[PATCH RFC] enclosure: fix symlinks creation

[Maurizio Lombardi <mlombard@redhat.com>]

James,

one of our customers complains that in some cases, when using multipath,
the enclosure driver fails to create the symlinks in sysfs.

This is an example of what happens:

[   19.251902] scsi 0:0:27:0: Direct-Access     SEAGATE  ST8000NM0075     E002 PQ: 0 ANSI: 6
[   19.261874] scsi 0:0:27:0: SSP: handle(0x0027), sas_addr(0x5000c50085826dd6), phy(34), device_name(0x5000c50085826dd4)
[   19.274656] scsi 0:0:27:0: SSP: enclosure_logical_id(0x500093d001be4000), slot(57)
[   19.283944] scsi 0:0:27:0: SSP: enclosure level(0x0000), connector name(     )
[   19.292933] scsi 0:0:27:0: qdepth(254), tagged(1), simple(0), ordered(0), scsi_l
[...]
[   60.066524] enclosure_add_device(0:0:27:0) called, enclosure_add_links() failed with error -2
[...]
[   75.119146] sd 0:0:27:0: Attached scsi generic sg27 type 0
[   75.126722] sd 0:0:27:0: [sdaa] 15628053168 512-byte logical blocks: (8.00 TB/7.27 TiB)
[   75.126723] sd 0:0:27:0: [sdaa] 4096-byte physical blocks
[   75.129059] sd 0:0:27:0: [sdaa] Write Protect is off
[   75.129061] sd 0:0:27:0: [sdaa] Mode Sense: db 00 10 08
[   75.130417] sd 0:0:27:0: [sdaa] Write cache: enabled, read cache: enabled, supports DPO and FUA
[   75.158088] sd 0:0:27:0: [sdaa] Attached SCSI disk
[...]
[   75.192722] enclosure_add_device(0:0:27:0) called, device already exists

The first time enclosure_add_device() is called, the symlinks creation failed.
The second time it would have succeeded, but the enclosure_add_device() function returned immediately
without retrying to create the symlinks.

Maurizio Lombardi (1):
  enclosure: fix sysfs symlinks creation when using multipath

 drivers/misc/enclosure.c  | 16 ++++++++++++++--
 include/linux/enclosure.h |  1 +
 2 files changed, 15 insertions(+), 2 deletions(-)

-- 
Maurizio Lombardi