When xd->refcnt is checked whether this xdatum should be released
or not, atomic_dec_and_lock() is used to ensure holding the
c->erase_completion_lock.
This fix change a specification of delete_xattr_datum().
Previously, it's only called when xd->refcnt equals zero.
(calling it with positive xd->refcnt cause a BUG())
If you applied this patch, the function checks whether
xd->refcnt is zero or not under the spinlock if necessary.
Then, it marks xd DEAD flahs and links with xattr_dead_list
or releases it immediately when xd->refcnt become zero.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
In jffs2_release_xattr_datum(), it refers xd->refcnt to ensure
whether releasing xd is allowed or not.
But we can't hold xattr_sem since this function is called under
spin_lock(&c->erase_completion_lock). Thus we have to refer it
without any locking.
This patch redefine xd->refcnt as atomic_t. It enables to refer
xd->refcnt without any locking.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
In the followinf situation, an explicit delete marker is not
necessary, because we can certainlly detect those obsolete
xattr_datum or xattr_ref on next mounting.
- When to delete xattr_datum node.
- When to delete xattr_ref node on removing inode.
- When to delete xattr_ref node on updating xattr.
This patch rids writing delete marker in those situations.
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
- When xdatum is removed, a new xdatum with 'delete marker' is
written. (version==0xffffffff means 'delete marker')
- When xref is removed, a new xref with 'delete marker' is written.
(odd-numbered xseqno means 'delete marker')
- delete_xattr_(datum/xref)_delay() are new deletion functions
are added. We can only use them if we can detect the target
obsolete xdatum/xref as a orphan or errir one.
(e.g when inode deletion, or detecting crc error)
[1/3] jffs2-xattr-v6-01-delete_marker.patch
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
As the first step towards eliminating the ref->next_phys member and saving
memory by using an _array_ of struct jffs2_raw_node_ref per eraseblock,
stop the write functions from allocating their own refs; have them just
_reserve_ the appropriate number instead. Then jffs2_link_node_ref() can
just fill them in.
Use a linked list of pre-allocated refs in the superblock, for now. Once
we switch to an array, it'll just be a case of extending that array.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
We don't need the upper layers to deal with the physical offset. It's
_always_ c->nextblock->offset + c->sector_size - c->nextblock->free_size
so we might as well just let the actual write functions deal with that.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Let's avoid the potential for forgetting to set ref->next_in_ino, by doing
it within jffs2_link_node_ref() instead.
This highlights the ugliness of what we're currently doing with
xattr_datum and xattr_ref structures -- we should find a nicer way of
dealing with that.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
If __totlen is going away, we need to pass the length in separately.
Also stop callers from needlessly setting ref->next_phys to NULL,
since that's done for them... and since that'll also be going away soon.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Remove jffs2_garbage_collect_xattr(c, ic).
jffs2_garbage_collect_xattr_datum/ref() are called from gc.c directly.
In original implementation, jffs2_garbage_collect_xattr(c, ic) returns
with holding a spinlock if 'ic' is inode_cache. But it returns after
releasing a spinlock if 'ic' is xattr_datum/ref.
It looks so confusable behavior. Thus, this patch makes caller manage
locking/unlocking.
[5/10] jffs2-xattr-v5.1-05-update_xattr_gc.patch
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
This patch can reduce 4-byte of memory usage per inode_cache.
[4/10] jffs2-xattr-v5.1-04-remove_ilist_from_ic.patch
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
This attached patches provide xattr support including POSIX-ACL and
SELinux support on JFFS2 (version.5).
There are some significant differences from previous version posted
at last December.
The biggest change is addition of EBS(Erase Block Summary) support.
Currently, both kernel and usermode utility (sumtool) can recognize
xattr nodes which have JFFS2_NODETYPE_XATTR/_XREF nodetype.
In addition, some bugs are fixed.
- A potential race condition was fixed.
- Unexpected fail when updating a xattr by same name/value pair was fixed.
- A bug when removing xattr name/value pair was fixed.
The fundamental structures (such as using two new nodetypes and exclusion
mechanism by rwsem) are unchanged. But most of implementation were reviewed
and updated if necessary.
Espacially, we had to change several internal implementations related to
load_xattr_datum() to avoid a potential race condition.
[1/2] xattr_on_jffs2.kernel.version-5.patch
[2/2] xattr_on_jffs2.utils.version-5.patch
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
