diff options
| author | Steffen Maier <maier@linux.vnet.ibm.com> | 2012-09-04 15:23:34 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-13 05:28:09 +0900 |
| commit | 9745d6cb3feb21fd6d9098317a92f2f5c1371519 (patch) | |
| tree | d32af462dddf8779f055d4e7d7b47c32f4742f12 /drivers/s390/scsi/zfcp_sysfs.c | |
| parent | 2e54c4fb47ffcc687457f9bcd9bba895f2a84963 (diff) | |
| download | kernel_samsung_smdk4412-9745d6cb3feb21fd6d9098317a92f2f5c1371519.zip kernel_samsung_smdk4412-9745d6cb3feb21fd6d9098317a92f2f5c1371519.tar.gz kernel_samsung_smdk4412-9745d6cb3feb21fd6d9098317a92f2f5c1371519.tar.bz2 | |
SCSI: zfcp: restore refcount check on port_remove
commit d99b601b63386f3395dc26a699ae703a273d9982 upstream.
Upstream commit f3450c7b917201bb49d67032e9f60d5125675d6a
"[SCSI] zfcp: Replace local reference counting with common kref"
accidentally dropped a reference count check before tearing down
zfcp_ports that are potentially in use by zfcp_units.
Even remote ports in use can be removed causing
unreachable garbage objects zfcp_ports with zfcp_units.
Thus units won't come back even after a manual port_rescan.
The kref of zfcp_port->dev.kobj is already used by the driver core.
We cannot re-use it to track the number of zfcp_units.
Re-introduce our own counter for units per port
and check on port_remove.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390/scsi/zfcp_sysfs.c')
| -rw-r--r-- | drivers/s390/scsi/zfcp_sysfs.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c index cdc4ff7..9e62210 100644 --- a/drivers/s390/scsi/zfcp_sysfs.c +++ b/drivers/s390/scsi/zfcp_sysfs.c @@ -227,6 +227,8 @@ static ssize_t zfcp_sysfs_port_rescan_store(struct device *dev, static ZFCP_DEV_ATTR(adapter, port_rescan, S_IWUSR, NULL, zfcp_sysfs_port_rescan_store); +DEFINE_MUTEX(zfcp_sysfs_port_units_mutex); + static ssize_t zfcp_sysfs_port_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) @@ -249,6 +251,16 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev, else retval = 0; + mutex_lock(&zfcp_sysfs_port_units_mutex); + if (atomic_read(&port->units) > 0) { + retval = -EBUSY; + mutex_unlock(&zfcp_sysfs_port_units_mutex); + goto out; + } + /* port is about to be removed, so no more unit_add */ + atomic_set(&port->units, -1); + mutex_unlock(&zfcp_sysfs_port_units_mutex); + write_lock_irq(&adapter->port_list_lock); list_del(&port->list); write_unlock_irq(&adapter->port_list_lock); @@ -289,12 +301,14 @@ static ssize_t zfcp_sysfs_unit_add_store(struct device *dev, { struct zfcp_port *port = container_of(dev, struct zfcp_port, dev); u64 fcp_lun; + int retval; if (strict_strtoull(buf, 0, (unsigned long long *) &fcp_lun)) return -EINVAL; - if (zfcp_unit_add(port, fcp_lun)) - return -EINVAL; + retval = zfcp_unit_add(port, fcp_lun); + if (retval) + return retval; return count; } |