diff options
| author | Akinobu Mita <akinobu.mita@gmail.com> | 2008-06-05 22:46:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-06-06 11:29:11 -0700 |
| commit | 93b071139a956e51c98cdefd50a47981a4eb852e (patch) | |
| tree | 877e8b03abbd5ae6e1d89836d9f97e33156c1082 | |
| parent | 3527fb326f07bc8e85cf66d4f987ebeea24e8e4a (diff) | |
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.c | 18 | ||||
| -rw-r--r-- | include/linux/fs.h | 5 |
2 files changed, 22 insertions, 1 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index b004dfadd891..892d41cb3382 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 f413085f748e..d490779f18d9 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 *, |