Can't find CDR device in -mm only

Can't find CDR device in -mm only

[Shane Shrybman]

Hi,

The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
It is present in all -mm releases since.

I have an IDE LG CDRW burner that has always worked fine both with
ide-scsi in 2.4 and without in 2.5. As can be seen in the inquiry out
put below the cdr device is not detected correctly by the -mm kernels.
It seems likely to be a kernel bug but I can't be certain.

Here is the inquiry output from cdrecord 2.0 from 2.5.69-mm3 which is
not working and 2.5.68-mm2 which is. I have straces of this too if that
would be useful. Same config was used for all kernels.

scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
scg__open(/dev/hdc) -2,-2,-2
Warning: Open by 'devname' is unintentional and not supported.
l1: 0x0 l2: 0x10
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Linux sg driver version: 3.5.27
l1: 0x0 l2: 0x3
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Target (0,0,0): DMA max 129024 old max: 64512
SCSI buffer size: 64512
Target (0,0,0): DMA max 129024 old max: 64512
scgo_getbuf: 64512 bytes
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
dev: '/dev/hdc' speed: -1 fs: 4194304 driveropts '(NULL POINTER)'
Cdrecord 2.0 (i686-pc-linux-gnu) Copyright (C) 1995-2002 Jörg Schilling
TOC Type: 1 = CD-ROM
Using libscg version 'schily-0.7'
atapi: 1
Device type    : Disk
Version        : 2
Response Format: 2
Capabilities   : 
Vendor_info    : 'ADAPTEC '
Identifikation : 'ACB-5500        '
Revision       : 'FAKE'
Device seems to be: Adaptec 5500.

scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
scg__open(/dev/hdc) -2,-2,-2
Warning: Open by 'devname' is unintentional and not supported.
l1: 0x0 l2: 0x10
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Linux sg driver version: 3.5.27
l1: 0x0 l2: 0x3
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Target (0,0,0): DMA max 129024 old max: 64512
SCSI buffer size: 64512
Target (0,0,0): DMA max 129024 old max: 64512
scgo_getbuf: 64512 bytes
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
dev: '/dev/hdc' speed: -1 fs: 4194304 driveropts '(NULL POINTER)'
Cdrecord 2.0 (i686-pc-linux-gnu) Copyright (C) 1995-2002 Jörg Schilling
TOC Type: 1 = CD-ROM
Using libscg version 'schily-0.7'
atapi: 1
Device type    : Removable CD-ROM
Version        : 2
Response Format: 2
Capabilities   : 
Vendor_info    : 'LG      '
Identifikation : 'CD-RW CED-8120B '
Revision       : '1.03'
Device seems to be: Generic mmc CD-RW.

Regards,

Shane

Re: Can't find CDR device in -mm only

[Andrew Morton]

Shane Shrybman <shrybman@sympatico.ca> wrote:
>
> The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
>  It is present in all -mm releases since.

Could you try reverting the 64-bit dev_t patch?  Do a `patch -p1 -R'
of the below.    Thanks.


diff -puN drivers/s390/block/dasd_int.h~64-bit-dev_t-kdev_t drivers/s390/block/dasd_int.h
--- 25/drivers/s390/block/dasd_int.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/drivers/s390/block/dasd_int.h	2003-05-03 15:06:44.000000000 -0700
@@ -14,7 +14,8 @@
 
 #ifdef __KERNEL__
 
-#define DASD_PER_MAJOR ( 1U<<(MINORBITS-DASD_PARTN_BITS))
+#define DASD_MINORBITS 8
+#define DASD_PER_MAJOR ( 1U<<(DASD_MINORBITS-DASD_PARTN_BITS))
 #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
 
 /*
diff -puN drivers/scsi/sg.c~64-bit-dev_t-kdev_t drivers/scsi/sg.c
--- 25/drivers/scsi/sg.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/drivers/scsi/sg.c	2003-05-03 15:06:44.000000000 -0700
@@ -80,7 +80,7 @@ static void sg_proc_cleanup(void);
 #define SG_ALLOW_DIO_DEF 0
 #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
 
-#define SG_MAX_DEVS_MASK ((1U << KDEV_MINOR_BITS) - 1)
+#define SG_MAX_DEVS_MASK 255
 
 /*
  * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
@@ -1331,8 +1331,8 @@ static ssize_t
 sg_device_kdev_read(struct device *driverfs_dev, char *page)
 {
 	Sg_device *sdp = list_entry(driverfs_dev, Sg_device, sg_driverfs_dev);
-	return sprintf(page, "%x\n", MKDEV(sdp->disk->major,
-					   sdp->disk->first_minor));
+	dev_t dev = MKDEV(sdp->disk->major, sdp->disk->first_minor);
+	return sprintf(page, "%llx\n", (unsigned long long) dev);
 }
 static DEVICE_ATTR(kdev,S_IRUGO,sg_device_kdev_read,NULL);
 
diff -puN drivers/scsi/sr.c~64-bit-dev_t-kdev_t drivers/scsi/sr.c
--- 25/drivers/scsi/sr.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/drivers/scsi/sr.c	2003-05-03 15:06:44.000000000 -0700
@@ -56,7 +56,7 @@
 MODULE_PARM(xa_test, "i");	/* see sr_ioctl.c */
 
 
-#define SR_DISKS	(1 << KDEV_MINOR_BITS)
+#define SR_DISKS	256
 
 #define MAX_RETRIES	3
 #define SR_TIMEOUT	(30 * HZ)
diff -puN fs/xfs/linux/xfs_super.c~64-bit-dev_t-kdev_t fs/xfs/linux/xfs_super.c
--- 25/fs/xfs/linux/xfs_super.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/fs/xfs/linux/xfs_super.c	2003-05-03 15:06:44.000000000 -0700
@@ -251,8 +251,8 @@ xfs_setsize_buftarg(
 
 	if (set_blocksize(btp->pbr_bdev, sectorsize)) {
 		printk(KERN_WARNING
-			"XFS: Cannot set_blocksize to %u on device 0x%x\n",
-			sectorsize, btp->pbr_dev);
+			"XFS: Cannot set_blocksize to %u on device 0x%llx\n",
+			sectorsize, (unsigned long long) btp->pbr_dev);
 	}
 }
 
diff -puN include/asm-i386/posix_types.h~64-bit-dev_t-kdev_t include/asm-i386/posix_types.h
--- 25/include/asm-i386/posix_types.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/include/asm-i386/posix_types.h	2003-05-03 15:06:44.000000000 -0700
@@ -7,7 +7,9 @@
  * assume GCC is being used.
  */
 
-typedef unsigned short	__kernel_dev_t;
+#ifdef __GNUC__
+typedef unsigned long long	__kernel_dev_t;
+#endif
 typedef unsigned long	__kernel_ino_t;
 typedef unsigned short	__kernel_mode_t;
 typedef unsigned short	__kernel_nlink_t;
diff -puN include/linux/kdev_t.h~64-bit-dev_t-kdev_t include/linux/kdev_t.h
--- 25/include/linux/kdev_t.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/include/linux/kdev_t.h	2003-05-03 15:06:44.000000000 -0700
@@ -1,82 +1,14 @@
 #ifndef _LINUX_KDEV_T_H
 #define _LINUX_KDEV_T_H
 #ifdef __KERNEL__
-/*
-As a preparation for the introduction of larger device numbers,
-we introduce a type kdev_t to hold them. No information about
-this type is known outside of this include file.
-
-Objects of type kdev_t designate a device. Outside of the kernel
-the corresponding things are objects of type dev_t - usually an
-integral type with the device major and minor in the high and low
-bits, respectively. Conversion is done by
-
-extern kdev_t to_kdev_t(int);
-
-It is up to the various file systems to decide how objects of type
-dev_t are stored on disk.
-The only other point of contact between kernel and outside world
-are the system calls stat and mknod, new versions of which will
-eventually have to be used in libc.
-
-[Unfortunately, the floppy control ioctls fail to hide the internal
-kernel structures, and the fd_device field of a struct floppy_drive_struct
-is user-visible. So, it remains a dev_t for the moment, with some ugly
-conversions in floppy.c.]
-
-Inside the kernel, we aim for a kdev_t type that is a pointer
-to a structure with information about the device (like major,
-minor, size, blocksize, sectorsize, name, read-only flag,
-struct file_operations etc.).
-
-However, for the time being we let kdev_t be almost the same as dev_t:
-
-typedef struct { unsigned short major, minor; } kdev_t;
-
-Admissible operations on an object of type kdev_t:
-- passing it along
-- comparing it for equality with another such object
-- storing it in inode->i_rdev or tty->device
-- using its bit pattern as argument in a hash function
-- finding its major and minor
-- complaining about it
-
-An object of type kdev_t is created only by the function MKDEV(),
-with the single exception of the constant 0 (no device).
-
-Right now the other information mentioned above is usually found
-in static arrays indexed by major or major,minor.
-
-An obstacle to immediately using
-    typedef struct { ... (* lots of information *) } *kdev_t
-is the case of mknod used to create a block device that the
-kernel doesn't know about at present (but first learns about
-when some module is inserted).
-
-aeb - 950811
-*/
 
+#include <linux/types.h>       /* for dev_t */
 
-/*
- * NOTE NOTE NOTE!
- *
- * The kernel-internal "kdev_t" will eventually have
- * 20 bits for minor numbers, and 12 bits for majors.
- *
- * HOWEVER, the external representation is still 8+8
- * bits, and there is no way to generate the extended
- * "kdev_t" format yet. Which is just as well, since
- * we still use "minor" as an index into various
- * static arrays, and they are sized for a 8-bit index.
- */
 typedef struct {
-	unsigned short value;
+	unsigned long long value;
 } kdev_t;
 
-#define KDEV_MINOR_BITS		8
-#define KDEV_MAJOR_BITS		8
-
-#define __mkdev(major,minor)	(((major) << KDEV_MINOR_BITS) + (minor))
+#define __mkdev(major, minor)	(((unsigned long long)(major) << 32) + (minor))
 
 #define mk_kdev(major, minor)	((kdev_t) { __mkdev(major,minor) } )
 
@@ -85,12 +17,12 @@ typedef struct {
  * internal equality comparisons and for things
  * like NFS filehandle conversion.
  */
-static inline unsigned int kdev_val(kdev_t dev)
+static inline unsigned long long kdev_val(kdev_t dev)
 {
 	return dev.value;
 }
 
-static inline kdev_t val_to_kdev(unsigned int val)
+static inline kdev_t val_to_kdev(unsigned long long val)
 {
 	kdev_t dev;
 	dev.value = val;
@@ -107,30 +39,68 @@ static inline int kdev_same(kdev_t dev1,
 
 #define kdev_none(d1)	(!kdev_val(d1))
 
-/* Mask off the high bits for now.. */
-#define minor(dev)	((dev).value & 0xff)
-#define major(dev)	(((dev).value >> KDEV_MINOR_BITS) & 0xff)
+#define minor(dev)	(unsigned int)((dev).value & 0xffffffff)
+#define major(dev)	(unsigned int)((dev).value >> 32)
 
 /* These are for user-level "dev_t" */
-#define MINORBITS	8
-#define MINORMASK	((1U << MINORBITS) - 1)
+/* Going back and forth between dev and (ma,mi) is one-to-one
+   provided ma is nonzero or ma is zero and mi is 8-bit only.
+   Never use major 0 together with a minor larger than 255. */
+#if 0
+/* readable versions */
+static inline unsigned int
+MAJOR(dev_t dev) {
+        return (dev & ~0xffffffffULL) ? (dev >> 32) :
+                (dev & ~0xffff) ? (dev >> 16) : (dev >> 8);
+}
+
+static inline unsigned int
+MINOR(dev_t dev) {
+        return (dev & ~0xffffffffULL) ? (dev & 0xffffffff) :
+                (dev & ~0xffff) ? (dev & 0xffff) : (dev & 0xff);
+}
 
-#define MAJOR(dev)	((unsigned int) ((dev) >> MINORBITS))
-#define MINOR(dev)	((unsigned int) ((dev) & MINORMASK))
-#define MKDEV(ma,mi)	(((ma) << MINORBITS) | (mi))
+static inline dev_t
+MKDEV(unsigned int major, unsigned int minor) {
+        unsigned int both = (major | minor);
+        return ((both & ~0xffff) ? (((dev_t) major) << 32) :
+                (both & ~0xff) ? (((dev_t) major) << 16) :
+                (((dev_t) major) << 8) ) | minor;
+}
+#else
+/* ugly macro versions */
+#define MAJOR(dev) ((unsigned int)({ dev_t __dev = dev; \
+   (__dev & ~0xffffffffULL) ? (__dev >> 32) : \
+   (__dev & ~0xffff) ? (__dev >> 16) : (__dev >> 8); }))
+#define MINOR(dev) ((unsigned int)({ dev_t __dev = dev; \
+   (__dev & ~0xffffffffULL) ? (__dev & 0xffffffff) : \
+   (__dev & ~0xffff) ? (__dev & 0xffff) : (__dev & 0xff); }))
+#define constant_MKDEV(ma, mi) \
+   ((((ma)|(mi)) & ~0xffff) ? ((ma) << 32) | (mi) : \
+    (((ma)|(mi)) & ~0xff) ? ((ma) << 16) | (mi) : ((ma) << 8) | (mi))
+#define MKDEV(major, minor) ({ \
+   unsigned int __ma = major, __mi = minor, __both = (__ma | __mi); \
+   ((sizeof(dev_t) > 4 && (__both & ~0xffff)) ? (((dev_t) __ma) << 32) : \
+    (__both & ~0xff) ? (((dev_t) __ma) << 16) : (((dev_t) __ma) << 8) \
+   ) | __mi; })
+#endif
 
 /*
  * Conversion functions
  */
 
-static inline int kdev_t_to_nr(kdev_t dev)
+static inline dev_t kdev_t_to_nr(kdev_t dev)
 {
-	return MKDEV(major(dev), minor(dev));
+	unsigned int ma = major(dev);
+	unsigned int mi = minor(dev);
+	return MKDEV(ma, mi);
 }
 
-static inline kdev_t to_kdev_t(int dev)
+static inline kdev_t to_kdev_t(dev_t dev)
 {
-	return mk_kdev(MAJOR(dev),MINOR(dev));
+	unsigned int ma = MAJOR(dev);
+	unsigned int mi = MINOR(dev);
+	return mk_kdev(ma, mi);
 }
 
 #else /* __KERNEL__ */
@@ -138,6 +108,7 @@ static inline kdev_t to_kdev_t(int dev)
 /*
 Some programs want their definitions of MAJOR and MINOR and MKDEV
 from the kernel sources. These must be the externally visible ones.
+Of course such programs should be updated.
 */
 #define MAJOR(dev)	((dev)>>8)
 #define MINOR(dev)	((dev) & 0xff)
diff -puN include/linux/raid/md_k.h~64-bit-dev_t-kdev_t include/linux/raid/md_k.h
--- 25/include/linux/raid/md_k.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/include/linux/raid/md_k.h	2003-05-03 15:06:44.000000000 -0700
@@ -64,11 +64,7 @@ static inline int level_to_pers (int lev
 typedef struct mddev_s mddev_t;
 typedef struct mdk_rdev_s mdk_rdev_t;
 
-#if (MINORBITS != 8)
-#error MD does not handle bigger kdev yet
-#endif
-
-#define MAX_MD_DEVS  (1<<MINORBITS)	/* Max number of md dev */
+#define MAX_MD_DEVS  256	/* Max number of md dev */
 
 /*
  * options passed in raidrun:
diff -puN include/linux/root_dev.h~64-bit-dev_t-kdev_t include/linux/root_dev.h
--- 25/include/linux/root_dev.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
+++ 25-akpm/include/linux/root_dev.h	2003-05-03 15:06:44.000000000 -0700
@@ -1,18 +1,16 @@
 #ifndef _ROOT_DEV_H_
 #define _ROOT_DEV_H_
 
-enum {
-	Root_NFS = MKDEV(UNNAMED_MAJOR, 255),
-	Root_RAM0 = MKDEV(RAMDISK_MAJOR, 0),
-	Root_RAM1 = MKDEV(RAMDISK_MAJOR, 1),
-	Root_FD0 = MKDEV(FLOPPY_MAJOR, 0),
-	Root_HDA1 = MKDEV(IDE0_MAJOR, 1),
-	Root_HDA2 = MKDEV(IDE0_MAJOR, 2),
-	Root_SDA1 = MKDEV(SCSI_DISK0_MAJOR, 1),
-	Root_SDA2 = MKDEV(SCSI_DISK0_MAJOR, 2),
-	Root_HDC1 = MKDEV(IDE1_MAJOR, 1),
-	Root_SR0 = MKDEV(SCSI_CDROM_MAJOR, 0),
-};
+#define	Root_NFS	MKDEV(UNNAMED_MAJOR, 255)
+#define	Root_RAM0	MKDEV(RAMDISK_MAJOR, 0)
+#define	Root_RAM1	MKDEV(RAMDISK_MAJOR, 1)
+#define	Root_FD0	MKDEV(FLOPPY_MAJOR, 0)
+#define	Root_HDA1	MKDEV(IDE0_MAJOR, 1)
+#define	Root_HDA2	MKDEV(IDE0_MAJOR, 2)
+#define	Root_SDA1	MKDEV(SCSI_DISK0_MAJOR, 1)
+#define	Root_SDA2	MKDEV(SCSI_DISK0_MAJOR, 2)
+#define	Root_HDC1	MKDEV(IDE1_MAJOR, 1)
+#define	Root_SR0	MKDEV(SCSI_CDROM_MAJOR, 0)
 
 extern dev_t ROOT_DEV;
 

_

Re: Can't find CDR device in -mm only

[Shane Shrybman]

Thats already backed out due to LVM issues.

On Fri, 2003-05-09 at 23:41, Andrew Morton wrote:
> Shane Shrybman <shrybman@sympatico.ca> wrote:
> >
> > The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> >  It is present in all -mm releases since.
> 
> Could you try reverting the 64-bit dev_t patch?  Do a `patch -p1 -R'
> of the below.    Thanks.
> 
> 
> diff -puN drivers/s390/block/dasd_int.h~64-bit-dev_t-kdev_t drivers/s390/block/dasd_int.h
> --- 25/drivers/s390/block/dasd_int.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/drivers/s390/block/dasd_int.h	2003-05-03 15:06:44.000000000 -0700
> @@ -14,7 +14,8 @@
>  
>  #ifdef __KERNEL__
>  
> -#define DASD_PER_MAJOR ( 1U<<(MINORBITS-DASD_PARTN_BITS))
> +#define DASD_MINORBITS 8
> +#define DASD_PER_MAJOR ( 1U<<(DASD_MINORBITS-DASD_PARTN_BITS))
>  #define DASD_PARTN_MASK ((1 << DASD_PARTN_BITS) - 1)
>  
>  /*
> diff -puN drivers/scsi/sg.c~64-bit-dev_t-kdev_t drivers/scsi/sg.c
> --- 25/drivers/scsi/sg.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/drivers/scsi/sg.c	2003-05-03 15:06:44.000000000 -0700
> @@ -80,7 +80,7 @@ static void sg_proc_cleanup(void);
>  #define SG_ALLOW_DIO_DEF 0
>  #define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
>  
> -#define SG_MAX_DEVS_MASK ((1U << KDEV_MINOR_BITS) - 1)
> +#define SG_MAX_DEVS_MASK 255
>  
>  /*
>   * Suppose you want to calculate the formula muldiv(x,m,d)=int(x * m / d)
> @@ -1331,8 +1331,8 @@ static ssize_t
>  sg_device_kdev_read(struct device *driverfs_dev, char *page)
>  {
>  	Sg_device *sdp = list_entry(driverfs_dev, Sg_device, sg_driverfs_dev);
> -	return sprintf(page, "%x\n", MKDEV(sdp->disk->major,
> -					   sdp->disk->first_minor));
> +	dev_t dev = MKDEV(sdp->disk->major, sdp->disk->first_minor);
> +	return sprintf(page, "%llx\n", (unsigned long long) dev);
>  }
>  static DEVICE_ATTR(kdev,S_IRUGO,sg_device_kdev_read,NULL);
>  
> diff -puN drivers/scsi/sr.c~64-bit-dev_t-kdev_t drivers/scsi/sr.c
> --- 25/drivers/scsi/sr.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/drivers/scsi/sr.c	2003-05-03 15:06:44.000000000 -0700
> @@ -56,7 +56,7 @@
>  MODULE_PARM(xa_test, "i");	/* see sr_ioctl.c */
>  
> 
> -#define SR_DISKS	(1 << KDEV_MINOR_BITS)
> +#define SR_DISKS	256
>  
>  #define MAX_RETRIES	3
>  #define SR_TIMEOUT	(30 * HZ)
> diff -puN fs/xfs/linux/xfs_super.c~64-bit-dev_t-kdev_t fs/xfs/linux/xfs_super.c
> --- 25/fs/xfs/linux/xfs_super.c~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/fs/xfs/linux/xfs_super.c	2003-05-03 15:06:44.000000000 -0700
> @@ -251,8 +251,8 @@ xfs_setsize_buftarg(
>  
>  	if (set_blocksize(btp->pbr_bdev, sectorsize)) {
>  		printk(KERN_WARNING
> -			"XFS: Cannot set_blocksize to %u on device 0x%x\n",
> -			sectorsize, btp->pbr_dev);
> +			"XFS: Cannot set_blocksize to %u on device 0x%llx\n",
> +			sectorsize, (unsigned long long) btp->pbr_dev);
>  	}
>  }
>  
> diff -puN include/asm-i386/posix_types.h~64-bit-dev_t-kdev_t include/asm-i386/posix_types.h
> --- 25/include/asm-i386/posix_types.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/include/asm-i386/posix_types.h	2003-05-03 15:06:44.000000000 -0700
> @@ -7,7 +7,9 @@
>   * assume GCC is being used.
>   */
>  
> -typedef unsigned short	__kernel_dev_t;
> +#ifdef __GNUC__
> +typedef unsigned long long	__kernel_dev_t;
> +#endif
>  typedef unsigned long	__kernel_ino_t;
>  typedef unsigned short	__kernel_mode_t;
>  typedef unsigned short	__kernel_nlink_t;
> diff -puN include/linux/kdev_t.h~64-bit-dev_t-kdev_t include/linux/kdev_t.h
> --- 25/include/linux/kdev_t.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/include/linux/kdev_t.h	2003-05-03 15:06:44.000000000 -0700
> @@ -1,82 +1,14 @@
>  #ifndef _LINUX_KDEV_T_H
>  #define _LINUX_KDEV_T_H
>  #ifdef __KERNEL__
> -/*
> -As a preparation for the introduction of larger device numbers,
> -we introduce a type kdev_t to hold them. No information about
> -this type is known outside of this include file.
> -
> -Objects of type kdev_t designate a device. Outside of the kernel
> -the corresponding things are objects of type dev_t - usually an
> -integral type with the device major and minor in the high and low
> -bits, respectively. Conversion is done by
> -
> -extern kdev_t to_kdev_t(int);
> -
> -It is up to the various file systems to decide how objects of type
> -dev_t are stored on disk.
> -The only other point of contact between kernel and outside world
> -are the system calls stat and mknod, new versions of which will
> -eventually have to be used in libc.
> -
> -[Unfortunately, the floppy control ioctls fail to hide the internal
> -kernel structures, and the fd_device field of a struct floppy_drive_struct
> -is user-visible. So, it remains a dev_t for the moment, with some ugly
> -conversions in floppy.c.]
> -
> -Inside the kernel, we aim for a kdev_t type that is a pointer
> -to a structure with information about the device (like major,
> -minor, size, blocksize, sectorsize, name, read-only flag,
> -struct file_operations etc.).
> -
> -However, for the time being we let kdev_t be almost the same as dev_t:
> -
> -typedef struct { unsigned short major, minor; } kdev_t;
> -
> -Admissible operations on an object of type kdev_t:
> -- passing it along
> -- comparing it for equality with another such object
> -- storing it in inode->i_rdev or tty->device
> -- using its bit pattern as argument in a hash function
> -- finding its major and minor
> -- complaining about it
> -
> -An object of type kdev_t is created only by the function MKDEV(),
> -with the single exception of the constant 0 (no device).
> -
> -Right now the other information mentioned above is usually found
> -in static arrays indexed by major or major,minor.
> -
> -An obstacle to immediately using
> -    typedef struct { ... (* lots of information *) } *kdev_t
> -is the case of mknod used to create a block device that the
> -kernel doesn't know about at present (but first learns about
> -when some module is inserted).
> -
> -aeb - 950811
> -*/
>  
> +#include <linux/types.h>       /* for dev_t */
>  
> -/*
> - * NOTE NOTE NOTE!
> - *
> - * The kernel-internal "kdev_t" will eventually have
> - * 20 bits for minor numbers, and 12 bits for majors.
> - *
> - * HOWEVER, the external representation is still 8+8
> - * bits, and there is no way to generate the extended
> - * "kdev_t" format yet. Which is just as well, since
> - * we still use "minor" as an index into various
> - * static arrays, and they are sized for a 8-bit index.
> - */
>  typedef struct {
> -	unsigned short value;
> +	unsigned long long value;
>  } kdev_t;
>  
> -#define KDEV_MINOR_BITS		8
> -#define KDEV_MAJOR_BITS		8
> -
> -#define __mkdev(major,minor)	(((major) << KDEV_MINOR_BITS) + (minor))
> +#define __mkdev(major, minor)	(((unsigned long long)(major) << 32) + (minor))
>  
>  #define mk_kdev(major, minor)	((kdev_t) { __mkdev(major,minor) } )
>  
> @@ -85,12 +17,12 @@ typedef struct {
>   * internal equality comparisons and for things
>   * like NFS filehandle conversion.
>   */
> -static inline unsigned int kdev_val(kdev_t dev)
> +static inline unsigned long long kdev_val(kdev_t dev)
>  {
>  	return dev.value;
>  }
>  
> -static inline kdev_t val_to_kdev(unsigned int val)
> +static inline kdev_t val_to_kdev(unsigned long long val)
>  {
>  	kdev_t dev;
>  	dev.value = val;
> @@ -107,30 +39,68 @@ static inline int kdev_same(kdev_t dev1,
>  
>  #define kdev_none(d1)	(!kdev_val(d1))
>  
> -/* Mask off the high bits for now.. */
> -#define minor(dev)	((dev).value & 0xff)
> -#define major(dev)	(((dev).value >> KDEV_MINOR_BITS) & 0xff)
> +#define minor(dev)	(unsigned int)((dev).value & 0xffffffff)
> +#define major(dev)	(unsigned int)((dev).value >> 32)
>  
>  /* These are for user-level "dev_t" */
> -#define MINORBITS	8
> -#define MINORMASK	((1U << MINORBITS) - 1)
> +/* Going back and forth between dev and (ma,mi) is one-to-one
> +   provided ma is nonzero or ma is zero and mi is 8-bit only.
> +   Never use major 0 together with a minor larger than 255. */
> +#if 0
> +/* readable versions */
> +static inline unsigned int
> +MAJOR(dev_t dev) {
> +        return (dev & ~0xffffffffULL) ? (dev >> 32) :
> +                (dev & ~0xffff) ? (dev >> 16) : (dev >> 8);
> +}
> +
> +static inline unsigned int
> +MINOR(dev_t dev) {
> +        return (dev & ~0xffffffffULL) ? (dev & 0xffffffff) :
> +                (dev & ~0xffff) ? (dev & 0xffff) : (dev & 0xff);
> +}
>  
> -#define MAJOR(dev)	((unsigned int) ((dev) >> MINORBITS))
> -#define MINOR(dev)	((unsigned int) ((dev) & MINORMASK))
> -#define MKDEV(ma,mi)	(((ma) << MINORBITS) | (mi))
> +static inline dev_t
> +MKDEV(unsigned int major, unsigned int minor) {
> +        unsigned int both = (major | minor);
> +        return ((both & ~0xffff) ? (((dev_t) major) << 32) :
> +                (both & ~0xff) ? (((dev_t) major) << 16) :
> +                (((dev_t) major) << 8) ) | minor;
> +}
> +#else
> +/* ugly macro versions */
> +#define MAJOR(dev) ((unsigned int)({ dev_t __dev = dev; \
> +   (__dev & ~0xffffffffULL) ? (__dev >> 32) : \
> +   (__dev & ~0xffff) ? (__dev >> 16) : (__dev >> 8); }))
> +#define MINOR(dev) ((unsigned int)({ dev_t __dev = dev; \
> +   (__dev & ~0xffffffffULL) ? (__dev & 0xffffffff) : \
> +   (__dev & ~0xffff) ? (__dev & 0xffff) : (__dev & 0xff); }))
> +#define constant_MKDEV(ma, mi) \
> +   ((((ma)|(mi)) & ~0xffff) ? ((ma) << 32) | (mi) : \
> +    (((ma)|(mi)) & ~0xff) ? ((ma) << 16) | (mi) : ((ma) << 8) | (mi))
> +#define MKDEV(major, minor) ({ \
> +   unsigned int __ma = major, __mi = minor, __both = (__ma | __mi); \
> +   ((sizeof(dev_t) > 4 && (__both & ~0xffff)) ? (((dev_t) __ma) << 32) : \
> +    (__both & ~0xff) ? (((dev_t) __ma) << 16) : (((dev_t) __ma) << 8) \
> +   ) | __mi; })
> +#endif
>  
>  /*
>   * Conversion functions
>   */
>  
> -static inline int kdev_t_to_nr(kdev_t dev)
> +static inline dev_t kdev_t_to_nr(kdev_t dev)
>  {
> -	return MKDEV(major(dev), minor(dev));
> +	unsigned int ma = major(dev);
> +	unsigned int mi = minor(dev);
> +	return MKDEV(ma, mi);
>  }
>  
> -static inline kdev_t to_kdev_t(int dev)
> +static inline kdev_t to_kdev_t(dev_t dev)
>  {
> -	return mk_kdev(MAJOR(dev),MINOR(dev));
> +	unsigned int ma = MAJOR(dev);
> +	unsigned int mi = MINOR(dev);
> +	return mk_kdev(ma, mi);
>  }
>  
>  #else /* __KERNEL__ */
> @@ -138,6 +108,7 @@ static inline kdev_t to_kdev_t(int dev)
>  /*
>  Some programs want their definitions of MAJOR and MINOR and MKDEV
>  from the kernel sources. These must be the externally visible ones.
> +Of course such programs should be updated.
>  */
>  #define MAJOR(dev)	((dev)>>8)
>  #define MINOR(dev)	((dev) & 0xff)
> diff -puN include/linux/raid/md_k.h~64-bit-dev_t-kdev_t include/linux/raid/md_k.h
> --- 25/include/linux/raid/md_k.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/include/linux/raid/md_k.h	2003-05-03 15:06:44.000000000 -0700
> @@ -64,11 +64,7 @@ static inline int level_to_pers (int lev
>  typedef struct mddev_s mddev_t;
>  typedef struct mdk_rdev_s mdk_rdev_t;
>  
> -#if (MINORBITS != 8)
> -#error MD does not handle bigger kdev yet
> -#endif
> -
> -#define MAX_MD_DEVS  (1<<MINORBITS)	/* Max number of md dev */
> +#define MAX_MD_DEVS  256	/* Max number of md dev */
>  
>  /*
>   * options passed in raidrun:
> diff -puN include/linux/root_dev.h~64-bit-dev_t-kdev_t include/linux/root_dev.h
> --- 25/include/linux/root_dev.h~64-bit-dev_t-kdev_t	2003-05-03 15:06:44.000000000 -0700
> +++ 25-akpm/include/linux/root_dev.h	2003-05-03 15:06:44.000000000 -0700
> @@ -1,18 +1,16 @@
>  #ifndef _ROOT_DEV_H_
>  #define _ROOT_DEV_H_
>  
> -enum {
> -	Root_NFS = MKDEV(UNNAMED_MAJOR, 255),
> -	Root_RAM0 = MKDEV(RAMDISK_MAJOR, 0),
> -	Root_RAM1 = MKDEV(RAMDISK_MAJOR, 1),
> -	Root_FD0 = MKDEV(FLOPPY_MAJOR, 0),
> -	Root_HDA1 = MKDEV(IDE0_MAJOR, 1),
> -	Root_HDA2 = MKDEV(IDE0_MAJOR, 2),
> -	Root_SDA1 = MKDEV(SCSI_DISK0_MAJOR, 1),
> -	Root_SDA2 = MKDEV(SCSI_DISK0_MAJOR, 2),
> -	Root_HDC1 = MKDEV(IDE1_MAJOR, 1),
> -	Root_SR0 = MKDEV(SCSI_CDROM_MAJOR, 0),
> -};
> +#define	Root_NFS	MKDEV(UNNAMED_MAJOR, 255)
> +#define	Root_RAM0	MKDEV(RAMDISK_MAJOR, 0)
> +#define	Root_RAM1	MKDEV(RAMDISK_MAJOR, 1)
> +#define	Root_FD0	MKDEV(FLOPPY_MAJOR, 0)
> +#define	Root_HDA1	MKDEV(IDE0_MAJOR, 1)
> +#define	Root_HDA2	MKDEV(IDE0_MAJOR, 2)
> +#define	Root_SDA1	MKDEV(SCSI_DISK0_MAJOR, 1)
> +#define	Root_SDA2	MKDEV(SCSI_DISK0_MAJOR, 2)
> +#define	Root_HDC1	MKDEV(IDE1_MAJOR, 1)
> +#define	Root_SR0	MKDEV(SCSI_CDROM_MAJOR, 0)
>  
>  extern dev_t ROOT_DEV;
>  
> 
> _
> 

Re: Can't find CDR device in -mm only

[Jens Axboe]

[-- Attachment #1: Type: text/plain, Size: 543 bytes --]

On Fri, May 09 2003, Shane Shrybman wrote:
> Hi,
> 
> The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> It is present in all -mm releases since.

Curious. Looking at patches between .68-mm2 and -mm3 reveals nothing
major, in fact the only thing touching anything in that area seems to be
the dynamic request allocation patch. Could you try 2.5.69 with the
attached patch to verify that it still works (or doesn't)? There might
be a small offset in deadline-iosched.c, should be nothing to worry
about.

-- 
Jens Axboe


[-- Attachment #2: rq-dyn --]
[-- Type: text/plain, Size: 19997 bytes --]

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.1084  -> 1.1085 
#	include/linux/elevator.h	1.19    -> 1.20   
#	drivers/block/ll_rw_blk.c	1.168   -> 1.169  
#	include/linux/blkdev.h	1.102   -> 1.103  
#	drivers/block/elevator.c	1.40    -> 1.41   
#	drivers/block/deadline-iosched.c	1.18    -> 1.19   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/05/09	axboe@smithers.home.kernel.dk	1.1085
# This patch adds dynamic allocation of request structures. Right now we
# are reserving 256 requests per initialized queue, which adds up to quite
# a lot of memory for even a modest number of queues. For the quoted 4000
# disk systems, it's a disaster.
# 
# Instead, we mempool 4 requests per queue and put an upper limit on the
# number of requests that we will put in-flight as well. I've kept the 128
# read/write max in-flight limit for now. It is trivial to experiement
# with larger queue sizes now, but I want to change one thing at the time
# (the truncate scenario doesn't look all that good with a huge number of
# requests, for instance).
# 
# Patch has been in -mm for a while, I'm running it here against stock 2.5
# as well. Additionally, it actually kills quite a bit of code as well
# --------------------------------------------
#
diff -Nru a/drivers/block/deadline-iosched.c b/drivers/block/deadline-iosched.c
--- a/drivers/block/deadline-iosched.c	Fri May  9 09:36:46 2003
+++ b/drivers/block/deadline-iosched.c	Fri May  9 09:36:46 2003
@@ -71,6 +71,8 @@
 	int fifo_batch;
 	int writes_starved;
 	int front_merges;
+
+	mempool_t *drq_pool;
 };
 
 /*
@@ -690,28 +692,11 @@
 static void deadline_exit(request_queue_t *q, elevator_t *e)
 {
 	struct deadline_data *dd = e->elevator_data;
-	struct deadline_rq *drq;
-	struct request *rq;
-	int i;
 
 	BUG_ON(!list_empty(&dd->fifo_list[READ]));
 	BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
 
-	for (i = READ; i <= WRITE; i++) {
-		struct request_list *rl = &q->rq[i];
-		struct list_head *entry;
-
-		list_for_each(entry, &rl->free) {
-			rq = list_entry_rq(entry);
-
-			if ((drq = RQ_DATA(rq)) == NULL)
-				continue;
-
-			rq->elevator_private = NULL;
-			kmem_cache_free(drq_pool, drq);
-		}
-	}
-
+	mempool_destroy(dd->drq_pool);
 	kfree(dd->hash);
 	kfree(dd);
 }
@@ -723,9 +708,7 @@
 static int deadline_init(request_queue_t *q, elevator_t *e)
 {
 	struct deadline_data *dd;
-	struct deadline_rq *drq;
-	struct request *rq;
-	int i, ret = 0;
+	int i;
 
 	if (!drq_pool)
 		return -ENOMEM;
@@ -741,6 +724,13 @@
 		return -ENOMEM;
 	}
 
+	dd->drq_pool = mempool_create(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, drq_pool);
+	if (!dd->drq_pool) {
+		kfree(dd->hash);
+		kfree(dd);
+		return -ENOMEM;
+	}
+
 	for (i = 0; i < DL_HASH_ENTRIES; i++)
 		INIT_LIST_HEAD(&dd->hash[i]);
 
@@ -756,33 +746,41 @@
 	dd->front_merges = 1;
 	dd->fifo_batch = fifo_batch;
 	e->elevator_data = dd;
+	return 0;
+}
 
-	for (i = READ; i <= WRITE; i++) {
-		struct request_list *rl = &q->rq[i];
-		struct list_head *entry;
-
-		list_for_each(entry, &rl->free) {
-			rq = list_entry_rq(entry);
-
-			drq = kmem_cache_alloc(drq_pool, GFP_KERNEL);
-			if (!drq) {
-				ret = -ENOMEM;
-				break;
-			}
+static void deadline_put_request(request_queue_t *q, struct request *rq)
+{
+	struct deadline_data *dd = q->elevator.elevator_data;
+	struct deadline_rq *drq = RQ_DATA(rq);
 
-			memset(drq, 0, sizeof(*drq));
-			INIT_LIST_HEAD(&drq->fifo);
-			INIT_LIST_HEAD(&drq->hash);
-			RB_CLEAR(&drq->rb_node);
-			drq->request = rq;
-			rq->elevator_private = drq;
-		}
+	if (drq) {
+		mempool_free(drq, dd->drq_pool);
+		rq->elevator_private = NULL;
 	}
+}
 
-	if (ret)
-		deadline_exit(q, e);
+static int
+deadline_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
+{
+	struct deadline_data *dd = q->elevator.elevator_data;
+	struct deadline_rq *drq;
 
-	return ret;
+	drq = mempool_alloc(dd->drq_pool, gfp_mask);
+	if (drq) {
+		RB_CLEAR(&drq->rb_node);
+		drq->request = rq;
+
+		INIT_LIST_HEAD(&drq->hash);
+		drq->hash_valid_count = 0;
+
+		INIT_LIST_HEAD(&drq->fifo);
+
+		rq->elevator_private = drq;
+		return 0;
+	}
+
+	return 1;
 }
 
 /*
@@ -933,6 +931,8 @@
 	.elevator_queue_empty_fn =	deadline_queue_empty,
 	.elevator_former_req_fn =	deadline_former_request,
 	.elevator_latter_req_fn =	deadline_latter_request,
+	.elevator_set_req_fn =		deadline_set_request,
+	.elevator_put_req_fn = 		deadline_put_request,
 	.elevator_init_fn =		deadline_init,
 	.elevator_exit_fn =		deadline_exit,
 
diff -Nru a/drivers/block/elevator.c b/drivers/block/elevator.c
--- a/drivers/block/elevator.c	Fri May  9 09:36:45 2003
+++ b/drivers/block/elevator.c	Fri May  9 09:36:46 2003
@@ -408,6 +408,25 @@
 	return NULL;
 }
 
+int elv_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
+{
+	elevator_t *e = &q->elevator;
+
+	if (e->elevator_set_req_fn)
+		return e->elevator_set_req_fn(q, rq, gfp_mask);
+
+	rq->elevator_private = NULL;
+	return 0;
+}
+
+void elv_put_request(request_queue_t *q, struct request *rq)
+{
+	elevator_t *e = &q->elevator;
+
+	if (e->elevator_put_req_fn)
+		e->elevator_put_req_fn(q, rq);
+}
+
 int elv_register_queue(struct gendisk *disk)
 {
 	request_queue_t *q = disk->queue;
diff -Nru a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
--- a/drivers/block/ll_rw_blk.c	Fri May  9 09:36:45 2003
+++ b/drivers/block/ll_rw_blk.c	Fri May  9 09:36:45 2003
@@ -48,12 +48,6 @@
  */
 static int queue_nr_requests;
 
-/*
- * How many free requests must be available before we wake a process which
- * is waiting for a request?
- */
-static int batch_requests;
-
 unsigned long blk_max_low_pfn, blk_max_pfn;
 int blk_nohighio = 0;
 
@@ -419,7 +413,7 @@
 {
 	struct blk_queue_tag *bqt = q->queue_tags;
 
-	if(unlikely(bqt == NULL || bqt->max_depth < tag))
+	if (unlikely(bqt == NULL || bqt->max_depth < tag))
 		return NULL;
 
 	return bqt->tag_index[tag];
@@ -1122,26 +1116,6 @@
 	spin_unlock_irq(&blk_plug_lock);
 }
 
-static int __blk_cleanup_queue(struct request_list *list)
-{
-	struct list_head *head = &list->free;
-	struct request *rq;
-	int i = 0;
-
-	while (!list_empty(head)) {
-		rq = list_entry(head->next, struct request, queuelist);
-		list_del_init(&rq->queuelist);
-		kmem_cache_free(request_cachep, rq);
-		i++;
-	}
-
-	if (i != list->count)
-		printk("request list leak!\n");
-
-	list->count = 0;
-	return i;
-}
-
 /**
  * blk_cleanup_queue: - release a &request_queue_t when it is no longer needed
  * @q:    the request queue to be released
@@ -1158,18 +1132,14 @@
  **/
 void blk_cleanup_queue(request_queue_t * q)
 {
-	int count = (queue_nr_requests*2);
+	struct request_list *rl = &q->rq;
 
 	elevator_exit(q);
 
-	count -= __blk_cleanup_queue(&q->rq[READ]);
-	count -= __blk_cleanup_queue(&q->rq[WRITE]);
-
 	del_timer_sync(&q->unplug_timer);
 	flush_scheduled_work();
 
-	if (count)
-		printk("blk_cleanup_queue: leaked requests (%d)\n", count);
+	mempool_destroy(rl->rq_pool);
 
 	if (blk_queue_tagged(q))
 		blk_queue_free_tags(q);
@@ -1179,42 +1149,16 @@
 
 static int blk_init_free_list(request_queue_t *q)
 {
-	struct request_list *rl;
-	struct request *rq;
-	int i;
+	struct request_list *rl = &q->rq;
 
-	INIT_LIST_HEAD(&q->rq[READ].free);
-	INIT_LIST_HEAD(&q->rq[WRITE].free);
-	q->rq[READ].count = 0;
-	q->rq[WRITE].count = 0;
+	rl->count[READ] = rl->count[WRITE] = 0;
 
-	/*
-	 * Divide requests in half between read and write
-	 */
-	rl = &q->rq[READ];
-	for (i = 0; i < (queue_nr_requests*2); i++) {
-		rq = kmem_cache_alloc(request_cachep, SLAB_KERNEL);
-		if (!rq)
-			goto nomem;
+	rl->rq_pool = mempool_create(BLKDEV_MIN_RQ, mempool_alloc_slab, mempool_free_slab, request_cachep);
 
-		/*
-		 * half way through, switch to WRITE list
-		 */
-		if (i == queue_nr_requests)
-			rl = &q->rq[WRITE];
-
-		memset(rq, 0, sizeof(struct request));
-		rq->rq_status = RQ_INACTIVE;
-		list_add(&rq->queuelist, &rl->free);
-		rl->count++;
-	}
+	if (!rl->rq_pool)
+		return -ENOMEM;
 
-	init_waitqueue_head(&q->rq[READ].wait);
-	init_waitqueue_head(&q->rq[WRITE].wait);
 	return 0;
-nomem:
-	blk_cleanup_queue(q);
-	return 1;
 }
 
 static int __make_request(request_queue_t *, struct bio *);
@@ -1276,41 +1220,79 @@
 	blk_queue_max_hw_segments(q, MAX_HW_SEGMENTS);
 	blk_queue_max_phys_segments(q, MAX_PHYS_SEGMENTS);
 
-	INIT_LIST_HEAD(&q->plug_list);
-
 	return 0;
 }
 
+static inline void blk_free_request(request_queue_t *q, struct request *rq)
+{
+	elv_put_request(q, rq);
+	mempool_free(rq, q->rq.rq_pool);
+}
+
+static inline struct request *blk_alloc_request(request_queue_t *q,int gfp_mask)
+{
+	struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
+
+	if (!rq)
+		return NULL;
+
+	if (!elv_set_request(q, rq, gfp_mask))
+		return rq;
+
+	mempool_free(rq, q->rq.rq_pool);
+	return NULL;
+}
+
 #define blkdev_free_rq(list) list_entry((list)->next, struct request, queuelist)
 /*
- * Get a free request. queue lock must be held and interrupts
- * disabled on the way in.
+ * Get a free request, queue_lock must not be held
  */
-static struct request *get_request(request_queue_t *q, int rw)
+static struct request *get_request(request_queue_t *q, int rw, int gfp_mask)
 {
 	struct request *rq = NULL;
-	struct request_list *rl = q->rq + rw;
+	struct request_list *rl = &q->rq;
 
-	if (!list_empty(&rl->free)) {
-		rq = blkdev_free_rq(&rl->free);
-		list_del_init(&rq->queuelist);
-		rq->ref_count = 1;
-		rl->count--;
-		if (rl->count < queue_congestion_on_threshold())
-			set_queue_congested(q, rw);
-		rq->flags = 0;
-		rq->rq_status = RQ_ACTIVE;
-		rq->errors = 0;
-		rq->special = NULL;
-		rq->buffer = NULL;
-		rq->data = NULL;
-		rq->sense = NULL;
-		rq->waiting = NULL;
-		rq->bio = rq->biotail = NULL;
-		rq->q = q;
-		rq->rl = rl;
+	spin_lock_irq(q->queue_lock);
+	if (rl->count[rw] == BLKDEV_MAX_RQ) {
+		spin_unlock_irq(q->queue_lock);
+		goto out;
 	}
+	rl->count[rw]++;
+	if ((BLKDEV_MAX_RQ - rl->count[rw]) < queue_congestion_on_threshold())
+		set_queue_congested(q, rw);
+	spin_unlock_irq(q->queue_lock);
 
+	rq = blk_alloc_request(q, gfp_mask);
+	if (!rq) {
+		spin_lock_irq(q->queue_lock);
+		rl->count[rw]--;
+		if ((BLKDEV_MAX_RQ - rl->count[rw]) >= queue_congestion_off_threshold())
+                        clear_queue_congested(q, rw);
+		spin_unlock_irq(q->queue_lock);
+		goto out;
+	}
+	
+	INIT_LIST_HEAD(&rq->queuelist);
+
+	/*
+	 * first three bits are identical in rq->flags and bio->bi_rw,
+	 * see bio.h and blkdev.h
+	 */
+	rq->flags = rw;
+
+	rq->errors = 0;
+	rq->rq_status = RQ_ACTIVE;
+	rq->bio = rq->biotail = NULL;
+	rq->buffer = NULL;
+	rq->ref_count = 1;
+	rq->q = q;
+	rq->rl = rl;
+	rq->waiting = NULL;
+	rq->special = NULL;
+	rq->data = NULL;
+	rq->sense = NULL;
+
+out:
 	return rq;
 }
 
@@ -1319,31 +1301,16 @@
  */
 static struct request *get_request_wait(request_queue_t *q, int rw)
 {
-	DEFINE_WAIT(wait);
-	struct request_list *rl = &q->rq[rw];
 	struct request *rq;
 
-	spin_lock_prefetch(q->queue_lock);
-
 	generic_unplug_device(q);
 	do {
-		int block = 0;
-
-		prepare_to_wait_exclusive(&rl->wait, &wait,
-					TASK_UNINTERRUPTIBLE);
-		spin_lock_irq(q->queue_lock);
-		if (!rl->count)
-			block = 1;
-		spin_unlock_irq(q->queue_lock);
+		rq = get_request(q, rw, GFP_NOIO);
 
-		if (block)
-			io_schedule();
-		finish_wait(&rl->wait, &wait);
+		if (!rq)
+			blk_congestion_wait(rw, HZ / 50);
+	} while (!rq);
 
-		spin_lock_irq(q->queue_lock);
-		rq = get_request(q, rw);
-		spin_unlock_irq(q->queue_lock);
-	} while (rq == NULL);
 	return rq;
 }
 
@@ -1353,39 +1320,11 @@
 
 	BUG_ON(rw != READ && rw != WRITE);
 
-	spin_lock_irq(q->queue_lock);
-	rq = get_request(q, rw);
-	spin_unlock_irq(q->queue_lock);
+	rq = get_request(q, rw, gfp_mask);
 
 	if (!rq && (gfp_mask & __GFP_WAIT))
 		rq = get_request_wait(q, rw);
 
-	if (rq) {
-		rq->flags = 0;
-		rq->buffer = NULL;
-		rq->bio = rq->biotail = NULL;
-		rq->waiting = NULL;
-	}
-	return rq;
-}
-
-/*
- * Non-locking blk_get_request variant, for special requests from drivers.
- */
-struct request *__blk_get_request(request_queue_t *q, int rw)
-{
-	struct request *rq;
-
-	BUG_ON(rw != READ && rw != WRITE);
-
-	rq = get_request(q, rw);
-
-	if (rq) {
-		rq->flags = 0;
-		rq->buffer = NULL;
-		rq->bio = rq->biotail = NULL;
-		rq->waiting = NULL;
-	}
 	return rq;
 }
 
@@ -1503,14 +1442,17 @@
 	disk->stamp_idle = now;
 }
 
+/*
+ * queue lock must be held
+ */
 void __blk_put_request(request_queue_t *q, struct request *req)
 {
 	struct request_list *rl = req->rl;
 
-	if (unlikely(--req->ref_count))
-		return;
 	if (unlikely(!q))
 		return;
+	if (unlikely(--req->ref_count))
+		return;
 
 	req->rq_status = RQ_INACTIVE;
 	req->q = NULL;
@@ -1521,24 +1463,15 @@
 	 * it didn't come out of our reserved rq pools
 	 */
 	if (rl) {
-		int rw = 0;
+		int rw = rq_data_dir(req);
 
 		BUG_ON(!list_empty(&req->queuelist));
 
-		list_add(&req->queuelist, &rl->free);
+		blk_free_request(q, req);
 
-		if (rl == &q->rq[WRITE])
-			rw = WRITE;
-		else if (rl == &q->rq[READ])
-			rw = READ;
-		else
-			BUG();
-
-		rl->count++;
-		if (rl->count >= queue_congestion_off_threshold())
+		rl->count[rw]--;
+		if ((BLKDEV_MAX_RQ - rl->count[rw]) >= queue_congestion_off_threshold())
 			clear_queue_congested(q, rw);
-		if (rl->count >= batch_requests && waitqueue_active(&rl->wait))
-			wake_up(&rl->wait);
 	}
 }
 
@@ -1605,24 +1538,23 @@
 	 * will have updated segment counts, update sector
 	 * counts here.
 	 */
-	if (q->merge_requests_fn(q, req, next)) {
-		req->biotail->bi_next = next->bio;
-		req->biotail = next->biotail;
+	if (!q->merge_requests_fn(q, req, next))
+		return 0;
 
-		req->nr_sectors = req->hard_nr_sectors += next->hard_nr_sectors;
+	req->biotail->bi_next = next->bio;
+	req->biotail = next->biotail;
 
-		elv_merge_requests(q, req, next);
+	req->nr_sectors = req->hard_nr_sectors += next->hard_nr_sectors;
 
-		if (req->rq_disk) {
-			disk_round_stats(req->rq_disk);
-			disk_stat_dec(req->rq_disk, in_flight);
-		}
+	elv_merge_requests(q, req, next);
 
-		__blk_put_request(q, next);
-		return 1;
+	if (req->rq_disk) {
+		disk_round_stats(req->rq_disk);
+		disk_stat_dec(req->rq_disk, in_flight);
 	}
 
-	return 0;
+	__blk_put_request(q, next);
+	return 1;
 }
 
 static inline int attempt_back_merge(request_queue_t *q, struct request *rq)
@@ -1698,9 +1630,9 @@
 
 	barrier = test_bit(BIO_RW_BARRIER, &bio->bi_rw);
 
-	spin_lock_irq(q->queue_lock);
 again:
 	insert_here = NULL;
+	spin_lock_irq(q->queue_lock);
 
 	if (elv_queue_empty(q)) {
 		blk_plug_device(q);
@@ -1776,17 +1708,17 @@
 	if (freereq) {
 		req = freereq;
 		freereq = NULL;
-	} else if ((req = get_request(q, rw)) == NULL) {
+	} else {
 		spin_unlock_irq(q->queue_lock);
-
-		/*
-		 * READA bit set
-		 */
-		if (bio_flagged(bio, BIO_RW_AHEAD))
-			goto end_io;
-
-		freereq = get_request_wait(q, rw);
-		spin_lock_irq(q->queue_lock);
+		if ((freereq = get_request(q, rw, GFP_ATOMIC)) == NULL) {
+			/*
+			 * READA bit set
+			 */
+			if (bio_flagged(bio, BIO_RW_AHEAD))
+				goto end_io;
+	
+			freereq = get_request_wait(q, rw);
+		}
 		goto again;
 	}
 
@@ -1813,14 +1745,15 @@
 	req->bio = req->biotail = bio;
 	req->rq_disk = bio->bi_bdev->bd_disk;
 	req->start_time = jiffies;
+
 	add_request(q, req, insert_here);
 out:
 	if (freereq)
 		__blk_put_request(q, freereq);
 
 	if (blk_queue_plugged(q)) {
-		int nr_queued = (queue_nr_requests - q->rq[0].count) +
-				(queue_nr_requests - q->rq[1].count);
+		int nr_queued = q->rq.count[0] + q->rq.count[1];
+
 		if (nr_queued == q->unplug_thresh)
 			__generic_unplug_device(q);
 	}
@@ -2213,7 +2146,6 @@
 
 int __init blk_dev_init(void)
 {
-	int total_ram = nr_free_pages() << (PAGE_SHIFT - 10);
 	int i;
 
 	request_cachep = kmem_cache_create("blkdev_requests",
@@ -2221,24 +2153,11 @@
 	if (!request_cachep)
 		panic("Can't create request pool slab cache\n");
 
-	/*
-	 * Free request slots per queue.  One per quarter-megabyte.
-	 * We use this many requests for reads, and this many for writes.
-	 */
-	queue_nr_requests = (total_ram >> 9) & ~7;
-	if (queue_nr_requests < 16)
-		queue_nr_requests = 16;
-	if (queue_nr_requests > 128)
-		queue_nr_requests = 128;
-
-	batch_requests = queue_nr_requests / 8;
-	if (batch_requests > 8)
-		batch_requests = 8;
+	queue_nr_requests = BLKDEV_MAX_RQ;
 
 	printk("block request queues:\n");
-	printk(" %d requests per read queue\n", queue_nr_requests);
-	printk(" %d requests per write queue\n", queue_nr_requests);
-	printk(" %d requests per batch\n", batch_requests);
+	printk(" %d/%d requests per read queue\n", BLKDEV_MIN_RQ, queue_nr_requests);
+	printk(" %d/%d requests per write queue\n", BLKDEV_MIN_RQ, queue_nr_requests);
 	printk(" enter congestion at %d\n", queue_congestion_on_threshold());
 	printk(" exit congestion at %d\n", queue_congestion_off_threshold());
 
@@ -2281,7 +2200,6 @@
 EXPORT_SYMBOL(blk_phys_contig_segment);
 EXPORT_SYMBOL(blk_hw_contig_segment);
 EXPORT_SYMBOL(blk_get_request);
-EXPORT_SYMBOL(__blk_get_request);
 EXPORT_SYMBOL(blk_put_request);
 EXPORT_SYMBOL(blk_insert_request);
 
diff -Nru a/include/linux/blkdev.h b/include/linux/blkdev.h
--- a/include/linux/blkdev.h	Fri May  9 09:36:45 2003
+++ b/include/linux/blkdev.h	Fri May  9 09:36:45 2003
@@ -10,6 +10,7 @@
 #include <linux/pagemap.h>
 #include <linux/backing-dev.h>
 #include <linux/wait.h>
+#include <linux/mempool.h>
 
 #include <asm/scatterlist.h>
 
@@ -18,10 +19,12 @@
 struct elevator_s;
 typedef struct elevator_s elevator_t;
 
+#define BLKDEV_MIN_RQ	4
+#define BLKDEV_MAX_RQ	128
+
 struct request_list {
-	unsigned int count;
-	struct list_head free;
-	wait_queue_head_t wait;
+	int count[2];
+	mempool_t *rq_pool;
 };
 
 /*
@@ -180,7 +183,7 @@
 	/*
 	 * the queue request freelist, one for reads and one for writes
 	 */
-	struct request_list	rq[2];
+	struct request_list	rq;
 
 	request_fn_proc		*request_fn;
 	merge_request_fn	*back_merge_fn;
@@ -329,7 +332,6 @@
 extern void blk_attempt_remerge(request_queue_t *, struct request *);
 extern void __blk_attempt_remerge(request_queue_t *, struct request *);
 extern struct request *blk_get_request(request_queue_t *, int, int);
-extern struct request *__blk_get_request(request_queue_t *, int);
 extern void blk_put_request(struct request *);
 extern void blk_insert_request(request_queue_t *, struct request *, int, void *);
 extern void blk_plug_device(request_queue_t *);
diff -Nru a/include/linux/elevator.h b/include/linux/elevator.h
--- a/include/linux/elevator.h	Fri May  9 09:36:45 2003
+++ b/include/linux/elevator.h	Fri May  9 09:36:45 2003
@@ -15,6 +15,8 @@
 typedef void (elevator_remove_req_fn) (request_queue_t *, struct request *);
 typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *);
 typedef struct list_head *(elevator_get_sort_head_fn) (request_queue_t *, struct request *);
+typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, int);
+typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
 
 typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
 typedef void (elevator_exit_fn) (request_queue_t *, elevator_t *);
@@ -34,6 +36,9 @@
 	elevator_request_list_fn *elevator_former_req_fn;
 	elevator_request_list_fn *elevator_latter_req_fn;
 
+	elevator_set_req_fn *elevator_set_req_fn;
+	elevator_put_req_fn *elevator_put_req_fn;
+
 	elevator_init_fn *elevator_init_fn;
 	elevator_exit_fn *elevator_exit_fn;
 
@@ -59,6 +64,8 @@
 extern struct request *elv_latter_request(request_queue_t *, struct request *);
 extern int elv_register_queue(struct gendisk *);
 extern void elv_unregister_queue(struct gendisk *);
+extern int elv_set_request(request_queue_t *, struct request *, int);
+extern void elv_put_request(request_queue_t *, struct request *);
 
 #define __elv_add_request_pos(q, rq, pos)	\
 	(q)->elevator.elevator_add_req_fn((q), (rq), (pos))

Re: Can't find CDR device in -mm only

[Shane Shrybman]

Hi Jens,

On Sat, 2003-05-10 at 05:20, Jens Axboe wrote:
> On Fri, May 09 2003, Shane Shrybman wrote:
> > Hi,
> > 
> > The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> > It is present in all -mm releases since.
> 
> Curious. Looking at patches between .68-mm2 and -mm3 reveals nothing
> major, in fact the only thing touching anything in that area seems to be
> the dynamic request allocation patch. Could you try 2.5.69 with the
> attached patch to verify that it still works (or doesn't)? There might
> be a small offset in deadline-iosched.c, should be nothing to worry
> about.

Still doesn't work with 2.5.69 + rq_dyn. The output from cdrecord is
below.

BTW, I also tried a 2.5.68-mm3 with 64bit_dev_t, blockdev-aio-support,
and disk_name-size-check backed out but still encountered the problem.

scsidev: '/dev/hdc'
devname: '/dev/hdc'
scsibus: -2 target: -2 lun: -2
scg__open(/dev/hdc) -2,-2,-2
Warning: Open by 'devname' is unintentional and not supported.
l1: 0x0 l2: 0x10
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Linux sg driver version: 3.5.27
l1: 0x0 l2: 0x3
Bus: 0 Target: 0 Lun: 0 Chan: 0 Ino: 0
Target (0,0,0): DMA max 129024 old max: 64512
SCSI buffer size: 64512
Target (0,0,0): DMA max 129024 old max: 64512
scgo_getbuf: 64512 bytes
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
ioctl ret: 0
host_status: 00 driver_status: 00
dev: '/dev/hdc' speed: -1 fs: 4194304 driveropts '(NULL POINTER)'
Cdrecord 2.0 (i686-pc-linux-gnu) Copyright (C) 1995-2002 Jörg Schilling
TOC Type: 1 = CD-ROM
Using libscg version 'schily-0.7'
atapi: 1
Device type    : Disk
Version        : 2
Response Format: 2
Capabilities   : 
Vendor_info    : 'ADAPTEC '
Identifikation : 'ACB-5500        '
Revision       : 'FAKE'
Device seems to be: Adaptec 5500.

Regards,

Shane

Re: Can't find CDR device in -mm only

[Jens Axboe]

On Sat, May 10 2003, Shane Shrybman wrote:
> Hi Jens,
> 
> On Sat, 2003-05-10 at 05:20, Jens Axboe wrote:
> > On Fri, May 09 2003, Shane Shrybman wrote:
> > > Hi,
> > > 
> > > The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> > > It is present in all -mm releases since.
> > 
> > Curious. Looking at patches between .68-mm2 and -mm3 reveals nothing
> > major, in fact the only thing touching anything in that area seems to be
> > the dynamic request allocation patch. Could you try 2.5.69 with the
> > attached patch to verify that it still works (or doesn't)? There might
> > be a small offset in deadline-iosched.c, should be nothing to worry
> > about.
> 
> Still doesn't work with 2.5.69 + rq_dyn. The output from cdrecord is
> below.

Ah thanks, that kind of narrows it down then. I'll take a look at the
problem tomorrow, should be easy to reproduce. Thanks for reporting!

-- 
Jens Axboe

Re: Can't find CDR device in -mm only

[Jens Axboe]

On Sat, May 10 2003, Jens Axboe wrote:
> On Sat, May 10 2003, Shane Shrybman wrote:
> > Hi Jens,
> > 
> > On Sat, 2003-05-10 at 05:20, Jens Axboe wrote:
> > > On Fri, May 09 2003, Shane Shrybman wrote:
> > > > Hi,
> > > > 
> > > > The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> > > > It is present in all -mm releases since.
> > > 
> > > Curious. Looking at patches between .68-mm2 and -mm3 reveals nothing
> > > major, in fact the only thing touching anything in that area seems to be
> > > the dynamic request allocation patch. Could you try 2.5.69 with the
> > > attached patch to verify that it still works (or doesn't)? There might
> > > be a small offset in deadline-iosched.c, should be nothing to worry
> > > about.
> > 
> > Still doesn't work with 2.5.69 + rq_dyn. The output from cdrecord is
> > below.
> 
> Ah thanks, that kind of narrows it down then. I'll take a look at the
> problem tomorrow, should be easy to reproduce. Thanks for reporting!

Please try this patch, it should fix the issue for you. The reason is
that the RW bit is set from get_request() now, and scsi_ioctl always
uses WRITE as arguement to the function. So every request would be
turned into a write, oops :)

===== drivers/block/scsi_ioctl.c 1.25 vs edited =====
--- 1.25/drivers/block/scsi_ioctl.c	Tue Apr 29 13:41:31 2003
+++ edited/drivers/block/scsi_ioctl.c	Wed May 14 09:42:19 2003
@@ -229,6 +229,8 @@
 	rq->flags |= REQ_BLOCK_PC;
 	if (writing)
 		rq->flags |= REQ_RW;
+	else
+		rq->flags &= ~REQ_RW;
 
 	rq->hard_nr_sectors = rq->nr_sectors = nr_sectors;
 	rq->hard_cur_sectors = rq->current_nr_sectors = nr_sectors;
@@ -375,6 +377,8 @@
 	rq->flags |= REQ_BLOCK_PC;
 	if (in_len)
 		rq->flags |= REQ_RW;
+	else
+		rq->flags &= ~REQ_RW;
 
 	blk_do_rq(q, bdev, rq);
 	err = rq->errors & 0xff;	/* only 8 bit SCSI status */

-- 
Jens Axboe

Re: Can't find CDR device in -mm only

[Shane Shrybman]

Thanks Jens! I can now see my burner.

There was the other problem I mentioned too. I use the xcdroast front
end to cdrecord and when I try and dupe a cd it always thinks the cd is
an audio cd and tries to copy it with cdda2wav. This is a big problem
for data cds :) Any idea on what might cause this? I think it has been
this ever since I stopped using ide-scsi in 2.5. There is detailed debug
output in the email I sent you on May 10. I can send it again if
needed.  

On Wed, 2003-05-14 at 03:43, Jens Axboe wrote:
> On Sat, May 10 2003, Jens Axboe wrote:
> > On Sat, May 10 2003, Shane Shrybman wrote:
> > > Hi Jens,
> > > 
> > > On Sat, 2003-05-10 at 05:20, Jens Axboe wrote:
> > > > On Fri, May 09 2003, Shane Shrybman wrote:
> > > > > Hi,
> > > > > 
> > > > > The problem first appeared in 2.5.68-mm3 and is not in mainline 2.5.69.
> > > > > It is present in all -mm releases since.
> > > > 
> > > > Curious. Looking at patches between .68-mm2 and -mm3 reveals nothing
> > > > major, in fact the only thing touching anything in that area seems to be
> > > > the dynamic request allocation patch. Could you try 2.5.69 with the
> > > > attached patch to verify that it still works (or doesn't)? There might
> > > > be a small offset in deadline-iosched.c, should be nothing to worry
> > > > about.
> > > 
> > > Still doesn't work with 2.5.69 + rq_dyn. The output from cdrecord is
> > > below.
> > 
> > Ah thanks, that kind of narrows it down then. I'll take a look at the
> > problem tomorrow, should be easy to reproduce. Thanks for reporting!
> 
> Please try this patch, it should fix the issue for you. The reason is
> that the RW bit is set from get_request() now, and scsi_ioctl always
> uses WRITE as arguement to the function. So every request would be
> turned into a write, oops :)
> 
> ===== drivers/block/scsi_ioctl.c 1.25 vs edited =====
> --- 1.25/drivers/block/scsi_ioctl.c	Tue Apr 29 13:41:31 2003
> +++ edited/drivers/block/scsi_ioctl.c	Wed May 14 09:42:19 2003
> @@ -229,6 +229,8 @@
>  	rq->flags |= REQ_BLOCK_PC;
>  	if (writing)
>  		rq->flags |= REQ_RW;
> +	else
> +		rq->flags &= ~REQ_RW;
>  
>  	rq->hard_nr_sectors = rq->nr_sectors = nr_sectors;
>  	rq->hard_cur_sectors = rq->current_nr_sectors = nr_sectors;
> @@ -375,6 +377,8 @@
>  	rq->flags |= REQ_BLOCK_PC;
>  	if (in_len)
>  		rq->flags |= REQ_RW;
> +	else
> +		rq->flags &= ~REQ_RW;
>  
>  	blk_do_rq(q, bdev, rq);
>  	err = rq->errors & 0xff;	/* only 8 bit SCSI status */

Thanks,

shane