Felipe:
Here is a patch that does what $SUBJECT says, together with removing
the unwanted usages of the short_not_ok flag. It also removes some
questionable optimizations that involved aligning VFS I/O requests with
the page size. It does nothing to address the issue of bulk-OUT
requests not being an even multiple of the maxpacket size.
Like yours, this patch is completely untested.
Alan Stern
drivers/usb/gadget/file_storage.c | 71 +++++++++++++-------------------------
1 file changed, 25 insertions(+), 46 deletions(-)
Index: usb-2.6/drivers/usb/gadget/file_storage.c
===================================================================
--- usb-2.6.orig/drivers/usb/gadget/file_storage.c
+++ usb-2.6/drivers/usb/gadget/file_storage.c
@@ -436,7 +436,6 @@ struct fsg_dev {
int intreq_busy;
struct fsg_buffhd *intr_buffhd;
- unsigned int bulk_out_maxpacket;
enum fsg_state state; // For exception handling
unsigned int exception_req_tag;
@@ -1116,7 +1115,6 @@ static int do_read(struct fsg_dev *fsg)
u32 amount_left;
loff_t file_offset, file_offset_tmp;
unsigned int amount;
- unsigned int partial_page;
ssize_t nread;
/* Get the starting Logical Block Address and check that it's
@@ -1151,17 +1149,10 @@ static int do_read(struct fsg_dev *fsg)
* Try to read the remaining amount.
* But don't read more than the buffer size.
* And don't try to read past the end of the file.
- * Finally, if we're not at a page boundary, don't read past
- * the next page.
- * If this means reading 0 then we were asked to read past
- * the end of file. */
+ */
amount = min((unsigned int) amount_left, mod_data.buflen);
amount = min((loff_t) amount,
curlun->file_length - file_offset);
- partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
- if (partial_page > 0)
- amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
- partial_page);
/* Wait for the next buffer to become available */
bh = fsg->next_buffhd_to_fill;
@@ -1206,6 +1197,11 @@ static int do_read(struct fsg_dev *fsg)
file_offset += nread;
amount_left -= nread;
fsg->residue -= nread;
+
+ /* Except at the end of the transfer, nread will be
+ * equal to the buffer size, which is divisible by the
+ * page size and hence by the bulk-in maxpacket size.
+ */
bh->inreq->length = nread;
bh->state = BUF_STATE_FULL;
@@ -1242,7 +1238,6 @@ static int do_write(struct fsg_dev *fsg)
u32 amount_left_to_req, amount_left_to_write;
loff_t usb_offset, file_offset, file_offset_tmp;
unsigned int amount;
- unsigned int partial_page;
ssize_t nwritten;
int rc;
@@ -1293,38 +1288,21 @@ static int do_write(struct fsg_dev *fsg)
if (bh->state == BUF_STATE_EMPTY && get_some_more) {
/* Figure out how much we want to get:
- * Try to get the remaining amount.
- * But don't get more than the buffer size.
- * And don't try to go past the end of the file.
- * If we're not at a page boundary,
- * don't go past the next page.
- * If this means getting 0, then we were asked
- * to write past the end of file.
- * Finally, round down to a block boundary. */
+ * Try to get the remaining amount,
+ * but not more than the buffer size.
+ */
amount = min(amount_left_to_req, mod_data.buflen);
- amount = min((loff_t) amount, curlun->file_length -
- usb_offset);
- partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
- if (partial_page > 0)
- amount = min(amount,
- (unsigned int) PAGE_CACHE_SIZE - partial_page);
- if (amount == 0) {
+ /* Beyond the end of the backing file? */
+ if (usb_offset >= curlun->file_length) {
get_some_more = 0;
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
- curlun->sense_data_info = usb_offset >> 9;
+ curlun->sense_data_info =
+ curlun->file_length >> 9;
curlun->info_valid = 1;
continue;
}
- amount -= (amount & 511);
- if (amount == 0) {
-
- /* Why were we were asked to transfer a
- * partial block? */
- get_some_more = 0;
- continue;
- }
/* Get the next buffer */
usb_offset += amount;
@@ -1333,10 +1311,12 @@ static int do_write(struct fsg_dev *fsg)
if (amount_left_to_req == 0)
get_some_more = 0;
- /* amount is always divisible by 512, hence by
- * the bulk-out maxpacket size */
+ /* Except at the end of the transfer, amount will be
+ * equal to the buffer size, which is divisible by
+ * the page size and hence by the bulk-out maxpacket
+ * size.
+ */
bh->outreq->length = amount;
- bh->outreq->short_not_ok = 1;
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
fsg->next_buffhd_to_fill = bh->next;
@@ -1369,6 +1349,11 @@ static int do_write(struct fsg_dev *fsg)
amount = curlun->file_length - file_offset;
}
+ /* Don't write a partial block */
+ amount -= (amount & 511);
+ if (amount == 0)
+ goto empty_write;
+
/* Perform the write */
file_offset_tmp = file_offset;
nwritten = vfs_write(curlun->filp,
@@ -1402,6 +1387,7 @@ static int do_write(struct fsg_dev *fsg)
break;
}
+ empty_write:
/* Did the host decide to stop early? */
if (bh->outreq->actual != bh->outreq->length) {
fsg->short_packet_received = 1;
@@ -1498,8 +1484,7 @@ static int do_verify(struct fsg_dev *fsg
* Try to read the remaining amount, but not more than
* the buffer size.
* And don't try to read past the end of the file.
- * If this means reading 0 then we were asked to read
- * past the end of file. */
+ */
amount = min((unsigned int) amount_left, mod_data.buflen);
amount = min((loff_t) amount,
curlun->file_length - file_offset);
@@ -1961,11 +1946,7 @@ static int throw_away_data(struct fsg_de
if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
amount = min(fsg->usb_amount_left,
(u32) mod_data.buflen);
-
- /* amount is always divisible by 512, hence by
- * the bulk-out maxpacket size */
bh->outreq->length = amount;
- bh->outreq->short_not_ok = 1;
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
fsg->next_buffhd_to_fill = bh->next;
@@ -2644,7 +2625,6 @@ static int get_next_command(struct fsg_d
/* Queue a request to read a Bulk-only CBW */
bh->outreq->length = USB_BULK_CB_WRAP_LEN;
- bh->outreq->short_not_ok = 0;
start_transfer(fsg, fsg->bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state);
@@ -2778,7 +2758,6 @@ reset:
if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
goto reset;
fsg->bulk_out_enabled = 1;
- fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
if (transport_is_cbi()) {
--
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