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Commit 08261673 authored by Andrew Perepechko's avatar Andrew Perepechko Committed by Jan Kara
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quota: Fix possible dq_flags corruption 



dq_flags are modified non-atomically in do_set_dqblk via __set_bit calls and
atomically for example in mark_dquot_dirty or clear_dquot_dirty.  Hence a
change done by an atomic operation can be overwritten by a change done by a
non-atomic one. Fix the problem by using atomic bitops even in do_set_dqblk.

Signed-off-by: default avatarAndrew Perepechko <andrew.perepechko@sun.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 4c5e6c0e

fs/quota/dquot.c

+6 −6
Original line number Diff line number Diff line
@@ -2328,34 +2328,34 @@ static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) 
	if (di->dqb_valid & QIF_SPACE) {

		dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace;

		check_blim = 1;

		__set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);

	}

	if (di->dqb_valid & QIF_BLIMITS) {

		dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit);

		dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit);

		check_blim = 1;

		__set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);

	}

	if (di->dqb_valid & QIF_INODES) {

		dm->dqb_curinodes = di->dqb_curinodes;

		check_ilim = 1;

		__set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);

	}

	if (di->dqb_valid & QIF_ILIMITS) {

		dm->dqb_isoftlimit = di->dqb_isoftlimit;

		dm->dqb_ihardlimit = di->dqb_ihardlimit;

		check_ilim = 1;

		__set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);

	}

	if (di->dqb_valid & QIF_BTIME) {

		dm->dqb_btime = di->dqb_btime;

		check_blim = 1;

		__set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);

	}

	if (di->dqb_valid & QIF_ITIME) {

		dm->dqb_itime = di->dqb_itime;

		check_ilim = 1;

		__set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);

		set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);

	}



	if (check_blim) {