From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- Documentation/ABI/testing/sysfs-class-mtd | 242 ++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-mtd (limited to 'Documentation/ABI/testing/sysfs-class-mtd') diff --git a/Documentation/ABI/testing/sysfs-class-mtd b/Documentation/ABI/testing/sysfs-class-mtd new file mode 100644 index 000000000..f77fa4f6d --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-mtd @@ -0,0 +1,242 @@ +What: /sys/class/mtd/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + The mtd/ class subdirectory belongs to the MTD subsystem + (MTD core). + +What: /sys/class/mtd/mtdX/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + The /sys/class/mtd/mtd{0,1,2,3,...} directories correspond + to each /dev/mtdX character device. These may represent + physical/simulated flash devices, partitions on a flash + device, or concatenated flash devices. + +What: /sys/class/mtd/mtdXro/ +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + These directories provide the corresponding read-only device + nodes for /sys/class/mtd/mtdX/ . + +What: /sys/class/mtd/mtdX/dev +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Major and minor numbers of the character device corresponding + to this MTD device (in : format). This is the + read-write device so will be even. + +What: /sys/class/mtd/mtdXro/dev +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Major and minor numbers of the character device corresponding + to the read-only variant of the MTD device (in + : format). In this case will be odd. + +What: /sys/class/mtd/mtdX/erasesize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + "Major" erase size for the device. If numeraseregions is + zero, this is the eraseblock size for the entire device. + Otherwise, the MEMGETREGIONCOUNT/MEMGETREGIONINFO ioctls + can be used to determine the actual eraseblock layout. + +What: /sys/class/mtd/mtdX/flags +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + A hexadecimal value representing the device flags, ORed + together: + + 0x0400: MTD_WRITEABLE - device is writable + 0x0800: MTD_BIT_WRITEABLE - single bits can be flipped + 0x1000: MTD_NO_ERASE - no erase necessary + 0x2000: MTD_POWERUP_LOCK - always locked after reset + +What: /sys/class/mtd/mtdX/name +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + A human-readable ASCII name for the device or partition. + This will match the name in /proc/mtd . + +What: /sys/class/mtd/mtdX/numeraseregions +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + For devices that have variable eraseblock sizes, this + provides the total number of erase regions. Otherwise, + it will read back as zero. + +What: /sys/class/mtd/mtdX/oobsize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Number of OOB bytes per page. + +What: /sys/class/mtd/mtdX/size +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Total size of the device/partition, in bytes. + +What: /sys/class/mtd/mtdX/type +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + One of the following ASCII strings, representing the device + type: + + absent, ram, rom, nor, nand, mlc-nand, dataflash, ubi, unknown + +What: /sys/class/mtd/mtdX/writesize +Date: April 2009 +KernelVersion: 2.6.29 +Contact: linux-mtd@lists.infradead.org +Description: + Minimal writable flash unit size. This will always be + a positive integer. + + In the case of NOR flash it is 1 (even though individual + bits can be cleared). + + In the case of NAND flash it is one NAND page (or a + half page, or a quarter page). + + In the case of ECC NOR, it is the ECC block size. + +What: /sys/class/mtd/mtdX/ecc_strength +Date: April 2012 +KernelVersion: 3.4 +Contact: linux-mtd@lists.infradead.org +Description: + Maximum number of bit errors that the device is capable of + correcting within each region covering an ECC step (see + ecc_step_size). This will always be a non-negative integer. + + In the case of devices lacking any ECC capability, it is 0. + +What: /sys/class/mtd/mtdX/bitflip_threshold +Date: April 2012 +KernelVersion: 3.4 +Contact: linux-mtd@lists.infradead.org +Description: + This allows the user to examine and adjust the criteria by which + mtd returns -EUCLEAN from mtd_read() and mtd_read_oob(). If the + maximum number of bit errors that were corrected on any single + region comprising an ecc step (as reported by the driver) equals + or exceeds this value, -EUCLEAN is returned. Otherwise, absent + an error, 0 is returned. Higher layers (e.g., UBI) use this + return code as an indication that an erase block may be + degrading and should be scrutinized as a candidate for being + marked as bad. + + The initial value may be specified by the flash device driver. + If not, then the default value is ecc_strength. + + The introduction of this feature brings a subtle change to the + meaning of the -EUCLEAN return code. Previously, it was + interpreted to mean simply "one or more bit errors were + corrected". Its new interpretation can be phrased as "a + dangerously high number of bit errors were corrected on one or + more regions comprising an ecc step". The precise definition of + "dangerously high" can be adjusted by the user with + bitflip_threshold. Users are discouraged from doing this, + however, unless they know what they are doing and have intimate + knowledge of the properties of their device. Broadly speaking, + bitflip_threshold should be low enough to detect genuine erase + block degradation, but high enough to avoid the consequences of + a persistent return value of -EUCLEAN on devices where sticky + bitflips occur. Note that if bitflip_threshold exceeds + ecc_strength, -EUCLEAN is never returned by the read operations. + Conversely, if bitflip_threshold is zero, -EUCLEAN is always + returned, absent a hard error. + + This is generally applicable only to NAND flash devices with ECC + capability. It is ignored on devices lacking ECC capability; + i.e., devices for which ecc_strength is zero. + +What: /sys/class/mtd/mtdX/ecc_step_size +Date: May 2013 +KernelVersion: 3.10 +Contact: linux-mtd@lists.infradead.org +Description: + The size of a single region covered by ECC, known as the ECC + step. Devices may have several equally sized ECC steps within + each writesize region. + + It will always be a non-negative integer. In the case of + devices lacking any ECC capability, it is 0. + +What: /sys/class/mtd/mtdX/ecc_failures +Date: June 2014 +KernelVersion: 3.17 +Contact: linux-mtd@lists.infradead.org +Description: + The number of failures reported by this device's ECC. Typically, + these failures are associated with failed read operations. + + It will always be a non-negative integer. In the case of + devices lacking any ECC capability, it is 0. + +What: /sys/class/mtd/mtdX/corrected_bits +Date: June 2014 +KernelVersion: 3.17 +Contact: linux-mtd@lists.infradead.org +Description: + The number of bits that have been corrected by means of the + device's ECC. + + It will always be a non-negative integer. In the case of + devices lacking any ECC capability, it is 0. + +What: /sys/class/mtd/mtdX/bad_blocks +Date: June 2014 +KernelVersion: 3.17 +Contact: linux-mtd@lists.infradead.org +Description: + The number of blocks marked as bad, if any, in this partition. + +What: /sys/class/mtd/mtdX/bbt_blocks +Date: June 2014 +KernelVersion: 3.17 +Contact: linux-mtd@lists.infradead.org +Description: + The number of blocks that are marked as reserved, if any, in + this partition. These are typically used to store the in-flash + bad block table (BBT). + +What: /sys/class/mtd/mtdX/offset +Date: March 2015 +KernelVersion: 4.1 +Contact: linux-mtd@lists.infradead.org +Description: + For a partition, the offset of that partition from the start + of the parent (another partition or a flash device) in bytes. + This attribute is absent on flash devices, so it can be used + to distinguish them from partitions. + +What: /sys/class/mtd/mtdX/oobavail +Date: April 2018 +KernelVersion: 4.16 +Contact: linux-mtd@lists.infradead.org +Description: + Number of bytes available for a client to place data into + the out of band area. -- cgit v1.3.1