From 1e3d9b8612a3f2a4c907b98d6465fcf4e7a53c4e Mon Sep 17 00:00:00 2001 From: Vladimir 'phcoder' Serbinenko Date: Mon, 27 Jun 2011 10:12:35 +0200 Subject: [PATCH] * grub-core/disk/scsi.c (grub_scsi_read): Limit SCSI reads to 32K because of underlying system restrictions. --- ChangeLog | 5 +++++ grub-core/disk/scsi.c | 33 ++++++++++++++++++++++++++------- 2 files changed, 31 insertions(+), 7 deletions(-) diff --git a/ChangeLog b/ChangeLog index ca4145e33..360842279 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2011-06-27 Vladimir Serbinenko + + * grub-core/disk/scsi.c (grub_scsi_read): Limit SCSI reads to 32K + because of underlying system restrictions. + 2011-06-27 Vladimir Serbinenko * util/grub-mkrescue.in: Rename "ata" to "pata" and add ahci when diff --git a/grub-core/disk/scsi.c b/grub-core/disk/scsi.c index 35b8525c2..902564164 100644 --- a/grub-core/disk/scsi.c +++ b/grub-core/disk/scsi.c @@ -524,17 +524,36 @@ grub_scsi_read (grub_disk_t disk, grub_disk_addr_t sector, scsi = disk->data; - /* Depending on the type, select a read function. */ - switch (scsi->devtype) + while (size) { - case grub_scsi_devtype_direct: - return grub_scsi_read10 (disk, sector, size, buf); + /* PATA doesn't support more than 32K reads. + Not sure about AHCI and USB. If it's confirmed that either of + them can do bigger reads reliably this value can be moved to 'scsi' + structure. */ + grub_size_t len = 32768 >> disk->log_sector_size; + grub_err_t err; + if (len > size) + len = size; + /* Depending on the type, select a read function. */ + switch (scsi->devtype) + { + case grub_scsi_devtype_direct: + err = grub_scsi_read10 (disk, sector, len, buf); + if (err) + return err; + break; - case grub_scsi_devtype_cdrom: - return grub_scsi_read12 (disk, sector, size, buf); + case grub_scsi_devtype_cdrom: + err = grub_scsi_read12 (disk, sector, len, buf); + if (err) + return err; + break; + } + size -= len; + sector += len; + buf += len << disk->log_sector_size; } - /* XXX: Never reached. */ return GRUB_ERR_NONE; #if 0 /* Workaround - it works - but very slowly, from some reason