- 20 9月, 2016 1 次提交
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由 Ian Kent 提交于
Somewhere along the way the autofs expire operation has changed to hold a spin lock over expired dentry selection. The autofs indirect mount expired dentry selection is complicated and quite lengthy so it isn't appropriate to hold a spin lock over the operation. Commit 47be6184 ("fs/dcache.c: avoid soft-lockup in dput()") added a might_sleep() to dput() causing a WARN_ONCE() about this usage to be issued. But the spin lock doesn't need to be held over this check, the autofs dentry info. flags are enough to block walks into dentrys during the expire. I've left the direct mount expire as it is (for now) because it is much simpler and quicker than the indirect mount expire and adding spin lock release and re-aquires would do nothing more than add overhead. Fixes: 47be6184 ("fs/dcache.c: avoid soft-lockup in dput()") Link: http://lkml.kernel.org/r/20160912014017.1773.73060.stgit@pluto.themaw.netSigned-off-by: NIan Kent <raven@themaw.net> Reported-by: NTakashi Iwai <tiwai@suse.de> Tested-by: NTakashi Iwai <tiwai@suse.de> Cc: Takashi Iwai <tiwai@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 6月, 2016 1 次提交
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由 Al Viro 提交于
* make autofs4_expire_indirect() skip the dentries being in process of expiry * do *not* mess with list_move(); making sure that dentry with AUTOFS_INF_EXPIRING are not picked for expiry is enough. * do not remove NO_RCU when we set EXPIRING, don't bother with smp_mb() there. Clear it at the same time we clear EXPIRING. Makes a bunch of tests simpler. * rename NO_RCU to WANT_EXPIRE, which is what it really is. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 16 3月, 2016 3 次提交
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由 Ian Kent 提交于
Use the standard pr_xxx() log macros directly for log prints instead of the AUTOFS_XXX() macros. Signed-off-by: NIan Kent <ikent@redhat.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ian Kent 提交于
Common kernel coding practice is to include the newline of log prints within the log text rather than hidden away in a macro. To avoid introducing inconsistencies as changes are made change the log macros to not include the newline. Signed-off-by: NIan Kent <raven@themaw.net> Cc: Joe Perches <joe@perches.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ian Kent 提交于
Try and make the coding style completely consistent throughtout the autofs module and inline with kernel coding style recommendations. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 4月, 2015 1 次提交
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由 David Howells 提交于
that's the bulk of filesystem drivers dealing with inodes of their own Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 23 2月, 2015 1 次提交
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由 David Howells 提交于
Convert the following where appropriate: (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry). (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry). (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more complicated than it appears as some calls should be converted to d_can_lookup() instead. The difference is whether the directory in question is a real dir with a ->lookup op or whether it's a fake dir with a ->d_automount op. In some circumstances, we can subsume checks for dentry->d_inode not being NULL into this, provided we the code isn't in a filesystem that expects d_inode to be NULL if the dirent really *is* negative (ie. if we're going to use d_inode() rather than d_backing_inode() to get the inode pointer). Note that the dentry type field may be set to something other than DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS manages the fall-through from a negative dentry to a lower layer. In such a case, the dentry type of the negative union dentry is set to the same as the type of the lower dentry. However, if you know d_inode is not NULL at the call site, then you can use the d_is_xxx() functions even in a filesystem. There is one further complication: a 0,0 chardev dentry may be labelled DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was intended for special directory entry types that don't have attached inodes. The following perl+coccinelle script was used: use strict; my @callers; open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') || die "Can't grep for S_ISDIR and co. callers"; @callers = <$fd>; close($fd); unless (@callers) { print "No matches\n"; exit(0); } my @cocci = ( '@@', 'expression E;', '@@', '', '- S_ISLNK(E->d_inode->i_mode)', '+ d_is_symlink(E)', '', '@@', 'expression E;', '@@', '', '- S_ISDIR(E->d_inode->i_mode)', '+ d_is_dir(E)', '', '@@', 'expression E;', '@@', '', '- S_ISREG(E->d_inode->i_mode)', '+ d_is_reg(E)' ); my $coccifile = "tmp.sp.cocci"; open($fd, ">$coccifile") || die $coccifile; print($fd "$_\n") || die $coccifile foreach (@cocci); close($fd); foreach my $file (@callers) { chomp $file; print "Processing ", $file, "\n"; system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 || die "spatch failed"; } [AV: overlayfs parts skipped] Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 20 11月, 2014 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 04 11月, 2014 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 14 10月, 2014 4 次提交
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由 NeilBrown 提交于
->fs_lock protects AUTOFS_INF_EXPIRING. We need to be sure that once the flag is set, no new references beneath the dentry are taken. So rcu-walk currently needs to take fs_lock before checking the flag. This hurts performance. Change the expiry to a two-stage process. First set AUTOFS_INF_NO_RCU which forces any path walk into ref-walk mode, then drop the lock and call synchronize_rcu(). Once that returns we can be sure no rcu-walk is active beneath the dentry and we can check reference counts again. Now during an RCU-walk we can test AUTOFS_INF_EXPIRING without taking the lock as along as we test AUTOFS_INF_NO_RCU too. If either are set, we must abort the RCU-walk If neither are set, we know that refcounts will be tested again after we finish the RCU-walk so we are safe to continue. ->fs_lock is still taken in d_manage() to check for a non-trap directory. That will be resolved in the next patch. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
Have a "test" function change the value it is testing can be confusing, particularly as a future patch will be calling this function twice. So move the update for 'last_used' to avoid repeat expiry to the place where the final determination on what to expire is known. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
Future patch will potentially call this twice, so make it separate. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
This series teaches autofs about RCU-walk so that we don't drop straight into REF-walk when we hit an autofs directory, and so that we avoid spinlocks as much as possible when performing an RCU-walk. This is needed so that the benefits of the recent NFS support for RCU-walk are fully available when NFS filesystems are automounted. Patches have been carefully reviewed and tested both with test suites and in production - thanks a lot to Ian Kent for his support there. This patch (of 6): Any attempt to look up a pathname that passes though an autofs4 mount is currently forced out of RCU-walk into REF-walk. This can significantly hurt performance of many-thread work loads on many-core systems, especially if the automounted filesystem supports RCU-walk but doesn't get to benefit from it. So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD if it is necessary to wait longer than a spinlock. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 09 10月, 2014 1 次提交
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由 Ian Kent 提交于
Biederman's umount-on-rmdir series changes d_invalidate() to sumarily remove mounts under the passed in dentry regardless of whether they are busy or not. So calling this in fs/autofs4/expire.c:autofs4_tree_busy() is definitely the wrong thing to do becuase it will silently umount entries instead of just cleaning stale dentrys. But this call shouldn't be needed and testing shows that automounting continues to function without it. As Al Viro correctly surmises the original intent of the call was to perform what shrink_dcache_parent() does. If at some time in the future I see stale dentries accumulating following failed mounts I'll revisit the issue and possibly add a shrink_dcache_parent() call if needed. Signed-off-by: NIan Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 09 8月, 2014 1 次提交
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由 NeilBrown 提交于
The variable 'ino' already exists and already has the correct value. The d_fsdata of a dentry is never changed after the d_fsdata is instantiated, so this new assignment cannot be necessary. It was introduced in commit b5b80177 ("autofs4: Add d_manage() dentry operation"). Signed-off-by: NNeilBrown <neilb@suse.de> Acked-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 24 1月, 2014 1 次提交
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由 Ian Kent 提交于
The autofs4 module doesn't consider symlinks for expire as it did in the older autofs v3 module (so it's actually a long standing regression). The user space daemon has focused on the use of bind mounts instead of symlinks for a long time now and that's why this has not been noticed. But with the future addition of amd map parsing to automount(8), not to mention amd itself (of am-utils), symlink expiry will be needed. The direct and offset mount types can't be symlinks and the tree mounts of version 4 were always real mounts so only indirect mounts need expire symlinks. Since the current users of the autofs4 module haven't reported this as a problem to date this patch probably isn't a candidate for backport to stable. Signed-off-by: NIan Kent <ikent@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 7月, 2013 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 07 5月, 2013 1 次提交
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由 David Jeffery 提交于
When checking if an autofs mount point is busy it isn't sufficient to only check if it's a mount point. For example, if the mount of an offset mountpoint in a tree is denied for this host by its export and the dentry becomes a process working directory the check incorrectly returns the mount as not in use at expire. This can happen since the default when mounting within a tree is nostrict, which means ingnore mount fails on mounts within the tree and continue. The nostrict option is meant to allow mounting in this case. Signed-off-by: NDavid Jeffery <djeffery@redhat.com> Signed-off-by: NIan Kent <raven@themaw.net> Cc: stable@vger.kernel.org Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 12月, 2012 1 次提交
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由 Ian Kent 提交于
The DCACHE_NEED_AUTOMOUNT flag is cleared on mount and set on expire for autofs rootless multi-mount dentrys to prevent unnecessary calls to ->d_automount(). Since DCACHE_MANAGE_TRANSIT is always set on autofs dentrys ->d_managed() is always called so the check can be done in ->d_manage() without the need to change the flag. This still avoids unnecessary calls to ->d_automount(), adds negligible overhead and eliminates a seriously ugly check in the expire code. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 8月, 2012 2 次提交
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由 Ian Kent 提交于
In some cases when an autofs indirect mount is contained in a file system that is marked as shared (such as when systemd does the equivalent of "mount --make-rshared /" early in the boot), mounts stop expiring. When this happens the first expiry check on a mountpoint dentry in autofs_expire_indirect() sees a mountpoint dentry with a higher than minimal reference count. Consequently the dentry is condidered busy and the actual expiry check is never done. This particular check was originally meant as an optimisation to detect a path walk in progress but with the addition of rcu-walk it can be ineffective anyway. Removing the test allows automounts to expire again since the actual expire check doesn't rely on the dentry reference count. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ian Kent 提交于
Following a report of a crash during an automount expire I found that the locking in fs/autofs4/expire.c:get_next_positive_subdir() was wrong. Not only is the locking wrong but the function is more complex than it needs to be. The function is meant to calculate (and dget) the next entry in the list of directories contained in the root of an autofs mount point (an autofs indirect mount to be precise). The main problem was that the d_lock of the owner of the list was not being taken when walking the list, which lead to list corruption under load. The only other lock that needs to be taken is against the next dentry candidate so it can be checked for usability. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 2月, 2012 1 次提交
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由 Steven Rostedt 提交于
When recursing down the locks when traversing a tree/list in get_next_positive_dentry() or get_next_positive_subdir() a lock can change from being nested to being a parent which breaks lockdep. This patch tells lockdep about what we did. Signed-off-by: NSteven Rostedt <rostedt@goodmis.org> Acked-by: NIan Kent <raven@themaw.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 25 3月, 2011 4 次提交
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由 Ian Kent 提交于
The autofs4_lock introduced by the rcu-walk changes has unnecessarily broad scope. The locking is better handled by the per-autofs super block lookup_lock. Signed-off-by: NIan Kent <raven@themaw.net> Acked-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Ian Kent 提交于
The vfs-scale changes changed the traversal used in autofs4_expire_indirect() from a list to a depth first tree traversal which isn't right. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Ian Kent 提交于
There is a missing dput() when returning from autofs4_expire_direct() when we see that the dentry is already a pending mount. Signed-off-by: NIan Kent <raven@themaw.net> Acked-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Ian Kent 提交于
When direct (and offset) mounts were introduced the the last used timeout could no longer be updated in ->d_revalidate(). This is because covered direct mounts would be followed over without calling the autofs file system. As a result the definition of the busyness check for all entries was changed to be "actually busy" being an open file or working directory within the automount. But now we have a call back in the follow so the last used update on any access can be re-instated. This requires DCACHE_MANAGE_TRANSIT to always be set. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 18 1月, 2011 1 次提交
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由 Ian Kent 提交于
The initialization condition in fs/autofs4/expire.c:get_next_positive_dentry() appears to be incorrect. If prev == NULL I believe that root should be returned. Further down, at the current dentry check for it being simple_positive() it looks like the d_lock for dentry p should be dropped instead of dentry ret, otherwise when p is assinged to ret we end up with no lock on p and a lost lock on ret, which leads to a deadlock. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 16 1月, 2011 3 次提交
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由 Ian Kent 提交于
This patch required a previous patch to add the ->d_automount() dentry operation. Add a function to use the newly defined ->d_manage() dentry operation for blocking during mount and expire. Whether the VFS calls the dentry operations d_automount() and d_manage() is controled by the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags. autofs uses the d_automount() operation to callback to user space to request mount operations and the d_manage() operation to block walks into mounts that are under construction or destruction. In order to prevent these functions from being called unnecessarily the DMANAGED_* flags are cleared for cases which would cause this. In the common case the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags are both set for dentrys waiting to be mounted. The DMANAGED_TRANSIT flag is cleared upon successful mount request completion and set during expire runs, both during the dentry expire check, and if selected for expire, is left set until a subsequent successful mount request completes. The exception to this is the so-called rootless multi-mount which has no actual mount at its base. In this case the DMANAGED_AUTOMOUNT flag is cleared upon successful mount request completion as well and set again after a successful expire. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Ian Kent 提交于
Add a function to use the newly defined ->d_automount() dentry operation for triggering mounts instead of doing the user space callback in ->lookup() and ->d_revalidate(). Note, to be useful the subsequent patch to add the ->d_manage() dentry operation is also needed so the discussion of functionality is deferred to that patch. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 David Howells 提交于
Add a dentry op (d_manage) to permit a filesystem to hold a process and make it sleep when it tries to transit away from one of that filesystem's directories during a pathwalk. The operation is keyed off a new dentry flag (DCACHE_MANAGE_TRANSIT). The filesystem is allowed to be selective about which processes it holds and which it permits to continue on or prohibits from transiting from each flagged directory. This will allow autofs to hold up client processes whilst letting its userspace daemon through to maintain the directory or the stuff behind it or mounted upon it. The ->d_manage() dentry operation: int (*d_manage)(struct path *path, bool mounting_here); takes a pointer to the directory about to be transited away from and a flag indicating whether the transit is undertaken by do_add_mount() or do_move_mount() skipping through a pile of filesystems mounted on a mountpoint. It should return 0 if successful and to let the process continue on its way; -EISDIR to prohibit the caller from skipping to overmounted filesystems or automounting, and to use this directory; or some other error code to return to the user. ->d_manage() is called with namespace_sem writelocked if mounting_here is true and no other locks held, so it may sleep. However, if mounting_here is true, it may not initiate or wait for a mount or unmount upon the parameter directory, even if the act is actually performed by userspace. Within fs/namei.c, follow_managed() is extended to check with d_manage() first on each managed directory, before transiting away from it or attempting to automount upon it. follow_down() is renamed follow_down_one() and should only be used where the filesystem deliberately intends to avoid management steps (e.g. autofs). A new follow_down() is added that incorporates the loop done by all other callers of follow_down() (do_add/move_mount(), autofs and NFSD; whilst AFS, NFS and CIFS do use it, their use is removed by converting them to use d_automount()). The new follow_down() calls d_manage() as appropriate. It also takes an extra parameter to indicate if it is being called from mount code (with namespace_sem writelocked) which it passes to d_manage(). follow_down() ignores automount points so that it can be used to mount on them. __follow_mount_rcu() is made to abort rcu-walk mode if it hits a directory with DCACHE_MANAGE_TRANSIT set on the basis that we're probably going to have to sleep. It would be possible to enter d_manage() in rcu-walk mode too, and have that determine whether to abort or not itself. That would allow the autofs daemon to continue on in rcu-walk mode. Note that DCACHE_MANAGE_TRANSIT on a directory should be cleared when it isn't required as every tranist from that directory will cause d_manage() to be invoked. It can always be set again when necessary. ========================== WHAT THIS MEANS FOR AUTOFS ========================== Autofs currently uses the lookup() inode op and the d_revalidate() dentry op to trigger the automounting of indirect mounts, and both of these can be called with i_mutex held. autofs knows that the i_mutex will be held by the caller in lookup(), and so can drop it before invoking the daemon - but this isn't so for d_revalidate(), since the lock is only held on _some_ of the code paths that call it. This means that autofs can't risk dropping i_mutex from its d_revalidate() function before it calls the daemon. The bug could manifest itself as, for example, a process that's trying to validate an automount dentry that gets made to wait because that dentry is expired and needs cleaning up: mkdir S ffffffff8014e05a 0 32580 24956 Call Trace: [<ffffffff885371fd>] :autofs4:autofs4_wait+0x674/0x897 [<ffffffff80127f7d>] avc_has_perm+0x46/0x58 [<ffffffff8009fdcf>] autoremove_wake_function+0x0/0x2e [<ffffffff88537be6>] :autofs4:autofs4_expire_wait+0x41/0x6b [<ffffffff88535cfc>] :autofs4:autofs4_revalidate+0x91/0x149 [<ffffffff80036d96>] __lookup_hash+0xa0/0x12f [<ffffffff80057a2f>] lookup_create+0x46/0x80 [<ffffffff800e6e31>] sys_mkdirat+0x56/0xe4 versus the automount daemon which wants to remove that dentry, but can't because the normal process is holding the i_mutex lock: automount D ffffffff8014e05a 0 32581 1 32561 Call Trace: [<ffffffff80063c3f>] __mutex_lock_slowpath+0x60/0x9b [<ffffffff8000ccf1>] do_path_lookup+0x2ca/0x2f1 [<ffffffff80063c89>] .text.lock.mutex+0xf/0x14 [<ffffffff800e6d55>] do_rmdir+0x77/0xde [<ffffffff8005d229>] tracesys+0x71/0xe0 [<ffffffff8005d28d>] tracesys+0xd5/0xe0 which means that the system is deadlocked. This patch allows autofs to hold up normal processes whilst the daemon goes ahead and does things to the dentry tree behind the automouter point without risking a deadlock as almost no locks are held in d_manage() and none in d_automount(). Signed-off-by: NDavid Howells <dhowells@redhat.com> Was-Acked-by: NIan Kent <raven@themaw.net> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 07 1月, 2011 5 次提交
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由 Nick Piggin 提交于
Rather than keep a d_mounted count in the dentry, set a dentry flag instead. The flag can be cleared by checking the hash table to see if there are any mounts left, which is not time critical because it is performed at detach time. The mounted state of a dentry is only used to speculatively take a look in the mount hash table if it is set -- before following the mount, vfsmount lock is taken and mount re-checked without races. This saves 4 bytes on 32-bit, nothing on 64-bit but it does provide a hole I might use later (and some configs have larger than 32-bit spinlocks which might make use of the hole). Autofs4 conversion and changelog by Ian Kent <raven@themaw.net>: In autofs4, when expring direct (or offset) mounts we need to ensure that we block user path walks into the autofs mount, which is covered by another mount. To do this we clear the mounted status so that follows stop before walking into the mount and are essentially blocked until the expire is completed. The automount daemon still finds the correct dentry for the umount due to the follow mount logic in fs/autofs4/root.c:autofs4_follow_link(), which is set as an inode operation for direct and offset mounts only and is called following the lookup that stopped at the covered mount. At the end of the expire the covering mount probably has gone away so the mounted status need not be restored. But we need to check this and only restore the mounted status if the expire failed. XXX: autofs may not work right if we have other mounts go over the top of it? Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
dcache_lock no longer protects anything. remove it. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't using dcache_lock for these anyway (eg. using i_mutex). Note: if we change the locking rule in future so that ->d_child protection is provided only with ->d_parent->d_lock, it may allow us to reduce some locking. But it would be an exception to an otherwise regular locking scheme, so we'd have to see some good results. Probably not worthwhile. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Protect d_unhashed(dentry) condition with d_lock. This means keeping DCACHE_UNHASHED bit in synch with hash manipulations. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a 0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when we start protecting many other dentry members with d_lock. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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- 04 3月, 2010 1 次提交
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由 Al Viro 提交于
This reverts commit 213614d5. Alas, ->d_revalidate() can't rely on ->lookup() finishing what it's started; if d_alloc() in do_lookup() fails, we are not going to call ->lookup() at all. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 16 12月, 2009 2 次提交
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由 Ian Kent 提交于
We need to be able to cope with the directory mutex being held during ->d_revalidate() in some cases, but not all cases, and not necessarily by us. Because we need to release the mutex when we call back to the daemon to do perform a mount we must be sure that it is us who holds the mutex so we must redirect mount requests to ->lookup() if the mutex is held. Signed-off-by: NIan Kent <raven@themaw.net> Cc: Sage Weil <sage@newdream.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Yehuda Saheh <yehuda@newdream.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Ian Kent 提交于
Eliminate the use of the d_lock spin lock by using the autofs super block info spin lock. This reduces the number of spin locks we use by one and makes the code for the following patch (to redirect ->d_revalidate() to ->lookup()) a little simpler. Signed-off-by: NIan Kent <raven@themaw.net> Cc: Sage Weil <sage@newdream.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Yehuda Saheh <yehuda@newdream.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 01 9月, 2009 1 次提交
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由 Ian Kent 提交于
In the recent change by Al Viro that changes verious subsystems to use "struct path" one case was missed in the autofs4 module which causes mounts to no longer expire. Signed-off-by: NIan Kent <raven@themaw.net> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 6月, 2009 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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