user/sven/linux.git/drivers/s390/block/dasd_devmap.c, branch v4.14.151

s390/dasd: blk-mq conversion

2017-09-08T13:31:08Z

Use new blk-mq interfaces. Use multiple queues and also use the block layer complete helper that finish the IO on the CPU that initiated it. Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: Add discard support for FBA devices

2017-08-29T14:31:26Z

The z/VM hypervisor provides virtual disks (VDISK) which are backed by main memory of the hypervisor. Those devices are seen as DASD FBA disks within the Linux guest. Whenever data is written to such a device, memory is allocated on-the-fly by z/VM accordingly. This memory, however, is not being freed if data on the device is deleted by the guest OS. In order to make memory usable after deletion again, add discard support to the FBA discipline. While at it, update comments regarding the DASD_FEATURE_* flags. Reviewed-by: Stefan Haberland Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky

s390/dasd: constify attribute_group structures.

2017-07-26T06:25:17Z

attribute_group are not supposed to change at runtime. All functions working with attribute_group provided by work with const attribute_group. So mark the non-const structs as const. Signed-off-by: Arvind Yadav Signed-off-by: Martin Schwidefsky

s390/dasd: remove unneeded code

2017-07-05T05:35:29Z

Fix these set but not used warnings: drivers/s390/block/dasd.c:3933:6: warning: variable 'rc' set but not used [-Wunused-but-set-variable] drivers/s390/block/dasd_alias.c:757:6: warning: variable 'rc' set but not used [-Wunused-but-set-variable] In addition to that remove the test if an unsigned is < 0: drivers/s390/block/dasd_devmap.c:153:11: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky

s390/dasd: Fix faulty ENODEV for RO sysfs attribute

2017-06-28T05:32:15Z

If a device is offline it can still be set to read-only via the bus id through sysfs. Only the read-only feature flag for the ccw_device is then set. If the device is online the corresponding block device needs to be set to read-only as well (via set_disk_ro()). The check whether there is a device to do so, however, happens after the feature flag was set. This leads to an unnecessary "no such device" error in the offline case. This bug was introduced by commit 7571cb1c8e3cc ("s390/dasd: Make use of dasd_set_feature() more often"). Fix this by simply returning count if no device is available. Fixes: 7571cb1c8e3cc ("s390/dasd: Make use of dasd_set_feature() more often") Reviewed-by: Stefan Haberland Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky

s390/dasd: fix unusable device after safe offline processing

2017-06-12T14:26:01Z

The safe offline processing needs, as well as the normal offline processing, to be locked against multiple parallel executions. But it should be able to be overtaken by a normal offline processing to make sure that the device does not wait forever for outstanding I/O if the user wants to. Unfortunately the parallel processing of safe offline and normal offline might lead to a race situation where both threads report successful execution to the CIO layer which in turn tries to deregister the kobject of the device twice. This leads to a refcount_t: underflow; use-after-free. error and the device is not able to be set online again afterwards without a reboot. Correct the locking of the safe offline processing by doing the following: - Use the cdev lock to secure all set and test operations to the device flags. - Two safe offline processes are locked against each other using the DASD_FLAG_SAFE_OFFLINE and DASD_FLAG_SAFE_OFFLINE_RUNNING device flags. The differentiation between offline triggered and offline running is needed since the normal offline attribute is owned by CIO and we have to pass over control in between. - The dasd_generic_set_offline process handles the offline processing. It is locked against parallel execution using the DASD_FLAG_OFFLINE. - Only a running safe offline should be able to be overtaken by a single normal offline. This is ensured by clearing the DASD_FLAG_SAFE_OFFLINE_RUNNING flag when a normal offline overtakes. So this can only happen ones. - The safe offline just aborts in this case doing nothing and the normal offline processing finishes as usual. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: Display read-only attribute correctly

2017-06-12T14:26:00Z

We have two flags, DASD_FLAG_DEVICE_RO and DASD_FEATURE_READONLY, that tell us whether a device is read-only. DASD_FLAG_DEVICE_RO is set when a device is attached as read-only to z/VM and DASD_FEATURE_READONLY is set when either the corresponding kernel parameter is configured, or the read-only state is changed via sysfs. This is valuable information in any case. However, only the feature flag is being checked at the moment when we display the current state. Fix this by checking both flags. Reviewed-by: Stefan Haberland Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky

s390/dasd: Remove variable sized array

2017-06-12T14:25:56Z

Dynamic stack allocations are considered bad. Get rid of this one occurrence and use kstrdup() instead. Also, set the return codes so that we have only one exit where we can call kfree(). Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky

s390/dasd: allow 0 for path_threshold attribute

2017-01-31T09:47:08Z

Allow 0 as valid input for the path_threshold attribute to deactivate the IFCC/CCC error handling. Signed-off-by: Stefan Haberland Signed-off-by: Martin Schwidefsky

s390/dasd: Improve parameter list parsing

2017-01-31T09:46:32Z

The function dasd_busid() still uses simple_strtoul() to convert a string to an integer value. This function is obsolete for quite some time already and should be replaced. The whole parameter parsing semantic still relies somewhat on the fact, that simple_strtoul() parses a string containing literals without complains and just returns the parsed integer value plus the residual string. kstrtoint(), however, would return -EINVAL in such a case. Since we want to get rid of simple_strtoul() and now have a nice dasd[] containing only single elements, we can clean up and simplify a few things. Replace simple_strtoul() with kstrtouint(), improve and simplify the overall parameter parsing by the following: - instead of residual strings return proper error codes - remove dasd_parse_next_element() and decide directly what sort of element is being parsed - if we parse a device or a range of devices, split that element into separate bits with a new function - remove warning about invalid ending as it doesn't apply anymore - annotate all parsing functions and data that can be freed after initialisation with __init and __initdata respectively - clean up bits and pieces while at it Reviewed-by: Stefan Haberland Reviewed-by: Sebastian Ott Signed-off-by: Jan Höppner Signed-off-by: Martin Schwidefsky