diff options
author | Jaegeuk Kim <jaegeuk@kernel.org> | 2014-10-06 17:39:50 -0700 |
---|---|---|
committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2014-10-06 17:39:50 -0700 |
commit | 88b88a66797159949cec32eaab12b4968f6fae2d (patch) | |
tree | da80cebeb9cc86d5f9f16718ce7921eef16ed30e /fs/f2fs/file.c | |
parent | 120c2cba1d76494a68e36a11eb630cb335ed1494 (diff) |
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: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/file.c')
-rw-r--r-- | fs/f2fs/file.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 735e9a20f939..3708b80125d0 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -862,6 +862,41 @@ out: 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: |