tree 1cfcfdaeda81e1d17725bdd1e1a964cc5a0b40b5
parent 684a3ff7e69acc7c678d1a1394fe9e757993fd34
author Tyler Hicks <tyhicks@canonical.com> 1326933004 -0600
committer Tyler Hicks <tyhicks@canonical.com> 1327524220 -0600

eCryptfs: Make truncate path killable

ecryptfs_write() handles the truncation of eCryptfs inodes. It grabs a
page, zeroes out the appropriate portions, and then encrypts the page
before writing it to the lower filesystem. It was unkillable and due to
the lack of sparse file support could result in tying up a large portion
of system resources, while encrypting pages of zeros, with no way for
the truncate operation to be stopped from userspace.

This patch adds the ability for ecryptfs_write() to detect a pending
fatal signal and return as gracefully as possible. The intent is to
leave the lower file in a useable state, while still allowing a user to
break out of the encryption loop. If a pending fatal signal is detected,
the eCryptfs inode size is updated to reflect the modified inode size
and then -EINTR is returned.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: <stable@vger.kernel.org>