Commit 88b88a66 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: support atomic writes

This patch introduces a very limited functionality for atomic write support.
In order to support atomic write, this patch adds two ioctls:
 o F2FS_IOC_START_ATOMIC_WRITE
 o F2FS_IOC_COMMIT_ATOMIC_WRITE

The database engine should be aware of the following sequence.
1. open
 -> ioctl(F2FS_IOC_START_ATOMIC_WRITE);
2. writes
  : all the written data will be treated as atomic pages.
3. commit
 -> ioctl(F2FS_IOC_COMMIT_ATOMIC_WRITE);
  : this flushes all the data blocks to the disk, which will be shown all or
  nothing by f2fs recovery procedure.
4. repeat to #2

.

The IO pattens should be:

  ,- START_ATOMIC_WRITE                  ,- COMMIT_ATOMIC_WRITE
 CP | D D D D D D | FSYNC | D D D D | FSYNC ...
                      `- COMMIT_ATOMIC_WRITE
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 120c2cba
......@@ -1052,7 +1052,10 @@ static int f2fs_write_end(struct file *file,
trace_f2fs_write_end(inode, pos, len, copied);
set_page_dirty(page);
if (f2fs_is_atomic_file(inode))
register_inmem_page(inode, page);
else
set_page_dirty(page);
if (pos + copied > i_size_read(inode)) {
i_size_write(inode, pos + copied);
......
......@@ -192,8 +192,12 @@ static inline bool __has_cursum_space(struct f2fs_summary_block *sum, int size,
/*
* ioctl commands
*/
#define F2FS_IOC_GETFLAGS FS_IOC_GETFLAGS
#define F2FS_IOC_SETFLAGS FS_IOC_SETFLAGS
#define F2FS_IOC_GETFLAGS FS_IOC_GETFLAGS
#define F2FS_IOC_SETFLAGS FS_IOC_SETFLAGS
#define F2FS_IOCTL_MAGIC 0xf5
#define F2FS_IOC_START_ATOMIC_WRITE _IO(F2FS_IOCTL_MAGIC, 1)
#define F2FS_IOC_COMMIT_ATOMIC_WRITE _IO(F2FS_IOCTL_MAGIC, 2)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
......@@ -263,6 +267,9 @@ struct f2fs_inode_info {
unsigned long long xattr_ver; /* cp version of xattr modification */
struct extent_info ext; /* in-memory extent cache entry */
struct dir_inode_entry *dirty_dir; /* the pointer of dirty dir */
struct list_head inmem_pages; /* inmemory pages managed by f2fs */
struct mutex inmem_lock; /* lock for inmemory pages */
};
static inline void get_extent_info(struct extent_info *ext,
......@@ -1051,7 +1058,8 @@ enum {
FI_INLINE_DATA, /* used for inline data*/
FI_APPEND_WRITE, /* inode has appended data */
FI_UPDATE_WRITE, /* inode has in-place-update data */
FI_NEED_IPU, /* used fo ipu for fdatasync */
FI_NEED_IPU, /* used for ipu per file */
FI_ATOMIC_FILE, /* indicate atomic file */
};
static inline void set_inode_flag(struct f2fs_inode_info *fi, int flag)
......@@ -1138,6 +1146,11 @@ static inline int f2fs_has_inline_data(struct inode *inode)
return is_inode_flag_set(F2FS_I(inode), FI_INLINE_DATA);
}
static inline bool f2fs_is_atomic_file(struct inode *inode)
{
return is_inode_flag_set(F2FS_I(inode), FI_ATOMIC_FILE);
}
static inline void *inline_data_addr(struct page *page)
{
struct f2fs_inode *ri = F2FS_INODE(page);
......@@ -1275,6 +1288,8 @@ void destroy_node_manager_caches(void);
/*
* segment.c
*/
void register_inmem_page(struct inode *, struct page *);
void commit_inmem_pages(struct inode *, bool);
void f2fs_balance_fs(struct f2fs_sb_info *);
void f2fs_balance_fs_bg(struct f2fs_sb_info *);
int f2fs_issue_flush(struct f2fs_sb_info *);
......
......@@ -862,6 +862,41 @@ static int f2fs_ioc_setflags(struct file *filp, unsigned long arg)
return ret;
}
static int f2fs_ioc_start_atomic_write(struct file *filp)
{
struct inode *inode = file_inode(filp);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
if (!inode_owner_or_capable(inode))
return -EACCES;
f2fs_balance_fs(sbi);
set_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
return f2fs_convert_inline_data(inode, MAX_INLINE_DATA + 1, NULL);
}
static int f2fs_ioc_commit_atomic_write(struct file *filp)
{
struct inode *inode = file_inode(filp);
int ret;
if (!inode_owner_or_capable(inode))
return -EACCES;
ret = mnt_want_write_file(filp);
if (ret)
return ret;
if (f2fs_is_atomic_file(inode))
commit_inmem_pages(inode, false);
ret = f2fs_sync_file(filp, 0, LONG_MAX, 0);
mnt_drop_write_file(filp);
return ret;
}
static int f2fs_ioc_fitrim(struct file *filp, unsigned long arg)
{
struct inode *inode = file_inode(filp);
......@@ -899,6 +934,10 @@ long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return f2fs_ioc_getflags(filp, arg);
case F2FS_IOC_SETFLAGS:
return f2fs_ioc_setflags(filp, arg);
case F2FS_IOC_START_ATOMIC_WRITE:
return f2fs_ioc_start_atomic_write(filp);
case F2FS_IOC_COMMIT_ATOMIC_WRITE:
return f2fs_ioc_commit_atomic_write(filp);
case FITRIM:
return f2fs_ioc_fitrim(filp, arg);
default:
......
......@@ -21,6 +21,9 @@ bool f2fs_may_inline(struct inode *inode)
if (!test_opt(F2FS_I_SB(inode), INLINE_DATA))
return false;
if (f2fs_is_atomic_file(inode))
return false;
nr_blocks = F2FS_I(inode)->i_xattr_nid ? 3 : 2;
if (inode->i_blocks > nr_blocks)
return false;
......
......@@ -269,6 +269,10 @@ void f2fs_evict_inode(struct inode *inode)
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
nid_t xnid = F2FS_I(inode)->i_xattr_nid;
/* some remained atomic pages should discarded */
if (f2fs_is_atomic_file(inode))
commit_inmem_pages(inode, true);
trace_f2fs_evict_inode(inode);
truncate_inode_pages_final(&inode->i_data);
......
......@@ -26,6 +26,7 @@
static struct kmem_cache *discard_entry_slab;
static struct kmem_cache *sit_entry_set_slab;
static struct kmem_cache *inmem_entry_slab;
/*
* __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
......@@ -173,6 +174,60 @@ static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
return result + __reverse_ffz(tmp);
}
void register_inmem_page(struct inode *inode, struct page *page)
{
struct f2fs_inode_info *fi = F2FS_I(inode);
struct inmem_pages *new;
new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
/* add atomic page indices to the list */
new->page = page;
INIT_LIST_HEAD(&new->list);
/* increase reference count with clean state */
mutex_lock(&fi->inmem_lock);
get_page(page);
list_add_tail(&new->list, &fi->inmem_pages);
mutex_unlock(&fi->inmem_lock);
}
void commit_inmem_pages(struct inode *inode, bool abort)
{
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
struct f2fs_inode_info *fi = F2FS_I(inode);
struct inmem_pages *cur, *tmp;
bool submit_bio = false;
struct f2fs_io_info fio = {
.type = DATA,
.rw = WRITE_SYNC,
};
f2fs_balance_fs(sbi);
f2fs_lock_op(sbi);
mutex_lock(&fi->inmem_lock);
list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
lock_page(cur->page);
if (!abort && cur->page->mapping == inode->i_mapping) {
f2fs_wait_on_page_writeback(cur->page, DATA);
if (clear_page_dirty_for_io(cur->page))
inode_dec_dirty_pages(inode);
do_write_data_page(cur->page, &fio);
submit_bio = true;
}
f2fs_put_page(cur->page, 1);
list_del(&cur->list);
kmem_cache_free(inmem_entry_slab, cur);
}
if (submit_bio)
f2fs_submit_merged_bio(sbi, DATA, WRITE);
mutex_unlock(&fi->inmem_lock);
filemap_fdatawait_range(inode->i_mapping, 0, LLONG_MAX);
f2fs_unlock_op(sbi);
}
/*
* This function balances dirty node and dentry pages.
* In addition, it controls garbage collection.
......@@ -2148,8 +2203,15 @@ int __init create_segment_manager_caches(void)
sizeof(struct nat_entry_set));
if (!sit_entry_set_slab)
goto destory_discard_entry;
inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
sizeof(struct inmem_pages));
if (!inmem_entry_slab)
goto destroy_sit_entry_set;
return 0;
destroy_sit_entry_set:
kmem_cache_destroy(sit_entry_set_slab);
destory_discard_entry:
kmem_cache_destroy(discard_entry_slab);
fail:
......@@ -2160,4 +2222,5 @@ void destroy_segment_manager_caches(void)
{
kmem_cache_destroy(sit_entry_set_slab);
kmem_cache_destroy(discard_entry_slab);
kmem_cache_destroy(inmem_entry_slab);
}
......@@ -175,6 +175,11 @@ struct segment_allocation {
void (*allocate_segment)(struct f2fs_sb_info *, int, bool);
};
struct inmem_pages {
struct list_head list;
struct page *page;
};
struct sit_info {
const struct segment_allocation *s_ops;
......@@ -504,7 +509,7 @@ static inline bool need_inplace_update(struct inode *inode)
unsigned int policy = SM_I(sbi)->ipu_policy;
/* IPU can be done only for the user data */
if (S_ISDIR(inode->i_mode))
if (S_ISDIR(inode->i_mode) || f2fs_is_atomic_file(inode))
return false;
if (policy & (0x1 << F2FS_IPU_FORCE))
......
......@@ -373,6 +373,8 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
fi->i_advise = 0;
rwlock_init(&fi->ext.ext_lock);
init_rwsem(&fi->i_sem);
INIT_LIST_HEAD(&fi->inmem_pages);
mutex_init(&fi->inmem_lock);
set_inode_flag(fi, FI_NEW_INODE);
......
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