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path: root/fs/autofs/expire.c
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2019-12-05Merge branch 'next.autofs' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull autofs updates from Al Viro: "autofs misuses checks for ->d_subdirs emptiness; the cursors are in the same lists, resulting in false negatives. It's not needed anyway, since autofs maintains counter in struct autofs_info, containing 0 for removed ones, 1 for live symlinks and 1 + number of children for live directories, which is precisely what we need for those checks. This series switches to use of that counter and untangles the crap around its uses (it needs not be atomic and there's a bunch of completely pointless "defensive" checks). This fell out of dcache_readdir work; the main point is to get rid of ->d_subdirs abuses in there. I've more followup cleanups, but I hadn't run those by Ian yet, so they can go next cycle" * 'next.autofs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: autofs: don't bother with atomics for ino->count autofs_dir_rmdir(): check ino->count for deciding whether it's empty... autofs: get rid of pointless checks around ->count handling autofs_clear_leaf_automount_flags(): use ino->count instead of ->d_subdirs
2019-10-25autofs: fix a leak in autofs_expire_indirect()Al Viro
if the second call of should_expire() in there ends up grabbing and returning a new reference to dentry, we need to drop it before continuing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-17autofs: don't bother with atomics for ino->countAl Viro
All writers are serialized on inode->i_rwsem. So are the readers outside of expire.c. And the readers in expire.c are in the code that really doesn't care about narrow races - it's looking for expiry candidates and its callers have to cope with the possibility of a good candidate becoming busy right under them. No point bothering with atomic operations - just use int and mark the non-serialized readers with READ_ONCE(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-24autofs: simplify get_next_positive_...(), get rid of trylocksAl Viro
* new helper: positive_after(parent, child); parent->d_lock is held by caller, grabs and returns the first thing after child in the list of children that has simple_positive() true. NULL if nothing's found; NULL child == search the entire list. * get_next_positive_subdir() loses the redundant check for d_count and switches to use of that helper. BTW, dput(NULL) is a no-op for a good reason... * get_next_positive_dentry() switched to the same helper. Logics: look for positive child in prev; if not found, look for the positive child of prev's parent following prev, etc. That way we are guaranteed that we are only moving rootwards through the ancestors of prev, which is pinned and thus not going anywhere. Since ->d_parent on autofs never changes, the same goes for the entire chain of ancestors and we don't need overlapping ->d_lock on them. Which avoids the trylock loops, in addition to simplifying the logics in there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 83Thomas Gleixner
Based on 1 normalized pattern(s): this file is part of the linux kernel and is made available under the terms of the gnu general public license version 2 or at your option any later version incorporated herein by reference extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 18 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520075211.321157221@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01autofs: drop dentry reference only when it is never usedPan Bian
autofs_expire_run() calls dput(dentry) to drop the reference count of dentry. However, dentry is read via autofs_dentry_ino(dentry) after that. This may result in a use-free-bug. The patch drops the reference count of dentry only when it is never used. Link: http://lkml.kernel.org/r/154725122396.11260.16053424107144453867.stgit@pluto-themaw-net Signed-off-by: Pan Bian <bianpan2016@163.com> Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: add AUTOFS_EXP_FORCED flagIan Kent
The userspace automount(8) daemon is meant to perform a forced expire when sent a SIGUSR2. But since the expiration is routed through the kernel and the kernel doesn't send an expire request if the mount is busy this hasn't worked at least since autofs version 5. Add an AUTOFS_EXP_FORCED flag to allow implemention of the feature and bump the protocol version so user space can check if it's implemented if needed. Link: http://lkml.kernel.org/r/152937734715.21213.6594007182776598970.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: make expire flags usage consistent with v5 paramsIan Kent
Make the usage of the expire flags consistent by naming the expire flags the same as it is named in the version 5 miscelaneous ioctl parameters and only check the bit flags when needed. Link: http://lkml.kernel.org/r/152937734046.21213.9454131988766280028.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: make autofs_expire_indirect() staticIan Kent
autofs_expire_indirect() isn't used outside of fs/autofs/expire.c so make it static. Link: http://lkml.kernel.org/r/152937733512.21213.10509996499623738446.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: make autofs_expire_direct() staticIan Kent
autofs_expire_direct() isn't used outside of fs/autofs/expire.c so make it static. Link: http://lkml.kernel.org/r/152937732944.21213.11821977712410930973.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: fix clearing AUTOFS_EXP_LEAVES in autofs_expire_indirect()Ian Kent
The expire flag AUTOFS_EXP_LEAVES is cleared before the second call to should_expire() in autofs_expire_indirect() but the parameter passed in the second call is incorrect. Fortunately AUTOFS_EXP_LEAVES expire flag has not been used for a long time but might be needed in the future so fix it rather than remove the expire leaves functionality. Link: http://lkml.kernel.org/r/152937732410.21213.7447294898147765076.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22autofs: fix inconsistent use of now variableIan Kent
The global variable "now" in fs/autofs/expire.c is used in an inconsistent way, sometimes using jiffies directly, and sometimes using the "now" variable, and setting it isn't done consistently either. But the autofs dentry info last_used field is only updated during path walks or during expire so jiffies can be used directly and the global variable "now" removed. Link: http://lkml.kernel.org/r/152937731702.21213.7371321165189170865.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07autofs: copy autofs4 to autofsIan Kent
Copy source files from the autofs4 directory to the autofs directory. Link: http://lkml.kernel.org/r/152626705013.28589.931913083997578251.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>