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udf: Fix deadlock when converting file from in-ICB one to normal one

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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().

CC: stable@kernel.org
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>
This commit is contained in:
Jan Kara
2011-12-10 02:30:48 +01:00
parent 7b0b0933a3
commit d2eb8c3593
2 changed files with 21 additions and 6 deletions
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6
fs/udf/file.c
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@@ -125,7 +125,6 @@ static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
err = udf_expand_file_adinicb(inode);
if (err) {
udf_debug("udf_expand_adinicb: err=%d\n", err);
up_write(&iinfo->i_data_sem);
return err;
}
} else {
@@ -133,9 +132,10 @@ static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
iinfo->i_lenAlloc = pos + count;
else
iinfo->i_lenAlloc = inode->i_size;
up_write(&iinfo->i_data_sem);
}
}
up_write(&iinfo->i_data_sem);
} else
up_write(&iinfo->i_data_sem);
retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
if (retval > 0)