user/sven/linux.git/Documentation/blockdev, branch leds/master

zram: add dynamic device add/remove functionality

2015-06-26T00:00:36Z

We currently don't support on-demand device creation. The one and only way to have N zram devices is to specify num_devices module parameter (default value: 1). IOW if, for some reason, at some point, user wants to have N + 1 devies he/she must umount all the existing devices, unload the module, load the module passing num_devices equals to N + 1. And do this again, if needed. This patch introduces zram control sysfs class, which has two sysfs attrs: - hot_add -- add a new zram device - hot_remove -- remove a specific (device_id) zram device hot_add sysfs attr is read-only and has only automatic device id assignment mode (as requested by Minchan Kim). read operation performed on this attr creates a new zram device and returns back its device_id or error status. Usage example: # add a new specific zram device cat /sys/class/zram-control/hot_add 2 # remove a specific zram device echo 4 > /sys/class/zram-control/hot_remove Returning zram_add() error code back to user (-ENOMEM in this case) cat /sys/class/zram-control/hot_add cat: /sys/class/zram-control/hot_add: Cannot allocate memory NOTE, there might be users who already depend on the fact that at least zram0 device gets always created by zram_init(). Preserve this behavior. [minchan@kernel.org: use zram->claim to avoid lockdep splat] Signed-off-by: Sergey Senozhatsky Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: remove max_num_devices limitation

2015-06-26T00:00:36Z

Limiting the number of zram devices to 32 (default max_num_devices value) is confusing, let's drop it. A user with 2TB or 4TB of RAM, for example, can request as many devices as he can handle. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: add `compact` sysfs entry to documentation

2015-06-26T00:00:36Z

We currently don't support zram on-demand device creation. The only way to have N zram devices is to specify num_devices module parameter (default value 1). That means that if, for some reason, at some point, user wants to have N + 1 devies he/she must umount all the existing devices, unload the module, load the module passing num_devices equals to N + 1. This patchset introduces zram-control sysfs class, which has two sysfs attrs: - hot_add -- add a new zram device - hot_remove -- remove a specific (device_id) zram device Usage example: # add a new specific zram device cat /sys/class/zram-control/hot_add 1 # remove a specific zram device echo 4 > /sys/class/zram-control/hot_remove This patch (of 10): Briefly describe missing `compact` sysfs entry. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-4.1/drivers' of git://git.kernel.dk/linux-block

2015-04-17T02:05:27Z

Pull block driver updates from Jens Axboe: "This is the block driver pull request for 4.1. As with the core bits, this is a relatively slow round. This pull request contains: - Various fixes and cleanups for NVMe, from Alexey Khoroshilov, Chong Yuan, myself, Keith Busch, and Murali Iyer. - Documentation and code cleanups for nbd from Markus Pargmann. - Change of brd maintainer to me, from Ross Zwisler. At least the email doesn't bounce anymore then. - Two xen-blkback fixes from Tao Chen" * 'for-4.1/drivers' of git://git.kernel.dk/linux-block: (23 commits) NVMe: Meta data handling through submit io ioctl NVMe: Add translation for block limits NVMe: Remove check for null NVMe: Fix error handling of class_create("nvme") xen-blkback: define pr_fmt macro to avoid the duplication of DRV_PFX xen-blkback: enlarge the array size of blkback name nbd: Return error pointer directly nbd: Return error code directly nbd: Remove fixme that was already fixed nbd: Restructure debugging prints nbd: Fix device bytesize type nbd: Replace kthread_create with kthread_run nbd: Remove kernel internal header Documentation: nbd: Add list of module parameters Documentation: nbd: Reformat to allow more documentation NVMe: increase depth of admin queue nvme: Fix PRP list calculation for non-4k system page size NVMe: Fix blk-mq hot cpu notification NVMe: embedded iod mask cleanup NVMe: Freeze admin queue on device failure ...

zram: deprecate zram attrs sysfs nodes

2015-04-15T23:35:21Z

Add Documentation/ABI/obsolete/sysfs-block-zram file and list obsolete and deprecated attributes there. The patch also adds additional information to zram documentation and describes the basic strategy: - the existing RW nodes will be downgraded to WO nodes (in 4.11) - deprecated RO sysfs nodes will eventually be removed (in 4.11) Users will be additionally notified about deprecated attr usage by pr_warn_once() (added to every deprecated attr _show()), as suggested by Minchan Kim. User space is advised to use zram/stat, zram/io_stat and zram/mm_stat files. Signed-off-by: Sergey Senozhatsky Reported-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: export new 'mm_stat' sysfs attrs

2015-04-15T23:35:21Z

Per-device `zram/mm_stat' file provides mm statistics of a particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): orig_data_size compr_data_size mem_used_total mem_limit mem_used_max zero_pages num_migrated Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: export new 'io_stat' sysfs attrs

2015-04-15T23:35:21Z

Per-device `zram/io_stat' file provides accumulated I/O statistics of particular zram device in a format similar to block layer statistics. The file consists of a single line and represents the following stats (separated by whitespace): failed_reads failed_writes invalid_io notify_free Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

zram: describe device attrs in documentation

2015-04-15T23:35:21Z

Briefly describe exported device stat attrs in zram documentation. We will eventually get rid of per-stat sysfs nodes and, thus, clean up Documentation/ABI/testing/sysfs-block-zram file, which is the only source of information about device sysfs nodes. Add `num_migrated' description, since there is no independent `num_migrated' sysfs node (and no corresponding sysfs-block-zram entry), it will be exported via zram/mm_stat file. At this point we can provide minimal description, because sysfs-block-zram still contains detailed information. Signed-off-by: Sergey Senozhatsky Acked-by: Minchan Kim Cc: Nitin Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation: nbd: Add list of module parameters

2015-04-02T18:39:15Z

Add a list of available module parameters as attachment to the documentation. Signed-off-by: Markus Pargmann Signed-off-by: Jens Axboe

Documentation: nbd: Reformat to allow more documentation

2015-04-02T18:39:13Z

Reformat the existing documentation to have more structure. This allows for more documentation seperated from the existing paragraphs. Signed-off-by: Markus Pargmann Signed-off-by: Jens Axboe