From: Chao Yu Date: Mon, 9 Oct 2017 09:55:19 +0000 (+0800) Subject: f2fs: fix to avoid race when accessing last_disk_size X-Git-Tag: Ubuntu-5.10.0-12.13~8998^2~55 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=a0d00fad353d4a315f54fb345aa1c65b3771389b;p=mirror_ubuntu-hirsute-kernel.git f2fs: fix to avoid race when accessing last_disk_size last_disk_size could be wrong due to concurrently updating, so using i_sem semaphore to make last_disk_size updating exclusive to fix this issue. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 60a07fb26475..95fdbe3e6cca 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1570,8 +1570,11 @@ write: err = do_write_data_page(&fio); } } + + down_write(&F2FS_I(inode)->i_sem); if (F2FS_I(inode)->last_disk_size < psize) F2FS_I(inode)->last_disk_size = psize; + up_write(&F2FS_I(inode)->i_sem); done: if (err && err != -ENOENT) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index dac50d8b2bb8..3cf7494408ff 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2284,9 +2284,10 @@ static inline void clear_file(struct inode *inode, int type) static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync) { + bool ret; + if (dsync) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - bool ret; spin_lock(&sbi->inode_lock[DIRTY_META]); ret = list_empty(&F2FS_I(inode)->gdirty_list); @@ -2297,7 +2298,12 @@ static inline bool f2fs_skip_inode_update(struct inode *inode, int dsync) file_keep_isize(inode) || i_size_read(inode) & PAGE_MASK) return false; - return F2FS_I(inode)->last_disk_size == i_size_read(inode); + + down_read(&F2FS_I(inode)->i_sem); + ret = F2FS_I(inode)->last_disk_size == i_size_read(inode); + up_read(&F2FS_I(inode)->i_sem); + + return ret; } static inline int f2fs_readonly(struct super_block *sb) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index cfee75bf88d9..9b93aea5cbeb 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -777,6 +777,10 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr) inode->i_mtime = inode->i_ctime = current_time(inode); } + down_write(&F2FS_I(inode)->i_sem); + F2FS_I(inode)->last_disk_size = i_size_read(inode); + up_write(&F2FS_I(inode)->i_sem); + size_changed = true; }