From 455e3a5887ee7ebec5c885a8f398c2c3c0a33165 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Fri, 27 Jul 2018 18:15:11 +0900 Subject: [PATCH] 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 --- fs/f2fs/data.c | 5 +++-- fs/f2fs/file.c | 7 ++++++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 7f860405cd6e..5d152de30449 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2291,8 +2291,9 @@ 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 ff2cb8fb6934..c2c47f3248c4 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); -- 2.11.0