UBI: amend commentaries WRT dtype (44156267) · Commits · 戴 / test

drivers/mtd/ubi/wl.c

+1 −8

Original line number	Diff line number	Diff line
		@@ -41,12 +41,6 @@
		* physical eraseblocks with low erase counter to free physical eraseblocks
		* with high erase counter.
		*
		* The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
		* an "optimal" physical eraseblock. For example, when it is known that the
		* physical eraseblock will be "put" soon because it contains short-term data,
		* the WL sub-system may pick a free physical eraseblock with low erase
		* counter, and so forth.
		*
		* If the WL sub-system fails to erase a physical eraseblock, it marks it as
		* bad.
		*
		@@ -70,8 +64,7 @@
		* to the user; instead, we first want to let users fill them up with data;
		*
		* o there is a chance that the user will put the physical eraseblock very
		* soon, so it makes sense not to move it for some time, but wait; this is
		* especially important in case of "short term" physical eraseblocks.
		* soon, so it makes sense not to move it for some time, but wait.
		*
		* Physical eraseblocks stay protected only for limited time. But the "time" is
		* measured in erase cycles in this case. This is implemented with help of the

+2 −3

Original line number	Diff line number	Diff line
		@@ -814,9 +814,8 @@ static int alloc_wbufs(struct ubifs_info *c)
		}

		/*
		* Garbage Collector head likely contains long-term data and
		* does not need to be synchronized by timer. Also GC head nodes are
		* not grouped.
		* Garbage Collector head does not need to be synchronized by timer.
		* Also GC head nodes are not grouped.
		*/
		c->jheads[GCHD].wbuf.no_timer = 1;
		c->jheads[GCHD].grouped = 0;

+11 −0

Original line number	Diff line number	Diff line
		@@ -358,7 +358,17 @@ struct ubi_rnvol_req {
		* requests.
		* @lnum: logical eraseblock number to change
		* @bytes: how many bytes will be written to the logical eraseblock
		* @dtype: pass "3" for better compatibility with old kernels
		* @padding: reserved for future, not used, has to be zeroed
		*
		* The @dtype field used to inform UBI about what kind of data will be written
		* to the LEB: long term (value 1), short term (value 2), unknown (value 3).
		* UBI tried to pick a PEB with lower erase counter for short term data and a
		* PEB with higher erase counter for long term data. But this was not really
		* used because users usually do not know this and could easily mislead UBI. We
		* removed this feature in May 2012. UBI currently just ignores the @dtype
		* field. But for better compatibility with older kernels it is recommended to
		* set @dtype to 3 (unknown).
		*/
		struct ubi_leb_change_req {
		__s32 lnum;
		@@ -369,6 +379,7 @@ struct ubi_leb_change_req {

		/**
		* struct ubi_map_req - a data structure used in map LEB requests.
		* @dtype: pass "3" for better compatibility with old kernels
		* @lnum: logical eraseblock number to unmap
		* @padding: reserved for future, not used, has to be zeroed
		*/