fs: use read_iter and write_iter rather than aio_read and aio_write

File systems implementing read_iter & write_iter should not be required
to keep aio_read and aio_write as well. The vfs should always call
read/write_iter if they exist. This will make it easier to remove the
aio_read/write operation in the future.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org

diff --git a/fs/aio.c b/fs/aio.c
index 06892dc58be21c24c6a036236667a6b90e3a8876..8ef3157c7943ee6c7b863bd4513c8b0f18367275 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1051,14 +1051,14 @@ static ssize_t aio_run_iocb(struct kiocb *req, bool compat)
        case IOCB_CMD_PREADV:
                mode    = FMODE_READ;
                rw      = READ;
-               rw_op   = file->f_op->aio_read;
+               rw_op   = do_aio_read;
                goto rw_common;
 
        case IOCB_CMD_PWRITE:
        case IOCB_CMD_PWRITEV:
                mode    = FMODE_WRITE;
                rw      = WRITE;
-               rw_op   = file->f_op->aio_write;
+               rw_op   = do_aio_write;
                goto rw_common;
 rw_common:
                if (unlikely(!(file->f_mode & mode)))

diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 7c93953030fbe5eda13d76b6a8c53d6f2a31902d..38651e5da183f80b60763c7423a1171e1dfc9d6f 100644 (file)
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -39,12 +39,24 @@ static ssize_t bad_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
        return -EIO;
 }
 
+static ssize_t bad_file_read_iter(struct kiocb *iocb, struct iov_iter *iter,
+                       loff_t pos)
+{
+       return -EIO;
+}
+
 static ssize_t bad_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
                        unsigned long nr_segs, loff_t pos)
 {
        return -EIO;
 }
 
+static ssize_t bad_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+                       loff_t pos)
+{
+       return -EIO;
+}
+
 static int bad_file_readdir(struct file *file, struct dir_context *ctx)
 {
        return -EIO;
@@ -151,7 +163,9 @@ static const struct file_operations bad_file_ops =
        .read           = bad_file_read,
        .write          = bad_file_write,
        .aio_read       = bad_file_aio_read,
+       .read_iter      = bad_file_read_iter,
        .aio_write      = bad_file_aio_write,
+       .write_iter     = bad_file_write_iter,
        .iterate        = bad_file_readdir,
        .poll           = bad_file_poll,
        .unlocked_ioctl = bad_file_unlocked_ioctl,

diff --git a/fs/internal.h b/fs/internal.h
index 7c5f01cf619d689d76ab51cc7cc221bead874cf4..143a903deb3d6494932f6e61e0f419c2b095530c 100644 (file)
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -132,6 +132,10 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
  */
 extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
 extern int rw_verify_area(int, struct file *, const loff_t *, size_t);
+extern ssize_t do_aio_read(struct kiocb *kiocb, const struct iovec *iov,
+                          unsigned long nr_segs, loff_t pos);
+extern ssize_t do_aio_write(struct kiocb *kiocb, const struct iovec *iov,
+                           unsigned long nr_segs, loff_t pos);
 
 /*
  * splice.c

diff --git a/fs/read_write.c b/fs/read_write.c
index 022929ceabd3064431e6e638122de71e23a2c48d..c3579a945a4dab7f438c31f89a8a2e8c7ed349c8 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -29,7 +29,7 @@ typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *,
 const struct file_operations generic_ro_fops = {
        .llseek         = generic_file_llseek,
        .read           = do_sync_read,
-       .aio_read       = generic_file_aio_read,
+       .read_iter      = generic_file_read_iter,
        .mmap           = generic_file_readonly_mmap,
        .splice_read    = generic_file_splice_read,
 };
@@ -359,6 +359,29 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
        return count > MAX_RW_COUNT ? MAX_RW_COUNT : count;
 }
 
+ssize_t do_aio_read(struct kiocb *kiocb, const struct iovec *iov,
+                   unsigned long nr_segs, loff_t pos)
+{
+       struct file *file = kiocb->ki_filp;
+
+       if (file->f_op->read_iter) {
+               size_t count;
+               struct iov_iter iter;
+               int ret;
+
+               count = 0;
+               ret = generic_segment_checks(iov, &nr_segs, &count,
+                                            VERIFY_WRITE);
+               if (ret)
+                       return ret;
+
+               iov_iter_init(&iter, iov, nr_segs, count, 0);
+               return file->f_op->read_iter(kiocb, &iter, pos);
+       }
+
+       return file->f_op->aio_read(kiocb, iov, nr_segs, pos);
+}
+
 ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
        struct iovec iov = { .iov_base = buf, .iov_len = len };
@@ -370,7 +393,7 @@ ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *pp
        kiocb.ki_left = len;
        kiocb.ki_nbytes = len;
 
-       ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
+       ret = do_aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
        if (-EIOCBQUEUED == ret)
                ret = wait_on_sync_kiocb(&kiocb);
        *ppos = kiocb.ki_pos;
@@ -409,6 +432,29 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 
 EXPORT_SYMBOL(vfs_read);
 
+ssize_t do_aio_write(struct kiocb *kiocb, const struct iovec *iov,
+                    unsigned long nr_segs, loff_t pos)
+{
+       struct file *file = kiocb->ki_filp;
+
+       if (file->f_op->write_iter) {
+               size_t count;
+               struct iov_iter iter;
+               int ret;
+
+               count = 0;
+               ret = generic_segment_checks(iov, &nr_segs, &count,
+                                            VERIFY_READ);
+               if (ret)
+                       return ret;
+
+               iov_iter_init(&iter, iov, nr_segs, count, 0);
+               return file->f_op->write_iter(kiocb, &iter, pos);
+       }
+
+       return file->f_op->aio_write(kiocb, iov, nr_segs, pos);
+}
+
 ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
 {
        struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
@@ -420,7 +466,7 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof
        kiocb.ki_left = len;
        kiocb.ki_nbytes = len;
 
-       ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
+       ret = do_aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
        if (-EIOCBQUEUED == ret)
                ret = wait_on_sync_kiocb(&kiocb);
        *ppos = kiocb.ki_pos;
@@ -748,10 +794,12 @@ static ssize_t do_readv_writev(int type, struct file *file,
        fnv = NULL;
        if (type == READ) {
                fn = file->f_op->read;
-               fnv = file->f_op->aio_read;
+               if (file->f_op->aio_read || file->f_op->read_iter)
+                       fnv = do_aio_read;
        } else {
                fn = (io_fn_t)file->f_op->write;
-               fnv = file->f_op->aio_write;
+               if (file->f_op->aio_write || file->f_op->write_iter)
+                       fnv = do_aio_write;
                file_start_write(file);
        }
 
@@ -930,10 +978,12 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
        fnv = NULL;
        if (type == READ) {
                fn = file->f_op->read;
-               fnv = file->f_op->aio_read;
+               if (file->f_op->aio_read || file->f_op->read_iter)
+                       fnv = do_aio_read;
        } else {
                fn = (io_fn_t)file->f_op->write;
-               fnv = file->f_op->aio_write;
+               if (file->f_op->aio_write || file->f_op->write_iter)
+                       fnv = do_aio_write;
                file_start_write(file);
        }
 

diff --git a/include/linux/fs.h b/include/linux/fs.h
index fc1e2a8cbf85e67021eeb8b46ec9a84ca9f341a3..26d9d8d4aa4ed3b31abb5638f7023218365f2fde 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1654,12 +1654,14 @@ struct file_operations {
 
 static inline int file_readable(struct file *filp)
 {
-       return filp && (filp->f_op->read || filp->f_op->aio_read);
+       return filp && (filp->f_op->read || filp->f_op->aio_read ||
+                       filp->f_op->read_iter);
 }
 
 static inline int file_writable(struct file *filp)
 {
-       return filp && (filp->f_op->write || filp->f_op->aio_write);
+       return filp && (filp->f_op->write || filp->f_op->aio_write ||
+                       filp->f_op->write_iter);
 }
 
 struct inode_operations {