diff options
author | David Howells <dhowells@redhat.com> | 2006-09-30 14:45:40 -0400 |
---|---|---|
committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-09-30 14:52:31 -0400 |
commit | 9361401eb7619c033e2394e4f9f6d410d6719ac7 (patch) | |
tree | 04b94a71f2366988c17740d1c16cfbdec41d5d2e /fs/proc | |
parent | d366e40a1cabd453be6e2609caa7e12f9ca17b1f (diff) |
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/proc_misc.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c index 5bbd60896050..66bc425f2f3d 100644 --- a/fs/proc/proc_misc.c +++ b/fs/proc/proc_misc.c | |||
@@ -277,12 +277,15 @@ static int devinfo_show(struct seq_file *f, void *v) | |||
277 | if (i == 0) | 277 | if (i == 0) |
278 | seq_printf(f, "Character devices:\n"); | 278 | seq_printf(f, "Character devices:\n"); |
279 | chrdev_show(f, i); | 279 | chrdev_show(f, i); |
280 | } else { | 280 | } |
281 | #ifdef CONFIG_BLOCK | ||
282 | else { | ||
281 | i -= CHRDEV_MAJOR_HASH_SIZE; | 283 | i -= CHRDEV_MAJOR_HASH_SIZE; |
282 | if (i == 0) | 284 | if (i == 0) |
283 | seq_printf(f, "\nBlock devices:\n"); | 285 | seq_printf(f, "\nBlock devices:\n"); |
284 | blkdev_show(f, i); | 286 | blkdev_show(f, i); |
285 | } | 287 | } |
288 | #endif | ||
286 | return 0; | 289 | return 0; |
287 | } | 290 | } |
288 | 291 | ||
@@ -355,6 +358,7 @@ static int stram_read_proc(char *page, char **start, off_t off, | |||
355 | } | 358 | } |
356 | #endif | 359 | #endif |
357 | 360 | ||
361 | #ifdef CONFIG_BLOCK | ||
358 | extern struct seq_operations partitions_op; | 362 | extern struct seq_operations partitions_op; |
359 | static int partitions_open(struct inode *inode, struct file *file) | 363 | static int partitions_open(struct inode *inode, struct file *file) |
360 | { | 364 | { |
@@ -378,6 +382,7 @@ static struct file_operations proc_diskstats_operations = { | |||
378 | .llseek = seq_lseek, | 382 | .llseek = seq_lseek, |
379 | .release = seq_release, | 383 | .release = seq_release, |
380 | }; | 384 | }; |
385 | #endif | ||
381 | 386 | ||
382 | #ifdef CONFIG_MODULES | 387 | #ifdef CONFIG_MODULES |
383 | extern struct seq_operations modules_op; | 388 | extern struct seq_operations modules_op; |
@@ -695,7 +700,9 @@ void __init proc_misc_init(void) | |||
695 | entry->proc_fops = &proc_kmsg_operations; | 700 | entry->proc_fops = &proc_kmsg_operations; |
696 | create_seq_entry("devices", 0, &proc_devinfo_operations); | 701 | create_seq_entry("devices", 0, &proc_devinfo_operations); |
697 | create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations); | 702 | create_seq_entry("cpuinfo", 0, &proc_cpuinfo_operations); |
703 | #ifdef CONFIG_BLOCK | ||
698 | create_seq_entry("partitions", 0, &proc_partitions_operations); | 704 | create_seq_entry("partitions", 0, &proc_partitions_operations); |
705 | #endif | ||
699 | create_seq_entry("stat", 0, &proc_stat_operations); | 706 | create_seq_entry("stat", 0, &proc_stat_operations); |
700 | create_seq_entry("interrupts", 0, &proc_interrupts_operations); | 707 | create_seq_entry("interrupts", 0, &proc_interrupts_operations); |
701 | #ifdef CONFIG_SLAB | 708 | #ifdef CONFIG_SLAB |
@@ -707,7 +714,9 @@ void __init proc_misc_init(void) | |||
707 | create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations); | 714 | create_seq_entry("buddyinfo",S_IRUGO, &fragmentation_file_operations); |
708 | create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations); | 715 | create_seq_entry("vmstat",S_IRUGO, &proc_vmstat_file_operations); |
709 | create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations); | 716 | create_seq_entry("zoneinfo",S_IRUGO, &proc_zoneinfo_file_operations); |
717 | #ifdef CONFIG_BLOCK | ||
710 | create_seq_entry("diskstats", 0, &proc_diskstats_operations); | 718 | create_seq_entry("diskstats", 0, &proc_diskstats_operations); |
719 | #endif | ||
711 | #ifdef CONFIG_MODULES | 720 | #ifdef CONFIG_MODULES |
712 | create_seq_entry("modules", 0, &proc_modules_operations); | 721 | create_seq_entry("modules", 0, &proc_modules_operations); |
713 | #endif | 722 | #endif |