Revision bce0b6c51ac76fc0e763262a6c2a9d05e486f0d8 authored by Steven Rostedt (Red Hat) on 21 August 2014, 03:57:04 UTC, committed by Steven Rostedt on 22 August 2014, 19:24:12 UTC
Now that a ftrace_hash can be shared by multiple ftrace_ops, they can dec the rec->flags by more than once (one per those that share the ftrace_hash). This means that the tramp_hash may not have a hash item when it was added. For example, if two ftrace_ops share a hash for a ftrace record, and the first ops has a trampoline, when it adds itself it will set the rec->flags TRAMP flag and increments its nr_trampolines counter. When the second ops is added, it must clear that tramp flag but also decrement the other ops that shares its hash. As the update to the function callbacks has not yet been performed, the other ops will not have the tramp hash set yet and it can not be used to know to decrement its nr_trampolines. Luckily, the tramp_hash does not need to be used. As the ftrace_mutex is held, a ops with a trampoline to a record during an update of another ops that shares the record will have its func_hash pointing to it. Since a trampoline can only be set for a record if only one ops is attached to it, we can just check if the record has a trampoline (the FTRACE_FL_TRAMP flag is set) and then find the ops that has this record in its hashes. Also added some output to help debug when things go wrong. Cc: stable@vger.kernel.org # 3.16+ (apply after 3.17-rc4 is out) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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scsi_devinfo.h
#ifndef _SCSI_SCSI_DEVINFO_H
#define _SCSI_SCSI_DEVINFO_H
/*
* Flags for SCSI devices that need special treatment
*/
#define BLIST_NOLUN 0x001 /* Only scan LUN 0 */
#define BLIST_FORCELUN 0x002 /* Known to have LUNs, force scanning,
deprecated: Use max_luns=N */
#define BLIST_BORKEN 0x004 /* Flag for broken handshaking */
#define BLIST_KEY 0x008 /* unlock by special command */
#define BLIST_SINGLELUN 0x010 /* Do not use LUNs in parallel */
#define BLIST_NOTQ 0x020 /* Buggy Tagged Command Queuing */
#define BLIST_SPARSELUN 0x040 /* Non consecutive LUN numbering */
#define BLIST_MAX5LUN 0x080 /* Avoid LUNS >= 5 */
#define BLIST_ISROM 0x100 /* Treat as (removable) CD-ROM */
#define BLIST_LARGELUN 0x200 /* LUNs past 7 on a SCSI-2 device */
#define BLIST_INQUIRY_36 0x400 /* override additional length field */
#define BLIST_INQUIRY_58 0x800 /* ... for broken inquiry responses */
#define BLIST_NOSTARTONADD 0x1000 /* do not do automatic start on add */
#define BLIST_MS_SKIP_PAGE_08 0x2000 /* do not send ms page 0x08 */
#define BLIST_MS_SKIP_PAGE_3F 0x4000 /* do not send ms page 0x3f */
#define BLIST_USE_10_BYTE_MS 0x8000 /* use 10 byte ms before 6 byte ms */
#define BLIST_MS_192_BYTES_FOR_3F 0x10000 /* 192 byte ms page 0x3f request */
#define BLIST_REPORTLUN2 0x20000 /* try REPORT_LUNS even for SCSI-2 devs
(if HBA supports more than 8 LUNs) */
#define BLIST_NOREPORTLUN 0x40000 /* don't try REPORT_LUNS scan (SCSI-3 devs) */
#define BLIST_NOT_LOCKABLE 0x80000 /* don't use PREVENT-ALLOW commands */
#define BLIST_NO_ULD_ATTACH 0x100000 /* device is actually for RAID config */
#define BLIST_SELECT_NO_ATN 0x200000 /* select without ATN */
#define BLIST_RETRY_HWERROR 0x400000 /* retry HARDWARE_ERROR */
#define BLIST_MAX_512 0x800000 /* maximum 512 sector cdb length */
#define BLIST_ATTACH_PQ3 0x1000000 /* Scan: Attach to PQ3 devices */
#define BLIST_NO_DIF 0x2000000 /* Disable T10 PI (DIF) */
#define BLIST_SKIP_VPD_PAGES 0x4000000 /* Ignore SBC-3 VPD pages */
#define BLIST_SCSI3LUN 0x8000000 /* Scan more than 256 LUNs
for sequential scan */
#define BLIST_TRY_VPD_PAGES 0x10000000 /* Attempt to read VPD pages */
#define BLIST_NO_RSOC 0x20000000 /* don't try to issue RSOC */
#endif
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