linux-master/fs/super.c

42 static int thaw_super_locked(struct super_block *sb, enum freeze_holder who);
1928 static inline int freeze_inc(struct super_block *sb, enum freeze_holder who)
1930 	WARN_ON_ONCE((who & ~FREEZE_FLAGS));
1931 	WARN_ON_ONCE(hweight32(who & FREEZE_HOLDERS) > 1);
1933 	if (who & FREEZE_HOLDER_KERNEL)
1935 	if (who & FREEZE_HOLDER_USERSPACE)
1940 static inline int freeze_dec(struct super_block *sb, enum freeze_holder who)
1942 	WARN_ON_ONCE((who & ~FREEZE_FLAGS));
1943 	WARN_ON_ONCE(hweight32(who & FREEZE_HOLDERS) > 1);
1945 	if ((who & FREEZE_HOLDER_KERNEL) && sb->s_writers.freeze_kcount)
1947 	if ((who & FREEZE_HOLDER_USERSPACE) && sb->s_writers.freeze_ucount)
1952 static inline bool may_freeze(struct super_block *sb, enum freeze_holder who)
1954 	WARN_ON_ONCE((who & ~FREEZE_FLAGS));
1955 	WARN_ON_ONCE(hweight32(who & FREEZE_HOLDERS) > 1);
1957 	if (who & FREEZE_HOLDER_KERNEL)
1958 		return (who & FREEZE_MAY_NEST) ||
1960 	if (who & FREEZE_HOLDER_USERSPACE)
1961 		return (who & FREEZE_MAY_NEST) ||
1969  * @who: context that wants to freeze
1975  * @who should be:
1980  * The @who argument distinguishes between the kernel and userspace trying to
2021 int freeze_super(struct super_block *sb, enum freeze_holder who)
2033 		if (may_freeze(sb, who))
2034 			ret = !!WARN_ON_ONCE(freeze_inc(sb, who) == 1);
2054 		WARN_ON_ONCE(freeze_inc(sb, who) > 1);
2101 	WARN_ON_ONCE(freeze_inc(sb, who) > 1);
2116 static int thaw_super_locked(struct super_block *sb, enum freeze_holder who)
2127 	if (freeze_dec(sb, who))
2142 			freeze_inc(sb, who);
2163  * @who: context that wants to freeze
2168  * @who should be:
2177 int thaw_super(struct super_block *sb, enum freeze_holder who)
2183 	return thaw_super_locked(sb, who);