| Message ID | 1499343241.5500.15.camel@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Jul 06, 2017 at 08:14:01AM -0400, Mimi Zohar wrote: > This patch defines an ->integrity_read file operation method to read data for > integrity hash collection. > -static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, > - size_t count, loff_t *ppos) > +static ssize_t __efivarfs_file_read(struct file *file, char __user *userbuf, > + size_t count, loff_t *ppos, > + struct iov_iter *iter) > { > struct efivar_entry *var = file->private_data; > unsigned long datasize = 0; > @@ -96,14 +98,32 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, > goto out_free; > > memcpy(data, &attributes, sizeof(attributes)); > - size = simple_read_from_buffer(userbuf, count, ppos, > - data, datasize + sizeof(attributes)); > + > + if (!iter) > + size = simple_read_from_buffer(userbuf, count, ppos, data, > + datasize + sizeof(attributes)); > + else > + size = copy_to_iter(data, datasize + sizeof(attributes), iter); Egads... This kind of kludges is too ugly to exist. What the hell for? If you want to define something that looks like ->read_iter(), bloody make it proper read_iter. Really working one, that is - without this "our oh-so-special needs do not include file position" crap. Seriously, this kind of calling conventions alone is enough for a NAK with extreme prejudice. Something like ssize_t simple_read_iter_from_buffer(struct kiocb *iocb, struct iov_iter *to, const void *from, size_t available) { loff_t pos = iocb->ki_pos; size_t ret; if (pos < 0) return -EINVAL; if (pos >= available) return 0; ret = copy_to_iter(to, from + pos, available - pos); if (!ret && iov_iter_count(to)) return -EFAULT; iocb->ki_pos = pos + ret; return ret; } EXPORT_SYMBOL(simple_read_iter_from_buffer); in fs/libfs.c and turn the efivarfs_file_read() into a real ->read_iter() by replacing simple_read_from_buffer to simple_read_iter_from_buffer (and adjusting the arguments, of course). All there is to it. Sheesh...
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c index 5f22e74bbade..b687c982e0a1 100644 --- a/fs/efivarfs/file.c +++ b/fs/efivarfs/file.c @@ -10,6 +10,7 @@ #include <linux/efi.h> #include <linux/fs.h> #include <linux/slab.h> +#include <linux/uio.h> #include <linux/mount.h> #include "internal.h" @@ -64,8 +65,9 @@ static ssize_t efivarfs_file_write(struct file *file, return bytes; } -static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, - size_t count, loff_t *ppos) +static ssize_t __efivarfs_file_read(struct file *file, char __user *userbuf, + size_t count, loff_t *ppos, + struct iov_iter *iter) { struct efivar_entry *var = file->private_data; unsigned long datasize = 0; @@ -96,14 +98,32 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, goto out_free; memcpy(data, &attributes, sizeof(attributes)); - size = simple_read_from_buffer(userbuf, count, ppos, - data, datasize + sizeof(attributes)); + + if (!iter) + size = simple_read_from_buffer(userbuf, count, ppos, data, + datasize + sizeof(attributes)); + else + size = copy_to_iter(data, datasize + sizeof(attributes), iter); out_free: kfree(data); return size; } +static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf, + size_t count, loff_t *ppos) +{ + return __efivarfs_file_read(file, userbuf, count, ppos, NULL); +} + +static ssize_t efivarfs_file_read_iter(struct kiocb *iocb, + struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + + return __efivarfs_file_read(file, NULL, 0, NULL, iter); +} + static int efivarfs_ioc_getxflags(struct file *file, void __user *arg) { @@ -178,4 +198,5 @@ const struct file_operations efivarfs_file_operations = { .write = efivarfs_file_write, .llseek = no_llseek, .unlocked_ioctl = efivarfs_file_ioctl, + .integrity_read = efivarfs_file_read_iter, };
This patch defines an ->integrity_read file operation method to read data for integrity hash collection. (Posting separately for review, before being squashed with the others.) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> --- fs/efivarfs/file.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-)