kernel/linux.git/include/linux/device-mapper.h, branch v3.2.95

dm: fix printk() rate limiting code

2017-11-11T13:34:33+00:00

commit 604407890ecf624c2fb41013c82b22aade59b455 upstream. Using the same rate limiting state for different kinds of messages is wrong because this can cause a high frequency message to suppress a report of a low frequency message. Hence use a unique rate limiting state per message type. Fixes: 71a16736a15e ("dm: use local printk ratelimit") Signed-off-by: Bart Van Assche Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings

dm: convert DM printk macros to pr_ macros

2017-11-11T13:34:33+00:00

commit d2c3c8dcb5987b8352e82089c79a41b6e17e28d2 upstream. Using pr_ is the more common logging style. Standardize style and use new macro DM_FMT. Use no_printk in DMDEBUG macros when CONFIG_DM_DEBUG is not #defined. Signed-off-by: Joe Perches Signed-off-by: Mike Snitzer Signed-off-by: Ben Hutchings

dm snapshot: disallow the COW and origin devices from being identical

2016-04-30T22:05:17+00:00

commit 4df2bf466a9c9c92f40d27c4aa9120f4e8227bfc upstream. Otherwise loading a "snapshot" table using the same device for the origin and COW devices, e.g.: echo "0 20971520 snapshot 253:3 253:3 P 8" | dmsetup create snap will trigger: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 [ 1958.979934] IP: [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1958.989655] PGD 0 [ 1958.991903] Oops: 0000 [#1] SMP ... [ 1959.059647] CPU: 9 PID: 3556 Comm: dmsetup Tainted: G IO 4.5.0-rc5.snitm+ #150 ... [ 1959.083517] task: ffff8800b9660c80 ti: ffff88032a954000 task.ti: ffff88032a954000 [ 1959.091865] RIP: 0010:[] [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.104295] RSP: 0018:ffff88032a957b30 EFLAGS: 00010246 [ 1959.110219] RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000000001 [ 1959.118180] RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff880329334a00 [ 1959.126141] RBP: ffff88032a957b50 R08: 0000000000000000 R09: 0000000000000001 [ 1959.134102] R10: 000000000000000a R11: f000000000000000 R12: ffff880330884d80 [ 1959.142061] R13: 0000000000000008 R14: ffffc90001c13088 R15: ffff880330884d80 [ 1959.150021] FS: 00007f8926ba3840(0000) GS:ffff880333440000(0000) knlGS:0000000000000000 [ 1959.159047] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1959.165456] CR2: 0000000000000098 CR3: 000000032f48b000 CR4: 00000000000006e0 [ 1959.173415] Stack: [ 1959.175656] ffffc90001c13040 ffff880329334a00 ffff880330884ed0 ffff88032a957bdc [ 1959.183946] ffff88032a957bb8 ffffffffa040f225 ffff880329334a30 ffff880300000000 [ 1959.192233] ffffffffa04133e0 ffff880329334b30 0000000830884d58 00000000569c58cf [ 1959.200521] Call Trace: [ 1959.203248] [] dm_exception_store_create+0x1d5/0x240 [dm_snapshot] [ 1959.211986] [] snapshot_ctr+0x140/0x630 [dm_snapshot] [ 1959.219469] [] ? dm_split_args+0x64/0x150 [dm_mod] [ 1959.226656] [] dm_table_add_target+0x177/0x440 [dm_mod] [ 1959.234328] [] table_load+0x143/0x370 [dm_mod] [ 1959.241129] [] ? retrieve_status+0x1b0/0x1b0 [dm_mod] [ 1959.248607] [] ctl_ioctl+0x255/0x4d0 [dm_mod] [ 1959.255307] [] ? memzero_explicit+0x12/0x20 [ 1959.261816] [] dm_ctl_ioctl+0x13/0x20 [dm_mod] [ 1959.268615] [] do_vfs_ioctl+0xa6/0x5c0 [ 1959.274637] [] ? __audit_syscall_entry+0xaf/0x100 [ 1959.281726] [] ? do_audit_syscall_entry+0x66/0x70 [ 1959.288814] [] SyS_ioctl+0x79/0x90 [ 1959.294450] [] entry_SYSCALL_64_fastpath+0x12/0x71 ... [ 1959.323277] RIP [] dm_exception_store_set_chunk_size+0x7a/0x110 [dm_snapshot] [ 1959.333090] RSP [ 1959.336978] CR2: 0000000000000098 [ 1959.344121] ---[ end trace b049991ccad1169e ]--- Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1195899 Signed-off-by: Ding Xiang Signed-off-by: Mike Snitzer [bwh: Backported to 3.2: the device path parsing code is rather different, but move it into dm_get_dev_t() anyway] Signed-off-by: Ben Hutchings

dm: fix truncated status strings

2013-03-20T15:03:20+00:00

commit fd7c092e711ebab55b2688d3859d95dfd0301f73 upstream. Avoid returning a truncated table or status string instead of setting the DM_BUFFER_FULL_FLAG when the last target of a table fills the buffer. When processing a table or status request, the function retrieve_status calls ti->type->status. If ti->type->status returns non-zero, retrieve_status assumes that the buffer overflowed and sets DM_BUFFER_FULL_FLAG. However, targets don't return non-zero values from their status method on overflow. Most targets returns always zero. If a buffer overflow happens in a target that is not the last in the table, it gets noticed during the next iteration of the loop in retrieve_status; but if a buffer overflow happens in the last target, it goes unnoticed and erroneously truncated data is returned. In the current code, the targets behave in the following way: * dm-crypt returns -ENOMEM if there is not enough space to store the key, but it returns 0 on all other overflows. * dm-thin returns errors from the status method if a disk error happened. This is incorrect because retrieve_status doesn't check the error code, it assumes that all non-zero values mean buffer overflow. * all the other targets always return 0. This patch changes the ti->type->status function to return void (because most targets don't use the return code). Overflow is detected in retrieve_status: if the status method fills up the remaining space completely, it is assumed that buffer overflow happened. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon [bwh: Backported to 3.2: - Adjust context - dm_status_fn doesn't take a status_flags parameter - Bump the last component of each current version (verified not to match any version used in mainline) - Drop changes to dm-verity] Signed-off-by: Ben Hutchings

dm table: add immutable feature

2011-10-31T20:19:04+00:00

Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed with any other target type, and once loaded into a device, it cannot be replaced with a table containing a different type. The thin provisioning pool device will use this. Signed-off-by: Alasdair G Kergon

dm table: add always writeable feature

2011-10-31T20:19:02+00:00

Add a target feature flag DM_TARGET_ALWAYS_WRITEABLE to indicate that a target does not support read-only mode. The initial implementation of the thin provisioning target uses this. Signed-off-by: Alasdair G Kergon

dm table: add singleton feature

2011-10-31T20:19:00+00:00

Introduce the concept of a singleton table which contains exactly one target. If a target type sets the DM_TARGET_SINGLETON feature bit device-mapper will ensure that any table that includes that target contains no others. The thin provisioning pool target uses this. Signed-off-by: Alasdair G Kergon

dm: use local printk ratelimit

2011-10-31T20:18:54+00:00

printk_ratelimit() shares global ratelimiting state with all other subsystems, so its usage is discouraged. Instead, define and use dm's local state. Signed-off-by: Namhyung Kim Signed-off-by: Alasdair G Kergon

dm crypt: always disable discard_zeroes_data

2011-09-25T22:26:21+00:00

If optional discard support in dm-crypt is enabled, discards requests bypass the crypt queue and blocks of the underlying device are discarded. For the read path, discarded blocks are handled the same as normal ciphertext blocks, thus decrypted. So if the underlying device announces discarded regions return zeroes, dm-crypt must disable this flag because after decryption there is just random noise instead of zeroes. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon

dm table: share target argument parsing functions

2011-08-02T11:32:04+00:00

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