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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-26 13:41:00 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-26 13:41:00 -0500
commitcc597bc3d31468596af6b8ad2b1d1b593e308957 (patch)
tree303754908b583ff1da423bd37b56b01bd4585106 /fs/ocfs2
parented803862954528e6fcf7bd0f2b2e5a772a7c3281 (diff)
parentc475146d8f3b97e79f9ef88521e28ad40ac07de6 (diff)
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6: ocfs2: Remove ocfs2_dquot_initialize() and ocfs2_dquot_drop() quota: Improve locking
Diffstat (limited to 'fs/ocfs2')
-rw-r--r--fs/ocfs2/quota_global.c169
1 files changed, 2 insertions, 167 deletions
diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index 6aff8f2d3e49..f4efa89baee5 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -810,171 +810,6 @@ out:
810 return status; 810 return status;
811} 811}
812 812
813/* This is difficult. We have to lock quota inode and start transaction
814 * in this function but we don't want to take the penalty of exlusive
815 * quota file lock when we are just going to use cached structures. So
816 * we just take read lock check whether we have dquot cached and if so,
817 * we don't have to take the write lock... */
818static int ocfs2_dquot_initialize(struct inode *inode, int type)
819{
820 handle_t *handle = NULL;
821 int status = 0;
822 struct super_block *sb = inode->i_sb;
823 struct ocfs2_mem_dqinfo *oinfo;
824 int exclusive = 0;
825 int cnt;
826 qid_t id;
827
828 mlog_entry_void();
829
830 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
831 if (type != -1 && cnt != type)
832 continue;
833 if (!sb_has_quota_active(sb, cnt))
834 continue;
835 oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
836 status = ocfs2_lock_global_qf(oinfo, 0);
837 if (status < 0)
838 goto out;
839 /* This is just a performance optimization not a reliable test.
840 * Since we hold an inode lock, noone can actually release
841 * the structure until we are finished with initialization. */
842 if (inode->i_dquot[cnt] != NODQUOT) {
843 ocfs2_unlock_global_qf(oinfo, 0);
844 continue;
845 }
846 /* When we have inode lock, we know that no dquot_release() can
847 * run and thus we can safely check whether we need to
848 * read+modify global file to get quota information or whether
849 * our node already has it. */
850 if (cnt == USRQUOTA)
851 id = inode->i_uid;
852 else if (cnt == GRPQUOTA)
853 id = inode->i_gid;
854 else
855 BUG();
856 /* Obtain exclusion from quota off... */
857 down_write(&sb_dqopt(sb)->dqptr_sem);
858 exclusive = !dquot_is_cached(sb, id, cnt);
859 up_write(&sb_dqopt(sb)->dqptr_sem);
860 if (exclusive) {
861 status = ocfs2_lock_global_qf(oinfo, 1);
862 if (status < 0) {
863 exclusive = 0;
864 mlog_errno(status);
865 goto out_ilock;
866 }
867 handle = ocfs2_start_trans(OCFS2_SB(sb),
868 ocfs2_calc_qinit_credits(sb, cnt));
869 if (IS_ERR(handle)) {
870 status = PTR_ERR(handle);
871 mlog_errno(status);
872 goto out_ilock;
873 }
874 }
875 dquot_initialize(inode, cnt);
876 if (exclusive) {
877 ocfs2_commit_trans(OCFS2_SB(sb), handle);
878 ocfs2_unlock_global_qf(oinfo, 1);
879 }
880 ocfs2_unlock_global_qf(oinfo, 0);
881 }
882 mlog_exit(0);
883 return 0;
884out_ilock:
885 if (exclusive)
886 ocfs2_unlock_global_qf(oinfo, 1);
887 ocfs2_unlock_global_qf(oinfo, 0);
888out:
889 mlog_exit(status);
890 return status;
891}
892
893static int ocfs2_dquot_drop_slow(struct inode *inode)
894{
895 int status = 0;
896 int cnt;
897 int got_lock[MAXQUOTAS] = {0, 0};
898 handle_t *handle;
899 struct super_block *sb = inode->i_sb;
900 struct ocfs2_mem_dqinfo *oinfo;
901
902 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
903 if (!sb_has_quota_active(sb, cnt))
904 continue;
905 oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
906 status = ocfs2_lock_global_qf(oinfo, 1);
907 if (status < 0)
908 goto out;
909 got_lock[cnt] = 1;
910 }
911 handle = ocfs2_start_trans(OCFS2_SB(sb),
912 ocfs2_calc_qinit_credits(sb, USRQUOTA) +
913 ocfs2_calc_qinit_credits(sb, GRPQUOTA));
914 if (IS_ERR(handle)) {
915 status = PTR_ERR(handle);
916 mlog_errno(status);
917 goto out;
918 }
919 dquot_drop(inode);
920 ocfs2_commit_trans(OCFS2_SB(sb), handle);
921out:
922 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
923 if (got_lock[cnt]) {
924 oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
925 ocfs2_unlock_global_qf(oinfo, 1);
926 }
927 return status;
928}
929
930/* See the comment before ocfs2_dquot_initialize. */
931static int ocfs2_dquot_drop(struct inode *inode)
932{
933 int status = 0;
934 struct super_block *sb = inode->i_sb;
935 struct ocfs2_mem_dqinfo *oinfo;
936 int exclusive = 0;
937 int cnt;
938 int got_lock[MAXQUOTAS] = {0, 0};
939
940 mlog_entry_void();
941 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
942 if (!sb_has_quota_active(sb, cnt))
943 continue;
944 oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
945 status = ocfs2_lock_global_qf(oinfo, 0);
946 if (status < 0)
947 goto out;
948 got_lock[cnt] = 1;
949 }
950 /* Lock against anyone releasing references so that when when we check
951 * we know we are not going to be last ones to release dquot */
952 down_write(&sb_dqopt(sb)->dqptr_sem);
953 /* Urgh, this is a terrible hack :( */
954 for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
955 if (inode->i_dquot[cnt] != NODQUOT &&
956 atomic_read(&inode->i_dquot[cnt]->dq_count) > 1) {
957 exclusive = 1;
958 break;
959 }
960 }
961 if (!exclusive)
962 dquot_drop_locked(inode);
963 up_write(&sb_dqopt(sb)->dqptr_sem);
964out:
965 for (cnt = 0; cnt < MAXQUOTAS; cnt++)
966 if (got_lock[cnt]) {
967 oinfo = sb_dqinfo(sb, cnt)->dqi_priv;
968 ocfs2_unlock_global_qf(oinfo, 0);
969 }
970 /* In case we bailed out because we had to do expensive locking
971 * do it now... */
972 if (exclusive)
973 status = ocfs2_dquot_drop_slow(inode);
974 mlog_exit(status);
975 return status;
976}
977
978static struct dquot *ocfs2_alloc_dquot(struct super_block *sb, int type) 813static struct dquot *ocfs2_alloc_dquot(struct super_block *sb, int type)
979{ 814{
980 struct ocfs2_dquot *dquot = 815 struct ocfs2_dquot *dquot =
@@ -991,8 +826,8 @@ static void ocfs2_destroy_dquot(struct dquot *dquot)
991} 826}
992 827
993struct dquot_operations ocfs2_quota_operations = { 828struct dquot_operations ocfs2_quota_operations = {
994 .initialize = ocfs2_dquot_initialize, 829 .initialize = dquot_initialize,
995 .drop = ocfs2_dquot_drop, 830 .drop = dquot_drop,
996 .alloc_space = dquot_alloc_space, 831 .alloc_space = dquot_alloc_space,
997 .alloc_inode = dquot_alloc_inode, 832 .alloc_inode = dquot_alloc_inode,
998 .free_space = dquot_free_space, 833 .free_space = dquot_free_space,