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path: root/fs/autofs4/autofs_i.h
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2008-10-16autofs4: add miscellaneous device for ioctlsIan Kent
Add a miscellaneous device to the autofs4 module for routing ioctls. This provides the ability to obtain an ioctl file handle for an autofs mount point that is possibly covered by another mount. The actual problem with autofs is that it can't reconnect to existing mounts. Immediately one things of just adding the ability to remount autofs file systems would solve it, but alas, that can't work. This is because autofs direct mounts and the implementation of "on demand mount and expire" of nested mount trees have the file system mounted on top of the mount trigger dentry. To resolve this a miscellaneous device node for routing ioctl commands to these mount points has been implemented in the autofs4 kernel module and a library added to autofs. This provides the ability to open a file descriptor for these over mounted autofs mount points. Please refer to Documentation/filesystems/autofs4-mount-control.txt for a discussion of the problem, implementation alternatives considered and a description of the interface. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: build fix] 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>
2008-10-16autofs4: track uid and gid of last mount requesterIan Kent
Track the uid and gid of the last process to request a mount for on an autofs dentry. [akpm@linux-foundation.org: fix tpyo in comment] 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>
2008-10-16autofs4: cleanup autofs mount type usageIan Kent
Usage of the AUTOFS_TYPE_* defines is a little confusing and appears inconsistent. 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>
2008-07-24autofs4: reorganize expire pending wait function callsIan Kent
This patch re-orgnirzes the checking for and waiting on active expires and elininates redundant checks. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24autofs4: fix direct mount pending expire raceIan Kent
For direct and offset type mounts that are covered by another mount we cannot check the AUTOFS_INF_EXPIRING flag during a path walk which leads to lookups walking into an expiring mount while it is being expired. For example, for the direct multi-mount map entry with a couple of offsets: /race/mm1 / <server1>:/<path1> /om1 <server2>:/<path2> /om2 <server1>:/<path3> an autofs trigger mount is mounted on /race/mm1 and when accessed it is over mounted and trigger mounts made for /race/mm1/om1 and /race/mm1/om2. So it isn't possible for path walks to see the expiring flag at all and they happily walk into the file system while it is expiring. When expiring these mounts follow_down() must stop at the autofs mount and all processes must block in the ->follow_link() method (except the daemon) until the expire is complete. This is done by decrementing the d_mounted field of the autofs trigger mount root dentry until the expire is completed. In ->follow_link() all processes wait on the expire and the mount following is completed for the daemon until the expire is complete. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24autofs4: fix indirect mount pending expire raceIan Kent
The selection of a dentry for expiration and the setting of the AUTOFS_INF_EXPIRING flag isn't done atomically which can lead to lookups walking into an expiring mount. What happens is that an expire is initiated by the daemon and a dentry is selected for expire but, since there is no lock held between the selection and setting of the expiring flag, a process may find the flag clear and continue walking into the mount tree at the same time the daemon attempts the expire it. Signed-off-by: Ian Kent <raven@themaw.net> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24autofs4: fix waitq memory leakIan Kent
If an autofs mount becomes catatonic before autofs4_wait_release() is called the wait queue counter will not be decremented down to zero and the entry will never be freed. There are also races decrementing the wait counter in the wait release function. To deal with this the counter needs to be updated while holding the wait queue mutex and waiters need to be woken up unconditionally when the wait is removed from the queue to ensure we eventually free the wait. 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>
2008-07-24autofs4: use struct qstr in waitq.cJeff Moyer
The autofs_wait_queue already contains all of the fields of the struct qstr, so change it into a qstr. This patch, from Jeff Moyer, has been modified a liitle by myself. Signed-off-by: Jeff Moyer <jmoyer@redhat.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>
2008-07-24autofs4: use look aside list for lookupsIan Kent
A while ago a patch to resolve a deadlock during directory creation was merged. This delayed the hashing of lookup dentrys until the ->mkdir() (or ->symlink()) operation completed to ensure we always went through ->lookup() instead of also having processes go through ->revalidate() so our VFS locking remained consistent. Now we are seeing a couple of side affects of that change in situations with heavy mount activity. Two cases have been identified: 1) When a mount request is triggered, due to the delayed hashing, the directory created by user space for the mount point doesn't have the DCACHE_AUTOFS_PENDING flag set. In the case of an autofs multi-mount where a tree of mount point directories are created this can lead to the path walk continuing rather than the dentry being sent to the wait queue to wait for request completion. This is because, if the pending flag isn't set, the criteria for deciding this is a mount in progress fails to hold, namely that the dentry is not a mount point and has no subdirectories. 2) A mount request dentry is initially created negative and unhashed. It remains this way until the ->mkdir() callback completes. Since it is unhashed a fresh dentry is used when the user space mount request creates the mount point directory. This leaves the original dentry negative and unhashed. But revalidate has no way to tell the VFS that the dentry has changed, other than to force another ->lookup() by returning false, which is at best wastefull and at worst not possible. This results in an -ENOENT return from the original path walk when in fact the mount succeeded. To resolve this we need to ensure that the same dentry is used in all calls to ->lookup() during the course of a mount request. This patch achieves that by adding the initial dentry to a look aside list and removes it at ->mkdir() or ->symlink() completion (or when the dentry is released), since these are the only create operations autofs4 supports. 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>
2008-07-24autofs4: don't make expiring dentry negativeIan Kent
Correct the error of making a positive dentry negative after it has been instantiated. The code that makes this error attempts to re-use the dentry from a concurrent expire and mount to resolve a race and the dentry used for the lookup must be negative for mounts to trigger in the required cases. The fact is that the dentry doesn't need to be re-used because all that is needed is to preserve the flag that indicates an expire is still incomplete at the time of the mount request. This change uses the the dentry to check the flag and wait for the expire to complete then discards it instead of attempting to re-use it. 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>
2008-04-30fs: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19pid namespaces: round up the APIPavel Emelianov
The set of functions process_session, task_session, process_group and task_pgrp is confusing, as the names can be mixed with each other when looking at the code for a long time. The proposals are to * equip the functions that return the integer with _nr suffix to represent that fact, * and to make all functions work with task (not process) by making the common prefix of the same name. For monotony the routines signal_session() and set_signal_session() are replaced with task_session_nr() and set_task_session(), especially since they are only used with the explicit task->signal dereference. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-20[PATCH] autofs4: fix another race between mount and expireIan Kent
Jeff Moyer has identified a race between mount and expire. What happens is that during an expire the situation can arise that a directory is removed and another lookup is done before the expire issues a completion status to the kernel module. In this case, since the the lookup gets a new dentry, it doesn't know that there is an expire in progress and when it posts its mount request, matches the existing expire request and waits for its completion. ENOENT is then returned to user space from lookup (as the dentry passed in is now unhashed) without having performed the mount request. The solution used here is to keep track of dentrys in this unhashed state and reuse them, if possible, in order to preserve the flags. Additionally, this infrastructure will provide the framework for the reintroduction of caching of mount fails removed earlier in development. Signed-off-by: Ian Kent <raven@themaw.net> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] mark struct inode_operations const 1Arjan van de Ven
Many struct inode_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-08[PATCH] autofs4: change uses of f_{dentry, vfsmnt} to use f_pathJosef "Jeff" Sipek
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the autofs4 filesystem. Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-11[PATCH] AUTOFS: Make sure all dentries refs are released before calling ↵David Howells
kill_anon_super() Make sure all dentries refs are released before calling kill_anon_super() so that the assumption that generic_shutdown_super() can completely destroy the dentry tree for there will be no external references holds true. What was being done in the put_super() superblock op, is now done in the kill_sb() filesystem op instead, prior to calling kill_anon_super(). This makes the struct autofs_sb_info::root member variable redundant (since sb->s_root is still available), and so that is removed. The calls to shrink_dcache_sb() are also removed since they're also redundant as shrink_dcache_for_umount() will now be called after the cleanup routine. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Ian Kent <raven@themaw.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-24Move several *_SUPER_MAGIC symbols to include/linux/magic.h.Jeff Garzik
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-05-15[PATCH] autofs4: NFY_NONE wait race fixIan Kent
This patch fixes two problems. First, the comparison of entries in the waitq.c was incorrect. Second, the NFY_NONE check was incorrect. The test of whether the dentry is mounted if ineffective, for example, if an expire fails then we could wait forever on a non existant expire. The bug was identified by Jeff Moyer. The patch changes autofs4 to wait on expires only as this is all that's needed. If there is no existing wait when autofs4_wait is call with a type of NFY_NONE it delays until either a wait appears or the the expire flag is cleared. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28[PATCH] Make most file operations structs in fs/ constArjan van de Ven
This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-28[PATCH] autofs4: proper prototype for autofs4_dentry_release()Adrian Bunk
Add a proper prototype for autofs4_dentry_release() to autofs_i.h. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: atomic var underflowIan Kent
Fix accidental underflow of the atomic counter. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: change AUTOFS_TYP_* AUTOFS_TYPE_*Ian Kent
Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: add new packet type for v5 communicationsIan Kent
This patch define a new autofs packet for autofs v5 and updates the waitq.c functions to handle the additional packet type. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: add v5 follow_link mount trigger methodIan Kent
This patch adds a follow_link inode method for the root of an autofs direct mount trigger. It also adds the corresponding mount options and updates the show_mount method. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: rename simple_empty_nolock functionIan Kent
Rename the function simple_empty_nolock to __simple_empty in line with kernel naming conventions. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: add a show mount options for proc filesystemIan Kent
Add show_options method to display autofs4 mount options in the proc filesystem. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: fix false negative return from expireIan Kent
Fix the case where an expire returns busy on a tree mount when it is in fact not busy. This case was overlooked when the patch to prevent the expiring away of "scaffolding" directories for tree mounts was applied. The problem arises when a tree of mounts is a member of a map with other keys. The current logic will not expire the tree if any other mount in the map is busy. The solution is to maintain a "minimum" use count for each autofs dentry and compare this to the actual dentry usage count during expire. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-27[PATCH] autofs4: can't mount due to mount point dir not emptyIan Kent
Addresse a problem where stale dentrys stop mounts from happening. When a mount point directory is pre-created and a non-existent entry within it is requested a dentry ends up being created within the mount point directory which stops future mounts. The problem is solved by ignoring negative, unhashed dentrys in the mount point d_subdirs list. Additionally the apparent cacheing of -ENOENT returns from requests is removed. The test on d_time is a tautology and d_time is not initialised and has an unexpected value. In short it doesn't do what it's meant to. The cacheing of failed requests to the daemon is important and will be followed up later. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] sem2mutex: autofs4 wq_semIngo Molnar
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-08[PATCH] shrink dentry structEric Dumazet
Some long time ago, dentry struct was carefully tuned so that on 32 bits UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple of memory cache lines. Then RCU was added and dentry struct enlarged by two pointers, with nice results for SMP, but not so good on UP, because breaking the above tuning (128 + 8 = 136 bytes) This patch reverts this unwanted side effect, by using an union (d_u), where d_rcu and d_child are placed so that these two fields can share their memory needs. At the time d_free() is called (and d_rcu is really used), d_child is known to be empty and not touched by the dentry freeing. Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so the previous content of d_child is not needed if said dentry was unhashed but still accessed by a CPU because of RCU constraints) As dentry cache easily contains millions of entries, a size reduction is worth the extra complexity of the ugly C union. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Maneesh Soni <maneesh@in.ibm.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Ian Kent <raven@themaw.net> Cc: Paul Jackson <pj@sgi.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: James Morris <jmorris@namei.org> Cc: Stephen Smalley <sds@epoch.ncsc.mil> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27[PATCH] autofs4: fix infamous "Busy inodes after umount ..." messageIan Kent
If the automount daemon receives a signal which causes it to sumarily terminate the autofs4 module leaks dentries. The same problem exists with detached mount requests without the warning. This patch cleans these dentries at umount. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] autofs4: avoid panic on bind mount of autofs owned directoryIan Kent
While this is not a solution to bind and move mounts on autofs owned directories it is necessary to fix the trady error handling. At least it avoids the kernel panic I observed checking out bug #4589. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] autofs4: tree race fixIan Kent
For tree mount maps, a call to chdir or chroot, to a directory above the moint point directories at a certain time during the expire results in the expire incorrectly thinking the tree is not busy. This patch adds a check to see if the filesystem above the tree mount points is busy and also locks the filesystem during the tree mount expire to prevent the race. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] autofs4: wait order fixIan Kent
It's possible for an event wait request to arive before the event requestor. If this happens the daemon never gets notified and autofs hangs. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!