diff options
| -rw-r--r-- | drivers/usb/gadget/f_mass_storage.c | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index 9dbe86dec332..c904aa39ad84 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -163,6 +163,10 @@ * ro setting are not allowed when the medium is loaded or if CD-ROM * emulation is being used. * + * When a LUN receive an "eject" SCSI request (Start/Stop Unit), + * if the LUN is removable, the backing file is released to simulate + * ejection. + * * * This function is heavily based on "File-backed Storage Gadget" by * Alan Stern which in turn is heavily based on "Gadget Zero" by David @@ -1384,12 +1388,50 @@ static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh) static int do_start_stop(struct fsg_common *common) { - if (!common->curlun) { + struct fsg_lun *curlun = common->curlun; + int loej, start; + + if (!curlun) { return -EINVAL; - } else if (!common->curlun->removable) { - common->curlun->sense_data = SS_INVALID_COMMAND; + } else if (!curlun->removable) { + curlun->sense_data = SS_INVALID_COMMAND; + return -EINVAL; + } + + loej = common->cmnd[4] & 0x02; + start = common->cmnd[4] & 0x01; + + /* eject code from file_storage.c:do_start_stop() */ + + if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */ + (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */ + curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } + + if (!start) { + /* Are we allowed to unload the media? */ + if (curlun->prevent_medium_removal) { + LDBG(curlun, "unload attempt prevented\n"); + curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED; + return -EINVAL; + } + if (loej) { /* Simulate an unload/eject */ + up_read(&common->filesem); + down_write(&common->filesem); + fsg_lun_close(curlun); + up_write(&common->filesem); + down_read(&common->filesem); + } + } else { + + /* Our emulation doesn't support mounting; the medium is + * available for use as soon as it is loaded. */ + if (!fsg_lun_is_open(curlun)) { + curlun->sense_data = SS_MEDIUM_NOT_PRESENT; + return -EINVAL; + } + } return 0; } |
