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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-16 07:55:07 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-16 07:55:07 -0700 |
commit | 5c64e3a45d43c6e3fa87cbe02e10059171d10812 (patch) | |
tree | 4b913307a3f9785aebf6c9271f26ec79ab5db625 /include/linux/kref.h | |
parent | c240a539df4e2d50f86e2f31813ff6b7334cd493 (diff) | |
parent | ccf5ae83a6cf3d9cfe9a7038bfe7cd38ab03d5e1 (diff) | |
download | linux-5c64e3a45d43c6e3fa87cbe02e10059171d10812.tar.gz linux-5c64e3a45d43c6e3fa87cbe02e10059171d10812.tar.bz2 linux-5c64e3a45d43c6e3fa87cbe02e10059171d10812.zip |
Merge branch 'queue' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull target fixes from Nicholas Bellinger:
"A handful of fixes + minor changes this time around, along with one
important >= v3.9 regression fix for IBLOCK backends. The highlights
include:
- Use FD_MAX_SECTORS in FILEIO for block_device as
well as files (agrover)
- Fix processing of out-of-order CmdSNs with
iSBD driver (shlomo)
- Close long-standing target_put_sess_cmd() vs.
core_tmr_abort_task() race with the addition of
kref_put_spinlock_irqsave() (joern + greg-kh)
- Fix IBLOCK WCE=1 + DPOFUA=1 backend WRITE
regression in >= v3.9 (nab + bootc)
Note these four patches are CC'ed to stable.
Also, there is still some work left to be done on the active I/O
shutdown path in target_wait_for_sess_cmds() used by tcm_qla2xxx +
ib_isert fabrics that is still being discussed on the list, and will
hopefully be resolved soon."
* 'queue' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
target: close target_put_sess_cmd() vs. core_tmr_abort_task() race
target: removed unused transport_state flag
target/iblock: Fix WCE=1 + DPOFUA=1 backend WRITE regression
MAINTAINERS: Update target git tree URL
iscsi-target: Fix typos in RDMAEXTENSIONS macro usage
target/rd: Add ramdisk bit for NULLIO operation
iscsi-target: Fix processing of OOO commands
iscsi-target: Make buf param of iscsit_do_crypto_hash_buf() const void *
iscsi-target: Fix NULL pointer dereference in iscsit_send_reject
target: Have dev/enable show if TCM device is configured
target: Use FD_MAX_SECTORS/FD_BLOCKSIZE for blockdevs using fileio
target: Remove unused struct members in se_dev_entry
Diffstat (limited to 'include/linux/kref.h')
-rw-r--r-- | include/linux/kref.h | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h index e15828fd71f1..484604d184be 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <linux/kernel.h> #include <linux/mutex.h> +#include <linux/spinlock.h> struct kref { atomic_t refcount; @@ -98,6 +99,38 @@ static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref) return kref_sub(kref, 1, release); } +/** + * kref_put_spinlock_irqsave - decrement refcount for object. + * @kref: object. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. + * @lock: lock to take in release case + * + * Behaves identical to kref_put with one exception. If the reference count + * drops to zero, the lock will be taken atomically wrt dropping the reference + * count. The release function has to call spin_unlock() without _irqrestore. + */ +static inline int kref_put_spinlock_irqsave(struct kref *kref, + void (*release)(struct kref *kref), + spinlock_t *lock) +{ + unsigned long flags; + + WARN_ON(release == NULL); + if (atomic_add_unless(&kref->refcount, -1, 1)) + return 0; + spin_lock_irqsave(lock, flags); + if (atomic_dec_and_test(&kref->refcount)) { + release(kref); + local_irq_restore(flags); + return 1; + } + spin_unlock_irqrestore(lock, flags); + return 0; +} + static inline int kref_put_mutex(struct kref *kref, void (*release)(struct kref *kref), struct mutex *lock) |