Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH 18/18] BKL: introduce CONFIG_BKL. | Date | Tue, 14 Sep 2010 21:55:24 +0200 |
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With all the patches we have queued in the BKL removal tree, only a few dozen modules are left that actually rely on the BKL, and even there are lots of low-hanging fruit. We need to decide what to do about them, this patch illustrates one of the options:
Every user of the BKL is marked as 'depends on BKL' in Kconfig, and the CONFIG_BKL becomes a user-visible option. If it gets disabled, no BKL using module can be built any more and the BKL code itself is compiled out.
The one exception is file locking, which is practically always enabled and does a 'select BKL' instead. This effectively forces CONFIG_BKL to be enabled until we have solved the fs/lockd mess and can apply the patch that removes the BKL from fs/locks.c.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/gpu/drm/Kconfig | 5 ++++- drivers/isdn/capi/Kconfig | 2 +- drivers/media/Kconfig | 1 + drivers/net/appletalk/Kconfig | 1 + drivers/staging/cx25821/Kconfig | 1 + drivers/staging/easycap/Kconfig | 1 + drivers/staging/go7007/Kconfig | 1 + drivers/staging/usbip/Kconfig | 2 +- drivers/usb/gadget/Kconfig | 2 +- fs/Kconfig | 1 + fs/adfs/Kconfig | 1 + fs/afs/Kconfig | 1 + fs/autofs/Kconfig | 1 + fs/autofs4/Kconfig | 1 + fs/ceph/Kconfig | 1 + fs/coda/Kconfig | 1 + fs/ecryptfs/Kconfig | 1 + fs/freevxfs/Kconfig | 1 + fs/hpfs/Kconfig | 1 + fs/jffs2/Kconfig | 1 + fs/ncpfs/Kconfig | 1 + fs/nfs/Kconfig | 1 + fs/nfsd/Kconfig | 1 + fs/ocfs2/Kconfig | 1 + fs/qnx4/Kconfig | 1 + fs/reiserfs/Kconfig | 1 + fs/smbfs/Kconfig | 1 + fs/squashfs/Kconfig | 1 + fs/udf/Kconfig | 1 + fs/ufs/Kconfig | 1 + include/linux/smp_lock.h | 7 +++++-- init/Kconfig | 2 +- kernel/trace/Kconfig | 1 + lib/Kconfig.debug | 9 +++++++++ net/ipx/Kconfig | 1 + net/irda/Kconfig | 1 + net/irda/irnet/Kconfig | 1 + net/x25/Kconfig | 1 + 38 files changed, 53 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 4cab0c6..b755301 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -73,7 +73,8 @@ source "drivers/gpu/drm/radeon/Kconfig" config DRM_I810 tristate "Intel I810" - depends on DRM && AGP && AGP_INTEL + # BKL usage in order to avoid AB-BA deadlocks, may become BROKEN_ON_SMP + depends on DRM && AGP && AGP_INTEL && BKL help Choose this option if you have an Intel I810 graphics card. If M is selected, the module will be called i810. AGP support is required @@ -86,6 +87,8 @@ choice config DRM_I830 tristate "i830 driver" + # BKL usage in order to avoid AB-BA deadlocks, may become BROKEN_ON_SMP + depends on BKL help Choose this option if you have a system that has Intel 830M, 845G, 852GM, 855GM or 865G integrated graphics. If M is selected, the diff --git a/drivers/isdn/capi/Kconfig b/drivers/isdn/capi/Kconfig index a168e8a..bb40d8d 100644 --- a/drivers/isdn/capi/Kconfig +++ b/drivers/isdn/capi/Kconfig @@ -35,7 +35,7 @@ config ISDN_CAPI_CAPI20 config ISDN_CAPI_CAPIFS_BOOL bool "CAPI2.0 filesystem support (DEPRECATED)" - depends on ISDN_CAPI_MIDDLEWARE && ISDN_CAPI_CAPI20 + depends on ISDN_CAPI_MIDDLEWARE && ISDN_CAPI_CAPI20 && BKL help This option provides a special file system, similar to /dev/pts with device nodes for the special ttys established by using the diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index a28541b..bad2ced 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -19,6 +19,7 @@ comment "Multimedia core support" config VIDEO_DEV tristate "Video For Linux" + depends on BKL # used in many drivers for ioctl handling, need to kill ---help--- V4L core support for video capture and overlay devices, webcams and AM/FM radio cards. diff --git a/drivers/net/appletalk/Kconfig b/drivers/net/appletalk/Kconfig index 0a0e0cd..abe967a 100644 --- a/drivers/net/appletalk/Kconfig +++ b/drivers/net/appletalk/Kconfig @@ -3,6 +3,7 @@ # config ATALK tristate "Appletalk protocol support" + depends on BKL # used in net/appletalk/ddp.c, probably fixable select LLC ---help--- AppleTalk is the protocol that Apple computers can use to communicate diff --git a/drivers/staging/cx25821/Kconfig b/drivers/staging/cx25821/Kconfig index df7756a..813cb35 100644 --- a/drivers/staging/cx25821/Kconfig +++ b/drivers/staging/cx25821/Kconfig @@ -1,6 +1,7 @@ config VIDEO_CX25821 tristate "Conexant cx25821 support" depends on DVB_CORE && VIDEO_DEV && PCI && I2C && INPUT + depends on BKL # please fix select I2C_ALGOBIT select VIDEO_BTCX select VIDEO_TVEEPROM diff --git a/drivers/staging/easycap/Kconfig b/drivers/staging/easycap/Kconfig index bd96f39..9d5fe4d 100644 --- a/drivers/staging/easycap/Kconfig +++ b/drivers/staging/easycap/Kconfig @@ -1,6 +1,7 @@ config EASYCAP tristate "EasyCAP USB ID 05e1:0408 support" depends on USB && VIDEO_DEV + depends on BKL # please fix ---help--- This is an integrated audio/video driver for EasyCAP cards with diff --git a/drivers/staging/go7007/Kconfig b/drivers/staging/go7007/Kconfig index e47f683..75fa468 100644 --- a/drivers/staging/go7007/Kconfig +++ b/drivers/staging/go7007/Kconfig @@ -1,6 +1,7 @@ config VIDEO_GO7007 tristate "WIS GO7007 MPEG encoder support" depends on VIDEO_DEV && PCI && I2C && INPUT + depends on BKL # please fix depends on SND select VIDEOBUF_DMA_SG select VIDEO_IR diff --git a/drivers/staging/usbip/Kconfig b/drivers/staging/usbip/Kconfig index 2c1d10a..b11ec37 100644 --- a/drivers/staging/usbip/Kconfig +++ b/drivers/staging/usbip/Kconfig @@ -1,6 +1,6 @@ config USB_IP_COMMON tristate "USB IP support (EXPERIMENTAL)" - depends on USB && NET && EXPERIMENTAL + depends on USB && NET && EXPERIMENTAL && BKL default N ---help--- This enables pushing USB packets over IP to allow remote diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index cd27f9b..4de1fc6 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -697,7 +697,7 @@ config USB_ETH_EEM config USB_GADGETFS tristate "Gadget Filesystem (EXPERIMENTAL)" - depends on EXPERIMENTAL + depends on EXPERIMENTAL && BKL help This driver provides a filesystem based API that lets user mode programs implement a single-configuration USB device, including diff --git a/fs/Kconfig b/fs/Kconfig index 3d18530..56f20ee 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -50,6 +50,7 @@ endif # BLOCK config FILE_LOCKING bool "Enable POSIX file locking API" if EMBEDDED default y + select BKL help This option enables standard file locking support, required for filesystems like NFS and for the flock() system diff --git a/fs/adfs/Kconfig b/fs/adfs/Kconfig index e55182a..1dd5f34 100644 --- a/fs/adfs/Kconfig +++ b/fs/adfs/Kconfig @@ -1,6 +1,7 @@ config ADFS_FS tristate "ADFS file system support (EXPERIMENTAL)" depends on BLOCK && EXPERIMENTAL + depends on BKL # need to fix help The Acorn Disc Filing System is the standard file system of the RiscOS operating system which runs on Acorn's ARM-based Risc PC diff --git a/fs/afs/Kconfig b/fs/afs/Kconfig index 8f975f2..06e305c 100644 --- a/fs/afs/Kconfig +++ b/fs/afs/Kconfig @@ -1,6 +1,7 @@ config AFS_FS tristate "Andrew File System support (AFS) (EXPERIMENTAL)" depends on INET && EXPERIMENTAL + depends on BKL # need to fix select AF_RXRPC select DNS_RESOLVER help diff --git a/fs/autofs/Kconfig b/fs/autofs/Kconfig index 5f3bea9..480e210 100644 --- a/fs/autofs/Kconfig +++ b/fs/autofs/Kconfig @@ -1,5 +1,6 @@ config AUTOFS_FS tristate "Kernel automounter support" + depends on BKL # unfixable, just use autofs4 help The automounter is a tool to automatically mount remote file systems on demand. This implementation is partially kernel-based to reduce diff --git a/fs/autofs4/Kconfig b/fs/autofs4/Kconfig index 1204d63..a639b21 100644 --- a/fs/autofs4/Kconfig +++ b/fs/autofs4/Kconfig @@ -1,5 +1,6 @@ config AUTOFS4_FS tristate "Kernel automounter version 4 support (also supports v3)" + depends on BKL # need to fix help The automounter is a tool to automatically mount remote file systems on demand. This implementation is partially kernel-based to reduce diff --git a/fs/ceph/Kconfig b/fs/ceph/Kconfig index bc87b9c..5172f09 100644 --- a/fs/ceph/Kconfig +++ b/fs/ceph/Kconfig @@ -1,6 +1,7 @@ config CEPH_FS tristate "Ceph distributed file system (EXPERIMENTAL)" depends on INET && EXPERIMENTAL + depends on BKL # need to fix select LIBCRC32C select CRYPTO_AES help diff --git a/fs/coda/Kconfig b/fs/coda/Kconfig index c0e5a7f..ee99c5c 100644 --- a/fs/coda/Kconfig +++ b/fs/coda/Kconfig @@ -1,6 +1,7 @@ config CODA_FS tristate "Coda file system support (advanced network fs)" depends on INET + depends on BKL # probably unfixable, will become BROKEN_ON_SMP help Coda is an advanced network file system, similar to NFS in that it enables you to mount file systems of a remote server and access them diff --git a/fs/ecryptfs/Kconfig b/fs/ecryptfs/Kconfig index 1cd6d9d..ddfdfb5 100644 --- a/fs/ecryptfs/Kconfig +++ b/fs/ecryptfs/Kconfig @@ -1,6 +1,7 @@ config ECRYPT_FS tristate "eCrypt filesystem layer support (EXPERIMENTAL)" depends on EXPERIMENTAL && KEYS && CRYPTO + depends on BKL # need to fix select CRYPTO_ECB select CRYPTO_CBC select CRYPTO_MD5 diff --git a/fs/freevxfs/Kconfig b/fs/freevxfs/Kconfig index 8dc1cd5..3632242 100644 --- a/fs/freevxfs/Kconfig +++ b/fs/freevxfs/Kconfig @@ -1,6 +1,7 @@ config VXFS_FS tristate "FreeVxFS file system support (VERITAS VxFS(TM) compatible)" depends on BLOCK + depends on BKL # lookup/readdir, need to fix help FreeVxFS is a file system driver that support the VERITAS VxFS(TM) file system format. VERITAS VxFS(TM) is the standard file system diff --git a/fs/hpfs/Kconfig b/fs/hpfs/Kconfig index 56bd15c..a1f68ea 100644 --- a/fs/hpfs/Kconfig +++ b/fs/hpfs/Kconfig @@ -1,6 +1,7 @@ config HPFS_FS tristate "OS/2 HPFS file system support" depends on BLOCK + depends on BKL # probably unfixable, will become BROKEN_ON_SMP help OS/2 is IBM's operating system for PC's, the same as Warp, and HPFS is the file system used for organizing files on OS/2 hard disk diff --git a/fs/jffs2/Kconfig b/fs/jffs2/Kconfig index 6ae169c..b9afb6e 100644 --- a/fs/jffs2/Kconfig +++ b/fs/jffs2/Kconfig @@ -1,6 +1,7 @@ config JFFS2_FS tristate "Journalling Flash File System v2 (JFFS2) support" select CRC32 + depends on BKL # from pushdown, need to fix depends on MTD help JFFS2 is the second generation of the Journalling Flash File System diff --git a/fs/ncpfs/Kconfig b/fs/ncpfs/Kconfig index c931cf2..d0ed28d 100644 --- a/fs/ncpfs/Kconfig +++ b/fs/ncpfs/Kconfig @@ -3,6 +3,7 @@ # config NCP_FS tristate "NCP file system support (to mount NetWare volumes)" + depends on BKL depends on IPX!=n || INET help NCP (NetWare Core Protocol) is a protocol that runs over IPX and is diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index 6c2aad4..10b9524 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -1,6 +1,7 @@ config NFS_FS tristate "NFS client support" depends on INET && FILE_LOCKING + depends on BKL # fix as soon as lockd is done select LOCKD select SUNRPC select NFS_ACL_SUPPORT if NFS_V3_ACL diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig index 95932f5..429d4a1 100644 --- a/fs/nfsd/Kconfig +++ b/fs/nfsd/Kconfig @@ -2,6 +2,7 @@ config NFSD tristate "NFS server support" depends on INET depends on FILE_LOCKING + depends on BKL # fix as soon as lockd is done select LOCKD select SUNRPC select EXPORTFS diff --git a/fs/ocfs2/Kconfig b/fs/ocfs2/Kconfig index 0d84066..20a1f1b 100644 --- a/fs/ocfs2/Kconfig +++ b/fs/ocfs2/Kconfig @@ -1,5 +1,6 @@ config OCFS2_FS tristate "OCFS2 file system support" + depends on BKL # from pushdown, need to fix depends on NET && SYSFS select CONFIGFS_FS select JBD2 diff --git a/fs/qnx4/Kconfig b/fs/qnx4/Kconfig index 5f60899..1b86b15 100644 --- a/fs/qnx4/Kconfig +++ b/fs/qnx4/Kconfig @@ -1,5 +1,6 @@ config QNX4FS_FS tristate "QNX4 file system support (read only)" + depends on BKL # need to fix or will become BROKEN_ON_SMP depends on BLOCK help This is the file system used by the real-time operating systems diff --git a/fs/reiserfs/Kconfig b/fs/reiserfs/Kconfig index 513f431..342a59d 100644 --- a/fs/reiserfs/Kconfig +++ b/fs/reiserfs/Kconfig @@ -1,5 +1,6 @@ config REISERFS_FS tristate "Reiserfs support" + depends on BKL # trivial select CRC32 help Stores not just filenames but the files themselves in a balanced diff --git a/fs/smbfs/Kconfig b/fs/smbfs/Kconfig index e668127..2bc24a8 100644 --- a/fs/smbfs/Kconfig +++ b/fs/smbfs/Kconfig @@ -1,5 +1,6 @@ config SMB_FS tristate "SMB file system support (OBSOLETE, please use CIFS)" + depends on BKL # probably unfixable depends on INET select NLS help diff --git a/fs/squashfs/Kconfig b/fs/squashfs/Kconfig index e5f63da..33dbe68 100644 --- a/fs/squashfs/Kconfig +++ b/fs/squashfs/Kconfig @@ -1,6 +1,7 @@ config SQUASHFS tristate "SquashFS 4.0 - Squashed file system support" depends on BLOCK + depends on BKL # trivial to fix select ZLIB_INFLATE help Saying Y here includes support for SquashFS 4.0 (a Compressed diff --git a/fs/udf/Kconfig b/fs/udf/Kconfig index 0e0e99b..f8def3c 100644 --- a/fs/udf/Kconfig +++ b/fs/udf/Kconfig @@ -1,5 +1,6 @@ config UDF_FS tristate "UDF file system support" + depends on BKL # needs serious work to remove select CRC_ITU_T help This is the new file system used on some CD-ROMs and DVDs. Say Y if diff --git a/fs/ufs/Kconfig b/fs/ufs/Kconfig index e4f10a4..5061244 100644 --- a/fs/ufs/Kconfig +++ b/fs/ufs/Kconfig @@ -1,6 +1,7 @@ config UFS_FS tristate "UFS file system support (read only)" depends on BLOCK + depends on BKL # probably unfixable, will become BROKEN_ON_SMP help BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD, OpenBSD and NeXTstep) use a file system called UFS. Some System V diff --git a/include/linux/smp_lock.h b/include/linux/smp_lock.h index 2ea1dd1..291f721 100644 --- a/include/linux/smp_lock.h +++ b/include/linux/smp_lock.h @@ -54,12 +54,15 @@ static inline void cycle_kernel_lock(void) #else +#ifdef CONFIG_BKL /* provoke build bug if not set */ #define lock_kernel() #define unlock_kernel() -#define release_kernel_lock(task) do { } while(0) #define cycle_kernel_lock() do { } while(0) -#define reacquire_kernel_lock(task) 0 #define kernel_locked() 1 +#endif /* CONFIG_BKL */ + +#define release_kernel_lock(task) do { } while(0) +#define reacquire_kernel_lock(task) 0 #endif /* CONFIG_LOCK_KERNEL */ #endif /* __LINUX_SMPLOCK_H */ diff --git a/init/Kconfig b/init/Kconfig index 2de5b1c..2005a1d 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -64,7 +64,7 @@ config BROKEN_ON_SMP config LOCK_KERNEL bool - depends on SMP || PREEMPT + depends on (SMP || PREEMPT) && BKL default y config INIT_ENV_ARG_LIMIT diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 538501c..65d4023 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -327,6 +327,7 @@ config BLK_DEV_IO_TRACE bool "Support for tracing block IO actions" depends on SYSFS depends on BLOCK + depends on BKL # please use bd_mutex instead select RELAY select DEBUG_FS select TRACEPOINTS diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 1b4afd2..088eea1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -461,6 +461,15 @@ config DEBUG_MUTEXES This feature allows mutex semantics violations to be detected and reported. +config BKL + bool "Big Kernel Lock" if (SMP || PREEMPT) + default y + help + This is the traditional lock that is used in old code instead + of proper locking. All drivers that use the BKL should depend + on this symbol. + Say Y here unless you are working on removing the BKL. + config DEBUG_LOCK_ALLOC bool "Lock debugging: detect incorrect freeing of live locks" depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT diff --git a/net/ipx/Kconfig b/net/ipx/Kconfig index e9ad006..02549cb 100644 --- a/net/ipx/Kconfig +++ b/net/ipx/Kconfig @@ -3,6 +3,7 @@ # config IPX tristate "The IPX protocol" + depends on BKL # should be fixable select LLC ---help--- This is support for the Novell networking protocol, IPX, commonly diff --git a/net/irda/Kconfig b/net/irda/Kconfig index c8671a7..073243f 100644 --- a/net/irda/Kconfig +++ b/net/irda/Kconfig @@ -4,6 +4,7 @@ menuconfig IRDA depends on NET && !S390 + depends on BKL # should be fixable tristate "IrDA (infrared) subsystem support" select CRC_CCITT ---help--- diff --git a/net/irda/irnet/Kconfig b/net/irda/irnet/Kconfig index 28c557f..b1e68c1 100644 --- a/net/irda/irnet/Kconfig +++ b/net/irda/irnet/Kconfig @@ -1,6 +1,7 @@ config IRNET tristate "IrNET protocol" depends on IRDA && PPP + depends on BKL # might need to lock against AF_IRDA help Say Y here if you want to build support for the IrNET protocol. To compile it as a module, choose M here: the module will be diff --git a/net/x25/Kconfig b/net/x25/Kconfig index e6759c9..2196e55 100644 --- a/net/x25/Kconfig +++ b/net/x25/Kconfig @@ -5,6 +5,7 @@ config X25 tristate "CCITT X.25 Packet Layer (EXPERIMENTAL)" depends on EXPERIMENTAL + depends on BKL # should be fixable ---help--- X.25 is a set of standardized network protocols, similar in scope to frame relay; the one physical line from your box to the X.25 network -- 1.7.1
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