Fix for dirty node in jffs2 summary entry

jffs2_flash_direct_writev() always invokes jffs2_sum_add_kvec(), even
if mtd_writev() fails. Usually, this results in an extra summary entry
pointing to dirty node space, which should be ignored -- it is a bit of
a waste, but harmless.

When mtd_writev() returns *retlen == 0, though, the node space is not
reserved as dirty, but re-used; the extra summary entry then points
into the space of the next node. After the erase block has been closed,
we get the following messages on remount:

    jffs2: error: (79) jffs2_link_node_ref:
        Adding new ref c3048d18 at (0x00ec5b88-0x00ec6bcc)
        not immediately after previous (0x00ec5b88-0x00ec5b88)
    ...
    jffs2: Checked all inodes but still 0x2088 bytes of unchecked space?
    jffs2: No space for garbage collection. Aborting GC thread

The extra summary entries amount to "unchecked space", so that
jffs2_garbage_collect_pass() returns -ENOSPC. And without garbage
collection, the filesystem becomes unuseable over time as the erase
blocks fill up.

Fix this by skipping jffs2_sum_add_kvec() when the MTD write fails. We
don't need the summary entry anyway, and the behaviour matches that of
jffs2_flash_writev() in wbuf.c (with write buffering enabled).

Signed-off-by: Thomas Betker <thomas.betker@rohde-schwarz.com>

0 files changed, 0 insertions, 0 deletions