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linux/fs/f2fs/namei.c
Gu Zheng e479556bfd f2fs: use rw_sem instead of fs_lock(locks mutex) 
The fs_locks is used to block other ops(ex, recovery) when doing checkpoint.
And each other operate routine(besides checkpoint) needs to acquire a fs_lock,
there is a terrible problem here, if these are too many concurrency threads acquiring
fs_lock, so that they will block each other and may lead to some performance problem,
but this is not the phenomenon we want to see.
Though there are some optimization patches introduced to enhance the usage of fs_lock,
but the thorough solution is using a *rw_sem* to replace the fs_lock.
Checkpoint routine takes write_sem, and other ops take read_sem, so that we can block
other ops(ex, recovery) when doing checkpoint, and other ops will not disturb each other,
this can avoid the problem described above completely.
Because of the weakness of rw_sem, the above change may introduce a potential problem
that the checkpoint thread might get starved if other threads are intensively locking
the read semaphore for I/O.(Pointed out by Xu Jin)
In order to avoid this, a wait_list is introduced, the appending read semaphore ops
will be dropped into the wait_list if checkpoint thread is waiting for write semaphore,
and will be waked up when checkpoint thread gives up write semaphore.
Thanks to Kim's previous review and test, and will be very glad to see other guys'
performance tests about this patch.

V2:
  -fix the potential starvation problem.
  -use more suitable func name suggested by Xu Jin.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
[Jaegeuk Kim: adjust minor coding standard]
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-10-07 11:33:05 +09:00

532 lines
12 KiB
C
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/*
* fs/f2fs/namei.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* 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/fs.h>
#include <linux/f2fs_fs.h>
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include "f2fs.h"
#include "node.h"
#include "xattr.h"
#include "acl.h"
#include <trace/events/f2fs.h>
static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
{
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
nid_t ino;
struct inode *inode;
bool nid_free = false;
int err;
inode = new_inode(sb);
if (!inode)
return ERR_PTR(-ENOMEM);
f2fs_lock_op(sbi);
if (!alloc_nid(sbi, &ino)) {
f2fs_unlock_op(sbi);
err = -ENOSPC;
goto fail;
}
f2fs_unlock_op(sbi);
inode->i_uid = current_fsuid();
if (dir->i_mode & S_ISGID) {
inode->i_gid = dir->i_gid;
if (S_ISDIR(mode))
mode |= S_ISGID;
} else {
inode->i_gid = current_fsgid();
}
inode->i_ino = ino;
inode->i_mode = mode;
inode->i_blocks = 0;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_generation = sbi->s_next_generation++;
err = insert_inode_locked(inode);
if (err) {
err = -EINVAL;
nid_free = true;
goto out;
}
trace_f2fs_new_inode(inode, 0);
mark_inode_dirty(inode);
return inode;
out:
clear_nlink(inode);
unlock_new_inode(inode);
fail:
trace_f2fs_new_inode(inode, err);
make_bad_inode(inode);
iput(inode);
if (nid_free)
alloc_nid_failed(sbi, ino);
return ERR_PTR(err);
}
static int is_multimedia_file(const unsigned char *s, const char *sub)
{
size_t slen = strlen(s);
size_t sublen = strlen(sub);
if (sublen > slen)
return 0;
return !strncasecmp(s + slen - sublen, sub, sublen);
}
/*
* Set multimedia files as cold files for hot/cold data separation
*/
static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
const unsigned char *name)
{
int i;
__u8 (*extlist)[8] = sbi->raw_super->extension_list;
int count = le32_to_cpu(sbi->raw_super->extension_count);
for (i = 0; i < count; i++) {
if (is_multimedia_file(name, extlist[i])) {
file_set_cold(inode);
break;
}
}
}
static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *inode;
nid_t ino = 0;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
if (!test_opt(sbi, DISABLE_EXT_IDENTIFY))
set_cold_files(sbi, inode, dentry->d_name.name);
inode->i_op = &f2fs_file_inode_operations;
inode->i_fop = &f2fs_file_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
ino = inode->i_ino;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
alloc_nid_done(sbi, ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out:
clear_nlink(inode);
unlock_new_inode(inode);
make_bad_inode(inode);
iput(inode);
alloc_nid_failed(sbi, ino);
return err;
}
static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct inode *inode = old_dentry->d_inode;
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
int err;
f2fs_balance_fs(sbi);
inode->i_ctime = CURRENT_TIME;
ihold(inode);
set_inode_flag(F2FS_I(inode), FI_INC_LINK);
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
d_instantiate(dentry, inode);
return 0;
out:
clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
iput(inode);
return err;
}
struct dentry *f2fs_get_parent(struct dentry *child)
{
struct qstr dotdot = QSTR_INIT("..", 2);
unsigned long ino = f2fs_inode_by_name(child->d_inode, &dotdot);
if (!ino)
return ERR_PTR(-ENOENT);
return d_obtain_alias(f2fs_iget(child->d_inode->i_sb, ino));
}
static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = NULL;
struct f2fs_dir_entry *de;
struct page *page;
if (dentry->d_name.len > F2FS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
de = f2fs_find_entry(dir, &dentry->d_name, &page);
if (de) {
nid_t ino = le32_to_cpu(de->ino);
kunmap(page);
f2fs_put_page(page, 0);
inode = f2fs_iget(dir->i_sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
}
return d_splice_alias(inode, dentry);
}
static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
{
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *inode = dentry->d_inode;
struct f2fs_dir_entry *de;
struct page *page;
int err = -ENOENT;
trace_f2fs_unlink_enter(dir, dentry);
f2fs_balance_fs(sbi);
de = f2fs_find_entry(dir, &dentry->d_name, &page);
if (!de)
goto fail;
err = acquire_orphan_inode(sbi);
if (err) {
kunmap(page);
f2fs_put_page(page, 0);
goto fail;
}
f2fs_lock_op(sbi);
f2fs_delete_entry(de, page, inode);
f2fs_unlock_op(sbi);
/* In order to evict this inode, we set it dirty */
mark_inode_dirty(inode);
fail:
trace_f2fs_unlink_exit(inode, err);
return err;
}
static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *inode;
size_t symlen = strlen(symname) + 1;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &f2fs_symlink_inode_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
err = page_symlink(inode, symname, symlen);
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return err;
out:
clear_nlink(inode);
unlock_new_inode(inode);
make_bad_inode(inode);
iput(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
struct inode *inode;
int err;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, S_IFDIR | mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &f2fs_dir_inode_operations;
inode->i_fop = &f2fs_dir_operations;
inode->i_mapping->a_ops = &f2fs_dblock_aops;
mapping_set_gfp_mask(inode->i_mapping, GFP_F2FS_ZERO);
set_inode_flag(F2FS_I(inode), FI_INC_LINK);
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out_fail;
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out_fail:
clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
clear_nlink(inode);
unlock_new_inode(inode);
make_bad_inode(inode);
iput(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
if (f2fs_empty_dir(inode))
return f2fs_unlink(dir, dentry);
return -ENOTEMPTY;
}
static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct super_block *sb = dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *inode;
int err = 0;
if (!new_valid_dev(rdev))
return -EINVAL;
f2fs_balance_fs(sbi);
inode = f2fs_new_inode(dir, mode);
if (IS_ERR(inode))
return PTR_ERR(inode);
init_special_inode(inode, inode->i_mode, rdev);
inode->i_op = &f2fs_special_inode_operations;
f2fs_lock_op(sbi);
err = f2fs_add_link(dentry, inode);
f2fs_unlock_op(sbi);
if (err)
goto out;
alloc_nid_done(sbi, inode->i_ino);
d_instantiate(dentry, inode);
unlock_new_inode(inode);
return 0;
out:
clear_nlink(inode);
unlock_new_inode(inode);
make_bad_inode(inode);
iput(inode);
alloc_nid_failed(sbi, inode->i_ino);
return err;
}
static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct super_block *sb = old_dir->i_sb;
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *old_inode = old_dentry->d_inode;
struct inode *new_inode = new_dentry->d_inode;
struct page *old_dir_page;
struct page *old_page, *new_page;
struct f2fs_dir_entry *old_dir_entry = NULL;
struct f2fs_dir_entry *old_entry;
struct f2fs_dir_entry *new_entry;
int err = -ENOENT;
f2fs_balance_fs(sbi);
old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
if (!old_entry)
goto out;
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
old_dir_entry = f2fs_parent_dir(old_inode, &old_dir_page);
if (!old_dir_entry)
goto out_old;
}
f2fs_lock_op(sbi);
if (new_inode) {
err = -ENOTEMPTY;
if (old_dir_entry && !f2fs_empty_dir(new_inode))
goto out_dir;
err = -ENOENT;
new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
&new_page);
if (!new_entry)
goto out_dir;
err = acquire_orphan_inode(sbi);
if (err)
goto put_out_dir;
if (update_dent_inode(old_inode, &new_dentry->d_name)) {
release_orphan_inode(sbi);
goto put_out_dir;
}
f2fs_set_link(new_dir, new_entry, new_page, old_inode);
new_inode->i_ctime = CURRENT_TIME;
if (old_dir_entry)
drop_nlink(new_inode);
drop_nlink(new_inode);
if (!new_inode->i_nlink)
add_orphan_inode(sbi, new_inode->i_ino);
else
release_orphan_inode(sbi);
update_inode_page(old_inode);
update_inode_page(new_inode);
} else {
err = f2fs_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
if (old_dir_entry) {
inc_nlink(new_dir);
update_inode_page(new_dir);
}
}
old_inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(old_inode);
f2fs_delete_entry(old_entry, old_page, NULL);
if (old_dir_entry) {
if (old_dir != new_dir) {
f2fs_set_link(old_inode, old_dir_entry,
old_dir_page, new_dir);
} else {
kunmap(old_dir_page);
f2fs_put_page(old_dir_page, 0);
}
drop_nlink(old_dir);
update_inode_page(old_dir);
}
f2fs_unlock_op(sbi);
return 0;
put_out_dir:
f2fs_put_page(new_page, 1);
out_dir:
if (old_dir_entry) {
kunmap(old_dir_page);
f2fs_put_page(old_dir_page, 0);
}
f2fs_unlock_op(sbi);
out_old:
kunmap(old_page);
f2fs_put_page(old_page, 0);
out:
return err;
}
const struct inode_operations f2fs_dir_inode_operations = {
.create = f2fs_create,
.lookup = f2fs_lookup,
.link = f2fs_link,
.unlink = f2fs_unlink,
.symlink = f2fs_symlink,
.mkdir = f2fs_mkdir,
.rmdir = f2fs_rmdir,
.mknod = f2fs_mknod,
.rename = f2fs_rename,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
.get_acl = f2fs_get_acl,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
const struct inode_operations f2fs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
.put_link = page_put_link,
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
const struct inode_operations f2fs_special_inode_operations = {
.getattr = f2fs_getattr,
.setattr = f2fs_setattr,
.get_acl = f2fs_get_acl,
#ifdef CONFIG_F2FS_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = f2fs_listxattr,
.removexattr = generic_removexattr,
#endif
};
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