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* merged 3.0.101 tagWolfgang Wiedmeyer2015-10-221-0/+1
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* quota: Fix deadlock during path resolutionJan Kara2011-01-121-1/+4
| | | | | | | | | | | | | | | | | | | | As Al Viro pointed out path resolution during Q_QUOTAON calls to quotactl is prone to deadlocks. We hold s_umount semaphore for reading during the path resolution and resolution itself may need to acquire the semaphore for writing when e. g. autofs mountpoint is passed. Solve the problem by performing the resolution before we get hold of the superblock (and thus s_umount semaphore). The whole thing is complicated by the fact that some filesystems (OCFS2) ignore the path argument. So to distinguish between filesystem which want the path and which do not we introduce new .quota_on_meta callback which does not get the path. OCFS2 then uses this callback instead of old .quota_on. CC: Al Viro <viro@ZenIV.linux.org.uk> CC: Christoph Hellwig <hch@lst.de> CC: Ted Ts'o <tytso@mit.edu> CC: Joel Becker <joel.becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Convert quota statistics to generic percpu_counterDmitry Monakhov2010-05-271-12/+4
| | | | | | | | | | | | | Generic per-cpu counter has some memory overhead but it is negligible for modern systems and embedded systems compile without quota support. And code reuse is a good thing. This patch should fix complain from preemptive kernels which was introduced by dde9588853b1bde. [Jan Kara: Fixed patch to work on 32-bit archs as well] Reported-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: drop remount argument to ->quota_on and ->quota_offChristoph Hellwig2010-05-241-2/+2
| | | | | | | | Remount handling has fully moved into the filesystem, so all this is superflous now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: unify ->set_dqblkChristoph Hellwig2010-05-211-2/+1
| | | | | | | | | | | | | | Pass the larger struct fs_disk_quota to the ->set_dqblk operation so that the Q_SETQUOTA and Q_XSETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->set_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Add new fieldmask values for setting the numer of blocks and inodes values which is required for the VFS quota, but wasn't for XFS. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: unify ->get_dqblkChristoph Hellwig2010-05-211-2/+1
| | | | | | | | | | | Pass the larger struct fs_disk_quota to the ->get_dqblk operation so that the Q_GETQUOTA and Q_XGETQUOTA operations can be implemented with a single filesystem operation and we can retire the ->get_xquota operation. The additional information (RT-subvolume accounting and warn counts) are left zero for the VFS quota implementation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Make quota stat accounting lockless.Dmitry Monakhov2010-05-211-8/+34
| | | | | | | | | | | | Quota stats is mostly writable data structure. Let's alloc percpu bucket for each value. NOTE: dqstats_read() function is racy against dqstats_{inc,dec} and may return inconsistent value. But this is ok since absolute accuracy is not required. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: stop using QUOTA_OK / NO_QUOTAChristoph Hellwig2010-03-051-3/+0
| | | | | | | Just use 0 / -EDQUOT directly - that's what it translates to anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* dquot: cleanup dquot initialize routineChristoph Hellwig2010-03-051-1/+0
| | | | | | | | | | | | Get rid of the initialize dquot operation - it is now always called from the filesystem and if a filesystem really needs it's own (which none currently does) it can just call into it's own routine directly. Rename the now static low-level dquot_initialize helper to __dquot_initialize and vfs_dq_init to dquot_initialize to have a consistent namespace. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* dquot: cleanup dquot drop routineChristoph Hellwig2010-03-051-1/+0
| | | | | | | | | | | | Get rid of the drop dquot operation - it is now always called from the filesystem and if a filesystem really needs it's own (which none currently does) it can just call into it's own routine directly. Rename the now static low-level dquot_drop helper to __dquot_drop and vfs_dq_drop to dquot_drop to have a consistent namespace. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* dquot: cleanup dquot transfer routineChristoph Hellwig2010-03-051-1/+0
| | | | | | | | | | | | | | Get rid of the transfer dquot operation - it is now always called from the filesystem and if a filesystem really needs it's own (which none currently does) it can just call into it's own routine directly. Rename the now static low-level dquot_transfer helper to __dquot_transfer and vfs_dq_transfer to dquot_transfer to have a consistent namespace, and make the new dquot_transfer return a normal negative errno value which all callers expect. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* dquot: cleanup inode allocation / freeing routinesChristoph Hellwig2010-03-051-2/+0
| | | | | | | | | | | | | | Get rid of the alloc_inode and free_inode dquot operations - they are always called from the filesystem and if a filesystem really needs their own (which none currently does) it can just call into it's own routine directly. Also get rid of the vfs_dq_alloc/vfs_dq_free wrappers and always call the lowlevel dquot_alloc_inode / dqout_free_inode routines directly, which now lose the number argument which is always 1. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* dquot: cleanup space allocation / freeing routinesChristoph Hellwig2010-03-051-8/+0
| | | | | | | | | | | | | | | | Get rid of the alloc_space, free_space, reserve_space, claim_space and release_rsv dquot operations - they are always called from the filesystem and if a filesystem really needs their own (which none currently does) it can just call into it's own routine directly. Move shared logic into the common __dquot_alloc_space, dquot_claim_space_nodirty and __dquot_free_space low-level methods, and rationalize the wrappers around it to move as much as possible code into the common block for CONFIG_QUOTA vs not. Also rename all these helpers to be named dquot_* instead of vfs_dq_*. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: generalize quota transfer interfaceDmitry Monakhov2010-03-051-1/+1
| | | | | | | | | | Current quota transfer interface support only uid/gid. This patch extend interface in order to support various quotas types The goal is accomplished without changes in most frequently used vfs_dq_transfer() func. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: sb_quota state flags cleanupDmitry Monakhov2010-03-051-8/+7
| | | | | | | | - remove hardcoded USRQUOTA/GRPQUOTA flags - convert int to bool for appropriate functions Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: move code from sync_quota_sb into vfs_quota_syncChristoph Hellwig2010-03-051-1/+1
| | | | | | | | | | | | | Currenly sync_quota_sb does a lot of sync and truncate action that only applies to "VFS" style quotas and is actively harmful for the sync performance in XFS. Move it into vfs_quota_sync and add a wait parameter to ->quota_sync to tell if we need it or not. My audit of the GFS2 code says it's also not needed given the way GFS2 implements quotas, but I'd be happy if this can get a detailed review. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: decouple fs reserved space from quota reservationDmitry Monakhov2009-12-231-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Currently inode_reservation is managed by fs itself and this reservation is transfered on dquot_transfer(). This means what inode_reservation must always be in sync with dquot->dq_dqb.dqb_rsvspace. Otherwise dquot_transfer() will result in incorrect quota(WARN_ON in dquot_claim_reserved_space() will be triggered) This is not easy because of complex locking order issues for example http://bugzilla.kernel.org/show_bug.cgi?id=14739 The patch introduce quota reservation field for each fs-inode (fs specific inode is used in order to prevent bloating generic vfs inode). This reservation is managed by quota code internally similar to i_blocks/i_bytes and may not be always in sync with internal fs reservation. Also perform some code rearrangement: - Unify dquot_reserve_space() and dquot_reserve_space() - Unify dquot_release_reserved_space() and dquot_free_space() - Also this patch add missing warning update to release_rsv() dquot_release_reserved_space() must call flush_warnings() as dquot_free_space() does. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Implement quota format with 64-bit space and inode limitsJan Kara2009-12-101-0/+1
| | | | | | | | | | | | | So far the maximum quota space limit was 4TB. Apparently this isn't enough for Lustre guys anymore. So implement new quota format which raises block limits to 2^64 bytes. Also store number of inodes and inode limits in 64-bit variables as 2^32 files isn't that insanely high anymore. The first version of the patch has been developed by Andrew Perepechko <Andrew.Perepechko@Sun.COM>. CC: Andrew.Perepechko@Sun.COM Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Move definition of QFMT_OCFS2 to linux/quota.hJan Kara2009-12-101-0/+1
| | | | | | | | Move definition of this constant to linux/quota.h so that it cannot clash with other format IDs. CC: Joel Becker <joel.becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
* const: struct quota_format_opsAlexey Dobriyan2009-12-101-2/+2
| | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
* VFS: Export dquot_send_warningSteven Whitehouse2009-12-031-0/+11
| | | | | | | | | | | Sending a message to userspace in a generic format to warn of events (e.g. quota exceeded) in the quota subsystem is a generically useful feature. This patch makes some minor changes to the send_message function from dquot.c renaming it quota_send_message, moving it to quota.c and exporting it for use by filesystems which do not use the dquot code. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
* quota: Remove NODQUOT macroJan Kara2009-03-261-2/+0
| | | | | | | Remove this macro which is just a definition of NULL. Fix a few coding style issues along the way. Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Add quota reservation claim and released operationsMingming Cao2009-03-261-0/+6
| | | | | | | | Reserved quota will be claimed at the block allocation time. Over-booked quota could be returned back with the release callback function. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Add quota reservation supportMingming Cao2009-03-261-0/+3
| | | | | | | | | | | | | | Delayed allocation defers the block allocation at the dirty pages flush-out time, doing quota charge/check at that time is too late. But we can't charge the quota blocks until blocks are really allocated, otherwise users could get overcharged after reboot from system crash. This patch adds quota reservation for delayed allocation. Quota blocks are reserved in memory, inode and quota won't gets dirtied until later block allocation time. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: Jan Kara <jack@suse.cz>
* quota: Unexport dqblk_v1.h and dqblk_v2.hJan Kara2009-01-051-0/+4
| | | | | | | | | Unexport header files dqblk_v[12].h since except for quota format ID they don't contain information userspace should be interested in. Move ID definitions to quota.h. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Update version numberJan Kara2009-01-051-2/+1
| | | | | | | | Increase reported version number of quota support since quota core has changed significantly. Also remove __DQUOT_NUM_VERSION__ since nobody uses it. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Keep which entries were set by SETQUOTA quotactlJan Kara2009-01-051-6/+20
| | | | | | | | | | | | | Quota in a clustered environment needs to synchronize quota information among cluster nodes. This means we have to occasionally update some information in dquot from disk / network. On the other hand we have to be careful not to overwrite changes administrator did via SETQUOTA. So indicate in dquot->dq_flags which entries have been set by SETQUOTA and quota format can clear these flags when it properly propagated the changes. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Allow negative usage of space and inodesJan Kara2009-01-051-1/+2
| | | | | | | | | | | For clustered filesystems, it can happen that space / inode usage goes negative temporarily (because some node is allocating another node is freeing and they are not completely in sync). So let quota code allow this and change qsize_t so a signed type so that we don't underflow the variables. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Convert union in mem_dqinfo to a pointerJan Kara2009-01-051-4/+1
| | | | | | | | | | | Coming quota support for OCFS2 is going to need quite a bit of additional per-sb quota information. Moreover having fs.h include all the types needed for this structure would be a pain in the a**. So remove the union from mem_dqinfo and add a private pointer for filesystem's use. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Introduce DQUOT_QUOTA_SYS_FILE flagJan Kara2009-01-051-0/+7
| | | | | | | | | | If filesystem can handle quota files as system files hidden from users, we can skip a lot of cache invalidation, syncing, inode flags setting etc. when turning quotas on, off and quota_sync. Allow filesystem to indicate that it is hiding quota files from users by DQUOT_QUOTA_SYS_FILE flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Allow to separately enable quota accounting and enforcing limitsJan Kara2009-01-051-4/+26
| | | | | | | | | | | | | | | | Split DQUOT_USR_ENABLED (and DQUOT_GRP_ENABLED) into DQUOT_USR_USAGE_ENABLED and DQUOT_USR_LIMITS_ENABLED. This way we are able to separately enable / disable whether we should: 1) ignore quotas completely 2) just keep uptodate information about usage 3) actually enforce quota limits This is going to be useful when quota is treated as filesystem metadata - we then want to keep quota information uptodate all the time and just enable / disable limits enforcement. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Increase size of variables for limits and inode usageJan Kara2009-01-051-16/+12
| | | | | | | | | | | | | So far quota was fine with quota block limits and inode limits/numbers in a 32-bit type. Now with rapid increase in storage sizes there are coming requests to be able to handle quota limits above 4TB / more that 2^32 inodes. So bump up sizes of types in mem_dqblk structure to 64-bits to be able to handle this. Also update inode allocation / checking functions to use qsize_t and make global structure keep quota limits in bytes so that things are consistent. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: Add callbacks for allocating and destroying dquot structuresJan Kara2009-01-051-0/+2
| | | | | | | | | | Some filesystems would like to keep private information together with each dquot. Add callbacks alloc_dquot and destroy_dquot allowing filesystem to allocate larger dquots from their private slab in a similar fashion we currently allocate inodes. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
* quota: remove CVS keywordsAdrian Bunk2008-10-161-2/+0
| | | | | | | | | Remove CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: implement sending information via netlink about user below quotaJan Kara2008-07-251-0/+4
| | | | | | | | | | | | | Sometimes it may be useful for userspace to know (e.g. for some hosting guys) that some user stopped exceeding his hardlimit or softlimit in quotas. Implement sending of such events to userspace via quota netlink protocol so that they don't have to poll for such events. Based on idea and initial implementation by Vladislav Bogdanov. Cc: Vladislav Bogdanov <slava@nsys.by> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: convert macros to inline functionsJan Kara2008-07-251-1/+4
| | | | | | Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: move function-macros from quota.h to quotaops.hJan Kara2008-07-251-19/+3
| | | | | | | | | | | | | | | | Move declarations of some macros, which should be in fact functions to quotaops.h. This way they can be later converted to inline functions because we can now use declarations from quota.h. Also add necessary includes of quotaops.h to a few files. [akpm@linux-foundation.org: fix JFS build] [akpm@linux-foundation.org: fix UFS build] [vegard.nossum@gmail.com: fix QUOTA=n build] Signed-off-by: Jan Kara <jack@suse.cz> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Arjen Pool <arjenpool@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: cleanup loop in sync_dquots()Jan Kara2008-07-251-2/+0
| | | | | | | | | | | Make loop in sync_dquots() checking whether there's something to write more readable, remove useless variable and macro info_any_dirty() which is used only in this place. Signed-off-by: Jan Kara <jack@suse.cz> Cc: "Vegard Nossum" <vegard.nossum@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: add a convenience macro for filesystemsJan Kara2008-05-011-0/+3
| | | | | | | | | Note that it cannot be an inline function because we don't have struct super_block prototype... Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: quota core changes for quotaon on remountJan Kara2008-04-281-2/+12
| | | | | | | | | | | | | Currently, we just turn quotas off on remount of filesystem to read-only state. The patch below adds necessary framework so that we can turn quotas off on remount RO but we are able to automatically reenable them again when filesystem is remounted to RW state. All we need to do is to keep references to inodes of quota files when remounting RO and using these references to reenable quotas when remounting RW. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: various style cleanupsJan Kara2008-04-281-5/+0
| | | | | | | | | | | | | | Cleanups in quota code: Change __inline__ to inline. Change some macros to inline functions. Remove vfs_quota_off_mount() macro. DQUOT_OFF() should be (0) is CONFIG_QUOTA is disabled. Move declaration of mark_dquot_dirty and dirty_dquot from quota.h to dquot.c [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* quota: do not allow setting of quota limits to too high valuesAndrew Perepechko2008-04-281-0/+2
| | | | | | | | | | We should check whether quota limits set via Q_SETQUOTA are not exceeding limits which quota format is able to handle. Signed-off-by: Andrew Perepechko <andrew.perepechko@sun.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix quota.h includesMatthew Wilcox2008-04-171-2/+6
| | | | | | | | | | quota.h currently relies on asm/semaphore.h (through some chain; it doesn't actually include semaphore.h itself) to include wait.h. As well as being bad practice to rely on an implicit include, subsequent patches will break this. While I'm in this file, add atomic.h and list.h, and sort the list of includes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
* quota: send messages via netlinkJan Kara2007-10-171-0/+31
| | | | | | | | | | | | | Implement sending of quota messages via netlink interface. The advantage is that in userspace we can better decide what to do with the message - for example display a dialogue in your X session or just write the message to the console. As a bonus, we can get rid of problems with console locking deep inside filesystem code once we remove the old printing mechanism. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hide spinlock in linux/quota.h behind __KERNEL__Mike Frysinger2007-05-081-2/+2
| | | | | | | | Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Jan Kara <jack@ucw.cz> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] QUOTA: Have <linux/quota.h> include <linux/rwsem.h> explicitlyRobert P. J. Day2007-02-121-0/+1
| | | | | | | | | | Since quota.h declares a R/W semaphore, it should include rwsem.h explicitly. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Don't include private headers from user-visible parts of linux/quota.hDavid Woodhouse2006-04-251-2/+2
| | | | Signed-off-by: David Woodhouse <dwmw2@infradead.org>
* [PATCH] Small cleanup in quota.hJan Kara2006-03-251-1/+0
| | | | | | | | Remove unused quota flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sem2mutex: quotaIngo Molnar2006-03-231-3/+4
| | | | | | | | | | | | 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> Cc: Jan Kara <jack@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] saner handling of auto_acct_off() and DQUOT_OFF() in umountAl Viro2005-11-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The way we currently deal with quota and process accounting that might keep vfsmount busy at umount time is inherently broken; we try to turn them off just in case (not quite correctly, at that) and a) pray umount doesn't fail (otherwise they'll stay turned off) b) pray nobody doesn anything funny just as we turn quota off Moreover, LSM provides hooks for doing the same sort of broken logics. The proper way to deal with that is to introduce the second kind of reference to vfsmount. Semantics: - when the last normal reference is dropped, all special ones are converted to normal ones and if there had been any, cleanup is done. - normal reference can be cloned into a special one - special reference can be converted to normal one; that's a no-op if we'd already passed the point of no return (i.e. mntput() had converted special references to normal and started cleanup). The way it works: e.g. starting process accounting converts the vfsmount reference pinned by the opened file into special one and turns it back to normal when it gets shut down; acct_auto_close() is done when no normal references are left. That way it does *not* obstruct umount(2) and it silently gets turned off when the last normal reference to vfsmount is gone. Which is exactly what we want... The same should be done by LSM module that holds some internal references to vfsmount and wants to shut them down on umount - it should make them special and security_sb_umount_close() will be called exactly when the last normal reference to vfsmount is gone. quota handling is even simpler - we don't use normal file IO anymore, so there's no need to hold vfsmounts at all. DQUOT_OFF() is done from deactivate_super(), where it really belongs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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