From: Jaegeuk Kim Date: Fri, 27 Jul 2018 09:15:11 +0000 (+0900) Subject: f2fs: don't allow any writes on aborted atomic writes X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=06da8b3d9ba5904933b889f4a78987675d02c19b;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git f2fs: don't allow any writes on aborted atomic writes In order to prevent abusing atomic writes by abnormal users, we've added a threshold, 20% over memory footprint, which disallows further atomic writes. Previously, however, SQLite doesn't know the files became normal, so that it could write stale data and commit on revoked normal database file. Once f2fs detects such the abnormal behavior, this patch tries to avoid further writes in write_begin(). Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 60f8a92c117b..a9418f3f891a 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2288,8 +2288,9 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping, trace_f2fs_write_begin(inode, pos, len, flags); - if (f2fs_is_atomic_file(inode) && - !f2fs_available_free_memory(sbi, INMEM_PAGES)) { + if ((f2fs_is_atomic_file(inode) && + !f2fs_available_free_memory(sbi, INMEM_PAGES)) || + is_inode_flag_set(inode, FI_ATOMIC_REVOKE_REQUEST)) { err = -ENOMEM; drop_atomic = true; goto fail; diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index dd5f08943feb..53100ebac81e 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1708,8 +1708,11 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); - if (f2fs_is_atomic_file(inode)) + if (f2fs_is_atomic_file(inode)) { + if (is_inode_flag_set(inode, FI_ATOMIC_REVOKE_REQUEST)) + ret = -EINVAL; goto out; + } ret = f2fs_convert_inline_inode(inode); if (ret) @@ -1871,6 +1874,8 @@ static int f2fs_ioc_abort_volatile_write(struct file *filp) ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true); } + clear_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); + inode_unlock(inode); mnt_drop_write_file(filp);