user/sven/linux.git/kernel/acct.c, branch v4.9.147

kernel/acct.c: fix the acct->needcheck check in check_free_space()

2018-01-10T08:29:51Z

commit 4d9570158b6260f449e317a5f9ed030c2504a615 upstream. As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check is very wrong, we need time_is_after_jiffies() to make sys_acct() work. Ignoring the overflows, the code should "goto out" if needcheck > jiffies, while currently it checks "needcheck < jiffies" and thus in the likely case check_free_space() does nothing until jiffies overflow. In particular this means that sys_acct() is simply broken, acct_on() sets acct->needcheck = jiffies and expects that check_free_space() should set acct->active = 1 after the free-space check, but this won't happen if jiffies increments in between. This was broken by commit 32dc73086015 ("get rid of timer in kern/acct.c") in 2011, then another (correct) commit 795a2f22a8ea ("acct() should honour the limits from the very beginning") made the problem more visible. Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com Fixes: 32dc73086015 ("get rid of timer in kern/acct.c") Reported-by: TSUKADA Koutaro Suggested-by: TSUKADA Koutaro Signed-off-by: Oleg Nesterov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

acct: check FMODE_CAN_WRITE

2015-04-12T02:27:55Z

it's not calling ->write() directly anymore. Signed-off-by: Al Viro

new fs_pin killing logics

2015-01-26T04:17:28Z

Signed-off-by: Al Viro

get rid of the second argument of acct_kill()

2015-01-26T04:17:27Z

Replace the old ns->bacct only with NULL and only if it still points to acct. And assign the new value to it *before* calling acct_kill() in acct_on(). That way we don't need to pass the new acct to acct_kill(). Signed-off-by: Al Viro

take count and rcu_head out of fs_pin

2015-01-26T04:17:27Z

Signed-off-by: Al Viro

pull bumping refcount into ->kill()

2015-01-26T04:16:29Z

there will be one more change of ->kill() calling conventions; this isn't final. Signed-off-by: Al Viro

kill pin_put()

2015-01-26T04:16:28Z

Signed-off-by: Al Viro

acct: eliminate compile warning

2014-10-10T02:26:04Z

If ACCT_VERSION is not defined to 3, below warning appears: CC kernel/acct.o kernel/acct.c: In function `do_acct_process': kernel/acct.c:475:24: warning: unused variable `ns' [-Wunused-variable] [akpm@linux-foundation.org: retain the local for code size improvements Signed-off-by: Ying Xue Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/acct.c: fix coding style warnings and errors

2014-08-07T18:40:09Z

Signed-off-by: Ionut Alexa Signed-off-by: Andrew Morton Signed-off-by: Al Viro

death to mnt_pinned

2014-08-07T18:40:09Z

Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: Al Viro