If we don't do that, partitions might still be exposed while the underlying device is gone.

Fixes: 2a74930da57f ("mtd: mtdpart: implement proper partition handling") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com --- Changes in v2: - Fix build failures when CONFIG_MTD_PARTITIONS is not enabled --- drivers/mtd/mtdcore.c | 1 + include/linux/mtd/mtd.h | 15 +++++++++++++++ 2 files changed, 16 insertions(+)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 7a15ded8c883..46657fe7c949 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -528,6 +528,7 @@ int del_mtd_device(struct mtd_info *mtd) struct mtd_notifier *not; #endif

+ del_mtd_partitions(mtd); mutex_lock(&mtd_table_mutex);

if (idr_find(&mtd_idr, mtd->index) != mtd) { diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index d20ebd820289..4d0096d9f1d8 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -562,8 +562,23 @@ unsigned mtd_mmap_capabilities(struct mtd_info *mtd); /* drivers/mtd/mtdcore.h */ int add_mtd_device(struct mtd_info *mtd); int del_mtd_device(struct mtd_info *mtd); + +#ifdef CONFIG_MTD_PARTITIONS int add_mtd_partitions(struct mtd_info *, const struct mtd_partition *, int); int del_mtd_partitions(struct mtd_info *); +#else +static inline int add_mtd_partitions(struct mtd_info *mtd, + const struct mtd_partition *parts, + int nparts) +{ + return 0; +} + +static inline int del_mtd_partitions(struct mtd_info *mtd) +{ + return 0; +} +#endif

struct mtd_info *__mtd_next_device(int i); #define mtd_for_each_device(mtd) \

The environment is not guaranteed to contain a valid mtdids variable when called from mtd_search_alternate_name(). Call get_mtdids() instead of env_get("mtdids").

Fixes: ff4afa8a981e ("mtd: uboot: search for an equivalent MTD name with the mtdids") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com --- Changes in v2: - Add Miquel's R-b - Move board_mtdparts_default() prototype def to fix a build failure --- drivers/mtd/mtd_uboot.c | 49 ++++++++++++++++++++--------------------- 1 file changed, 24 insertions(+), 25 deletions(-)

diff --git a/drivers/mtd/mtd_uboot.c b/drivers/mtd/mtd_uboot.c index 6a3e64395de2..c4434d70520d 100644 --- a/drivers/mtd/mtd_uboot.c +++ b/drivers/mtd/mtd_uboot.c @@ -13,6 +13,29 @@

#define MTD_NAME_MAX_LEN 20

+void board_mtdparts_default(const char **mtdids, const char **mtdparts); + +static const char *get_mtdids(void) +{ + __maybe_unused const char *mtdparts = NULL; + const char *mtdids = env_get("mtdids"); + + if (mtdids) + return mtdids; + +#if defined(CONFIG_SYS_MTDPARTS_RUNTIME) + board_mtdparts_default(&mtdids, &mtdparts); +#elif defined(MTDIDS_DEFAULT) + mtdids = MTDIDS_DEFAULT; +#elif defined(CONFIG_MTDIDS_DEFAULT) + mtdids = CONFIG_MTDIDS_DEFAULT; +#endif + + if (mtdids) + env_set("mtdids", mtdids); + + return mtdids; +}

/** * mtd_search_alternate_name - Search an alternate name for @mtdname thanks to @@ -34,7 +57,7 @@ int mtd_search_alternate_name(const char *mtdname, char *altname, const char *mtdids, *equal, *comma, *dev_id, *mtd_id; int dev_id_len, mtd_id_len;

- mtdids = env_get("mtdids"); + mtdids = get_mtdids(); if (!mtdids) return -EINVAL;

@@ -92,30 +115,6 @@ static void mtd_probe_uclass_mtd_devs(void) { } #endif

#if defined(CONFIG_MTD_PARTITIONS) -extern void board_mtdparts_default(const char **mtdids, - const char **mtdparts); - -static const char *get_mtdids(void) -{ - __maybe_unused const char *mtdparts = NULL; - const char *mtdids = env_get("mtdids"); - - if (mtdids) - return mtdids; - -#if defined(CONFIG_SYS_MTDPARTS_RUNTIME) - board_mtdparts_default(&mtdids, &mtdparts); -#elif defined(MTDIDS_DEFAULT) - mtdids = MTDIDS_DEFAULT; -#elif defined(CONFIG_MTDIDS_DEFAULT) - mtdids = CONFIG_MTDIDS_DEFAULT; -#endif - - if (mtdids) - env_set("mtdids", mtdids); - - return mtdids; -}

#define MTDPARTS_MAXLEN 512

The local mtd_name[] variable is limited in size. Return an error if the name passed in mtdparts does not fit in this local var.

Fixes: 5db66b3aee6f ("cmd: mtd: add 'mtd' command") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com --- Changes in v2: - New patch --- drivers/mtd/mtd_uboot.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/mtd/mtd_uboot.c b/drivers/mtd/mtd_uboot.c index d551aee20203..0eda36278309 100644 --- a/drivers/mtd/mtd_uboot.c +++ b/drivers/mtd/mtd_uboot.c @@ -222,8 +222,8 @@ int mtd_probe_devices(void) while (mtdparts[0] != '\0') { char mtd_name[MTD_NAME_MAX_LEN], *colon; struct mtd_partition *parts; - int mtd_name_len, nparts; - int ret; + unsigned int mtd_name_len; + int nparts, ret;

colon = strchr(mtdparts, ':'); if (!colon) { @@ -231,7 +231,12 @@ int mtd_probe_devices(void) return -EINVAL; }

- mtd_name_len = colon - mtdparts; + mtd_name_len = (unsigned int)(colon - mtdparts); + if (mtd_name_len + 1 > sizeof(mtd_name)) { + printf("MTD name too long: %s\n", mtdparts); + return -EINVAL; + } + strncpy(mtd_name, mtdparts, mtd_name_len); mtd_name[mtd_name_len] = '\0'; /* Move the pointer forward (including the ':') */

MTD partition creation code is a bit tricky. It tries to figure out when things have changed (either MTD dev list or mtdparts/mtdids vars) and when that happens it first deletes all the partitions that had been previously created and then creates the new ones based on the new mtdparts/mtdids values. But before deleting the old partitions, it ensures that none of the currently registered parts are being used and bails out when that's not the case. So, we end up in a situation where, if at least one MTD dev has one of its partitions used by someone (UBI for instance), the partitions update logic no longer works for other devs.

Rework the code to relax the logic and allow updates of MTD parts on devices that are not being used (we still refuse to updates parts on devices who have at least one of their partitions used by someone).

Fixes: 5db66b3aee6f ("cmd: mtd: add 'mtd' command") Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com --- Changes in v2: - New patch --- drivers/mtd/mtd_uboot.c | 87 +++++++++++++++++++++++++++-------------- drivers/mtd/mtdpart.c | 12 ++++++ include/linux/mtd/mtd.h | 2 + 3 files changed, 72 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/mtd_uboot.c b/drivers/mtd/mtd_uboot.c index 6a36948b917b..c9909d56842e 100644 --- a/drivers/mtd/mtd_uboot.c +++ b/drivers/mtd/mtd_uboot.c @@ -149,6 +149,48 @@ static const char *get_mtdparts(void) return mtdparts; }

+static int mtd_del_parts(struct mtd_info *mtd, bool quiet) +{ + int ret; + + if (!mtd_has_partitions(mtd)) + return 0; + + /* do not delete partitions if they are in use. */ + if (mtd_partitions_used(mtd)) { + if (!quiet) + printf(""%s" partitions still in use, can't delete them\n", + mtd->name); + return -EACCES; + } + + ret = del_mtd_partitions(mtd); + if (ret) + return ret; + + return 1; +} + +static void mtd_del_all_parts(void) +{ + struct mtd_info *mtd; + int ret = 0; + + /* + * It is not safe to remove entries from the mtd_for_each_device loop + * as it uses idr indexes and the partitions removal is done in bulk + * (all partitions of one device at the same time), so break and + * iterate from start each time a new partition is found and deleted. + */ + do { + mtd_for_each_device(mtd) { + ret = mtd_del_parts(mtd, false); + if (ret > 0) + break; + } + } while (ret > 0); +} + int mtd_probe_devices(void) { static char *old_mtdparts; @@ -156,7 +198,6 @@ int mtd_probe_devices(void) const char *mtdparts = get_mtdparts(); const char *mtdids = get_mtdids(); const char *mtdparts_next = mtdparts; - bool remaining_partitions = true; struct mtd_info *mtd;

mtd_probe_uclass_mtd_devs(); @@ -178,37 +219,14 @@ int mtd_probe_devices(void) old_mtdparts = strdup(mtdparts); old_mtdids = strdup(mtdids);

- /* If at least one partition is still in use, do not delete anything */ - mtd_for_each_device(mtd) { - if (mtd->usecount) { - printf("Partition "%s" already in use, aborting\n", - mtd->name); - return -EACCES; - } - } - /* - * Everything looks clear, remove all partitions. It is not safe to - * remove entries from the mtd_for_each_device loop as it uses idr - * indexes and the partitions removal is done in bulk (all partitions of - * one device at the same time), so break and iterate from start each - * time a new partition is found and deleted. + * Remove all old parts. Note that partition removal can fail in case + * one of the partition is still being used by an MTD user, so this + * does not guarantee that all old partitions are gone. */ - while (remaining_partitions) { - remaining_partitions = false; - mtd_for_each_device(mtd) { - if (!mtd_is_partition(mtd) && mtd_has_partitions(mtd)) { - del_mtd_partitions(mtd); - remaining_partitions = true; - break; - } - } - } + mtd_del_all_parts();

- /* - * Call mtd_dev_list_updated() to clear updates generated by our own - * parts removal loop. - */ + /* Clear the "MTD dev list" updated flag. */ mtd_dev_list_updated();

/* If either mtdparts or mtdids is empty, then exit */ @@ -278,6 +296,17 @@ int mtd_probe_devices(void) } }

+ /* + * Call mtd_del_parts() again, even if it's already been called + * in mtd_del_all_parts(). We need to know if old partitions are + * still around (because they are still being used by someone), + * and if they are, we shouldn't create new partitions, so just + * skip this MTD device and try the next one. + */ + ret = mtd_del_parts(mtd, true); + if (ret < 0) + continue; + /* * Parse the MTD device partitions. It will update the mtdparts * pointer, create an array of parts (that must be freed), and diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index 4d2ac8107f01..fd8d8e5ea729 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -63,6 +63,18 @@ char *kstrdup(const char *s, gfp_t gfp) #define MTD_SIZE_REMAINING (~0LLU) #define MTD_OFFSET_NOT_SPECIFIED (~0LLU)

+bool mtd_partitions_used(struct mtd_info *master) +{ + struct mtd_info *slave; + + list_for_each_entry(slave, &master->partitions, node) { + if (slave->usecount) + return true; + } + + return false; +} + /** * mtd_parse_partition - Parse @mtdparts partition definition, fill @partition * with it and update the @mtdparts string pointer. diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 4d0096d9f1d8..cd1f557a2f31 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -366,6 +366,8 @@ static inline bool mtd_has_partitions(const struct mtd_info *mtd) return !list_empty(&mtd->partitions); }

+bool mtd_partitions_used(struct mtd_info *master); + int mtd_ooblayout_ecc(struct mtd_info *mtd, int section, struct mtd_oob_region *oobecc); int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,