IS_ERR() macro already has unlikely(), so do not use constructions
like 'if (unlikely(IS_ERR())'.
Signed-off-by: NHirofumi Nakagawa <hnakagawa@miraclelinux.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

- update GC sequence number if any nodes may have been moved
even if GC did not finish the LEB
- don't ignore error return when reading
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The TNC mutex is unlocked prematurely when reading leaf nodes
with non-hashed keys.  This is unsafe because the node may be
moved by garbage collection and the eraseblock unmapped, although
that has never actually happened during stress testing.

This patch fixes the flaw by detecting the race and retrying with
the TNC mutex locked.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Leaf-nodes that have a hashed key are stored in the
leaf-node-cache (LNC) which is protected by the TNC
mutex.  Consequently, when reading a leaf node with
a hashed key (i.e. directory entries, xattr entries)
the TNC mutex is always required.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.htmlSigned-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>