From a6e50b409d3f9e0833e69c3c9cca822e8fa4adbb Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 2 Aug 2011 12:32:04 +0100 Subject: dm snapshot: skip reading origin when overwriting complete chunk If we write a full chunk in the snapshot, skip reading the origin device because the whole chunk will be overwritten anyway. This patch changes the snapshot write logic when a full chunk is written. In this case: 1. allocate the exception 2. dispatch the bio (but don't report the bio completion to device mapper) 3. write the exception record 4. report bio completed Callbacks must be done through the kcopyd thread, because callbacks must not race with each other. So we create two new functions: dm_kcopyd_prepare_callback: allocate a job structure and prepare the callback. (This function must not be called from interrupt context.) dm_kcopyd_do_callback: submit callback. (This function may be called from interrupt context.) Performance test (on snapshots with 4k chunk size): without the patch: non-direct-io sequential write (dd): 17.7MB/s direct-io sequential write (dd): 20.9MB/s non-direct-io random write (mkfs.ext2): 0.44s with the patch: non-direct-io sequential write (dd): 26.5MB/s direct-io sequential write (dd): 33.2MB/s non-direct-io random write (mkfs.ext2): 0.27s Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- include/linux/dm-kcopyd.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h index 298d587e349b..5e54458e920f 100644 --- a/include/linux/dm-kcopyd.h +++ b/include/linux/dm-kcopyd.h @@ -42,5 +42,20 @@ int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, unsigned num_dests, struct dm_io_region *dests, unsigned flags, dm_kcopyd_notify_fn fn, void *context); +/* + * Prepare a callback and submit it via the kcopyd thread. + * + * dm_kcopyd_prepare_callback allocates a callback structure and returns it. + * It must not be called from interrupt context. + * The returned value should be passed into dm_kcopyd_do_callback. + * + * dm_kcopyd_do_callback submits the callback. + * It may be called from interrupt context. + * The callback is issued from the kcopyd thread. + */ +void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, + dm_kcopyd_notify_fn fn, void *context); +void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err); + #endif /* __KERNEL__ */ #endif /* _LINUX_DM_KCOPYD_H */ -- cgit v1.2.3 From 498f0103ea13123e007660def9072a0b7dd1c599 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 2 Aug 2011 12:32:04 +0100 Subject: dm table: share target argument parsing functions Move multipath target argument parsing code into dm-table so other targets can share it. Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- include/linux/device-mapper.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'include/linux') diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 4427e0454051..3fa1f3d90ce0 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -208,6 +208,49 @@ struct dm_target_callbacks { int dm_register_target(struct target_type *t); void dm_unregister_target(struct target_type *t); +/* + * Target argument parsing. + */ +struct dm_arg_set { + unsigned argc; + char **argv; +}; + +/* + * The minimum and maximum value of a numeric argument, together with + * the error message to use if the number is found to be outside that range. + */ +struct dm_arg { + unsigned min; + unsigned max; + char *error; +}; + +/* + * Validate the next argument, either returning it as *value or, if invalid, + * returning -EINVAL and setting *error. + */ +int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set, + unsigned *value, char **error); + +/* + * Process the next argument as the start of a group containing between + * arg->min and arg->max further arguments. Either return the size as + * *num_args or, if invalid, return -EINVAL and set *error. + */ +int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set, + unsigned *num_args, char **error); + +/* + * Return the current argument and shift to the next. + */ +const char *dm_shift_arg(struct dm_arg_set *as); + +/* + * Move through num_args arguments. + */ +void dm_consume_args(struct dm_arg_set *as, unsigned num_args); + /*----------------------------------------------------------------- * Functions for creating and manipulating mapped devices. * Drop the reference with dm_put when you finish with the object. -- cgit v1.2.3 From 0ddf9644cc26e74ed671525e61a17bdbebf18da6 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 2 Aug 2011 12:32:06 +0100 Subject: dm ioctl: fill in device parameters in more ioctls Move parameter filling from find_device to __find_device_hash_cell. This patch causes ioctls using __find_device_hash_cell (DM_DEV_REMOVE_CMD, DM_DEV_SUSPEND_CMD - resume, DM_TABLE_CLEAR_CMD) to return device parameters, bringing them into line with the other ioctls. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- include/linux/dm-ioctl.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h index 3708455ee6c3..0cb8eff76bd6 100644 --- a/include/linux/dm-ioctl.h +++ b/include/linux/dm-ioctl.h @@ -267,9 +267,9 @@ enum { #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 20 +#define DM_VERSION_MINOR 21 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2011-02-02)" +#define DM_VERSION_EXTRA "-ioctl (2011-07-06)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */ -- cgit v1.2.3