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authorBandan Das <bsd@redhat.com>2019-01-29 08:19:07 -0500
committerGerd Hoffmann <kraxel@redhat.com>2019-01-30 06:47:52 +0100
commitc1ef0f2519c706f738d76b9b68b6627c889bab14 (patch)
tree8fe4d8fa416eaf0499a696d833c04d7fa0bfa8a1 /hw
parent179fcf8a83a91c74e323b1fe1b5397520a8af047 (diff)
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usb-mtp: breakup MTP write into smaller chunks
For every MTP_WRITE_BUF_SZ copied, this patch writes it to file before getting the next block of data. The file is kept opened for the duration of the operation but the sanity checks on the write operation are performed only once when the write operation starts. Additionally, we also update the file size in the object metadata once the file has completely been written. Suggested-by: Gerd Hoffman <kraxel@redhat.com> Signed-off-by: Bandan Das <bsd@redhat.com> Message-id: 20190129131908.27924-3-bsd@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/usb/dev-mtp.c134
1 files changed, 91 insertions, 43 deletions
diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c
index 2e342c7..2ca25c9 100644
--- a/hw/usb/dev-mtp.c
+++ b/hw/usb/dev-mtp.c
@@ -36,6 +36,13 @@ enum mtp_container_type {
TYPE_EVENT = 4,
};
+/* MTP write stage, for internal use only */
+enum mtp_write_status {
+ WRITE_START = 1,
+ WRITE_CONTINUE = 2,
+ WRITE_END = 3,
+};
+
enum mtp_code {
/* command codes */
CMD_GET_DEVICE_INFO = 0x1001,
@@ -154,6 +161,9 @@ struct MTPData {
/* Used for >4G file sizes */
bool pending;
int fd;
+ uint8_t write_status;
+ /* Internal pointer per every MTP_WRITE_BUF_SZ */
+ uint64_t data_offset;
};
struct MTPObject {
@@ -1620,10 +1630,14 @@ static char *utf16_to_str(uint8_t len, uint16_t *arr)
}
/* Wrapper around write, returns 0 on failure */
-static uint64_t write_retry(int fd, void *buf, uint64_t size)
+static uint64_t write_retry(int fd, void *buf, uint64_t size, off_t offset)
{
uint64_t bytes_left = size, ret;
+ if (lseek(fd, offset, SEEK_SET) < 0) {
+ goto done;
+ }
+
while (bytes_left > 0) {
ret = write(fd, buf, bytes_left);
if ((ret == -1) && (errno != EINTR || errno != EAGAIN ||
@@ -1634,9 +1648,20 @@ static uint64_t write_retry(int fd, void *buf, uint64_t size)
buf += ret;
}
+done:
return size - bytes_left;
}
+static void usb_mtp_update_object(MTPObject *parent, char *name)
+{
+ MTPObject *o =
+ usb_mtp_object_lookup_name(parent, name, strlen(name));
+
+ if (o) {
+ lstat(o->path, &o->stat);
+ }
+}
+
static void usb_mtp_write_data(MTPState *s)
{
MTPData *d = s->data_out;
@@ -1648,48 +1673,56 @@ static void usb_mtp_write_data(MTPState *s)
assert(d != NULL);
- if (parent == NULL || !s->write_pending) {
- usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
- 0, 0, 0, 0);
+ switch (d->write_status) {
+ case WRITE_START:
+ if (!parent || !s->write_pending) {
+ usb_mtp_queue_result(s, RES_INVALID_OBJECTINFO, d->trans,
+ 0, 0, 0, 0);
return;
- }
-
- if (s->dataset.filename) {
- path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
- if (s->dataset.format == FMT_ASSOCIATION) {
- d->fd = mkdir(path, mask);
- goto free;
- }
- if ((s->dataset.size != 0xFFFFFFFF) && (s->dataset.size != d->offset)) {
- usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
- 0, 0, 0, 0);
- goto done;
- }
- d->fd = open(path, O_CREAT | O_WRONLY | O_CLOEXEC | O_NOFOLLOW, mask);
- if (d->fd == -1) {
- usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
- 0, 0, 0, 0);
- goto done;
}
- /*
- * Return success if initiator sent 0 sized data
- */
- if (!s->dataset.size) {
- goto success;
- }
+ if (s->dataset.filename) {
+ path = g_strdup_printf("%s/%s", parent->path, s->dataset.filename);
+ if (s->dataset.format == FMT_ASSOCIATION) {
+ d->fd = mkdir(path, mask);
+ goto free;
+ }
+ d->fd = open(path, O_CREAT | O_WRONLY |
+ O_CLOEXEC | O_NOFOLLOW, mask);
+ if (d->fd == -1) {
+ usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
+ 0, 0, 0, 0);
+ goto done;
+ }
- rc = write_retry(d->fd, d->data, d->offset);
- if (rc != d->offset) {
+ /* Return success if initiator sent 0 sized data */
+ if (!s->dataset.size) {
+ goto success;
+ }
+ if (d->length != MTP_WRITE_BUF_SZ && !d->pending) {
+ d->write_status = WRITE_END;
+ }
+ }
+ /* fall through */
+ case WRITE_CONTINUE:
+ case WRITE_END:
+ rc = write_retry(d->fd, d->data, d->data_offset,
+ d->offset - d->data_offset);
+ if (rc != d->data_offset) {
usb_mtp_queue_result(s, RES_STORE_FULL, d->trans,
0, 0, 0, 0);
goto done;
+ }
+ if (d->write_status != WRITE_END) {
+ return;
+ } else {
+ /* Only for < 4G file sizes */
+ if (s->dataset.size != 0xFFFFFFFF && d->offset != s->dataset.size) {
+ usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
+ 0, 0, 0, 0);
+ goto done;
}
- /* Only for < 4G file sizes */
- if (s->dataset.size != 0xFFFFFFFF && rc != s->dataset.size) {
- usb_mtp_queue_result(s, RES_INCOMPLETE_TRANSFER, d->trans,
- 0, 0, 0, 0);
- goto done;
+ usb_mtp_update_object(parent, s->dataset.filename);
}
}
@@ -1788,25 +1821,33 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container,
d->offset = 0;
d->first = false;
d->pending = false;
+ d->data_offset = 0;
+ d->write_status = WRITE_START;
}
if (d->pending) {
- usb_mtp_realloc(d, MTP_WRITE_BUF_SZ);
- d->length += MTP_WRITE_BUF_SZ;
+ memset(d->data, 0, d->length);
+ if (d->length != MTP_WRITE_BUF_SZ) {
+ usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - d->length);
+ d->length += (MTP_WRITE_BUF_SZ - d->length);
+ }
d->pending = false;
+ d->write_status = WRITE_CONTINUE;
+ d->data_offset = 0;
}
- if (d->length - d->offset > data_len) {
+ if (d->length - d->data_offset > data_len) {
dlen = data_len;
} else {
- dlen = d->length - d->offset;
+ dlen = d->length - d->data_offset;
}
switch (d->code) {
case CMD_SEND_OBJECT_INFO:
- usb_packet_copy(p, d->data + d->offset, dlen);
+ usb_packet_copy(p, d->data + d->data_offset, dlen);
d->offset += dlen;
- if (d->offset == d->length) {
+ d->data_offset += dlen;
+ if (d->data_offset == d->length) {
/* The operation might have already failed */
if (!s->result) {
usb_mtp_write_metadata(s, dlen);
@@ -1817,19 +1858,26 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container,
}
break;
case CMD_SEND_OBJECT:
- usb_packet_copy(p, d->data + d->offset, dlen);
+ usb_packet_copy(p, d->data + d->data_offset, dlen);
d->offset += dlen;
+ d->data_offset += dlen;
if ((p->iov.size % 64) || !p->iov.size) {
assert((s->dataset.size == 0xFFFFFFFF) ||
(s->dataset.size == d->offset));
+ if (d->length == MTP_WRITE_BUF_SZ) {
+ d->write_status = WRITE_END;
+ } else {
+ d->write_status = WRITE_START;
+ }
usb_mtp_write_data(s);
usb_mtp_data_free(s->data_out);
s->data_out = NULL;
return;
}
- if (d->offset == d->length) {
+ if (d->data_offset == d->length) {
d->pending = true;
+ usb_mtp_write_data(s);
}
break;
default: