpu(entry->e_value_size); - if (buffer) { - error = -ERANGE; - if (size > buffer_size) - goto cleanup; - memcpy(buffer, (void *)IFIRST(header) + - le16_to_cpu(entry->e_value_offs), size); - } - error = size; - -cleanup: - brelse(iloc.bh); - return error; -} - -/* - * ext4_xattr_get() - * - * Copy an extended attribute into the buffer - * provided, or compute the buffer size required. - * Buffer is NULL to compute the size of the buffer required. - * - * Returns a negative error number on failure, or the number of bytes - * used / required on success. - */ -int -ext4_xattr_get(struct inode *inode, int name_index, const char *name, - void *buffer, size_t buffer_size) -{ - int error; - - down_read(&EXT4_I(inode)->xattr_sem); - error = ext4_xattr_ibody_get(inode, name_index, name, buffer, - buffer_size); - if (error == -ENODATA) - error = ext4_xattr_block_get(inode, name_index, name, buffer, - buffer_size); - up_read(&EXT4_I(inode)->xattr_sem); - return error; -} - -static int -ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry, - char *buffer, size_t buffer_size) -{ - size_t rest = buffer_size; - - for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { - const struct xattr_handler *handler = - ext4_xattr_handler(entry->e_name_index); - - if (handler) { - size_t size = handler->list(dentry, buffer, rest, - entry->e_name, - entry->e_name_len, - handler->flags); - if (buffer) { - if (size > rest) - return -ERANGE; - buffer += size; - } - rest -= size; - } - } - return buffer_size - rest; -} - -static int -ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size) -{ - struct inode *inode = dentry->d_inode; - struct buffer_head *bh = NULL; - int error; - - ea_idebug(inode, "buffer=%p, buffer_size=%ld", - buffer, (long)buffer_size); - - error = 0; - if (!EXT4_I(inode)->i_file_acl) - goto cleanup; - ea_idebug(inode, "reading block %llu", - (unsigned long long)EXT4_I(inode)->i_file_acl); - bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); - error = -EIO; - if (!bh) - goto cleanup; - ea_bdebug(bh, "b_count=%d, refcount=%d", - atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount)); - if (ext4_xattr_check_block(bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EIO; - goto cleanup; - } - ext4_xattr_cache_insert(bh); - error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size); - -cleanup: - brelse(bh); - - return error; -} - -static int -ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) -{ - struct inode *inode = dentry->d_inode; - struct ext4_xattr_ibody_header *header; - struct ext4_inode *raw_inode; - struct ext4_iloc iloc; - void *end; - int error; - - if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR)) - return 0; - error = ext4_get_inode_loc(inode, &iloc); - if (error) - return error; - raw_inode = ext4_raw_inode(&iloc); - header = IHDR(inode, raw_inode); - end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(IFIRST(header), end); - if (error) - goto cleanup; - error = ext4_xattr_list_entries(dentry, IFIRST(header), - buffer, buffer_size); - -cleanup: - brelse(iloc.bh); - return error; -} - -/* - * ext4_xattr_list() - * - * Copy a list of attribute names into the buffer - * provided, or compute the buffer size required. - * Buffer is NULL to compute the size of the buffer required. - * - * Returns a negative error number on failure, or the number of bytes - * used / required on success. - */ -static int -ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size) -{ - int ret, ret2; - - down_read(&EXT4_I(dentry->d_inode)->xattr_sem); - ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size); - if (ret < 0) - goto errout; - if (buffer) { - buffer += ret; - buffer_size -= ret; - } - ret = ext4_xattr_block_list(dentry, buffer, buffer_size); - if (ret < 0) - goto errout; - ret += ret2; -errout: - up_read(&EXT4_I(dentry->d_inode)->xattr_sem); - return ret; -} - -/* - * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is - * not set, set it. - */ -static void ext4_xattr_update_super_block(handle_t *handle, - struct super_block *sb) -{ - if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR)) - return; - - if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { - EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR); - ext4_handle_dirty_super(handle, sb); - } -} - -/* - * Release the xattr block BH: If the reference count is > 1, decrement - * it; otherwise free the block. - */ -static void -ext4_xattr_release_block(handle_t *handle, struct inode *inode, - struct buffer_head *bh) -{ - struct mb_cache_entry *ce = NULL; - int error = 0; - - ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr); - error = ext4_journal_get_write_access(handle, bh); - if (error) - goto out; - - lock_buffer(bh); - if (BHDR(bh)->h_refcount == cpu_to_le32(1)) { - ea_bdebug(bh, "refcount now=0; freeing"); - if (ce) - mb_cache_entry_free(ce); - get_bh(bh); - ext4_free_blocks(handle, inode, bh, 0, 1, - EXT4_FREE_BLOCKS_METADATA | - EXT4_FREE_BLOCKS_FORGET); - unlock_buffer(bh); - } else { - le32_add_cpu(&BHDR(bh)->h_refcount, -1); - if (ce) - mb_cache_entry_release(ce); - unlock_buffer(bh); - error = ext4_handle_dirty_metadata(handle, inode, bh); - if (IS_SYNC(inode)) - ext4_handle_sync(handle); - dquot_free_block(inode, 1); - ea_bdebug(bh, "refcount now=%d; releasing", - le32_to_cpu(BHDR(bh)->h_refcount)); - } -out: - ext4_std_error(inode->i_sb, error); - return; -} - -/* - * Find the available free space for EAs. This also returns the total number of - * bytes used by EA entries. - */ -static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last, - size_t *min_offs, void *base, int *total) -{ - for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { - *total += EXT4_XATTR_LEN(last->e_name_len); - if (!last->e_value_block && last->e_value_size) { - size_t offs = le16_to_cpu(last->e_value_offs); - if (offs < *min_offs) - *min_offs = offs; - } - } - return (*min_offs - ((void *)last - base) - sizeof(__u32)); -} - -struct ext4_xattr_info { - int name_index; - const char *name; - const void *value; - size_t value_len; -}; - -struct ext4_xattr_search { - struct ext4_xattr_entry *first; - void *base; - void *end; - struct ext4_xattr_entry *here; - int not_found; -}; - -static int -ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s) -{ - struct ext4_xattr_entry *last; - size_t free, min_offs = s->end - s->base, name_len = strlen(i->name); - - /* Compute min_offs and last. */ - last = s->first; - for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { - if (!last->e_value_block && last->e_value_size) { - size_t offs = le16_to_cpu(last->e_value_offs); - if (offs < min_offs) - min_offs = offs; - } - } - free = min_offs - ((void *)last - s->base) - sizeof(__u32); - if (!s->not_found) { - if (!s->here->e_value_block && s->here->e_value_size) { - size_t size = le32_to_cpu(s->here->e_value_size); - free += EXT4_XATTR_SIZE(size); - } - free += EXT4_XATTR_LEN(name_len); - } - if (i->value) { - if (free < EXT4_XATTR_SIZE(i->value_len) || - free < EXT4_XATTR_LEN(name_len) + - EXT4_XATTR_SIZE(i->value_len)) - return -ENOSPC; - } - - if (i->value && s->not_found) { - /* Insert the new name. */ - size_t size = EXT4_XATTR_LEN(name_len); - size_t rest = (void *)last - (void *)s->here + sizeof(__u32); - memmove((void *)s->here + size, s->here, rest); - memset(s->here, 0, size); - s->here->e_name_index = i->name_index; - s->here->e_name_len = name_len; - memcpy(s->here->e_name, i->name, name_len); - } else { - if (!s->here->e_value_block && s->here->e_value_size) { - void *first_val = s->base + min_offs; - size_t offs = le16_to_cpu(s->here->e_value_offs); - void *val = s->base + offs; - size_t size = EXT4_XATTR_SIZE( - le32_to_cpu(s->here->e_value_size)); - - if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) { - /* The old and the new value have the same - size. Just replace. */ - s->here->e_value_size = - cpu_to_le32(i->value_len); - memset(val + size - EXT4_XATTR_PAD, 0, - EXT4_XATTR_PAD); /* Clear pad bytes. */ - memcpy(val, i->value, i->value_len); - return 0; - } - - /* Remove the old value. */ - memmove(first_val + size, first_val, val - first_val); - memset(first_val, 0, size); - s->here->e_value_size = 0; - s->here->e_value_offs = 0; - min_offs += size; - - /* Adjust all value offsets. */ - last = s->first; - while (!IS_LAST_ENTRY(last)) { - size_t o = le16_to_cpu(last->e_value_offs); - if (!last->e_value_block && - last->e_value_size && o < offs) - last->e_value_offs = - cpu_to_le16(o + size); - last = EXT4_XATTR_NEXT(last); - } - } - if (!i->value) { - /* Remove the old name. */ - size_t size = EXT4_XATTR_LEN(name_len); - last = ENTRY((void *)last - size); - memmove(s->here, (void *)s->here + size, - (void *)last - (void *)s->here + sizeof(__u32)); - memset(last, 0, size); - } - } - - if (i->value) { - /* Insert the new value. */ - s->here->e_value_size = cpu_to_le32(i->value_len); - if (i->value_len) { - size_t size = EXT4_XATTR_SIZE(i->value_len); - void *val = s->base + min_offs - size; - s->here->e_value_offs = cpu_to_le16(min_offs - size); - memset(val + size - EXT4_XATTR_PAD, 0, - EXT4_XATTR_PAD); /* Clear the pad bytes. */ - memcpy(val, i->value, i->value_len); - } - } - return 0; -} - -struct ext4_xattr_block_find { - struct ext4_xattr_search s; - struct buffer_head *bh; -}; - -static int -ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, - struct ext4_xattr_block_find *bs) -{ - struct super_block *sb = inode->i_sb; - int error; - - ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld", - i->name_index, i->name, i->value, (long)i->value_len); - - if (EXT4_I(inode)->i_file_acl) { - /* The inode already has an extended attribute block. */ - bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl); - error = -EIO; - if (!bs->bh) - goto cleanup; - ea_bdebug(bs->bh, "b_count=%d, refcount=%d", - atomic_read(&(bs->bh->b_count)), - le32_to_cpu(BHDR(bs->bh)->h_refcount)); - if (ext4_xattr_check_block(bs->bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EIO; - goto cleanup; - } - /* Find the named attribute. */ - bs->s.base = BHDR(bs->bh); - bs->s.first = BFIRST(bs->bh); - bs->s.end = bs->bh->b_data + bs->bh->b_size; - bs->s.here = bs->s.first; - error = ext4_xattr_find_entry(&bs->s.here, i->name_index, - i->name, bs->bh->b_size, 1); - if (error && error != -ENODATA) - goto cleanup; - bs->s.not_found = error; - } - error = 0; - -cleanup: - return error; -} - -static int -ext4_xattr_block_set(handle_t *handle, struct inode *inode, - struct ext4_xattr_info *i, - struct ext4_xattr_block_find *bs) -{ - struct super_block *sb = inode->i_sb; - struct buffer_head *new_bh = NULL; - struct ext4_xattr_search *s = &bs->s; - struct mb_cache_entry *ce = NULL; - int error = 0; - -#define header(x) ((struct ext4_xattr_header *)(x)) - - if (i->value && i->value_len > sb->s_blocksize) - return -ENOSPC; - if (s->base) { - ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev, - bs->bh->b_blocknr); - error = ext4_journal_get_write_access(handle, bs->bh); - if (error) - goto cleanup; - lock_buffer(bs->bh); - - if (header(s->base)->h_refcount == cpu_to_le32(1)) { - if (ce) { - mb_cache_entry_free(ce); - ce = NULL; - } - ea_bdebug(bs->bh, "modifying in-place"); - error = ext4_xattr_set_entry(i, s); - if (!error) { - if (!IS_LAST_ENTRY(s->first)) - ext4_xattr_rehash(header(s->base), - s->here); - ext4_xattr_cache_insert(bs->bh); - } - unlock_buffer(bs->bh); - if (error == -EIO) - goto bad_block; - if (!error) - error = ext4_handle_dirty_metadata(handle, - inode, - bs->bh); - if (error) - goto cleanup; - goto inserted; - } else { - int offset = (char *)s->here - bs->bh->b_data; - - unlock_buffer(bs->bh); - ext4_handle_release_buffer(handle, bs->bh); - if (ce) { - mb_cache_entry_release(ce); - ce = NULL; - } - ea_bdebug(bs->bh, "cloning"); - s->base = kmalloc(bs->bh->b_size, GFP_NOFS); - error = -ENOMEM; - if (s->base == NULL) - goto cleanup; - memcpy(s->base, BHDR(bs->bh), bs->bh->b_size); - s->first = ENTRY(header(s->base)+1); - header(s->base)->h_refcount = cpu_to_le32(1); - s->here = ENTRY(s->base + offset); - s->end = s->base + bs->bh->b_size; - } - } else { - /* Allocate a buffer where we construct the new block. */ - s->base = kzalloc(sb->s_blocksize, GFP_NOFS); - /* assert(header == s->base) */ - error = -ENOMEM; - if (s->base == NULL) - goto cleanup; - header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); - header(s->base)->h_blocks = cpu_to_le32(1); - header(s->base)->h_refcount = cpu_to_le32(1); - s->first = ENTRY(header(s->base)+1); - s->here = ENTRY(header(s->base)+1); - s->end = s->base + sb->s_blocksize; - } - - error = ext4_xattr_set_entry(i, s); - if (error == -EIO) - goto bad_block; - if (error) - goto cleanup; - if (!IS_LAST_ENTRY(s->first)) - ext4_xattr_rehash(header(s->base), s->here); - -inserted: - if (!IS_LAST_ENTRY(s->first)) { - new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce); - if (new_bh) { - /* We found an identical block in the cache. */ - if (new_bh == bs->bh) - ea_bdebug(new_bh, "keeping"); - else { - /* The old block is released after updating - the inode. */ - error = dquot_alloc_block(inode, 1); - if (error) - goto cleanup; - error = ext4_journal_get_write_access(handle, - new_bh); - if (error) - goto cleanup_dquot; - lock_buffer(new_bh); - le32_add_cpu(&BHDR(new_bh)->h_refcount, 1); - ea_bdebug(new_bh, "reusing; refcount now=%d", - le32_to_cpu(BHDR(new_bh)->h_refcount)); - unlock_buffer(new_bh); - error = ext4_handle_dirty_metadata(handle, - inode, - new_bh); - if (error) - goto cleanup_dquot; - } - mb_cache_entry_release(ce); - ce = NULL; - } else if (bs->bh && s->base == bs->bh->b_data) { - /* We were modifying this block in-place. */ - ea_bdebug(bs->bh, "keeping this block"); - new_bh = bs->bh; - get_bh(new_bh); - } else { - /* We need to allocate a new block */ - ext4_fsblk_t goal, block; - - goal = ext4_group_first_block_no(sb, - EXT4_I(inode)->i_block_group); - - /* non-extent files can't have physical blocks past 2^32 */ - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; - - /* - * take i_data_sem because we will test - * i_delalloc_reserved_flag in ext4_mb_new_blocks - */ - down_read((&EXT4_I(inode)->i_data_sem)); - block = ext4_new_meta_blocks(handle, inode, goal, 0, - NULL, &error); - up_read((&EXT4_I(inode)->i_data_sem)); - if (error) - goto cleanup; - - if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) - BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS); - - ea_idebug(inode, "creating block %llu", - (unsigned long long)block); - - new_bh = sb_getblk(sb, block); - if (!new_bh) { -getblk_failed: - ext4_free_blocks(handle, inode, NULL, block, 1, - EXT4_FREE_BLOCKS_METADATA); - error = -EIO; - goto cleanup; - } - lock_buffer(new_bh); - error = ext4_journal_get_create_access(handle, new_bh); - if (error) { - unlock_buffer(new_bh); - goto getblk_failed; - } - memcpy(new_bh->b_data, s->base, new_bh->b_size); - set_buffer_uptodate(new_bh); - unlock_buffer(new_bh); - ext4_xattr_cache_insert(new_bh); - error = ext4_handle_dirty_metadata(handle, - inode, new_bh); - if (error) - goto cleanup; - } - } - - /* Update the inode. */ - EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0; - - /* Drop the previous xattr block. */ - if (bs->bh && bs->bh != new_bh) - ext4_xattr_release_block(handle, inode, bs->bh); - error = 0; - -cleanup: - if (ce) - mb_cache_entry_release(ce); - brelse(new_bh); - if (!(bs->bh && s->base == bs->bh->b_data)) - kfree(s->base); - - return error; - -cleanup_dquot: - dquot_free_block(inode, 1); - goto cleanup; - -bad_block: - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - goto cleanup; - -#undef header -} - -struct ext4_xattr_ibody_find { - struct ext4_xattr_search s; - struct ext4_iloc iloc; -}; - -static int -ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, - struct ext4_xattr_ibody_find *is) -{ - struct ext4_xattr_ibody_header *header; - struct ext4_inode *raw_inode; - int error; - - if (EXT4_I(inode)->i_extra_isize == 0) - return 0; - raw_inode = ext4_raw_inode(&is->iloc); - header = IHDR(inode, raw_inode); - is->s.base = is->s.first = IFIRST(header); - is->s.here = is->s.first; - is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { - error = ext4_xattr_check_names(IFIRST(header), is->s.end); - if (error) - return error; - /* Find the named attribute. */ - error = ext4_xattr_find_entry(&is->s.here, i->name_index, - i->name, is->s.end - - (void *)is->s.base, 0); - if (error && error != -ENODATA) - return error; - is->s.not_found = error; - } - return 0; -} - -static int -ext4_xattr_ibody_set(handle_t *handle, struct inode *inode, - struct ext4_xattr_info *i, - struct ext4_xattr_ibody_find *is) -{ - struct ext4_xattr_ibody_header *header; - struct ext4_xattr_search *s = &is->s; - int error; - - if (EXT4_I(inode)->i_extra_isize == 0) - return -ENOSPC; - error = ext4_xattr_set_entry(i, s); - if (error) - return error; - header = IHDR(inode, ext4_raw_inode(&is->iloc)); - if (!IS_LAST_ENTRY(s->first)) { - header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC); - ext4_set_inode_state(inode, EXT4_STATE_XATTR); - } else { - header->h_magic = cpu_to_le32(0); - ext4_clear_inode_state(inode, EXT4_STATE_XATTR); - } - return 0; -} - -/* - * ext4_xattr_set_handle() - * - * Create, replace or remove an extended attribute for this inode. Value - * is NULL to remove an existing extended attribute, and non-NULL to - * either replace an existing extended attribute, or create a new extended - * attribute. The flags XATTR_REPLACE and XATTR_CREATE - * specify that an extended attribute must exist and must not exist - * previous to the call, respectively. - * - * Returns 0, or a negative error number on failure. - */ -int -ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, - const char *name, const void *value, size_t value_len, - int flags) -{ - struct ext4_xattr_info i = { - .name_index = name_index, - .name = name, - .value = value, - .value_len = value_len, - - }; - struct ext4_xattr_ibody_find is = { - .s = { .not_found = -ENODATA, }, - }; - struct ext4_xattr_block_find bs = { - .s = { .not_found = -ENODATA, }, - }; - unsigned long no_expand; - int error; - - if (!name) - return -EINVAL; - if (strlen(name) > 255) - return -ERANGE; - down_write(&EXT4_I(inode)->xattr_sem); - no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND); - ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND); - - error = ext4_reserve_inode_write(handle, inode, &is.iloc); - if (error) - goto cleanup; - - if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) { - struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc); - memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); - ext4_clear_inode_state(inode, EXT4_STATE_NEW); - } - - error = ext4_xattr_ibody_find(inode, &i, &is); - if (error) - goto cleanup; - if (is.s.not_found) - error = ext4_xattr_block_find(inode, &i, &bs); - if (error) - goto cleanup; - if (is.s.not_found && bs.s.not_found) { - error = -ENODATA; - if (flags & XATTR_REPLACE) - goto cleanup; - error = 0; - if (!value) - goto cleanup; - } else { - error = -EEXIST; - if (flags & XATTR_CREATE) - goto cleanup; - } - if (!value) { - if (!is.s.not_found) - error = ext4_xattr_ibody_set(handle, inode, &i, &is); - else if (!bs.s.not_found) - error = ext4_xattr_block_set(handle, inode, &i, &bs); - } else { - error = ext4_xattr_ibody_set(handle, inode, &i, &is); - if (!error && !bs.s.not_found) { - i.value = NULL; - error = ext4_xattr_block_set(handle, inode, &i, &bs); - } else if (error == -ENOSPC) { - if (EXT4_I(inode)->i_file_acl && !bs.s.base) { - error = ext4_xattr_block_find(inode, &i, &bs); - if (error) - goto cleanup; - } - error = ext4_xattr_block_set(handle, inode, &i, &bs); - if (error) - goto cleanup; - if (!is.s.not_found) { - i.value = NULL; - error = ext4_xattr_ibody_set(handle, inode, &i, - &is); - } - } - } - if (!error) { - ext4_xattr_update_super_block(handle, inode->i_sb); - inode->i_ctime = ext4_current_time(inode); - if (!value) - ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); - error = ext4_mark_iloc_dirty(handle, inode, &is.iloc); - /* - * The bh is consumed by ext4_mark_iloc_dirty, even with - * error != 0. - */ - is.iloc.bh = NULL; - if (IS_SYNC(inode)) - ext4_handle_sync(handle); - } - -cleanup: - brelse(is.iloc.bh); - brelse(bs.bh); - if (no_expand == 0) - ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND); - up_write(&EXT4_I(inode)->xattr_sem); - return error; -} - -/* - * ext4_xattr_set() - * - * Like ext4_xattr_set_handle, but start from an inode. This extended - * attribute modification is a filesystem transaction by itself. - * - * Returns 0, or a negative error number on failure. - */ -int -ext4_xattr_set(struct inode *inode, int name_index, const char *name, - const void *value, size_t value_len, int flags) -{ - handle_t *handle; - int error, retries = 0; - -retry: - handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); - if (IS_ERR(handle)) { - error = PTR_ERR(handle); - } else { - int error2; - - error = ext4_xattr_set_handle(handle, inode, name_index, name, - value, value_len, flags); - error2 = ext4_journal_stop(handle); - if (error == -ENOSPC && - ext4_should_retry_alloc(inode->i_sb, &retries)) - goto retry; - if (error == 0) - error = error2; - } - - return error; -} - -/* - * Shift the EA entries in the inode to create space for the increased - * i_extra_isize. - */ -static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry, - int value_offs_shift, void *to, - void *from, size_t n, int blocksize) -{ - struct ext4_xattr_entry *last = entry; - int new_offs; - - /* Adjust the value offsets of the entries */ - for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { - if (!last->e_value_block && last->e_value_size) { - new_offs = le16_to_cpu(last->e_value_offs) + - value_offs_shift; - BUG_ON(new_offs + le32_to_cpu(last->e_value_size) - > blocksize); - last->e_value_offs = cpu_to_le16(new_offs); - } - } - /* Shift the entries by n bytes */ - memmove(to, from, n); -} - -/* - * Expand an inode by new_extra_isize bytes when EAs are present. - * Returns 0 on success or negative error number on failure. - */ -int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize, - struct ext4_inode *raw_inode, handle_t *handle) -{ - struct ext4_xattr_ibody_header *header; - struct ext4_xattr_entry *entry, *last, *first; - struct buffer_head *bh = NULL; - struct ext4_xattr_ibody_find *is = NULL; - struct ext4_xattr_block_find *bs = NULL; - char *buffer = NULL, *b_entry_name = NULL; - size_t min_offs, free; - int total_ino, total_blk; - void *base, *start, *end; - int extra_isize = 0, error = 0, tried_min_extra_isize = 0; - int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize); - - down_write(&EXT4_I(inode)->xattr_sem); -retry: - if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) { - up_write(&EXT4_I(inode)->xattr_sem); - return 0; - } - - header = IHDR(inode, raw_inode); - entry = IFIRST(header); - - /* - * Check if enough free space is available in the inode to shift the - * entries ahead by new_extra_isize. - */ - - base = start = entry; - end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - min_offs = end - base; - last = entry; - total_ino = sizeof(struct ext4_xattr_ibody_header); - - free = ext4_xattr_free_space(last, &min_offs, base, &total_ino); - if (free >= new_extra_isize) { - entry = IFIRST(header); - ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize - - new_extra_isize, (void *)raw_inode + - EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize, - (void *)header, total_ino, - inode->i_sb->s_blocksize); - EXT4_I(inode)->i_extra_isize = new_extra_isize; - error = 0; - goto cleanup; - } - - /* - * Enough free space isn't available in the inode, check if - * EA block can hold new_extra_isize bytes. - */ - if (EXT4_I(inode)->i_file_acl) { - bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); - error = -EIO; - if (!bh) - goto cleanup; - if (ext4_xattr_check_block(bh)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - error = -EIO; - goto cleanup; - } - base = BHDR(bh); - first = BFIRST(bh); - end = bh->b_data + bh->b_size; - min_offs = end - base; - free = ext4_xattr_free_space(first, &min_offs, base, - &total_blk); - if (free < new_extra_isize) { - if (!tried_min_extra_isize && s_min_extra_isize) { - tried_min_extra_isize++; - new_extra_isize = s_min_extra_isize; - brelse(bh); - goto retry; - } - error = -1; - goto cleanup; - } - } else { - free = inode->i_sb->s_blocksize; - } - - while (new_extra_isize > 0) { - size_t offs, size, entry_size; - struct ext4_xattr_entry *small_entry = NULL; - struct ext4_xattr_info i = { - .value = NULL, - .value_len = 0, - }; - unsigned int total_size; /* EA entry size + value size */ - unsigned int shift_bytes; /* No. of bytes to shift EAs by? */ - unsigned int min_total_size = ~0U; - - is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS); - bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS); - if (!is || !bs) { - error = -ENOMEM; - goto cleanup; - } - - is->s.not_found = -ENODATA; - bs->s.not_found = -ENODATA; - is->iloc.bh = NULL; - bs->bh = NULL; - - last = IFIRST(header); - /* Find the entry best suited to be pushed into EA block */ - entry = NULL; - for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) { - total_size = - EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) + - EXT4_XATTR_LEN(last->e_name_len); - if (total_size <= free && total_size < min_total_size) { - if (total_size < new_extra_isize) { - small_entry = last; - } else { - entry = last; - min_total_size = total_size; - } - } - } - - if (entry == NULL) { - if (small_entry) { - entry = small_entry; - } else { - if (!tried_min_extra_isize && - s_min_extra_isize) { - tried_min_extra_isize++; - new_extra_isize = s_min_extra_isize; - goto retry; - } - error = -1; - goto cleanup; - } - } - offs = le16_to_cpu(entry->e_value_offs); - size = le32_to_cpu(entry->e_value_size); - entry_size = EXT4_XATTR_LEN(entry->e_name_len); - i.name_index = entry->e_name_index, - buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS); - b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS); - if (!buffer || !b_entry_name) { - error = -ENOMEM; - goto cleanup; - } - /* Save the entry name and the entry value */ - memcpy(buffer, (void *)IFIRST(header) + offs, - EXT4_XATTR_SIZE(size)); - memcpy(b_entry_name, entry->e_name, entry->e_name_len); - b_entry_name[entry->e_name_len] = '\0'; - i.name = b_entry_name; - - error = ext4_get_inode_loc(inode, &is->iloc); - if (error) - goto cleanup; - - error = ext4_xattr_ibody_find(inode, &i, is); - if (error) - goto cleanup; - - /* Remove the chosen entry from the inode */ - error = ext4_xattr_ibody_set(handle, inode, &i, is); - if (error) - goto cleanup; - - entry = IFIRST(header); - if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize) - shift_bytes = new_extra_isize; - else - shift_bytes = entry_size + size; - /* Adjust the offsets and shift the remaining entries ahead */ - ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize - - shift_bytes, (void *)raw_inode + - EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes, - (void *)header, total_ino - entry_size, - inode->i_sb->s_blocksize); - - extra_isize += shift_bytes; - new_extra_isize -= shift_bytes; - EXT4_I(inode)->i_extra_isize = extra_isize; - - i.name = b_entry_name; - i.value = buffer; - i.value_len = size; - error = ext4_xattr_block_find(inode, &i, bs); - if (error) - goto cleanup; - - /* Add entry which was removed from the inode into the block */ - error = ext4_xattr_block_set(handle, inode, &i, bs); - if (error) - goto cleanup; - kfree(b_entry_name); - kfree(buffer); - b_entry_name = NULL; - buffer = NULL; - brelse(is->iloc.bh); - kfree(is); - kfree(bs); - } - brelse(bh); - up_write(&EXT4_I(inode)->xattr_sem); - return 0; - -cleanup: - kfree(b_entry_name); - kfree(buffer); - if (is) - brelse(is->iloc.bh); - kfree(is); - kfree(bs); - brelse(bh); - up_write(&EXT4_I(inode)->xattr_sem); - return error; -} - - - -/* - * ext4_xattr_delete_inode() - * - * Free extended attribute resources associated with this inode. This - * is called immediately before an inode is freed. We have exclusive - * access to the inode. - */ -void -ext4_xattr_delete_inode(handle_t *handle, struct inode *inode) -{ - struct buffer_head *bh = NULL; - - if (!EXT4_I(inode)->i_file_acl) - goto cleanup; - bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl); - if (!bh) { - EXT4_ERROR_INODE(inode, "block %llu read error", - EXT4_I(inode)->i_file_acl); - goto cleanup; - } - if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) || - BHDR(bh)->h_blocks != cpu_to_le32(1)) { - EXT4_ERROR_INODE(inode, "bad block %llu", - EXT4_I(inode)->i_file_acl); - goto cleanup; - } - ext4_xattr_release_block(handle, inode, bh); - EXT4_I(inode)->i_file_acl = 0; - -cleanup: - brelse(bh); -} - -/* - * ext4_xattr_put_super() - * - * This is called when a file system is unmounted. - */ -void -ext4_xattr_put_super(struct super_block *sb) -{ - mb_cache_shrink(sb->s_bdev); -} - -/* - * ext4_xattr_cache_insert() - * - * Create a new entry in the extended attribute cache, and insert - * it unless such an entry is already in the cache. - * - * Returns 0, or a negative error number on failure. - */ -static void -ext4_xattr_cache_insert(struct buffer_head *bh) -{ - __u32 hash = le32_to_cpu(BHDR(bh)->h_hash); - struct mb_cache_entry *ce; - int error; - - ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS); - if (!ce) { - ea_bdebug(bh, "out of memory"); - return; - } - error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash); - if (error) { - mb_cache_entry_free(ce); - if (error == -EBUSY) { - ea_bdebug(bh, "already in cache"); - error = 0; - } - } else { - ea_bdebug(bh, "inserting [%x]", (int)hash); - mb_cache_entry_release(ce); - } -} - -/* - * ext4_xattr_cmp() - * - * Compare two extended attribute blocks for equality. - * - * Returns 0 if the blocks are equal, 1 if they differ, and - * a negative error number on errors. - */ -static int -ext4_xattr_cmp(struct ext4_xattr_header *header1, - struct ext4_xattr_header *header2) -{ - struct ext4_xattr_entry *entry1, *entry2; - - entry1 = ENTRY(header1+1); - entry2 = ENTRY(header2+1); - while (!IS_LAST_ENTRY(entry1)) { - if (IS_LAST_ENTRY(entry2)) - return 1; - if (entry1->e_hash != entry2->e_hash || - entry1->e_name_index != entry2->e_name_index || - entry1->e_name_len != entry2->e_name_len || - entry1->e_value_size != entry2->e_value_size || - memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len)) - return 1; - if (entry1->e_value_block != 0 || entry2->e_value_block != 0) - return -EIO; - if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs), - (char *)header2 + le16_to_cpu(entry2->e_value_offs), - le32_to_cpu(entry1->e_value_size))) - return 1; - - entry1 = EXT4_XATTR_NEXT(entry1); - entry2 = EXT4_XATTR_NEXT(entry2); - } - if (!IS_LAST_ENTRY(entry2)) - return 1; - return 0; -} - -/* - * ext4_xattr_cache_find() - * - * Find an identical extended attribute block. - * - * Returns a pointer to the block found, or NULL if such a block was - * not found or an error occurred. - */ -static struct buffer_head * -ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header, - struct mb_cache_entry **pce) -{ - __u32 hash = le32_to_cpu(header->h_hash); - struct mb_cache_entry *ce; - - if (!header->h_hash) - return NULL; /* never share */ - ea_idebug(inode, "looking for cached blocks [%x]", (int)hash); -again: - ce = mb_cache_entry_find_first(ext4_xattr_cache, inode->i_sb->s_bdev, - hash); - while (ce) { - struct buffer_head *bh; - - if (IS_ERR(ce)) { - if (PTR_ERR(ce) == -EAGAIN) - goto again; - break; - } - bh = sb_bread(inode->i_sb, ce->e_block); - if (!bh) { - EXT4_ERROR_INODE(inode, "block %lu read error", - (unsigned long) ce->e_block); - } else if (le32_to_cpu(BHDR(bh)->h_refcount) >= - EXT4_XATTR_REFCOUNT_MAX) { - ea_idebug(inode, "block %lu refcount %d>=%d", - (unsigned long) ce->e_block, - le32_to_cpu(BHDR(bh)->h_refcount), - EXT4_XATTR_REFCOUNT_MAX); - } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) { - *pce = ce; - return bh; - } - brelse(bh); - ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash); - } - return NULL; -} - -#define NAME_HASH_SHIFT 5 -#define VALUE_HASH_SHIFT 16 - -/* - * ext4_xattr_hash_entry() - * - * Compute the hash of an extended attribute. - */ -static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header, - struct ext4_xattr_entry *entry) -{ - __u32 hash = 0; - char *name = entry->e_name; - int n; - - for (n = 0; n < entry->e_name_len; n++) { - hash = (hash << NAME_HASH_SHIFT) ^ - (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^ - *name++; - } - - if (entry->e_value_block == 0 && entry->e_value_size != 0) { - __le32 *value = (__le32 *)((char *)header + - le16_to_cpu(entry->e_value_offs)); - for (n = (le32_to_cpu(entry->e_value_size) + - EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) { - hash = (hash << VALUE_HASH_SHIFT) ^ - (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^ - le32_to_cpu(*value++); - } - } - entry->e_hash = cpu_to_le32(hash); -} - -#undef NAME_HASH_SHIFT -#undef VALUE_HASH_SHIFT - -#define BLOCK_HASH_SHIFT 16 - -/* - * ext4_xattr_rehash() - * - * Re-compute the extended attribute hash value after an entry has changed. - */ -static void ext4_xattr_rehash(struct ext4_xattr_header *header, - struct ext4_xattr_entry *entry) -{ - struct ext4_xattr_entry *here; - __u32 hash = 0; - - ext4_xattr_hash_entry(header, entry); - here = ENTRY(header+1); - while (!IS_LAST_ENTRY(here)) { - if (!here->e_hash) { - /* Block is not shared if an entry's hash value == 0 */ - hash = 0; - break; - } - hash = (hash << BLOCK_HASH_SHIFT) ^ - (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^ - le32_to_cpu(here->e_hash); - here = EXT4_XATTR_NEXT(here); - } - header->h_hash = cpu_to_le32(hash); -} - -#undef BLOCK_HASH_SHIFT - -int __init -ext4_init_xattr(void) -{ - ext4_xattr_cache = mb_cache_create("ext4_xattr", 6); - if (!ext4_xattr_cache) - return -ENOMEM; - return 0; -} - -void -ext4_exit_xattr(void) -{ - if (ext4_xattr_cache) - mb_cache_destroy(ext4_xattr_cache); - ext4_xattr_cache = NULL; -} |