+++ /dev/null
-/*
- * linux/fs/ext3/xattr.c
- *
- * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
- *
- * Fix by Harrison Xing <harrison@mountainviewdata.com>.
- * Ext3 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
- * ----------------
- * EXT3_I(inode)->i_file_acl is protected by EXT3_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 "ext3.h"
-#include <linux/mbcache.h>
-#include <linux/quotaops.h>
-#include "xattr.h"
-#include "acl.h"
-
-#define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
-#define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
-#define BFIRST(bh) ENTRY(BHDR(bh)+1)
-#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
-
-#define IHDR(inode, raw_inode) \
- ((struct ext3_xattr_ibody_header *) \
- ((void *)raw_inode + \
- EXT3_GOOD_OLD_INODE_SIZE + \
- EXT3_I(inode)->i_extra_isize))
-#define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
-
-#ifdef EXT3_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(f...)
-# define ea_bdebug(f...)
-#endif
-
-static void ext3_xattr_cache_insert(struct buffer_head *);
-static struct buffer_head *ext3_xattr_cache_find(struct inode *,
- struct ext3_xattr_header *,
- struct mb_cache_entry **);
-static void ext3_xattr_rehash(struct ext3_xattr_header *,
- struct ext3_xattr_entry *);
-static int ext3_xattr_list(struct dentry *dentry, char *buffer,
- size_t buffer_size);
-
-static struct mb_cache *ext3_xattr_cache;
-
-static const struct xattr_handler *ext3_xattr_handler_map[] = {
- [EXT3_XATTR_INDEX_USER] = &ext3_xattr_user_handler,
-#ifdef CONFIG_EXT3_FS_POSIX_ACL
- [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
- [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
-#endif
- [EXT3_XATTR_INDEX_TRUSTED] = &ext3_xattr_trusted_handler,
-#ifdef CONFIG_EXT3_FS_SECURITY
- [EXT3_XATTR_INDEX_SECURITY] = &ext3_xattr_security_handler,
-#endif
-};
-
-const struct xattr_handler *ext3_xattr_handlers[] = {
- &ext3_xattr_user_handler,
- &ext3_xattr_trusted_handler,
-#ifdef CONFIG_EXT3_FS_POSIX_ACL
- &posix_acl_access_xattr_handler,
- &posix_acl_default_xattr_handler,
-#endif
-#ifdef CONFIG_EXT3_FS_SECURITY
- &ext3_xattr_security_handler,
-#endif
- NULL
-};
-
-static inline const struct xattr_handler *
-ext3_xattr_handler(int name_index)
-{
- const struct xattr_handler *handler = NULL;
-
- if (name_index > 0 && name_index < ARRAY_SIZE(ext3_xattr_handler_map))
- handler = ext3_xattr_handler_map[name_index];
- return handler;
-}
-
-/*
- * Inode operation listxattr()
- *
- * d_inode(dentry)->i_mutex: don't care
- */
-ssize_t
-ext3_listxattr(struct dentry *dentry, char *buffer, size_t size)
-{
- return ext3_xattr_list(dentry, buffer, size);
-}
-
-static int
-ext3_xattr_check_names(struct ext3_xattr_entry *entry, void *end)
-{
- while (!IS_LAST_ENTRY(entry)) {
- struct ext3_xattr_entry *next = EXT3_XATTR_NEXT(entry);
- if ((void *)next >= end)
- return -EIO;
- entry = next;
- }
- return 0;
-}
-
-static inline int
-ext3_xattr_check_block(struct buffer_head *bh)
-{
- int error;
-
- if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
- BHDR(bh)->h_blocks != cpu_to_le32(1))
- return -EIO;
- error = ext3_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
- return error;
-}
-
-static inline int
-ext3_xattr_check_entry(struct ext3_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
-ext3_xattr_find_entry(struct ext3_xattr_entry **pentry, int name_index,
- const char *name, size_t size, int sorted)
-{
- struct ext3_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 = EXT3_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 && ext3_xattr_check_entry(entry, size))
- return -EIO;
- return cmp ? -ENODATA : 0;
-}
-
-static int
-ext3_xattr_block_get(struct inode *inode, int name_index, const char *name,
- void *buffer, size_t buffer_size)
-{
- struct buffer_head *bh = NULL;
- struct ext3_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 (!EXT3_I(inode)->i_file_acl)
- goto cleanup;
- ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
- bh = sb_bread(inode->i_sb, EXT3_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 (ext3_xattr_check_block(bh)) {
-bad_block: ext3_error(inode->i_sb, __func__,
- "inode %lu: bad block "E3FSBLK, inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- error = -EIO;
- goto cleanup;
- }
- ext3_xattr_cache_insert(bh);
- entry = BFIRST(bh);
- error = ext3_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
-ext3_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
- void *buffer, size_t buffer_size)
-{
- struct ext3_xattr_ibody_header *header;
- struct ext3_xattr_entry *entry;
- struct ext3_inode *raw_inode;
- struct ext3_iloc iloc;
- size_t size;
- void *end;
- int error;
-
- if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
- return -ENODATA;
- error = ext3_get_inode_loc(inode, &iloc);
- if (error)
- return error;
- raw_inode = ext3_raw_inode(&iloc);
- header = IHDR(inode, raw_inode);
- entry = IFIRST(header);
- end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
- error = ext3_xattr_check_names(entry, end);
- if (error)
- goto cleanup;
- error = ext3_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;
-}
-
-/*
- * ext3_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
-ext3_xattr_get(struct inode *inode, int name_index, const char *name,
- void *buffer, size_t buffer_size)
-{
- int error;
-
- down_read(&EXT3_I(inode)->xattr_sem);
- error = ext3_xattr_ibody_get(inode, name_index, name, buffer,
- buffer_size);
- if (error == -ENODATA)
- error = ext3_xattr_block_get(inode, name_index, name, buffer,
- buffer_size);
- up_read(&EXT3_I(inode)->xattr_sem);
- return error;
-}
-
-static int
-ext3_xattr_list_entries(struct dentry *dentry, struct ext3_xattr_entry *entry,
- char *buffer, size_t buffer_size)
-{
- size_t rest = buffer_size;
-
- for (; !IS_LAST_ENTRY(entry); entry = EXT3_XATTR_NEXT(entry)) {
- const struct xattr_handler *handler =
- ext3_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
-ext3_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
-{
- struct inode *inode = d_inode(dentry);
- struct buffer_head *bh = NULL;
- int error;
-
- ea_idebug(inode, "buffer=%p, buffer_size=%ld",
- buffer, (long)buffer_size);
-
- error = 0;
- if (!EXT3_I(inode)->i_file_acl)
- goto cleanup;
- ea_idebug(inode, "reading block %u", EXT3_I(inode)->i_file_acl);
- bh = sb_bread(inode->i_sb, EXT3_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 (ext3_xattr_check_block(bh)) {
- ext3_error(inode->i_sb, __func__,
- "inode %lu: bad block "E3FSBLK, inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- error = -EIO;
- goto cleanup;
- }
- ext3_xattr_cache_insert(bh);
- error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
-
-cleanup:
- brelse(bh);
-
- return error;
-}
-
-static int
-ext3_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
-{
- struct inode *inode = d_inode(dentry);
- struct ext3_xattr_ibody_header *header;
- struct ext3_inode *raw_inode;
- struct ext3_iloc iloc;
- void *end;
- int error;
-
- if (!ext3_test_inode_state(inode, EXT3_STATE_XATTR))
- return 0;
- error = ext3_get_inode_loc(inode, &iloc);
- if (error)
- return error;
- raw_inode = ext3_raw_inode(&iloc);
- header = IHDR(inode, raw_inode);
- end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
- error = ext3_xattr_check_names(IFIRST(header), end);
- if (error)
- goto cleanup;
- error = ext3_xattr_list_entries(dentry, IFIRST(header),
- buffer, buffer_size);
-
-cleanup:
- brelse(iloc.bh);
- return error;
-}
-
-/*
- * ext3_xattr_list()
- *
- * Copy a list of attribute names into the buffer
- * provided, or compute the buffer size required.
- * Buffer is NULL to compute the size of the buffer required.
- *
- * Returns a negative error number on failure, or the number of bytes
- * used / required on success.
- */
-static int
-ext3_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
-{
- int i_error, b_error;
-
- down_read(&EXT3_I(d_inode(dentry))->xattr_sem);
- i_error = ext3_xattr_ibody_list(dentry, buffer, buffer_size);
- if (i_error < 0) {
- b_error = 0;
- } else {
- if (buffer) {
- buffer += i_error;
- buffer_size -= i_error;
- }
- b_error = ext3_xattr_block_list(dentry, buffer, buffer_size);
- if (b_error < 0)
- i_error = 0;
- }
- up_read(&EXT3_I(d_inode(dentry))->xattr_sem);
- return i_error + b_error;
-}
-
-/*
- * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
- * not set, set it.
- */
-static void ext3_xattr_update_super_block(handle_t *handle,
- struct super_block *sb)
-{
- if (EXT3_HAS_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR))
- return;
-
- if (ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh) == 0) {
- EXT3_SET_COMPAT_FEATURE(sb, EXT3_FEATURE_COMPAT_EXT_ATTR);
- ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
- }
-}
-
-/*
- * Release the xattr block BH: If the reference count is > 1, decrement
- * it; otherwise free the block.
- */
-static void
-ext3_xattr_release_block(handle_t *handle, struct inode *inode,
- struct buffer_head *bh)
-{
- struct mb_cache_entry *ce = NULL;
- int error = 0;
-
- ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
- error = ext3_journal_get_write_access(handle, bh);
- if (error)
- goto out;
-
- lock_buffer(bh);
-
- if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
- ea_bdebug(bh, "refcount now=0; freeing");
- if (ce)
- mb_cache_entry_free(ce);
- ext3_free_blocks(handle, inode, bh->b_blocknr, 1);
- get_bh(bh);
- ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
- } else {
- le32_add_cpu(&BHDR(bh)->h_refcount, -1);
- error = ext3_journal_dirty_metadata(handle, bh);
- if (IS_SYNC(inode))
- handle->h_sync = 1;
- dquot_free_block(inode, 1);
- ea_bdebug(bh, "refcount now=%d; releasing",
- le32_to_cpu(BHDR(bh)->h_refcount));
- if (ce)
- mb_cache_entry_release(ce);
- }
- unlock_buffer(bh);
-out:
- ext3_std_error(inode->i_sb, error);
- return;
-}
-
-struct ext3_xattr_info {
- int name_index;
- const char *name;
- const void *value;
- size_t value_len;
-};
-
-struct ext3_xattr_search {
- struct ext3_xattr_entry *first;
- void *base;
- void *end;
- struct ext3_xattr_entry *here;
- int not_found;
-};
-
-static int
-ext3_xattr_set_entry(struct ext3_xattr_info *i, struct ext3_xattr_search *s)
-{
- struct ext3_xattr_entry *last;
- size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
-
- /* Compute min_offs and last. */
- last = s->first;
- for (; !IS_LAST_ENTRY(last); last = EXT3_XATTR_NEXT(last)) {
- if (!last->e_value_block && last->e_value_size) {
- size_t offs = le16_to_cpu(last->e_value_offs);
- if (offs < min_offs)
- min_offs = offs;
- }
- }
- free = min_offs - ((void *)last - s->base) - sizeof(__u32);
- if (!s->not_found) {
- if (!s->here->e_value_block && s->here->e_value_size) {
- size_t size = le32_to_cpu(s->here->e_value_size);
- free += EXT3_XATTR_SIZE(size);
- }
- free += EXT3_XATTR_LEN(name_len);
- }
- if (i->value) {
- if (free < EXT3_XATTR_LEN(name_len) +
- EXT3_XATTR_SIZE(i->value_len))
- return -ENOSPC;
- }
-
- if (i->value && s->not_found) {
- /* Insert the new name. */
- size_t size = EXT3_XATTR_LEN(name_len);
- size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
- memmove((void *)s->here + size, s->here, rest);
- memset(s->here, 0, size);
- s->here->e_name_index = i->name_index;
- s->here->e_name_len = name_len;
- memcpy(s->here->e_name, i->name, name_len);
- } else {
- if (!s->here->e_value_block && s->here->e_value_size) {
- void *first_val = s->base + min_offs;
- size_t offs = le16_to_cpu(s->here->e_value_offs);
- void *val = s->base + offs;
- size_t size = EXT3_XATTR_SIZE(
- le32_to_cpu(s->here->e_value_size));
-
- if (i->value && size == EXT3_XATTR_SIZE(i->value_len)) {
- /* The old and the new value have the same
- size. Just replace. */
- s->here->e_value_size =
- cpu_to_le32(i->value_len);
- memset(val + size - EXT3_XATTR_PAD, 0,
- EXT3_XATTR_PAD); /* Clear pad bytes. */
- memcpy(val, i->value, i->value_len);
- return 0;
- }
-
- /* Remove the old value. */
- memmove(first_val + size, first_val, val - first_val);
- memset(first_val, 0, size);
- s->here->e_value_size = 0;
- s->here->e_value_offs = 0;
- min_offs += size;
-
- /* Adjust all value offsets. */
- last = s->first;
- while (!IS_LAST_ENTRY(last)) {
- size_t o = le16_to_cpu(last->e_value_offs);
- if (!last->e_value_block &&
- last->e_value_size && o < offs)
- last->e_value_offs =
- cpu_to_le16(o + size);
- last = EXT3_XATTR_NEXT(last);
- }
- }
- if (!i->value) {
- /* Remove the old name. */
- size_t size = EXT3_XATTR_LEN(name_len);
- last = ENTRY((void *)last - size);
- memmove(s->here, (void *)s->here + size,
- (void *)last - (void *)s->here + sizeof(__u32));
- memset(last, 0, size);
- }
- }
-
- if (i->value) {
- /* Insert the new value. */
- s->here->e_value_size = cpu_to_le32(i->value_len);
- if (i->value_len) {
- size_t size = EXT3_XATTR_SIZE(i->value_len);
- void *val = s->base + min_offs - size;
- s->here->e_value_offs = cpu_to_le16(min_offs - size);
- memset(val + size - EXT3_XATTR_PAD, 0,
- EXT3_XATTR_PAD); /* Clear the pad bytes. */
- memcpy(val, i->value, i->value_len);
- }
- }
- return 0;
-}
-
-struct ext3_xattr_block_find {
- struct ext3_xattr_search s;
- struct buffer_head *bh;
-};
-
-static int
-ext3_xattr_block_find(struct inode *inode, struct ext3_xattr_info *i,
- struct ext3_xattr_block_find *bs)
-{
- struct super_block *sb = inode->i_sb;
- int error;
-
- ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
- i->name_index, i->name, i->value, (long)i->value_len);
-
- if (EXT3_I(inode)->i_file_acl) {
- /* The inode already has an extended attribute block. */
- bs->bh = sb_bread(sb, EXT3_I(inode)->i_file_acl);
- error = -EIO;
- if (!bs->bh)
- goto cleanup;
- ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
- atomic_read(&(bs->bh->b_count)),
- le32_to_cpu(BHDR(bs->bh)->h_refcount));
- if (ext3_xattr_check_block(bs->bh)) {
- ext3_error(sb, __func__,
- "inode %lu: bad block "E3FSBLK, inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- error = -EIO;
- goto cleanup;
- }
- /* Find the named attribute. */
- bs->s.base = BHDR(bs->bh);
- bs->s.first = BFIRST(bs->bh);
- bs->s.end = bs->bh->b_data + bs->bh->b_size;
- bs->s.here = bs->s.first;
- error = ext3_xattr_find_entry(&bs->s.here, i->name_index,
- i->name, bs->bh->b_size, 1);
- if (error && error != -ENODATA)
- goto cleanup;
- bs->s.not_found = error;
- }
- error = 0;
-
-cleanup:
- return error;
-}
-
-static int
-ext3_xattr_block_set(handle_t *handle, struct inode *inode,
- struct ext3_xattr_info *i,
- struct ext3_xattr_block_find *bs)
-{
- struct super_block *sb = inode->i_sb;
- struct buffer_head *new_bh = NULL;
- struct ext3_xattr_search *s = &bs->s;
- struct mb_cache_entry *ce = NULL;
- int error = 0;
-
-#define header(x) ((struct ext3_xattr_header *)(x))
-
- if (i->value && i->value_len > sb->s_blocksize)
- return -ENOSPC;
- if (s->base) {
- ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
- bs->bh->b_blocknr);
- error = ext3_journal_get_write_access(handle, bs->bh);
- if (error)
- goto cleanup;
- lock_buffer(bs->bh);
-
- if (header(s->base)->h_refcount == cpu_to_le32(1)) {
- if (ce) {
- mb_cache_entry_free(ce);
- ce = NULL;
- }
- ea_bdebug(bs->bh, "modifying in-place");
- error = ext3_xattr_set_entry(i, s);
- if (!error) {
- if (!IS_LAST_ENTRY(s->first))
- ext3_xattr_rehash(header(s->base),
- s->here);
- ext3_xattr_cache_insert(bs->bh);
- }
- unlock_buffer(bs->bh);
- if (error == -EIO)
- goto bad_block;
- if (!error)
- error = ext3_journal_dirty_metadata(handle,
- bs->bh);
- if (error)
- goto cleanup;
- goto inserted;
- } else {
- int offset = (char *)s->here - bs->bh->b_data;
-
- unlock_buffer(bs->bh);
- journal_release_buffer(handle, bs->bh);
-
- if (ce) {
- mb_cache_entry_release(ce);
- ce = NULL;
- }
- ea_bdebug(bs->bh, "cloning");
- s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
- error = -ENOMEM;
- if (s->base == NULL)
- goto cleanup;
- memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
- s->first = ENTRY(header(s->base)+1);
- header(s->base)->h_refcount = cpu_to_le32(1);
- s->here = ENTRY(s->base + offset);
- s->end = s->base + bs->bh->b_size;
- }
- } else {
- /* Allocate a buffer where we construct the new block. */
- s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
- /* assert(header == s->base) */
- error = -ENOMEM;
- if (s->base == NULL)
- goto cleanup;
- header(s->base)->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
- header(s->base)->h_blocks = cpu_to_le32(1);
- header(s->base)->h_refcount = cpu_to_le32(1);
- s->first = ENTRY(header(s->base)+1);
- s->here = ENTRY(header(s->base)+1);
- s->end = s->base + sb->s_blocksize;
- }
-
- error = ext3_xattr_set_entry(i, s);
- if (error == -EIO)
- goto bad_block;
- if (error)
- goto cleanup;
- if (!IS_LAST_ENTRY(s->first))
- ext3_xattr_rehash(header(s->base), s->here);
-
-inserted:
- if (!IS_LAST_ENTRY(s->first)) {
- new_bh = ext3_xattr_cache_find(inode, header(s->base), &ce);
- if (new_bh) {
- /* We found an identical block in the cache. */
- if (new_bh == bs->bh)
- ea_bdebug(new_bh, "keeping");
- else {
- /* The old block is released after updating
- the inode. */
- error = dquot_alloc_block(inode, 1);
- if (error)
- goto cleanup;
- error = ext3_journal_get_write_access(handle,
- new_bh);
- if (error)
- goto cleanup_dquot;
- lock_buffer(new_bh);
- le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
- ea_bdebug(new_bh, "reusing; refcount now=%d",
- le32_to_cpu(BHDR(new_bh)->h_refcount));
- unlock_buffer(new_bh);
- error = ext3_journal_dirty_metadata(handle,
- new_bh);
- if (error)
- goto cleanup_dquot;
- }
- mb_cache_entry_release(ce);
- ce = NULL;
- } else if (bs->bh && s->base == bs->bh->b_data) {
- /* We were modifying this block in-place. */
- ea_bdebug(bs->bh, "keeping this block");
- new_bh = bs->bh;
- get_bh(new_bh);
- } else {
- /* We need to allocate a new block */
- ext3_fsblk_t goal = ext3_group_first_block_no(sb,
- EXT3_I(inode)->i_block_group);
- ext3_fsblk_t block;
-
- /*
- * Protect us agaist concurrent allocations to the
- * same inode from ext3_..._writepage(). Reservation
- * code does not expect racing allocations.
- */
- mutex_lock(&EXT3_I(inode)->truncate_mutex);
- block = ext3_new_block(handle, inode, goal, &error);
- mutex_unlock(&EXT3_I(inode)->truncate_mutex);
- if (error)
- goto cleanup;
- ea_idebug(inode, "creating block %d", block);
-
- new_bh = sb_getblk(sb, block);
- if (unlikely(!new_bh)) {
-getblk_failed:
- ext3_free_blocks(handle, inode, block, 1);
- error = -ENOMEM;
- goto cleanup;
- }
- lock_buffer(new_bh);
- error = ext3_journal_get_create_access(handle, new_bh);
- if (error) {
- unlock_buffer(new_bh);
- goto getblk_failed;
- }
- memcpy(new_bh->b_data, s->base, new_bh->b_size);
- set_buffer_uptodate(new_bh);
- unlock_buffer(new_bh);
- ext3_xattr_cache_insert(new_bh);
- error = ext3_journal_dirty_metadata(handle, new_bh);
- if (error)
- goto cleanup;
- }
- }
-
- /* Update the inode. */
- EXT3_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
-
- /* Drop the previous xattr block. */
- if (bs->bh && bs->bh != new_bh)
- ext3_xattr_release_block(handle, inode, bs->bh);
- error = 0;
-
-cleanup:
- if (ce)
- mb_cache_entry_release(ce);
- brelse(new_bh);
- if (!(bs->bh && s->base == bs->bh->b_data))
- kfree(s->base);
-
- return error;
-
-cleanup_dquot:
- dquot_free_block(inode, 1);
- goto cleanup;
-
-bad_block:
- ext3_error(inode->i_sb, __func__,
- "inode %lu: bad block "E3FSBLK, inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- goto cleanup;
-
-#undef header
-}
-
-struct ext3_xattr_ibody_find {
- struct ext3_xattr_search s;
- struct ext3_iloc iloc;
-};
-
-static int
-ext3_xattr_ibody_find(struct inode *inode, struct ext3_xattr_info *i,
- struct ext3_xattr_ibody_find *is)
-{
- struct ext3_xattr_ibody_header *header;
- struct ext3_inode *raw_inode;
- int error;
-
- if (EXT3_I(inode)->i_extra_isize == 0)
- return 0;
- raw_inode = ext3_raw_inode(&is->iloc);
- header = IHDR(inode, raw_inode);
- is->s.base = is->s.first = IFIRST(header);
- is->s.here = is->s.first;
- is->s.end = (void *)raw_inode + EXT3_SB(inode->i_sb)->s_inode_size;
- if (ext3_test_inode_state(inode, EXT3_STATE_XATTR)) {
- error = ext3_xattr_check_names(IFIRST(header), is->s.end);
- if (error)
- return error;
- /* Find the named attribute. */
- error = ext3_xattr_find_entry(&is->s.here, i->name_index,
- i->name, is->s.end -
- (void *)is->s.base, 0);
- if (error && error != -ENODATA)
- return error;
- is->s.not_found = error;
- }
- return 0;
-}
-
-static int
-ext3_xattr_ibody_set(handle_t *handle, struct inode *inode,
- struct ext3_xattr_info *i,
- struct ext3_xattr_ibody_find *is)
-{
- struct ext3_xattr_ibody_header *header;
- struct ext3_xattr_search *s = &is->s;
- int error;
-
- if (EXT3_I(inode)->i_extra_isize == 0)
- return -ENOSPC;
- error = ext3_xattr_set_entry(i, s);
- if (error)
- return error;
- header = IHDR(inode, ext3_raw_inode(&is->iloc));
- if (!IS_LAST_ENTRY(s->first)) {
- header->h_magic = cpu_to_le32(EXT3_XATTR_MAGIC);
- ext3_set_inode_state(inode, EXT3_STATE_XATTR);
- } else {
- header->h_magic = cpu_to_le32(0);
- ext3_clear_inode_state(inode, EXT3_STATE_XATTR);
- }
- return 0;
-}
-
-/*
- * ext3_xattr_set_handle()
- *
- * Create, replace or remove an extended attribute for this inode. Value
- * is NULL to remove an existing extended attribute, and non-NULL to
- * either replace an existing extended attribute, or create a new extended
- * attribute. The flags XATTR_REPLACE and XATTR_CREATE
- * specify that an extended attribute must exist and must not exist
- * previous to the call, respectively.
- *
- * Returns 0, or a negative error number on failure.
- */
-int
-ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
- const char *name, const void *value, size_t value_len,
- int flags)
-{
- struct ext3_xattr_info i = {
- .name_index = name_index,
- .name = name,
- .value = value,
- .value_len = value_len,
-
- };
- struct ext3_xattr_ibody_find is = {
- .s = { .not_found = -ENODATA, },
- };
- struct ext3_xattr_block_find bs = {
- .s = { .not_found = -ENODATA, },
- };
- int error;
-
- if (!name)
- return -EINVAL;
- if (strlen(name) > 255)
- return -ERANGE;
- down_write(&EXT3_I(inode)->xattr_sem);
- error = ext3_get_inode_loc(inode, &is.iloc);
- if (error)
- goto cleanup;
-
- error = ext3_journal_get_write_access(handle, is.iloc.bh);
- if (error)
- goto cleanup;
-
- if (ext3_test_inode_state(inode, EXT3_STATE_NEW)) {
- struct ext3_inode *raw_inode = ext3_raw_inode(&is.iloc);
- memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
- ext3_clear_inode_state(inode, EXT3_STATE_NEW);
- }
-
- error = ext3_xattr_ibody_find(inode, &i, &is);
- if (error)
- goto cleanup;
- if (is.s.not_found)
- error = ext3_xattr_block_find(inode, &i, &bs);
- if (error)
- goto cleanup;
- if (is.s.not_found && bs.s.not_found) {
- error = -ENODATA;
- if (flags & XATTR_REPLACE)
- goto cleanup;
- error = 0;
- if (!value)
- goto cleanup;
- } else {
- error = -EEXIST;
- if (flags & XATTR_CREATE)
- goto cleanup;
- }
- if (!value) {
- if (!is.s.not_found)
- error = ext3_xattr_ibody_set(handle, inode, &i, &is);
- else if (!bs.s.not_found)
- error = ext3_xattr_block_set(handle, inode, &i, &bs);
- } else {
- error = ext3_xattr_ibody_set(handle, inode, &i, &is);
- if (!error && !bs.s.not_found) {
- i.value = NULL;
- error = ext3_xattr_block_set(handle, inode, &i, &bs);
- } else if (error == -ENOSPC) {
- if (EXT3_I(inode)->i_file_acl && !bs.s.base) {
- error = ext3_xattr_block_find(inode, &i, &bs);
- if (error)
- goto cleanup;
- }
- error = ext3_xattr_block_set(handle, inode, &i, &bs);
- if (error)
- goto cleanup;
- if (!is.s.not_found) {
- i.value = NULL;
- error = ext3_xattr_ibody_set(handle, inode, &i,
- &is);
- }
- }
- }
- if (!error) {
- ext3_xattr_update_super_block(handle, inode->i_sb);
- inode->i_ctime = CURRENT_TIME_SEC;
- error = ext3_mark_iloc_dirty(handle, inode, &is.iloc);
- /*
- * The bh is consumed by ext3_mark_iloc_dirty, even with
- * error != 0.
- */
- is.iloc.bh = NULL;
- if (IS_SYNC(inode))
- handle->h_sync = 1;
- }
-
-cleanup:
- brelse(is.iloc.bh);
- brelse(bs.bh);
- up_write(&EXT3_I(inode)->xattr_sem);
- return error;
-}
-
-/*
- * ext3_xattr_set()
- *
- * Like ext3_xattr_set_handle, but start from an inode. This extended
- * attribute modification is a filesystem transaction by itself.
- *
- * Returns 0, or a negative error number on failure.
- */
-int
-ext3_xattr_set(struct inode *inode, int name_index, const char *name,
- const void *value, size_t value_len, int flags)
-{
- handle_t *handle;
- int error, retries = 0;
-
-retry:
- handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
- if (IS_ERR(handle)) {
- error = PTR_ERR(handle);
- } else {
- int error2;
-
- error = ext3_xattr_set_handle(handle, inode, name_index, name,
- value, value_len, flags);
- error2 = ext3_journal_stop(handle);
- if (error == -ENOSPC &&
- ext3_should_retry_alloc(inode->i_sb, &retries))
- goto retry;
- if (error == 0)
- error = error2;
- }
-
- return error;
-}
-
-/*
- * ext3_xattr_delete_inode()
- *
- * Free extended attribute resources associated with this inode. This
- * is called immediately before an inode is freed. We have exclusive
- * access to the inode.
- */
-void
-ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
-{
- struct buffer_head *bh = NULL;
-
- if (!EXT3_I(inode)->i_file_acl)
- goto cleanup;
- bh = sb_bread(inode->i_sb, EXT3_I(inode)->i_file_acl);
- if (!bh) {
- ext3_error(inode->i_sb, __func__,
- "inode %lu: block "E3FSBLK" read error", inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- goto cleanup;
- }
- if (BHDR(bh)->h_magic != cpu_to_le32(EXT3_XATTR_MAGIC) ||
- BHDR(bh)->h_blocks != cpu_to_le32(1)) {
- ext3_error(inode->i_sb, __func__,
- "inode %lu: bad block "E3FSBLK, inode->i_ino,
- EXT3_I(inode)->i_file_acl);
- goto cleanup;
- }
- ext3_xattr_release_block(handle, inode, bh);
- EXT3_I(inode)->i_file_acl = 0;
-
-cleanup:
- brelse(bh);
-}
-
-/*
- * ext3_xattr_put_super()
- *
- * This is called when a file system is unmounted.
- */
-void
-ext3_xattr_put_super(struct super_block *sb)
-{
- mb_cache_shrink(sb->s_bdev);
-}
-
-/*
- * ext3_xattr_cache_insert()
- *
- * Create a new entry in the extended attribute cache, and insert
- * it unless such an entry is already in the cache.
- *
- * Returns 0, or a negative error number on failure.
- */
-static void
-ext3_xattr_cache_insert(struct buffer_head *bh)
-{
- __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
- struct mb_cache_entry *ce;
- int error;
-
- ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS);
- if (!ce) {
- ea_bdebug(bh, "out of memory");
- return;
- }
- error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
- if (error) {
- mb_cache_entry_free(ce);
- if (error == -EBUSY) {
- ea_bdebug(bh, "already in cache");
- error = 0;
- }
- } else {
- ea_bdebug(bh, "inserting [%x]", (int)hash);
- mb_cache_entry_release(ce);
- }
-}
-
-/*
- * ext3_xattr_cmp()
- *
- * Compare two extended attribute blocks for equality.
- *
- * Returns 0 if the blocks are equal, 1 if they differ, and
- * a negative error number on errors.
- */
-static int
-ext3_xattr_cmp(struct ext3_xattr_header *header1,
- struct ext3_xattr_header *header2)
-{
- struct ext3_xattr_entry *entry1, *entry2;
-
- entry1 = ENTRY(header1+1);
- entry2 = ENTRY(header2+1);
- while (!IS_LAST_ENTRY(entry1)) {
- if (IS_LAST_ENTRY(entry2))
- return 1;
- if (entry1->e_hash != entry2->e_hash ||
- entry1->e_name_index != entry2->e_name_index ||
- entry1->e_name_len != entry2->e_name_len ||
- entry1->e_value_size != entry2->e_value_size ||
- memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
- return 1;
- if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
- return -EIO;
- if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
- (char *)header2 + le16_to_cpu(entry2->e_value_offs),
- le32_to_cpu(entry1->e_value_size)))
- return 1;
-
- entry1 = EXT3_XATTR_NEXT(entry1);
- entry2 = EXT3_XATTR_NEXT(entry2);
- }
- if (!IS_LAST_ENTRY(entry2))
- return 1;
- return 0;
-}
-
-/*
- * ext3_xattr_cache_find()
- *
- * Find an identical extended attribute block.
- *
- * Returns a pointer to the block found, or NULL if such a block was
- * not found or an error occurred.
- */
-static struct buffer_head *
-ext3_xattr_cache_find(struct inode *inode, struct ext3_xattr_header *header,
- struct mb_cache_entry **pce)
-{
- __u32 hash = le32_to_cpu(header->h_hash);
- struct mb_cache_entry *ce;
-
- if (!header->h_hash)
- return NULL; /* never share */
- ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
-again:
- ce = mb_cache_entry_find_first(ext3_xattr_cache, inode->i_sb->s_bdev,
- hash);
- while (ce) {
- struct buffer_head *bh;
-
- if (IS_ERR(ce)) {
- if (PTR_ERR(ce) == -EAGAIN)
- goto again;
- break;
- }
- bh = sb_bread(inode->i_sb, ce->e_block);
- if (!bh) {
- ext3_error(inode->i_sb, __func__,
- "inode %lu: block %lu read error",
- inode->i_ino, (unsigned long) ce->e_block);
- } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
- EXT3_XATTR_REFCOUNT_MAX) {
- ea_idebug(inode, "block %lu refcount %d>=%d",
- (unsigned long) ce->e_block,
- le32_to_cpu(BHDR(bh)->h_refcount),
- EXT3_XATTR_REFCOUNT_MAX);
- } else if (ext3_xattr_cmp(header, BHDR(bh)) == 0) {
- *pce = ce;
- return bh;
- }
- brelse(bh);
- ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
- }
- return NULL;
-}
-
-#define NAME_HASH_SHIFT 5
-#define VALUE_HASH_SHIFT 16
-
-/*
- * ext3_xattr_hash_entry()
- *
- * Compute the hash of an extended attribute.
- */
-static inline void ext3_xattr_hash_entry(struct ext3_xattr_header *header,
- struct ext3_xattr_entry *entry)
-{
- __u32 hash = 0;
- char *name = entry->e_name;
- int n;
-
- for (n=0; n < entry->e_name_len; n++) {
- hash = (hash << NAME_HASH_SHIFT) ^
- (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
- *name++;
- }
-
- if (entry->e_value_block == 0 && entry->e_value_size != 0) {
- __le32 *value = (__le32 *)((char *)header +
- le16_to_cpu(entry->e_value_offs));
- for (n = (le32_to_cpu(entry->e_value_size) +
- EXT3_XATTR_ROUND) >> EXT3_XATTR_PAD_BITS; n; n--) {
- hash = (hash << VALUE_HASH_SHIFT) ^
- (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
- le32_to_cpu(*value++);
- }
- }
- entry->e_hash = cpu_to_le32(hash);
-}
-
-#undef NAME_HASH_SHIFT
-#undef VALUE_HASH_SHIFT
-
-#define BLOCK_HASH_SHIFT 16
-
-/*
- * ext3_xattr_rehash()
- *
- * Re-compute the extended attribute hash value after an entry has changed.
- */
-static void ext3_xattr_rehash(struct ext3_xattr_header *header,
- struct ext3_xattr_entry *entry)
-{
- struct ext3_xattr_entry *here;
- __u32 hash = 0;
-
- ext3_xattr_hash_entry(header, entry);
- here = ENTRY(header+1);
- while (!IS_LAST_ENTRY(here)) {
- if (!here->e_hash) {
- /* Block is not shared if an entry's hash value == 0 */
- hash = 0;
- break;
- }
- hash = (hash << BLOCK_HASH_SHIFT) ^
- (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
- le32_to_cpu(here->e_hash);
- here = EXT3_XATTR_NEXT(here);
- }
- header->h_hash = cpu_to_le32(hash);
-}
-
-#undef BLOCK_HASH_SHIFT
-
-int __init
-init_ext3_xattr(void)
-{
- ext3_xattr_cache = mb_cache_create("ext3_xattr", 6);
- if (!ext3_xattr_cache)
- return -ENOMEM;
- return 0;
-}
-
-void
-exit_ext3_xattr(void)
-{
- if (ext3_xattr_cache)
- mb_cache_destroy(ext3_xattr_cache);
- ext3_xattr_cache = NULL;
-}
Code Review / kvmfornfv.git / blobdiff