Most embedded systems have no use for /dev/full, and omitting it saves
space. Add a new EMBEDDED config option to disable it.
bloat-o-meter (based on tinyconfig):
add/remove: 0/2 grow/shrink: 0/0 up/down: 0/-122 (-122)
function old new delta
write_full 6 - -6
full_fops 116 - -116
Signed-off-by: Tom Zanussi <tom.zanu...@linux.intel.com>
---
drivers/char/Kconfig | 11 +++++++++++
drivers/char/mem.c | 6 ++++++
2 files changed, 17 insertions(+)
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 00f9b8a..62290e0 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -56,6 +56,17 @@ config DEVZERO
systems with strictly controlled userspace may not need it.
When in doubt, say "Y".
+config DEVFULL
+ bool "/dev/full virtual device support" if EMBEDDED
+ depends on DEVMEM_BASE
+ default y
+ help
+ Say Y here if you want to support the /dev/full device. The
+ /dev/full device is used mainly for testing how programs
+ respond to ENOSPC, and can be disabled on systems that will
+ never use it in production, such as many embedded systems.
+ When in doubt, say "Y".
+
config SGI_SNSC
bool "SGI Altix system controller communication support"
depends on (IA64_SGI_SN2 || IA64_GENERIC)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 96f7a9d..5b60003 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -665,11 +665,13 @@ static int mmap_zero(struct file *file, struct
vm_area_struct *vma)
}
#endif
+#ifdef CONFIG_DEVFULL
static ssize_t write_full(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
return -ENOSPC;
}
+#endif
/*
* Special lseek() function for /dev/null and /dev/zero. Most notably, you
@@ -791,12 +793,14 @@ static struct backing_dev_info zero_bdi = {
};
#endif
+#ifdef CONFIG_DEVFULL
static const struct file_operations full_fops = {
.llseek = full_lseek,
.read = new_sync_read,
.read_iter = read_iter_zero,
.write = write_full,
};
+#endif
static const struct memdev {
const char *name;
@@ -819,7 +823,9 @@ static const struct memdev {
#ifdef CONFIG_DEVZERO
[5] = { "zero", 0666, &zero_fops, &zero_bdi },
#endif
+#ifdef CONFIG_DEVFULL
[7] = { "full", 0666, &full_fops, NULL },
+#endif
[8] = { "random", 0666, &random_fops, NULL },
[9] = { "urandom", 0666, &urandom_fops, NULL },
#ifdef CONFIG_PRINTK
--
1.9.3
--
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