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linux-next/fs/f2fs/xattr.c
Jaegeuk Kim 399368372e f2fs: introduce a new global lock scheme
In the previous version, f2fs uses global locks according to the usage types,
such as directory operations, block allocation, block write, and so on.

Reference the following lock types in f2fs.h.
enum lock_type {
	RENAME,		/* for renaming operations */
	DENTRY_OPS,	/* for directory operations */
	DATA_WRITE,	/* for data write */
	DATA_NEW,	/* for data allocation */
	DATA_TRUNC,	/* for data truncate */
	NODE_NEW,	/* for node allocation */
	NODE_TRUNC,	/* for node truncate */
	NODE_WRITE,	/* for node write */
	NR_LOCK_TYPE,
};

In that case, we lose the performance under the multi-threading environment,
since every types of operations must be conducted one at a time.

In order to address the problem, let's share the locks globally with a mutex
array regardless of any types.
So, let users grab a mutex and perform their jobs in parallel as much as
possbile.

For this, I propose a new global lock scheme as follows.

0. Data structure
 - f2fs_sb_info -> mutex_lock[NR_GLOBAL_LOCKS]
 - f2fs_sb_info -> node_write

1. mutex_lock_op(sbi)
 - try to get an avaiable lock from the array.
 - returns the index of the gottern lock variable.

2. mutex_unlock_op(sbi, index of the lock)
 - unlock the given index of the lock.

3. mutex_lock_all(sbi)
 - grab all the locks in the array before the checkpoint.

4. mutex_unlock_all(sbi)
 - release all the locks in the array after checkpoint.

5. block_operations()
 - call mutex_lock_all()
 - sync_dirty_dir_inodes()
 - grab node_write
 - sync_node_pages()

Note that,
 the pairs of mutex_lock_op()/mutex_unlock_op() and
 mutex_lock_all()/mutex_unlock_all() should be used together.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-09 18:21:18 +09:00

448 lines
11 KiB
C

/*
* fs/f2fs/xattr.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* Portions of this code from linux/fs/ext2/xattr.c
*
* Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
*
* Fix by Harrison Xing <harrison@mountainviewdata.com>.
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/rwsem.h>
#include <linux/f2fs_fs.h>
#include "f2fs.h"
#include "xattr.h"
static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_len, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
int total_len, prefix_len = 0;
const char *prefix = NULL;
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
prefix = XATTR_USER_PREFIX;
prefix_len = XATTR_USER_PREFIX_LEN;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
prefix = XATTR_TRUSTED_PREFIX;
prefix_len = XATTR_TRUSTED_PREFIX_LEN;
break;
default:
return -EINVAL;
}
total_len = prefix_len + name_len + 1;
if (list && total_len <= list_size) {
memcpy(list, prefix, prefix_len);
memcpy(list+prefix_len, name, name_len);
list[prefix_len + name_len] = '\0';
}
return total_len;
}
static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
break;
default:
return -EINVAL;
}
if (strcmp(name, "") == 0)
return -EINVAL;
return f2fs_getxattr(dentry->d_inode, type, name,
buffer, size);
}
static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
switch (type) {
case F2FS_XATTR_INDEX_USER:
if (!test_opt(sbi, XATTR_USER))
return -EOPNOTSUPP;
break;
case F2FS_XATTR_INDEX_TRUSTED:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
break;
default:
return -EINVAL;
}
if (strcmp(name, "") == 0)
return -EINVAL;
return f2fs_setxattr(dentry->d_inode, type, name, value, size);
}
static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
size_t list_size, const char *name, size_t name_len, int type)
{
const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
size_t size;
if (type != F2FS_XATTR_INDEX_ADVISE)
return 0;
size = strlen(xname) + 1;
if (list && size <= list_size)
memcpy(list, xname, size);
return size;
}
static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
void *buffer, size_t size, int type)
{
struct inode *inode = dentry->d_inode;
if (strcmp(name, "") != 0)
return -EINVAL;
*((char *)buffer) = F2FS_I(inode)->i_advise;
return sizeof(char);
}
static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
const void *value, size_t size, int flags, int type)
{
struct inode *inode = dentry->d_inode;
if (strcmp(name, "") != 0)
return -EINVAL;
if (!inode_owner_or_capable(inode))
return -EPERM;
if (value == NULL)
return -EINVAL;
F2FS_I(inode)->i_advise |= *(char *)value;
return 0;
}
const struct xattr_handler f2fs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.flags = F2FS_XATTR_INDEX_USER,
.list = f2fs_xattr_generic_list,
.get = f2fs_xattr_generic_get,
.set = f2fs_xattr_generic_set,
};
const struct xattr_handler f2fs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.flags = F2FS_XATTR_INDEX_TRUSTED,
.list = f2fs_xattr_generic_list,
.get = f2fs_xattr_generic_get,
.set = f2fs_xattr_generic_set,
};
const struct xattr_handler f2fs_xattr_advise_handler = {
.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
.flags = F2FS_XATTR_INDEX_ADVISE,
.list = f2fs_xattr_advise_list,
.get = f2fs_xattr_advise_get,
.set = f2fs_xattr_advise_set,
};
static const struct xattr_handler *f2fs_xattr_handler_map[] = {
[F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
[F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &f2fs_xattr_acl_access_handler,
[F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &f2fs_xattr_acl_default_handler,
#endif
[F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
[F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
};
const struct xattr_handler *f2fs_xattr_handlers[] = {
&f2fs_xattr_user_handler,
#ifdef CONFIG_F2FS_FS_POSIX_ACL
&f2fs_xattr_acl_access_handler,
&f2fs_xattr_acl_default_handler,
#endif
&f2fs_xattr_trusted_handler,
&f2fs_xattr_advise_handler,
NULL,
};
static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
{
const struct xattr_handler *handler = NULL;
if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
handler = f2fs_xattr_handler_map[name_index];
return handler;
}
int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
void *buffer, size_t buffer_size)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *entry;
struct page *page;
void *base_addr;
int error = 0, found = 0;
size_t value_len, name_len;
if (name == NULL)
return -EINVAL;
name_len = strlen(name);
if (!fi->i_xattr_nid)
return -ENODATA;
page = get_node_page(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
list_for_each_xattr(entry, base_addr) {
if (entry->e_name_index != name_index)
continue;
if (entry->e_name_len != name_len)
continue;
if (!memcmp(entry->e_name, name, name_len)) {
found = 1;
break;
}
}
if (!found) {
error = -ENODATA;
goto cleanup;
}
value_len = le16_to_cpu(entry->e_value_size);
if (buffer && value_len > buffer_size) {
error = -ERANGE;
goto cleanup;
}
if (buffer) {
char *pval = entry->e_name + entry->e_name_len;
memcpy(buffer, pval, value_len);
}
error = value_len;
cleanup:
f2fs_put_page(page, 1);
return error;
}
ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
struct inode *inode = dentry->d_inode;
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_entry *entry;
struct page *page;
void *base_addr;
int error = 0;
size_t rest = buffer_size;
if (!fi->i_xattr_nid)
return 0;
page = get_node_page(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
list_for_each_xattr(entry, base_addr) {
const struct xattr_handler *handler =
f2fs_xattr_handler(entry->e_name_index);
size_t size;
if (!handler)
continue;
size = handler->list(dentry, buffer, rest, entry->e_name,
entry->e_name_len, handler->flags);
if (buffer && size > rest) {
error = -ERANGE;
goto cleanup;
}
if (buffer)
buffer += size;
rest -= size;
}
error = buffer_size - rest;
cleanup:
f2fs_put_page(page, 1);
return error;
}
int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
const void *value, size_t value_len)
{
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct f2fs_xattr_header *header = NULL;
struct f2fs_xattr_entry *here, *last;
struct page *page;
void *base_addr;
int error, found, free, newsize;
size_t name_len;
char *pval;
int ilock;
if (name == NULL)
return -EINVAL;
if (value == NULL)
value_len = 0;
name_len = strlen(name);
if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN)
return -ERANGE;
f2fs_balance_fs(sbi);
ilock = mutex_lock_op(sbi);
if (!fi->i_xattr_nid) {
/* Allocate new attribute block */
struct dnode_of_data dn;
if (!alloc_nid(sbi, &fi->i_xattr_nid)) {
error = -ENOSPC;
goto exit;
}
set_new_dnode(&dn, inode, NULL, NULL, fi->i_xattr_nid);
mark_inode_dirty(inode);
page = new_node_page(&dn, XATTR_NODE_OFFSET);
if (IS_ERR(page)) {
alloc_nid_failed(sbi, fi->i_xattr_nid);
fi->i_xattr_nid = 0;
error = PTR_ERR(page);
goto exit;
}
alloc_nid_done(sbi, fi->i_xattr_nid);
base_addr = page_address(page);
header = XATTR_HDR(base_addr);
header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
header->h_refcount = cpu_to_le32(1);
} else {
/* The inode already has an extended attribute block. */
page = get_node_page(sbi, fi->i_xattr_nid);
if (IS_ERR(page)) {
error = PTR_ERR(page);
goto exit;
}
base_addr = page_address(page);
header = XATTR_HDR(base_addr);
}
if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
error = -EIO;
goto cleanup;
}
/* find entry with wanted name. */
found = 0;
list_for_each_xattr(here, base_addr) {
if (here->e_name_index != name_index)
continue;
if (here->e_name_len != name_len)
continue;
if (!memcmp(here->e_name, name, name_len)) {
found = 1;
break;
}
}
last = here;
while (!IS_XATTR_LAST_ENTRY(last))
last = XATTR_NEXT_ENTRY(last);
newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
name_len + value_len);
/* 1. Check space */
if (value) {
/* If value is NULL, it is remove operation.
* In case of update operation, we caculate free.
*/
free = MIN_OFFSET - ((char *)last - (char *)header);
if (found)
free = free - ENTRY_SIZE(here);
if (free < newsize) {
error = -ENOSPC;
goto cleanup;
}
}
/* 2. Remove old entry */
if (found) {
/* If entry is found, remove old entry.
* If not found, remove operation is not needed.
*/
struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
int oldsize = ENTRY_SIZE(here);
memmove(here, next, (char *)last - (char *)next);
last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
memset(last, 0, oldsize);
}
/* 3. Write new entry */
if (value) {
/* Before we come here, old entry is removed.
* We just write new entry. */
memset(last, 0, newsize);
last->e_name_index = name_index;
last->e_name_len = name_len;
memcpy(last->e_name, name, name_len);
pval = last->e_name + name_len;
memcpy(pval, value, value_len);
last->e_value_size = cpu_to_le16(value_len);
}
set_page_dirty(page);
f2fs_put_page(page, 1);
if (is_inode_flag_set(fi, FI_ACL_MODE)) {
inode->i_mode = fi->i_acl_mode;
inode->i_ctime = CURRENT_TIME;
clear_inode_flag(fi, FI_ACL_MODE);
}
update_inode_page(inode);
mutex_unlock_op(sbi, ilock);
return 0;
cleanup:
f2fs_put_page(page, 1);
exit:
mutex_unlock_op(sbi, ilock);
return error;
}