[PATCH v2 1/3] libmtd: Add support to access OOB available size
Xiaolei Li
xiaolei.li at mediatek.com
Tue Apr 10 00:36:55 PDT 2018
This patch exposes OOB available size to user. Then user can use
OOB free area according to OOB available size.
Steps to get OOB available size:
First, access /sys/class/mtd/mtdX/oobavail. If not exist, then
try to get ecc layout by ioctl "ECCGETLAYOUT". If none of them
work, set OOB available size to 0.
Signed-off-by: Xiaolei Li <xiaolei.li at mediatek.com>
---
include/libmtd.h | 2 ++
lib/libmtd.c | 14 ++++++++++++++
lib/libmtd_int.h | 5 +++++
lib/libmtd_legacy.c | 43 +++++++++++++++++++++++++++++++++++++++++++
4 files changed, 64 insertions(+)
diff --git a/include/libmtd.h b/include/libmtd.h
index db85fb4..cc24af8 100644
--- a/include/libmtd.h
+++ b/include/libmtd.h
@@ -66,6 +66,7 @@ struct mtd_info
* @min_io_size: minimum input/output unit size
* @subpage_size: sub-page size
* @oob_size: OOB size (zero if the device does not have OOB area)
+ * @oobavail: free OOB size
* @region_cnt: count of additional erase regions
* @writable: zero if the device is read-only
* @bb_allowed: non-zero if the MTD device may have bad eraseblocks
@@ -84,6 +85,7 @@ struct mtd_dev_info
int min_io_size;
int subpage_size;
int oob_size;
+ int oobavail;
int region_cnt;
unsigned int writable:1;
unsigned int bb_allowed:1;
diff --git a/lib/libmtd.c b/lib/libmtd.c
index 86c89ae..7382229 100644
--- a/lib/libmtd.c
+++ b/lib/libmtd.c
@@ -614,6 +614,10 @@ libmtd_t libmtd_open(void)
if (!lib->mtd_oob_size)
goto out_error;
+ lib->mtd_oobavail = mkpath(lib->mtd, MTD_OOBAVAIL);
+ if (!lib->mtd_oobavail)
+ goto out_error;
+
lib->mtd_region_cnt = mkpath(lib->mtd, MTD_REGION_CNT);
if (!lib->mtd_region_cnt)
goto out_error;
@@ -637,6 +641,7 @@ void libmtd_close(libmtd_t desc)
free(lib->mtd_flags);
free(lib->mtd_region_cnt);
free(lib->mtd_oob_size);
+ free(lib->mtd_oobavail);
free(lib->mtd_subpage_size);
free(lib->mtd_min_io_size);
free(lib->mtd_size);
@@ -769,6 +774,15 @@ int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd)
return -1;
if (dev_read_pos_int(lib->mtd_oob_size, mtd_num, &mtd->oob_size))
return -1;
+ if (dev_read_pos_int(lib->mtd_oobavail, mtd_num, &mtd->oobavail)) {
+ /*
+ * Fail to access oobavail sysfs file,
+ * try ioctl ECCGETLAYOUT. */
+ mtd->oobavail = legacy_get_mtd_oobavail1(mtd_num);
+ /* Set 0 as default if can not get valid ecc layout */
+ if (mtd->oobavail < 0)
+ mtd->oobavail = 0;
+ }
if (dev_read_pos_int(lib->mtd_region_cnt, mtd_num, &mtd->region_cnt))
return -1;
if (dev_read_hex_int(lib->mtd_flags, mtd_num, &ret))
diff --git a/lib/libmtd_int.h b/lib/libmtd_int.h
index 03b0863..c0514d2 100644
--- a/lib/libmtd_int.h
+++ b/lib/libmtd_int.h
@@ -44,6 +44,7 @@ extern "C" {
#define MTD_MIN_IO_SIZE "writesize"
#define MTD_SUBPAGE_SIZE "subpagesize"
#define MTD_OOB_SIZE "oobsize"
+#define MTD_OOBAVAIL "oobavail"
#define MTD_REGION_CNT "numeraseregions"
#define MTD_FLAGS "flags"
@@ -63,6 +64,7 @@ extern "C" {
* @mtd_min_io_size: minimum I/O unit size file pattern
* @mtd_subpage_size: sub-page size file pattern
* @mtd_oob_size: MTD device OOB size file pattern
+ * @mtd_oobavail: MTD device free OOB size file pattern
* @mtd_region_cnt: count of additional erase regions file pattern
* @mtd_flags: MTD device flags file pattern
* @sysfs_supported: non-zero if sysfs is supported by MTD
@@ -92,6 +94,7 @@ struct libmtd
char *mtd_min_io_size;
char *mtd_subpage_size;
char *mtd_oob_size;
+ char *mtd_oobavail;
char *mtd_region_cnt;
char *mtd_flags;
unsigned int sysfs_supported:1;
@@ -103,6 +106,8 @@ int legacy_dev_present(int mtd_num);
int legacy_mtd_get_info(struct mtd_info *info);
int legacy_get_dev_info(const char *node, struct mtd_dev_info *mtd);
int legacy_get_dev_info1(int dev_num, struct mtd_dev_info *mtd);
+int legacy_get_mtd_oobavail(const char *node);
+int legacy_get_mtd_oobavail1(int mtd_num);
#ifdef __cplusplus
}
diff --git a/lib/libmtd_legacy.c b/lib/libmtd_legacy.c
index 46f51fd..e1ab48e 100644
--- a/lib/libmtd_legacy.c
+++ b/lib/libmtd_legacy.c
@@ -215,6 +215,46 @@ int legacy_mtd_get_info(struct mtd_info *info)
return 0;
}
+int legacy_get_mtd_oobavail(const char *node)
+{
+ struct stat st;
+ struct nand_ecclayout_user usrlay;
+ int fd, ret;
+
+ if (stat(node, &st))
+ return sys_errmsg("cannot open \"%s\"", node);
+
+ if (!S_ISCHR(st.st_mode)) {
+ errno = EINVAL;
+ return errmsg("\"%s\" is not a character device", node);
+ }
+
+ fd = open(node, O_RDONLY);
+ if (fd == -1)
+ return sys_errmsg("cannot open \"%s\"", node);
+
+ ret = ioctl(fd, ECCGETLAYOUT, &usrlay);
+ if (ret < 0) {
+ sys_errmsg("ECCGETLAYOUT ioctl request failed");
+ goto out_close;
+ }
+
+ ret = usrlay.oobavail;
+
+out_close:
+ close(fd);
+
+ return ret;
+}
+
+int legacy_get_mtd_oobavail1(int mtd_num)
+{
+ char node[sizeof(MTD_DEV_PATT) + 20];
+
+ sprintf(node, MTD_DEV_PATT, mtd_num);
+ return legacy_get_mtd_oobavail(node);
+}
+
/**
* legacy_get_dev_info - legacy version of 'mtd_get_dev_info()'.
* @node: name of the MTD device node
@@ -335,6 +375,9 @@ int legacy_get_dev_info(const char *node, struct mtd_dev_info *mtd)
close(fd);
+ ret = legacy_get_mtd_oobavail(node);
+ mtd->oobavail = ret > 0 ? ret : 0;
+
/*
* Unfortunately, the device name is not available via ioctl, and
* we have to parse /proc/mtd to get it.
--
1.9.1
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