evie/android_kernel_oneplus_msm8998
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[SCSI] st: remove st_mutex

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The st_mutex was created when the BKL was removed, and
prevents simultaneous st_open calls. It is better to
protect just the necessary data.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Acked-by: Kai Mäkisara <Kai.Makisara@kolumbus.fi>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Hannes Reinecke 2012-09-10 15:36:44 -07:00 • committed by James Bottomley
parent fe542396da
commit 0644f5393e
1 changed files with 2 additions and 6 deletions
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8
drivers/scsi/st.c
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@ -75,7 +75,6 @@ static const char *verstr = "20101219";
#include "st_options.h" #include "st_options.h"
#include "st.h" #include "st.h"
static DEFINE_MUTEX(st_mutex);
static int buffer_kbs; static int buffer_kbs;
static int max_sg_segs; static int max_sg_segs;
static int try_direct_io = TRY_DIRECT_IO; static int try_direct_io = TRY_DIRECT_IO;
@ -1185,7 +1184,6 @@ static int st_open(struct inode *inode, struct file *filp)
int dev = TAPE_NR(inode); int dev = TAPE_NR(inode);
char *name; char *name;
mutex_lock(&st_mutex);
/* /*
* We really want to do nonseekable_open(inode, filp); here, but some * We really want to do nonseekable_open(inode, filp); here, but some
* versions of tar incorrectly call lseek on tapes and bail out if that * versions of tar incorrectly call lseek on tapes and bail out if that
@ -1194,7 +1192,6 @@ static int st_open(struct inode *inode, struct file *filp)
filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
if (!(STp = scsi_tape_get(dev))) { if (!(STp = scsi_tape_get(dev))) {
mutex_unlock(&st_mutex);
return -ENXIO; return -ENXIO;
} }
@ -1205,7 +1202,6 @@ static int st_open(struct inode *inode, struct file *filp)
if (STp->in_use) { if (STp->in_use) {
spin_unlock(&st_use_lock); spin_unlock(&st_use_lock);
scsi_tape_put(STp); scsi_tape_put(STp);
mutex_unlock(&st_mutex);
DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); ) DEB( printk(ST_DEB_MSG "%s: Device already in use.\n", name); )
return (-EBUSY); return (-EBUSY);
} }
@ -1259,16 +1255,16 @@ static int st_open(struct inode *inode, struct file *filp)
retval = (-EIO); retval = (-EIO);
goto err_out; goto err_out;
} }
mutex_unlock(&st_mutex);
return 0; return 0;
err_out: err_out:
normalize_buffer(STp->buffer); normalize_buffer(STp->buffer);
spin_lock(&st_use_lock);
STp->in_use = 0; STp->in_use = 0;
spin_unlock(&st_use_lock);
scsi_tape_put(STp); scsi_tape_put(STp);
if (resumed) if (resumed)
scsi_autopm_put_device(STp->device); scsi_autopm_put_device(STp->device);
mutex_unlock(&st_mutex);
return retval; return retval;
} }