[PATCHv8 08/13] usb: gadget: mass_storage: optional SCSI WRITE FUA bit

[Michal Nazarewicz]

The nofua parameter (optionally ignore SCSI WRITE FUA) was added
to the File Storage Gadget some time ago.  This patch adds the
same functionality to the Mass Storage Function.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx>
Cc: Andy Shevchenko <ext-andriy.shevchenko@xxxxxxxxx>
---
 drivers/usb/gadget/f_mass_storage.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 32cce02..44e5ffe 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -73,6 +73,8 @@
  *				being removable.
  *	->cdrom		Flag specifying that LUN shall be reported as
  *				being a CD-ROM.
+ *	->nofua		Flag specifying that FUA flag in SCSI WRITE(10,12)
+ *				commands for this LUN shall be ignored.
  *
  *	lun_name_format	A printf-like format for names of the LUN
  *				devices.  This determines how the
@@ -127,6 +129,8 @@
  *			Default true, boolean for removable media.
  *	cdrom=b[,b...]	Default false, boolean for whether to emulate
  *				a CD-ROM drive.
+ *	nofua=b[,b...]	Default false, booleans for ignore FUA flag
+ *				in SCSI WRITE(10,12) commands
  *	luns=N		Default N = number of filenames, number of
  *				LUNs to support.
  *	stall		Default determined according to the type of
@@ -409,6 +413,7 @@ struct fsg_config {
 		char ro;
 		char removable;
 		char cdrom;
+		char nofua;
 	} luns[FSG_MAX_LUNS];
 
 	const char		*lun_name_format;
@@ -887,7 +892,7 @@ static int do_write(struct fsg_common *common)
 			curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 			return -EINVAL;
 		}
-		if (common->cmnd[1] & 0x08) {	/* FUA */
+		if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
 			spin_lock(&curlun->filp->f_lock);
 			curlun->filp->f_flags |= O_SYNC;
 			spin_unlock(&curlun->filp->f_lock);
@@ -2662,6 +2667,7 @@ static int fsg_main_thread(void *common_)
 
 /* Write permission is checked per LUN in store_*() functions. */
 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
+static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua);
 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
 
 
@@ -2768,6 +2774,9 @@ static struct fsg_common *fsg_common_init(struct fsg_common *common,
 		rc = device_create_file(&curlun->dev, &dev_attr_file);
 		if (rc)
 			goto error_luns;
+		rc = device_create_file(&curlun->dev, &dev_attr_nofua);
+		if (rc)
+			goto error_luns;
 
 		if (lcfg->filename) {
 			rc = fsg_lun_open(curlun, lcfg->filename);
@@ -2911,6 +2920,7 @@ static void fsg_common_release(struct kref *ref)
 
 		/* In error recovery common->nluns may be zero. */
 		for (; i; --i, ++lun) {
+			device_remove_file(&lun->dev, &dev_attr_nofua);
 			device_remove_file(&lun->dev, &dev_attr_ro);
 			device_remove_file(&lun->dev, &dev_attr_file);
 			fsg_lun_close(lun);
@@ -3069,8 +3079,10 @@ struct fsg_module_parameters {
 	int		ro[FSG_MAX_LUNS];
 	int		removable[FSG_MAX_LUNS];
 	int		cdrom[FSG_MAX_LUNS];
+	int		nofua[FSG_MAX_LUNS];
 
 	unsigned int	file_count, ro_count, removable_count, cdrom_count;
+	unsigned int	nofua_count;
 	unsigned int	luns;	/* nluns */
 	int		stall;	/* can_stall */
 };
@@ -3096,6 +3108,8 @@ struct fsg_module_parameters {
 				"true to simulate removable media");	\
 	_FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool,		\
 				"true to simulate CD-ROM instead of disk"); \
+	_FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool,		\
+				"true to ignore SCSI WRITE(10,12) FUA bit"); \
 	_FSG_MODULE_PARAM(prefix, params, luns, uint,			\
 			  "number of LUNs");				\
 	_FSG_MODULE_PARAM(prefix, params, stall, bool,			\
-- 
1.7.1

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