Hi,
I have one slow flash block device, which act as usb-mass storage
device, and during the data transfer with windows PC, it will get
ALLOW_MEDIUM_REMOVAL , and sync the file system cache, however, it
takes too much time (by log about 10s) and the usb reset occurs.
however, if the /proc/sys/vm_dirty_ratio changed from 20 to 0 or 4,
everything is ok.
I made some code change to defer the file cache flash for your
review, currently the do_verify() and do_synchronize_cache() not
touched.
diff --git a/drivers/usb/gadget/f_mass_storage.c
b/drivers/usb/gadget/f_mass_storage.c
index b02ff32..7ddcc5c 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -1491,6 +1491,14 @@ static int do_start_stop(struct fsg_common *common)
: 0;
}
+void fsg_lun_fsync_deferred_func(struct work_struct *work)
+{
+ struct fsg_lun *curlun =
+ container_of(work, struct fsg_lun, fsync_deferred_work);
+
+ fsg_lun_fsync_sub(curlun);
+}
+
static int do_prevent_allow(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
@@ -1510,7 +1518,7 @@ static int do_prevent_allow(struct fsg_common *common)
}
if (curlun->prevent_medium_removal && !prevent)
- fsg_lun_fsync_sub(curlun);
+ schedule_work(&curlun->fsync_deferred_work);
curlun->prevent_medium_removal = prevent;
return 0;
}
@@ -2835,6 +2843,8 @@ static struct fsg_common *fsg_common_init(struct
fsg_common *common,
? cfg->lun_name_format
: "lun%d",
i);
+ INIT_WORK(&curlun->fsync_deferred_work,
+ fsg_lun_fsync_deferred_func);
rc = device_register(&curlun->dev);
if (rc) {
diff --git a/drivers/usb/gadget/file_storage.c
b/drivers/usb/gadget/file_storage.c
index 0333cc5..c7266c0 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1853,6 +1853,13 @@ static int do_start_stop(struct fsg_dev *fsg)
return 0;
}
+void fsg_lun_fsync_deferred_func(struct work_struct *work)
+{
+ struct fsg_lun *curlun =
+ container_of(work, struct fsg_lun, fsync_deferred_work);
+
+ fsg_lun_fsync_sub(curlun);
+}
static int do_prevent_allow(struct fsg_dev *fsg)
{
@@ -1871,7 +1878,7 @@ static int do_prevent_allow(struct fsg_dev *fsg)
}
if (curlun->prevent_medium_removal && !prevent)
- fsg_lun_fsync_sub(curlun);
+ schedule_work(&curlun->fsync_deferred_work);
curlun->prevent_medium_removal = prevent;
return 0;
}
@@ -3420,6 +3427,8 @@ static int __init fsg_bind(struct usb_gadget *gadget)
dev_set_drvdata(&curlun->dev, &fsg->filesem);
dev_set_name(&curlun->dev,"%s-lun%d",
dev_name(&gadget->dev), i);
+ INIT_WORK(&curlun->fsync_deferred_work,
+ fsg_lun_fsync_deferred_func);
kref_get(&fsg->ref);
rc = device_register(&curlun->dev);
diff --git a/drivers/usb/gadget/storage_common.c
b/drivers/usb/gadget/storage_common.c
index 840a4be..16bcb3d 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -250,6 +250,7 @@ struct fsg_lun {
unsigned int blkbits; /* Bits of logical block size */
unsigned int blksize; /* logic block size of backing device */
struct device dev;
+ struct work_struct fsync_deferred_work;
};
#define fsg_lun_is_open(curlun) ((curlun)->filp != NULL)
thanks
Yuping Luo
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