From 4b1f1660710c2ddcefc08c289e66a32b6bc2a2e3 Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Sun, 27 Jul 2014 22:28:15 -0400 Subject: [PATCH] ext4: add i_data_sem sanity check Each caller of ext4_ext_dirty must hold i_data_sem, The only exception is migration code, let's make it convenient. Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara --- fs/ext4/extents.c | 2 ++ fs/ext4/migrate.c | 7 +++++++ 2 files changed, 9 insertions(+) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index b30172dd55eb..ee93f82630c6 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -161,6 +161,8 @@ int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { int err; + + WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem)); if (path->p_bh) { ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh)); /* path points to block */ diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index ec092437d3e0..d3567f27bae7 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -39,6 +39,8 @@ static int finish_range(handle_t *handle, struct inode *inode, newext.ee_block = cpu_to_le32(lb->first_block); newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1); ext4_ext_store_pblock(&newext, lb->first_pblock); + /* Locking only for convinience since we are operating on temp inode */ + down_write(&EXT4_I(inode)->i_data_sem); path = ext4_ext_find_extent(inode, lb->first_block, NULL, 0); if (IS_ERR(path)) { @@ -61,7 +63,9 @@ static int finish_range(handle_t *handle, struct inode *inode, */ if (needed && ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS)) { + up_write((&EXT4_I(inode)->i_data_sem)); retval = ext4_journal_restart(handle, needed); + down_write((&EXT4_I(inode)->i_data_sem)); if (retval) goto err_out; } else if (needed) { @@ -70,13 +74,16 @@ static int finish_range(handle_t *handle, struct inode *inode, /* * IF not able to extend the journal restart the journal */ + up_write((&EXT4_I(inode)->i_data_sem)); retval = ext4_journal_restart(handle, needed); + down_write((&EXT4_I(inode)->i_data_sem)); if (retval) goto err_out; } } retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0); err_out: + up_write((&EXT4_I(inode)->i_data_sem)); if (path) { ext4_ext_drop_refs(path); kfree(path);