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authorAkinobu Mita <akinobu.mita@gmail.com>2008-06-05 22:46:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-06 11:29:11 -0700
commit93b071139a956e51c98cdefd50a47981a4eb852e (patch)
tree877e8b03abbd5ae6e1d89836d9f97e33156c1082
parent3527fb326f07bc8e85cf66d4f987ebeea24e8e4a (diff)
downloadvexpress-lsk-93b071139a956e51c98cdefd50a47981a4eb852e.tar.gz
introduce memory_read_from_buffer()
This patch introduces memory_read_from_buffer(). The only difference between memory_read_from_buffer() and simple_read_from_buffer() is which address space the function copies to. simple_read_from_buffer copies to user space memory. memory_read_from_buffer copies to normal memory. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Doug Warzecha <Douglas_Warzecha@dell.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Cc: Abhay Salunke <Abhay_Salunke@dell.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Markus Rechberger <markus.rechberger@amd.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Bob Moore <robert.moore@intel.com> Cc: Thomas Renninger <trenn@suse.de> Cc: Len Brown <lenb@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Antonino A. Daplas" <adaplas@pol.net> Cc: Krzysztof Helt <krzysztof.h1@poczta.fm> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Cc: Michael Holzheu <holzheu@de.ibm.com> Cc: Brian King <brking@us.ibm.com> Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com> Cc: Andrew Vasquez <linux-driver@qlogic.com> Cc: Seokmann Ju <seokmann.ju@qlogic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/libfs.c18
-rw-r--r--include/linux/fs.h5
2 files changed, 22 insertions, 1 deletions
diff --git a/fs/libfs.c b/fs/libfs.c
index b004dfadd89..892d41cb338 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -528,6 +528,23 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
return count;
}
+ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
+ const void *from, size_t available)
+{
+ loff_t pos = *ppos;
+
+ if (pos < 0)
+ return -EINVAL;
+ if (pos >= available)
+ return 0;
+ if (count > available - pos)
+ count = available - pos;
+ memcpy(to, from + pos, count);
+ *ppos = pos + count;
+
+ return count;
+}
+
/*
* Transaction based IO.
* The file expects a single write which triggers the transaction, and then
@@ -800,6 +817,7 @@ EXPORT_SYMBOL(simple_statfs);
EXPORT_SYMBOL(simple_sync_file);
EXPORT_SYMBOL(simple_unlink);
EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(memory_read_from_buffer);
EXPORT_SYMBOL(simple_transaction_get);
EXPORT_SYMBOL(simple_transaction_read);
EXPORT_SYMBOL(simple_transaction_release);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f413085f748..d490779f18d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2000,7 +2000,10 @@ extern int simple_fill_super(struct super_block *, int, struct tree_descr *);
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
extern void simple_release_fs(struct vfsmount **mount, int *count);
-extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t);
+extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
+ loff_t *ppos, const void *from, size_t available);
+extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
+ const void *from, size_t available);
#ifdef CONFIG_MIGRATION
extern int buffer_migrate_page(struct address_space *,