udf: Fix deadlock when converting file from in-ICB one to normal one
authorJan Kara <jack@suse.cz>
Sat, 10 Dec 2011 01:30:48 +0000 (02:30 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 12 Jan 2012 19:33:25 +0000 (11:33 -0800)
commit1c44ff2c1b216cc53decad5e929fdb7dd61df0a9
tree66693d8327bd89dbac83bbdfed55982a720a93a5
parentb5c66ace2892b73dc2a55c1d3360224f388841cc
udf: Fix deadlock when converting file from in-ICB one to normal one

commit d2eb8c359309ec45d6bf5b147303ab8e13be86ea upstream.

During BKL removal in 2.6.38, conversion of files from in-ICB format to normal
format got broken. We call ->writepage with i_data_sem held but udf_get_block()
also acquires i_data_sem thus creating A-A deadlock.

We fix the problem by dropping i_data_sem before calling ->writepage() which is
safe since i_mutex still protects us against any changes in the file. Also fix
pagelock - i_data_sem lock inversion in udf_expand_file_adinicb() by dropping
i_data_sem before calling find_or_create_page().

Reported-by: Matthias Matiak <netzpython@mail-on.us>
Tested-by: Matthias Matiak <netzpython@mail-on.us>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/udf/file.c
fs/udf/inode.c