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authorGrant Likely <grant.likely@secretlab.ca>2010-05-22 00:36:56 -0600
committerGrant Likely <grant.likely@secretlab.ca>2010-05-22 00:36:56 -0600
commitcf9b59e9d3e008591d1f54830f570982bb307a0d (patch)
tree113478ce8fd8c832ba726ffdf59b82cb46356476 /fs/libfs.c
parent44504b2bebf8b5823c59484e73096a7d6574471d (diff)
parentf4b87dee923342505e1ddba8d34ce9de33e75050 (diff)
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Merge remote branch 'origin' into secretlab/next-devicetree
Merging in current state of Linus' tree to deal with merge conflicts and build failures in vio.c after merge. Conflicts: drivers/i2c/busses/i2c-cpm.c drivers/i2c/busses/i2c-mpc.c drivers/net/gianfar.c Also fixed up one line in arch/powerpc/kernel/vio.c to use the correct node pointer. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'fs/libfs.c')
-rw-r--r--fs/libfs.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/fs/libfs.c b/fs/libfs.c
index ea9a6cc..232bea4 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -547,6 +547,40 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,
}
/**
+ * simple_write_to_buffer - copy data from user space to the buffer
+ * @to: the buffer to write to
+ * @available: the size of the buffer
+ * @ppos: the current position in the buffer
+ * @from: the user space buffer to read from
+ * @count: the maximum number of bytes to read
+ *
+ * The simple_write_to_buffer() function reads up to @count bytes from the user
+ * space address starting at @from into the buffer @to at offset @ppos.
+ *
+ * On success, the number of bytes written is returned and the offset @ppos is
+ * advanced by this number, or negative value is returned on error.
+ **/
+ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
+ const void __user *from, size_t count)
+{
+ loff_t pos = *ppos;
+ size_t res;
+
+ if (pos < 0)
+ return -EINVAL;
+ if (pos >= available || !count)
+ return 0;
+ if (count > available - pos)
+ count = available - pos;
+ res = copy_from_user(to + pos, from, count);
+ if (res == count)
+ return -EFAULT;
+ count -= res;
+ *ppos = pos + count;
+ return count;
+}
+
+/**
* memory_read_from_buffer - copy data from the buffer
* @to: the kernel space buffer to read to
* @count: the maximum number of bytes to read
@@ -864,6 +898,7 @@ EXPORT_SYMBOL(simple_statfs);
EXPORT_SYMBOL(simple_sync_file);
EXPORT_SYMBOL(simple_unlink);
EXPORT_SYMBOL(simple_read_from_buffer);
+EXPORT_SYMBOL(simple_write_to_buffer);
EXPORT_SYMBOL(memory_read_from_buffer);
EXPORT_SYMBOL(simple_transaction_set);
EXPORT_SYMBOL(simple_transaction_get);