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path: root/fs/ocfs2/quota.h
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2010-05-21ocfs2: Fix NULL pointer deref when writing local dquotJan Kara
commit_dqblk() can write quota info to global file. That is actually a bad thing to do because if we are just modifying local quota file, we are not prepared (do not hold proper locks, do not have transaction credits) to do a modification of the global quota file. So do not use commit_dqblk() and instead call our writing function directly. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Fix quota lockingJan Kara
OCFS2 had three issues with quota locking: a) When reading dquot from global quota file, we started a transaction while holding dqio_mutex which is prone to deadlocks because other paths do it the other way around b) During ocfs2_sync_dquot we were not protected against concurrent writers on the same node. Because we first copy data to local buffer, a race could happen resulting in old data being written to global quota file and thus causing quota inconsistency after a crash. c) ip_alloc_sem of quota files was acquired while a transaction is started in ocfs2_quota_write which can deadlock because we first get ip_alloc_sem and then start a transaction when extending quota files. We fix the problem a) by pulling all necessary code to ocfs2_acquire_dquot and ocfs2_release_dquot. Thus we no longer depend on generic dquot_acquire to do the locking and can force proper lock ordering. Problems b) and c) are fixed by locking i_mutex and ip_alloc_sem of global quota file in ocfs2_lock_global_qf and removing ip_alloc_sem from ocfs2_quota_read and ocfs2_quota_write. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Avoid unnecessary block mapping when refreshing quota infoJan Kara
The position of global quota file info does not change. So we do not have to do logical -> physical block translation every time we reread it from disk. Thus we can also avoid taking ip_alloc_sem. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2010-05-21ocfs2: Do not map blocks from local quota file on each writeJan Kara
There is no need to map offset of local dquot structure to on disk block in each quota write. It is enough to map it just once and store the physical block number in quota structure in memory. Moreover this simplifies locking as we do not have to take ip_alloc_sem from quota write path. Acked-by: Joel Becker <Joel.Becker@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-10quota: Move definition of QFMT_OCFS2 to linux/quota.hJan Kara
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>
2009-09-22const: make struct super_block::dq_op constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-23ocfs2: Remove syncjiff field from quota infoJan Kara
syncjiff is just a converted value of syncms. Some places which are updating syncms forgot to update syncjiff as well. Since the conversion is just a simple division / multiplication and it does not happen frequently, just remove the syncjiff field to avoid forgotten conversions. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-01-05ocfs2: Fix ocfs2_read_quota_block() error handling.Joel Becker
ocfs2_bread() has become ocfs2_read_virt_blocks(), with a prototype to match ocfs2_read_blocks(). The quota code, converting from ocfs2_bread(), wraps the call to ocfs2_read_virt_blocks() in ocfs2_read_quota_block(). Unfortunately, the prototype of ocfs2_read_quota_block() matches the old prototype of ocfs2_bread(). The problem is that ocfs2_bread() returned the buffer head, and callers assumed that a NULL pointer was indicative of error. It wasn't. This is why ocfs2_bread() took an int*err argument as well. The new prototype of ocfs2_read_virt_blocks() avoids this error handling confusion. Let's change ocfs2_read_quota_block() to match. Signed-off-by: Joel Becker <joel.becker@oracle.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Implement quota recoveryJan Kara
Implement functions for recovery after a crash. Functions just read local quota file and sync info to global quota file. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2009-01-05ocfs2: Periodic quota syncingMark Fasheh
This patch creates a work queue for periodic syncing of locally cached quota information to the global quota files. We constantly queue a delayed work item, to get the periodic behavior. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Acked-by: Jan Kara <jack@suse.cz>
2009-01-05ocfs2: Implementation of local and global quota file handlingJan Kara
For each quota type each node has local quota file. In this file it stores changes users have made to disk usage via this node. Once in a while this information is synced to global file (and thus with other nodes) so that limits enforcement at least aproximately works. Global quota files contain all the information about usage and limits. It's mostly handled by the generic VFS code (which implements a trie of structures inside a quota file). We only have to provide functions to convert structures from on-disk format to in-memory one. We also have to provide wrappers for various quota functions starting transactions and acquiring necessary cluster locks before the actual IO is really started. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mark Fasheh <mfasheh@suse.com>