UBI: amend comments after all the renamings (fbd0107f) · Commits · e / devices / android_kernel_teracube_mt6765

drivers/mtd/ubi/build.c

+4 −8

Original line number	Diff line number	Diff line
		@@ -27,10 +27,6 @@
		* module load parameters or the kernel boot parameters. If MTD devices were
		* specified, UBI does not attach any MTD device, but it is possible to do
		* later using the "UBI control device".
		*
		* At the moment we only attach UBI devices by scanning, which will become a
		* bottleneck when flashes reach certain large size. Then one may improve UBI
		* and add other methods, although it does not seem to be easy to do.
		*/

		#include <linux/err.h>
		@@ -790,11 +786,11 @@ static int io_init(struct ubi_device *ubi)
		ubi_msg("data offset: %d", ubi->leb_start);

		/*
		* Note, ideally, we have to initialize ubi->bad_peb_count here. But
		* Note, ideally, we have to initialize @ubi->bad_peb_count here. But
		* unfortunately, MTD does not provide this information. We should loop
		* over all physical eraseblocks and invoke mtd->block_is_bad() for
		* each physical eraseblock. So, we skip ubi->bad_peb_count
		* uninitialized and initialize it after scanning.
		* each physical eraseblock. So, we leave @ubi->bad_peb_count
		* uninitialized so far.
		*/

		return 0;
		@@ -805,7 +801,7 @@ static int io_init(struct ubi_device *ubi)
		* @ubi: UBI device description object
		* @vol_id: ID of the volume to re-size
		*
		* This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
		* This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
		* the volume table to the largest possible size. See comments in ubi-header.h
		* for more description of the flag. Returns zero in case of success and a
		* negative error code in case of failure.

drivers/mtd/ubi/io.c

+1 −2

Original line number	Diff line number	Diff line
		@@ -513,8 +513,7 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
		* It is important to first invalidate the EC header, and then the VID
		* header. Otherwise a power cut may lead to valid EC header and
		* invalid VID header, in which case UBI will treat this PEB as
		* corrupted and will try to preserve it, and print scary warnings (see
		* the header comment in scan.c for more information).
		* corrupted and will try to preserve it, and print scary warnings.
		*/
		addr = (loff_t)pnum * ubi->peb_size;
		err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);

drivers/mtd/ubi/scan.c

+55 −56

Original line number	Diff line number	Diff line
		@@ -19,21 +19,21 @@
		*/

		/*
		* UBI scanning sub-system.
		* UBI attaching sub-system.
		*
		* This sub-system is responsible for scanning the flash media, checking UBI
		* headers and providing complete information about the UBI flash image.
		* This sub-system is responsible for attaching MTD devices and it also
		* implements flash media scanning.
		*
		* The attaching information is represented by a &struct ubi_attach_info'
		* object. Information about found volumes is represented by
		* &struct ubi_ainf_volume objects which are kept in volume RB-tree with root
		* at the @volumes field. The RB-tree is indexed by the volume ID.
		* object. Information about volumes is represented by &struct ubi_ainf_volume
		* objects which are kept in volume RB-tree with root at the @volumes field.
		* The RB-tree is indexed by the volume ID.
		*
		* Scanned logical eraseblocks are represented by &struct ubi_ainf_peb objects.
		* These objects are kept in per-volume RB-trees with the root at the
		* corresponding &struct ubi_ainf_volume object. To put it differently, we keep
		* an RB-tree of per-volume objects and each of these objects is the root of
		* RB-tree of per-eraseblock objects.
		* Logical eraseblocks are represented by &struct ubi_ainf_peb objects. These
		* objects are kept in per-volume RB-trees with the root at the corresponding
		* &struct ubi_ainf_volume object. To put it differently, we keep an RB-tree of
		* per-volume objects and each of these objects is the root of RB-tree of
		* per-LEB objects.
		*
		* Corrupted physical eraseblocks are put to the @corr list, free physical
		* eraseblocks are put to the @free list and the physical eraseblock to be
		@@ -51,28 +51,29 @@
		*
		* 1. Corruptions caused by power cuts. These are expected corruptions and UBI
		* tries to handle them gracefully, without printing too many warnings and
		* error messages. The idea is that we do not lose important data in these case
		* - we may lose only the data which was being written to the media just before
		* the power cut happened, and the upper layers (e.g., UBIFS) are supposed to
		* handle such data losses (e.g., by using the FS journal).
		* error messages. The idea is that we do not lose important data in these
		* cases - we may lose only the data which were being written to the media just
		* before the power cut happened, and the upper layers (e.g., UBIFS) are
		* supposed to handle such data losses (e.g., by using the FS journal).
		*
		* When UBI detects a corruption (CRC-32 mismatch) in a PEB, and it looks like
		* the reason is a power cut, UBI puts this PEB to the @erase list, and all
		* PEBs in the @erase list are scheduled for erasure later.
		*
		* 2. Unexpected corruptions which are not caused by power cuts. During
		* scanning, such PEBs are put to the @corr list and UBI preserves them.
		* attaching, such PEBs are put to the @corr list and UBI preserves them.
		* Obviously, this lessens the amount of available PEBs, and if at some point
		* UBI runs out of free PEBs, it switches to R/O mode. UBI also loudly informs
		* about such PEBs every time the MTD device is attached.
		*
		* However, it is difficult to reliably distinguish between these types of
		* corruptions and UBI's strategy is as follows. UBI assumes corruption type 2
		* if the VID header is corrupted and the data area does not contain all 0xFFs,
		* and there were no bit-flips or integrity errors while reading the data area.
		* Otherwise UBI assumes corruption type 1. So the decision criteria are as
		* follows.
		* o If the data area contains only 0xFFs, there is no data, and it is safe
		* corruptions and UBI's strategy is as follows (in case of attaching by
		* scanning). UBI assumes corruption type 2 if the VID header is corrupted and
		* the data area does not contain all 0xFFs, and there were no bit-flips or
		* integrity errors (e.g., ECC errors in case of NAND) while reading the data
		* area. Otherwise UBI assumes corruption type 1. So the decision criteria
		* are as follows.
		* o If the data area contains only 0xFFs, there are no data, and it is safe
		* to just erase this PEB - this is corruption type 1.
		* o If the data area has bit-flips or data integrity errors (ECC errors on
		* NAND), it is probably a PEB which was being erased when power cut
		@@ -102,7 +103,8 @@ static struct ubi_vid_hdr *vidh;
		* @to_head: if not zero, add to the head of the list
		* @list: the list to add to
		*
		* This function adds physical eraseblock @pnum to free, erase, or alien lists.
		* This function allocates a 'struct ubi_ainf_peb' object for physical
		* eraseblock @pnum and adds it to the "free", "erase", or "alien" lists.
		* If @to_head is not zero, PEB will be added to the head of the list, which
		* basically means it will be processed first later. E.g., we add corrupted
		* PEBs (corrupted due to power cuts) to the head of the erase list to make
		@@ -144,9 +146,10 @@ static int add_to_list(struct ubi_attach_info *ai, int pnum, int ec,
		* @pnum: physical eraseblock number to add
		* @ec: erase counter of the physical eraseblock
		*
		* This function adds corrupted physical eraseblock @pnum to the 'corr' list.
		* The corruption was presumably not caused by a power cut. Returns zero in
		* case of success and a negative error code in case of failure.
		* This function allocates a 'struct ubi_ainf_peb' object for a corrupted
		* physical eraseblock @pnum and adds it to the 'corr' list. The corruption
		* was presumably not caused by a power cut. Returns zero in case of success
		* and a negative error code in case of failure.
		*/
		static int add_corrupted(struct ubi_attach_info *ai, int pnum, int ec)
		{
		@@ -241,8 +244,8 @@ static int validate_vid_hdr(const struct ubi_vid_hdr *vid_hdr,
		* If the volume corresponding to the @vid_hdr logical eraseblock is already
		* present in the attaching information, this function does nothing. Otherwise
		* it adds corresponding volume to the attaching information. Returns a pointer
		* to the scanning volume object in case of success and a negative error code
		* in case of failure.
		* to the allocated "av" object in case of success and a negative error code in
		* case of failure.
		*/
		static struct ubi_ainf_volume add_volume(struct ubi_attach_info ai,
		int vol_id, int pnum,
		@@ -425,7 +428,7 @@ static int compare_lebs(struct ubi_device ubi, const struct ubi_ainf_peb aeb,
		}

		/**
		* ubi_add_to_av - add physical eraseblock to the attaching information.
		* ubi_add_to_av - add used physical eraseblock to the attaching information.
		* @ubi: UBI device description object
		* @ai: attaching information
		* @pnum: the physical eraseblock number
		@@ -692,8 +695,8 @@ static int early_erase_peb(struct ubi_device *ubi,
		* the lists, writes the EC header if it is needed, and removes it from the
		* list.
		*
		* This function returns scanning physical eraseblock information in case of
		* success and an error code in case of failure.
		* This function returns a pointer to the "aeb" of the found free PEB in case
		* of success and an error code in case of failure.
		*/
		struct ubi_ainf_peb ubi_early_get_peb(struct ubi_device ubi,
		struct ubi_attach_info *ai)
		@@ -793,15 +796,17 @@ static int check_corruption(struct ubi_device ubi, struct ubi_vid_hdr vid_hdr,
		}

		/**
		* process_eb - read, check UBI headers, and add them to attaching information.
		* scan_peb - scan and process UBI headers of a PEB.
		* @ubi: UBI device description object
		* @ai: attaching information
		* @pnum: the physical eraseblock number
		*
		* This function returns a zero if the physical eraseblock was successfully
		* handled and a negative error code in case of failure.
		* This function reads UBI headers of PEB @pnum, checks them, and adds
		* information about this PEB to the corresponding list or RB-tree in the
		* "attaching info" structure. Returns zero if the physical eraseblock was
		* successfully handled and a negative error code in case of failure.
		*/
		static int process_eb(struct ubi_device ubi, struct ubi_attach_info ai,
		static int scan_peb(struct ubi_device ubi, struct ubi_attach_info ai,
		int pnum)
		{
		long long uninitialized_var(ec);
		@@ -814,11 +819,6 @@ static int process_eb(struct ubi_device ubi, struct ubi_attach_info ai,
		if (err < 0)
		return err;
		else if (err) {
		/*
		* FIXME: this is actually duty of the I/O sub-system to
		* initialize this, but MTD does not provide enough
		* information.
		*/
		ai->bad_peb_count += 1;
		return 0;
		}
		@@ -1033,18 +1033,17 @@ static int process_eb(struct ubi_device ubi, struct ubi_attach_info ai,
		}

		/**
		* check_what_we_have - check what PEB were found by scanning.
		* late_analysis - analyze the overall situation with PEB.
		* @ubi: UBI device description object
		* @ai: attaching information
		*
		* This is a helper function which takes a look what PEBs were found by
		* scanning, and decides whether the flash is empty and should be formatted and
		* whether there are too many corrupted PEBs and we should not attach this
		* MTD device. Returns zero if we should proceed with attaching the MTD device,
		* and %-EINVAL if we should not.
		* This is a helper function which takes a look what PEBs we have after we
		* gather information about all of them ("ai" is compete). It decides whether
		* the flash is empty and should be formatted of whether there are too many
		* corrupted PEBs and we should not attach this MTD device. Returns zero if we
		* should proceed with attaching the MTD device, and %-EINVAL if we should not.
		*/
		static int check_what_we_have(struct ubi_device *ubi,
		struct ubi_attach_info *ai)
		static int late_analysis(struct ubi_device ubi, struct ubi_attach_info ai)
		{
		struct ubi_ainf_peb *aeb;
		int max_corr, peb_count;
		@@ -1112,7 +1111,8 @@ static int check_what_we_have(struct ubi_device *ubi,
		* @ubi: UBI device description object
		*
		* This function does full scanning of an MTD device and returns complete
		* information about it. In case of failure, an error code is returned.
		* information about it in form of a "struct ubi_attach_info" object. In case
		* of failure, an error code is returned.
		*/
		struct ubi_attach_info ubi_scan(struct ubi_device ubi)
		{
		@@ -1151,7 +1151,7 @@ struct ubi_attach_info ubi_scan(struct ubi_device ubi)
		cond_resched();

		dbg_gen("process PEB %d", pnum);
		err = process_eb(ubi, ai, pnum);
		err = scan_peb(ubi, ai, pnum);
		if (err < 0)
		goto out_vidh;
		}
		@@ -1162,7 +1162,7 @@ struct ubi_attach_info ubi_scan(struct ubi_device ubi)
		if (ai->ec_count)
		ai->mean_ec = div_u64(ai->ec_sum, ai->ec_count);

		err = check_what_we_have(ubi, ai);
		err = late_analysis(ubi, ai);
		if (err)
		goto out_vidh;

		@@ -1208,12 +1208,11 @@ struct ubi_attach_info ubi_scan(struct ubi_device ubi)
		}

		/**
		* destroy_av - free the scanning volume information
		* @av: scanning volume information
		* destroy_av - free volume attaching information.
		* @av: volume attaching information
		* @ai: attaching information
		*
		* This function destroys the volume RB-tree (@av->root) and the scanning
		* volume information.
		* This function destroys the volume attaching information.
		*/
		static void destroy_av(struct ubi_attach_info ai, struct ubi_ainf_volume av)
		{

drivers/mtd/ubi/scan.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -146,7 +146,7 @@ struct ubi_vid_hdr;
		* ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
		*
		* @av: volume attaching information
		* @aeb: scanning eraseblock information
		* @aeb: attaching eraseblock information
		* @list: the list to move to
		*/
		static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,

drivers/mtd/ubi/ubi-media.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -149,10 +149,10 @@ enum {
		* The @image_seq field is used to validate a UBI image that has been prepared
		* for a UBI device. The @image_seq value can be any value, but it must be the
		* same on all eraseblocks. UBI will ensure that all new erase counter headers
		* also contain this value, and will check the value when scanning at start-up.
		* also contain this value, and will check the value when attaching the flash.
		* One way to make use of @image_seq is to increase its value by one every time
		* an image is flashed over an existing image, then, if the flashing does not
		* complete, UBI will detect the error when scanning.
		* complete, UBI will detect the error when attaching the media.
		*/
		struct ubi_ec_hdr {
		__be32 magic;