f2fs: Provide a splice-read wrapper

Provide a splice_read wrapper for f2fs.  This does some checks and tracing
before calling filemap_splice_read() and will update the iostats
afterwards.  Direct I/O is handled by the caller.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Jaegeuk Kim <jaegeuk@kernel.org>
cc: Chao Yu <chao@kernel.org>
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-20-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5ac53d2627d20dc397cd6a0aae18ec6cdb224b8d..3fce122997ca80edf8d586ada574f9284d1f9f41 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4367,22 +4367,23 @@ out:
        return ret;
 }
 
-static void f2fs_trace_rw_file_path(struct kiocb *iocb, size_t count, int rw)
+static void f2fs_trace_rw_file_path(struct file *file, loff_t pos, size_t count,
+                                   int rw)
 {
-       struct inode *inode = file_inode(iocb->ki_filp);
+       struct inode *inode = file_inode(file);
        char *buf, *path;
 
        buf = f2fs_getname(F2FS_I_SB(inode));
        if (!buf)
                return;
-       path = dentry_path_raw(file_dentry(iocb->ki_filp), buf, PATH_MAX);
+       path = dentry_path_raw(file_dentry(file), buf, PATH_MAX);
        if (IS_ERR(path))
                goto free_buf;
        if (rw == WRITE)
-               trace_f2fs_datawrite_start(inode, iocb->ki_pos, count,
+               trace_f2fs_datawrite_start(inode, pos, count,
                                current->pid, path, current->comm);
        else
-               trace_f2fs_dataread_start(inode, iocb->ki_pos, count,
+               trace_f2fs_dataread_start(inode, pos, count,
                                current->pid, path, current->comm);
 free_buf:
        f2fs_putname(buf);
@@ -4398,7 +4399,8 @@ static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
                return -EOPNOTSUPP;
 
        if (trace_f2fs_dataread_start_enabled())
-               f2fs_trace_rw_file_path(iocb, iov_iter_count(to), READ);
+               f2fs_trace_rw_file_path(iocb->ki_filp, iocb->ki_pos,
+                                       iov_iter_count(to), READ);
 
        if (f2fs_should_use_dio(inode, iocb, to)) {
                ret = f2fs_dio_read_iter(iocb, to);
@@ -4413,6 +4415,30 @@ static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
        return ret;
 }
 
+static ssize_t f2fs_file_splice_read(struct file *in, loff_t *ppos,
+                                    struct pipe_inode_info *pipe,
+                                    size_t len, unsigned int flags)
+{
+       struct inode *inode = file_inode(in);
+       const loff_t pos = *ppos;
+       ssize_t ret;
+
+       if (!f2fs_is_compress_backend_ready(inode))
+               return -EOPNOTSUPP;
+
+       if (trace_f2fs_dataread_start_enabled())
+               f2fs_trace_rw_file_path(in, pos, len, READ);
+
+       ret = filemap_splice_read(in, ppos, pipe, len, flags);
+       if (ret > 0)
+               f2fs_update_iostat(F2FS_I_SB(inode), inode,
+                                  APP_BUFFERED_READ_IO, ret);
+
+       if (trace_f2fs_dataread_end_enabled())
+               trace_f2fs_dataread_end(inode, pos, ret);
+       return ret;
+}
+
 static ssize_t f2fs_write_checks(struct kiocb *iocb, struct iov_iter *from)
 {
        struct file *file = iocb->ki_filp;
@@ -4714,7 +4740,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
                ret = preallocated;
        } else {
                if (trace_f2fs_datawrite_start_enabled())
-                       f2fs_trace_rw_file_path(iocb, orig_count, WRITE);
+                       f2fs_trace_rw_file_path(iocb->ki_filp, iocb->ki_pos,
+                                               orig_count, WRITE);
 
                /* Do the actual write. */
                ret = dio ?
@@ -4919,7 +4946,7 @@ const struct file_operations f2fs_file_operations = {
 #ifdef CONFIG_COMPAT
        .compat_ioctl   = f2fs_compat_ioctl,
 #endif
-       .splice_read    = generic_file_splice_read,
+       .splice_read    = f2fs_file_splice_read,
        .splice_write   = iter_file_splice_write,
        .fadvise        = f2fs_file_fadvise,
 };