redonkable/remarkable-linux
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UBI: power cut emulation for testing

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Emulate random power cuts by switching device to ro after a number of
writes to allow simple power cut testing with nand-sim.

Maximum and minimum number of successful writes before power cut and
what kind of writes (EC header, VID header or none) to interrupt
configurable via debugfs.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
david.oberhollenzer@sigma-star.at 2015-03-26 23:59:50 +01:00 committed by Richard Weinberger
parent 1a7e985dd1
commit 5026906742
4 changed files with 120 additions and 2 deletions
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89
drivers/mtd/ubi/debug.c
View file

@ -263,7 +263,7 @@ static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
struct dentry *dent = file->f_path.dentry;
struct ubi_device *ubi;
struct ubi_debug_info *d;
char buf[3];
char buf[8];
int val;
ubi = ubi_get_device(ubi_num);
@ -283,6 +283,22 @@ static ssize_t dfs_file_read(struct file *file, char __user *user_buf,
val = d->emulate_bitflips;
else if (dent == d->dfs_emulate_io_failures)
val = d->emulate_io_failures;
else if (dent == d->dfs_emulate_power_cut) {
snprintf(buf, sizeof(buf), "%u\n", d->emulate_power_cut);
count = simple_read_from_buffer(user_buf, count, ppos,
buf, strlen(buf));
goto out;
} else if (dent == d->dfs_power_cut_min) {
snprintf(buf, sizeof(buf), "%u\n", d->power_cut_min);
count = simple_read_from_buffer(user_buf, count, ppos,
buf, strlen(buf));
goto out;
} else if (dent == d->dfs_power_cut_max) {
snprintf(buf, sizeof(buf), "%u\n", d->power_cut_max);
count = simple_read_from_buffer(user_buf, count, ppos,
buf, strlen(buf));
goto out;
}
else {
count = -EINVAL;
goto out;
@ -311,7 +327,7 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
struct ubi_device *ubi;
struct ubi_debug_info *d;
size_t buf_size;
char buf[8];
char buf[8] = {0};
int val;
ubi = ubi_get_device(ubi_num);
@ -325,6 +341,21 @@ static ssize_t dfs_file_write(struct file *file, const char __user *user_buf,
goto out;
}
if (dent == d->dfs_power_cut_min) {
if (kstrtouint(buf, 0, &d->power_cut_min) != 0)
count = -EINVAL;
goto out;
} else if (dent == d->dfs_power_cut_max) {
if (kstrtouint(buf, 0, &d->power_cut_max) != 0)
count = -EINVAL;
goto out;
} else if (dent == d->dfs_emulate_power_cut) {
if (kstrtoint(buf, 0, &val) != 0)
count = -EINVAL;
d->emulate_power_cut = val;
goto out;
}
if (buf[0] == '1')
val = 1;
else if (buf[0] == '0')
@ -438,6 +469,27 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi)
goto out_remove;
d->dfs_emulate_io_failures = dent;
fname = "tst_emulate_power_cut";
dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
&dfs_fops);
if (IS_ERR_OR_NULL(dent))
goto out_remove;
d->dfs_emulate_power_cut = dent;
fname = "tst_emulate_power_cut_min";
dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
&dfs_fops);
if (IS_ERR_OR_NULL(dent))
goto out_remove;
d->dfs_power_cut_min = dent;
fname = "tst_emulate_power_cut_max";
dent = debugfs_create_file(fname, S_IWUSR, d->dfs_dir, (void *)ubi_num,
&dfs_fops);
if (IS_ERR_OR_NULL(dent))
goto out_remove;
d->dfs_power_cut_max = dent;
return 0;
out_remove:
@ -458,3 +510,36 @@ void ubi_debugfs_exit_dev(struct ubi_device *ubi)
if (IS_ENABLED(CONFIG_DEBUG_FS))
debugfs_remove_recursive(ubi->dbg.dfs_dir);
}
/**
* ubi_dbg_power_cut - emulate a power cut if it is time to do so
* @ubi: UBI device description object
* @caller: Flags set to indicate from where the function is being called
*
* Returns non-zero if a power cut was emulated, zero if not.
*/
int ubi_dbg_power_cut(struct ubi_device *ubi, int caller)
{
unsigned int range;
if ((ubi->dbg.emulate_power_cut & caller) == 0)
return 0;
if (ubi->dbg.power_cut_counter == 0) {
ubi->dbg.power_cut_counter = ubi->dbg.power_cut_min;
if (ubi->dbg.power_cut_max > ubi->dbg.power_cut_min) {
range = ubi->dbg.power_cut_max - ubi->dbg.power_cut_min;
ubi->dbg.power_cut_counter += prandom_u32() % range;
}
return 0;
}
ubi->dbg.power_cut_counter--;
if (ubi->dbg.power_cut_counter)
return 0;
ubi_msg(ubi, "XXXXXXXXXXXXXXX emulating a power cut XXXXXXXXXXXXXXXX");
ubi_ro_mode(ubi);
return 1;
}

2
drivers/mtd/ubi/debug.h
View file

@ -137,4 +137,6 @@ static inline void ubi_enable_dbg_chk_fastmap(struct ubi_device *ubi)
{
ubi->dbg.chk_fastmap = 1;
}
int ubi_dbg_power_cut(struct ubi_device *ubi, int caller);
#endif /* !__UBI_DEBUG_H__ */

6
drivers/mtd/ubi/io.c
View file

@ -859,6 +859,9 @@ int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
if (err)
return err;
if (ubi_dbg_power_cut(ubi, POWER_CUT_EC_WRITE))
return -EROFS;
err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
return err;
}
@ -1106,6 +1109,9 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
if (err)
return err;
if (ubi_dbg_power_cut(ubi, POWER_CUT_VID_WRITE))
return -EROFS;
p = (char *)vid_hdr - ubi->vid_hdr_shift;
err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
ubi->vid_hdr_alsize);

25
drivers/mtd/ubi/ubi.h
View file

@ -151,6 +151,17 @@ enum {
UBI_BAD_FASTMAP,
};
/*
* Flags for emulate_power_cut in ubi_debug_info
*
* POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
* POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
*/
enum {
POWER_CUT_EC_WRITE = 0x01,
POWER_CUT_VID_WRITE = 0x02,
};
/**
* struct ubi_wl_entry - wear-leveling entry.
* @u.rb: link in the corresponding (free/used) RB-tree
@ -360,6 +371,10 @@ struct ubi_wl_entry;
* @disable_bgt: disable the background task for testing purposes
* @emulate_bitflips: emulate bit-flips for testing purposes
* @emulate_io_failures: emulate write/erase failures for testing purposes
* @emulate_power_cut: emulate power cut for testing purposes
* @power_cut_counter: count down for writes left until emulated power cut
* @power_cut_min: minimum number of writes before emulating a power cut
* @power_cut_max: maximum number of writes until emulating a power cut
* @dfs_dir_name: name of debugfs directory containing files of this UBI device
* @dfs_dir: direntry object of the UBI device debugfs directory
* @dfs_chk_gen: debugfs knob to enable UBI general extra checks
@ -368,6 +383,9 @@ struct ubi_wl_entry;
* @dfs_disable_bgt: debugfs knob to disable the background task
* @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
* @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
* @dfs_emulate_power_cut: debugfs knob to emulate power cuts
* @dfs_power_cut_min: debugfs knob for minimum writes before power cut
* @dfs_power_cut_max: debugfs knob for maximum writes until power cut
*/
struct ubi_debug_info {
unsigned int chk_gen:1;
@ -376,6 +394,10 @@ struct ubi_debug_info {
unsigned int disable_bgt:1;
unsigned int emulate_bitflips:1;
unsigned int emulate_io_failures:1;
unsigned int emulate_power_cut:2;
unsigned int power_cut_counter;
unsigned int power_cut_min;
unsigned int power_cut_max;
char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
struct dentry *dfs_dir;
struct dentry *dfs_chk_gen;
@ -384,6 +406,9 @@ struct ubi_debug_info {
struct dentry *dfs_disable_bgt;
struct dentry *dfs_emulate_bitflips;
struct dentry *dfs_emulate_io_failures;
struct dentry *dfs_emulate_power_cut;
struct dentry *dfs_power_cut_min;
struct dentry *dfs_power_cut_max;
};
/**