Paulo, When will you change the implementation to this way?
Thanks/Ray > -----Original Message----- > From: Paulo Alcantara [mailto:[email protected]] > Sent: Friday, September 15, 2017 1:38 PM > To: Ni, Ruiyu <[email protected]>; Laszlo Ersek <[email protected]> > Cc: [email protected]; Wu, Hao A <[email protected]>; Zeng, Star > <[email protected]> > Subject: RE: Functionality issues in UDF support > > > > Hi, > > On September 15, 2017 2:08:28 AM GMT-03:00, "Ni, Ruiyu" > <[email protected]> wrote: > >Hi Paulo, > >The responsibility of PartitionDxe driver is to partition the physical > >BLK (the entire CDROM) into logical BLKs (one BLK for each volume). > >It doesn't make sense to create a child BLK handle which still covers > >the entire CDROM. > >So as I suggested in below, PartitionInstallUdfChildHandles() should > >contain a for-loop to iterate all the volumes in the CDROM, and create > >child BLK handle for each volumes, but skipping Eltorito volume. > > Ah, makes sense to me now. Thanks for clarifying it. So I agree with you. > > In whatever you guys decide to do with it, count on me to give some help. > > Thanks! > Paulo > > > > >Thanks/Ray > > > >> -----Original Message----- > >> From: Paulo Alcantara [mailto:[email protected]] > >> Sent: Friday, September 15, 2017 12:58 PM > >> To: Ni, Ruiyu <[email protected]>; Laszlo Ersek <[email protected]> > >> Cc: [email protected]; Wu, Hao A <[email protected]>; Zeng, > >Star > >> <[email protected]> > >> Subject: Re: Functionality issues in UDF support > >> > >> > >> > >> Hi Ray, > >> > >> On September 15, 2017 12:33:04 AM GMT-03:00, "Ni, Ruiyu" > >> <[email protected]> wrote: > >> >Paulo, > >> >Before raising my questions, I'd like to confirm that for a single > >> >CD/DVD in UDF format, there might be multiple volumes. > >> >One of the volume could be Eltorito type. > >> >If my understanding is correct, please continue reading below. > >> > >> Right. > >> > >> > > >> >We found below mapping table using "map -r" shell command in a > >platform > >> >with only PartitionDxe change and without UdfDxe driver. > >> >It's a bug that <BLK6> and <BLK7/FS2> are created. Actually they are > >> >identical to <BLK3> and <BLK4/FS1>. > >> > > >> >--- Mapping table--- > >> > BLK2: Alias(s): > >> > PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0) > >> > > >> > BLK3: Alias(s): > >> > PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0)/CDROM(0x0) > >> > FS1: Alias(s):CD1a65535a1:;BLK4: > >> > PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0)/CDROM(0x1) > >> > > >> > BLK5: Alias(s): > >> >PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0)/VenMedia(C5BD4D42- > >> 1A76-4996-8956-73CDA326CD0A) > >> > BLK6: Alias(s): > >> >PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0)/VenMedia(C5BD4D42- > >> 1A76-4996-8956-73CDA326CD0A)/CDROM(0x0) > >> > FS2: Alias(s):CD1a65535ab:;BLK7: > >> >PciRoot(0x0)/Pci(0x1F,0x2)/Sata(0x0,0xFFFF,0x0)/VenMedia(C5BD4D42- > >> 1A76- > >> >4996-8956-73CDA326CD0A)/CDROM(0x1) > >> >--- End of mapping table --- > >> > > >> >After investigation, I found the UDF logic in Partition driver > >doesn't > >> >truly skip the Eltorito volume. > >> >The code flow is like below: > >> > > >> > 1. <BLK2> is created by ScsiDiskDxe driver. > >> > 2. By passing <BLK2> to PartitionDxe Start() > >> >* <BLK3> and <BLK4/FS1> are created by PartitionDxe driver, by > >> >PartitionInstallElToritoChildHandles(). > >> >* <BLK5> is created by PartitionDxe driver, by > >> >PartitionInstallUdfChildHandles(). > >> > 3. By passing <BLK5> to PartitionDxe Start() > >> >* <BLK6> and <BLK7/FS2> are created by PartitionDxe driver, by > >> >PartitionInstallElToritoChildHandles(). > >> > > >> >I think step 2.a is not correct if my understanding to UDF is > >correct. > >> >The PartitionInstallUdfChildHandles() should iterate all volumes in > >the > >> >media and creates the child BLK handle for each volume, but skipping > >> >Eltorito volume. > >> > > >> >Instead, the current implementation just creates one child BLK > >handle > >> >for the entire media. > >> >To avoid reclusively creating child BLK handle, the > >> >PartitionInstallUdfChildHandles() contains a logic to do nothing > >when > >> >the handle is created by ParititonDxe driver. The logic is not > >needed > >> >when the implementation follows my suggestion above. > >> >Due to this, step 3.a creates the additional but shouldn't-exist BLK > >> >handles <BLK6> and <BLK7/FS2>. > >> > > >> >UdfDxe driver is supposed to Start() on each volume and produce > >> >SimpleFileSystem protocol. > >> > >> It seems that PartitionInstallUdfChildHandles() indeed skips the > >ElTorito > >> partitions otherwise you'd see the ".../CDROM(0x1)/VenMedia()" and > >> ".../CDROM(0x0)/VenMedia()" device paths *also* in the mapping > >output. > >> > >> If I understand correctly, the problem is that when we create a child > >handle > >> for an UDF volume, Partition driver will execute again, parse the > >newly > >> created UDF handle, find again an ElTorito partition and then install > >a new > >> child handle (VenMedia()/CDROM()) > >> > >> So, the logic of skipping of ElTorito partitions in > >> PartitionInstallUdfChildHandles() is not enough. Unfortunately we > >can't > >> handle UDF bridge disks (ElTorito + UDF) entirely in > >> PartitionInstallUdfChildHandles() -- we should probably also skip UDF > >device > >> paths in PartitionInstallElToritoChildHandles(). > >> > >> Does it make sense to you, Ray? Thanks for raising this up. > >> > >> Paulo > >> > >> > > >> >Do you agree with my above suggestions? > >> > > >> >Laszlo, > >> >I understood your needs of this UDF support. But as you can see > >there > >> >are many build failures and even functionality issues due to this > >> >support. > >> >I am not sure how the other open source project handles such cases. > >> >But I am thinking maybe we could move the whole UDF support to > >> >edk2-staging firstly and move it back after all the issues are > >> >resolved. > >> >What's your suggestion? > >> > > >> >Thanks/Ray > >> > >> -- > >> Sent from my Android device with K-9 Mail. Please excuse my brevity. > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
