• Michael Halcrow's avatar
    eCryptfs: fix write zeros behavior · 240e2df5
    Michael Halcrow authored
    This patch fixes the processes involved in wiping regions of the data during
    truncate and write events, fixing a kernel hang in 2.6.22-rc4 while assuring
    that zero values are written out to the appropriate locations during events in
    which the i_size will change.
    
    The range passed to ecryptfs_truncate() from ecryptfs_prepare_write() includes
    the page that is the object of ecryptfs_prepare_write().  This leads to a
    kernel hang as read_cache_page() is executed on the same page in the
    ecryptfs_truncate() execution path.  This patch remedies this by limiting the
    range passed to ecryptfs_truncate() so as to exclude the page that is the
    object of ecryptfs_prepare_write(); it also adds code to
    ecryptfs_prepare_write() to zero out the region of its own page when writing
    past the i_size position.  This patch also modifies ecryptfs_truncate() so
    that when a file is truncated to a smaller size, eCryptfs will zero out the
    contents of the new last page from the new size through to the end of the last
    page.
    Signed-off-by: default avatarMichael Halcrow <mhalcrow@us.ibm.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    240e2df5
mmap.c 24.3 KB