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2fba46a04c
Before this patch, multiple users called gfs2_qa_alloc which allocated a qadata structure to the inode, if quotas are turned on. Later, in file close or evict, the structure was deleted with gfs2_qa_delete. But there can be several competing processes who need access to the structure. There were races between file close (release) and the others. Thus, a release could delete the structure out from under a process that relied upon its existence. For example, chown. This patch changes the management of the qadata structures to be a get/put scheme. Function gfs2_qa_alloc has been changed to gfs2_qa_get and if the structure is allocated, the count essentially starts out at 1. Function gfs2_qa_delete has been renamed to gfs2_qa_put, and the last guy to decrement the count to 0 frees the memory. Signed-off-by: Bob Peterson <rpeterso@redhat.com>
66 lines
2.0 KiB
C
66 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*/
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#ifndef __QUOTA_DOT_H__
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#define __QUOTA_DOT_H__
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#include <linux/list_lru.h>
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struct gfs2_inode;
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struct gfs2_sbd;
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#define NO_UID_QUOTA_CHANGE INVALID_UID
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#define NO_GID_QUOTA_CHANGE INVALID_GID
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extern int gfs2_qa_get(struct gfs2_inode *ip);
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extern void gfs2_qa_put(struct gfs2_inode *ip);
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extern int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid);
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extern void gfs2_quota_unhold(struct gfs2_inode *ip);
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extern int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid);
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extern void gfs2_quota_unlock(struct gfs2_inode *ip);
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extern int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid,
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struct gfs2_alloc_parms *ap);
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extern void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
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kuid_t uid, kgid_t gid);
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extern int gfs2_quota_sync(struct super_block *sb, int type);
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extern int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid);
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extern int gfs2_quota_init(struct gfs2_sbd *sdp);
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extern void gfs2_quota_cleanup(struct gfs2_sbd *sdp);
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extern int gfs2_quotad(void *data);
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extern void gfs2_wake_up_statfs(struct gfs2_sbd *sdp);
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static inline int gfs2_quota_lock_check(struct gfs2_inode *ip,
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struct gfs2_alloc_parms *ap)
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{
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struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
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int ret;
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ap->allowed = UINT_MAX; /* Assume we are permitted a whole lot */
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if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
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return 0;
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ret = gfs2_quota_lock(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
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if (ret)
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return ret;
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if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON)
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return 0;
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ret = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid, ap);
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if (ret)
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gfs2_quota_unlock(ip);
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return ret;
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}
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extern const struct quotactl_ops gfs2_quotactl_ops;
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extern struct shrinker gfs2_qd_shrinker;
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extern struct list_lru gfs2_qd_lru;
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extern void __init gfs2_quota_hash_init(void);
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#endif /* __QUOTA_DOT_H__ */
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