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linux-next/fs/ocfs2/quota.h
Jan Kara e3a767b60f ocfs2: implement delayed dropping of last dquot reference
We cannot drop last dquot reference from downconvert thread as that
creates the following deadlock:

NODE 1                                  NODE2
holds dentry lock for 'foo'
holds inode lock for GLOBAL_BITMAP_SYSTEM_INODE
                                        dquot_initialize(bar)
                                          ocfs2_dquot_acquire()
                                            ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
                                            ...
downconvert thread (triggered from another
node or a different process from NODE2)
  ocfs2_dentry_post_unlock()
    ...
    iput(foo)
      ocfs2_evict_inode(foo)
        ocfs2_clear_inode(foo)
          dquot_drop(inode)
            ...
	    ocfs2_dquot_release()
              ocfs2_inode_lock(USER_QUOTA_SYSTEM_INODE)
               - blocks
                                            finds we need more space in
                                            quota file
                                            ...
                                            ocfs2_extend_no_holes()
                                              ocfs2_inode_lock(GLOBAL_BITMAP_SYSTEM_INODE)
                                                - deadlocks waiting for
                                                  downconvert thread

We solve the problem by postponing dropping of the last dquot reference to
a workqueue if it happens from the downconvert thread.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:20:54 -07:00

120 lines
4.5 KiB
C

/*
* quota.h for OCFS2
*
* On disk quota structures for local and global quota file, in-memory
* structures.
*
*/
#ifndef _OCFS2_QUOTA_H
#define _OCFS2_QUOTA_H
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/quota.h>
#include <linux/list.h>
#include <linux/dqblk_qtree.h>
#include "ocfs2.h"
/*
* In-memory structures
*/
struct ocfs2_dquot {
struct dquot dq_dquot; /* Generic VFS dquot */
loff_t dq_local_off; /* Offset in the local quota file */
u64 dq_local_phys_blk; /* Physical block carrying quota structure */
struct ocfs2_quota_chunk *dq_chunk; /* Chunk dquot is in */
unsigned int dq_use_count; /* Number of nodes having reference to this entry in global quota file */
s64 dq_origspace; /* Last globally synced space usage */
s64 dq_originodes; /* Last globally synced inode usage */
struct llist_node list; /* Member of list of dquots to drop */
};
/* Description of one chunk to recover in memory */
struct ocfs2_recovery_chunk {
struct list_head rc_list; /* List of chunks */
int rc_chunk; /* Chunk number */
unsigned long *rc_bitmap; /* Bitmap of entries to recover */
};
struct ocfs2_quota_recovery {
struct list_head r_list[MAXQUOTAS]; /* List of chunks to recover */
};
/* In-memory structure with quota header information */
struct ocfs2_mem_dqinfo {
unsigned int dqi_type; /* Quota type this structure describes */
unsigned int dqi_chunks; /* Number of chunks in local quota file */
unsigned int dqi_blocks; /* Number of blocks allocated for local quota file */
unsigned int dqi_syncms; /* How often should we sync with other nodes */
struct list_head dqi_chunk; /* List of chunks */
struct inode *dqi_gqinode; /* Global quota file inode */
struct ocfs2_lock_res dqi_gqlock; /* Lock protecting quota information structure */
struct buffer_head *dqi_gqi_bh; /* Buffer head with global quota file inode - set only if inode lock is obtained */
int dqi_gqi_count; /* Number of holders of dqi_gqi_bh */
u64 dqi_giblk; /* Number of block with global information header */
struct buffer_head *dqi_lqi_bh; /* Buffer head with local quota file inode */
struct buffer_head *dqi_libh; /* Buffer with local information header */
struct qtree_mem_dqinfo dqi_gi; /* Info about global file */
struct delayed_work dqi_sync_work; /* Work for syncing dquots */
struct ocfs2_quota_recovery *dqi_rec; /* Pointer to recovery
* information, in case we
* enable quotas on file
* needing it */
};
static inline struct ocfs2_dquot *OCFS2_DQUOT(struct dquot *dquot)
{
return container_of(dquot, struct ocfs2_dquot, dq_dquot);
}
struct ocfs2_quota_chunk {
struct list_head qc_chunk; /* List of quotafile chunks */
int qc_num; /* Number of quota chunk */
struct buffer_head *qc_headerbh; /* Buffer head with chunk header */
};
extern struct kmem_cache *ocfs2_dquot_cachep;
extern struct kmem_cache *ocfs2_qf_chunk_cachep;
extern struct qtree_fmt_operations ocfs2_global_ops;
struct ocfs2_quota_recovery *ocfs2_begin_quota_recovery(
struct ocfs2_super *osb, int slot_num);
int ocfs2_finish_quota_recovery(struct ocfs2_super *osb,
struct ocfs2_quota_recovery *rec,
int slot_num);
void ocfs2_free_quota_recovery(struct ocfs2_quota_recovery *rec);
ssize_t ocfs2_quota_read(struct super_block *sb, int type, char *data,
size_t len, loff_t off);
ssize_t ocfs2_quota_write(struct super_block *sb, int type,
const char *data, size_t len, loff_t off);
int ocfs2_global_read_info(struct super_block *sb, int type);
int ocfs2_global_write_info(struct super_block *sb, int type);
int ocfs2_global_read_dquot(struct dquot *dquot);
int __ocfs2_sync_dquot(struct dquot *dquot, int freeing);
static inline int ocfs2_sync_dquot(struct dquot *dquot)
{
return __ocfs2_sync_dquot(dquot, 0);
}
static inline int ocfs2_global_release_dquot(struct dquot *dquot)
{
return __ocfs2_sync_dquot(dquot, 1);
}
int ocfs2_lock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex);
void ocfs2_unlock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex);
int ocfs2_validate_quota_block(struct super_block *sb, struct buffer_head *bh);
int ocfs2_read_quota_phys_block(struct inode *inode, u64 p_block,
struct buffer_head **bh);
int ocfs2_create_local_dquot(struct dquot *dquot);
int ocfs2_local_release_dquot(handle_t *handle, struct dquot *dquot);
int ocfs2_local_write_dquot(struct dquot *dquot);
void ocfs2_drop_dquot_refs(struct work_struct *work);
extern const struct dquot_operations ocfs2_quota_operations;
extern struct quota_format_type ocfs2_quota_format;
#endif /* _OCFS2_QUOTA_H */