From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: Christoph Hellwig <hch@lst.de>,
kent.overstreet@gmail.com, Matthew Wilcox <willy@infradead.org>
Subject: [PATCH v3 17/18] mm/filemap: Rename generic_file_buffered_read to filemap_read
Date: Tue, 10 Nov 2020 03:37:02 +0000 [thread overview]
Message-ID: <20201110033703.23261-18-willy@infradead.org> (raw)
In-Reply-To: <20201110033703.23261-1-willy@infradead.org>
From: Christoph Hellwig <hch@lst.de>
Rename generic_file_buffered_read to match the naming of filemap_fault,
also update the written parameter to a more descriptive name and
improve the kerneldoc comment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
---
fs/btrfs/file.c | 2 +-
include/linux/fs.h | 4 ++--
mm/filemap.c | 35 ++++++++++++++++-------------------
3 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 87355a38a654..1a4913e1fd12 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -3633,7 +3633,7 @@ static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
return ret;
}
- return generic_file_buffered_read(iocb, to, ret);
+ return filemap_read(iocb, to, ret);
}
const struct file_operations btrfs_file_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4ccc879ae845..413e327fa1c6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2946,8 +2946,8 @@ extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
extern int generic_write_check_limits(struct file *file, loff_t pos,
loff_t *count);
extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
-extern ssize_t generic_file_buffered_read(struct kiocb *iocb,
- struct iov_iter *to, ssize_t already_read);
+ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to,
+ ssize_t already_read);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
diff --git a/mm/filemap.c b/mm/filemap.c
index e39a255200d5..a080200a9fa0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2394,23 +2394,20 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter,
}
/**
- * generic_file_buffered_read - generic file read routine
- * @iocb: the iocb to read
- * @iter: data destination
- * @written: already copied
+ * filemap_read - Read data from the page cache.
+ * @iocb: The iocb to read.
+ * @iter: Destination for the data.
+ * @already_read: Number of bytes already read by the caller.
*
- * This is a generic file read routine, and uses the
- * mapping->a_ops->readpage() function for the actual low-level stuff.
+ * Copies data from the page cache. If the data is not currently present,
+ * uses the readahead and readpage address_space operations to fetch it.
*
- * This is really ugly. But the goto's actually try to clarify some
- * of the logic when it comes to error handling etc.
- *
- * Return:
- * * total number of bytes copied, including those the were already @written
- * * negative error code if nothing was copied
+ * Return: Total number of bytes copied, including those already read by
+ * the caller. If an error happens before any bytes are copied, returns
+ * a negative error number.
*/
-ssize_t generic_file_buffered_read(struct kiocb *iocb,
- struct iov_iter *iter, ssize_t written)
+ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *iter,
+ ssize_t already_read)
{
struct file *filp = iocb->ki_filp;
struct file_ra_state *ra = &filp->f_ra;
@@ -2434,7 +2431,7 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
* can no longer safely return -EIOCBQUEUED. Hence mark
* an async read NOWAIT at that point.
*/
- if ((iocb->ki_flags & IOCB_WAITQ) && written)
+ if ((iocb->ki_flags & IOCB_WAITQ) && already_read)
iocb->ki_flags |= IOCB_NOWAIT;
error = filemap_get_pages(iocb, iter, &pvec);
@@ -2494,7 +2491,7 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
copied = copy_page_to_iter(page, offset, bytes, iter);
- written += copied;
+ already_read += copied;
iocb->ki_pos += copied;
ra->prev_pos = iocb->ki_pos;
@@ -2511,9 +2508,9 @@ ssize_t generic_file_buffered_read(struct kiocb *iocb,
file_accessed(filp);
- return written ? written : error;
+ return already_read ? already_read : error;
}
-EXPORT_SYMBOL_GPL(generic_file_buffered_read);
+EXPORT_SYMBOL_GPL(filemap_read);
/**
* generic_file_read_iter - generic filesystem read routine
@@ -2587,7 +2584,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
goto out;
}
- retval = generic_file_buffered_read(iocb, iter, retval);
+ retval = filemap_read(iocb, iter, retval);
out:
return retval;
}
--
2.28.0
next prev parent reply other threads:[~2020-11-10 3:37 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 3:36 [PATCH v3 00/18] Refactor generic_file_buffered_read Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 01/18] mm/filemap: Rename generic_file_buffered_read subfunctions Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 02/18] mm/filemap: Remove dynamically allocated array from filemap_read Matthew Wilcox (Oracle)
2020-11-10 18:20 ` Christoph Hellwig
2020-11-10 3:36 ` [PATCH v3 03/18] mm/filemap: Convert filemap_get_pages to take a pagevec Matthew Wilcox (Oracle)
2020-11-10 18:21 ` Christoph Hellwig
2020-11-10 18:25 ` Matthew Wilcox
2020-11-10 3:36 ` [PATCH v3 04/18] mm/filemap: Use THPs in generic_file_buffered_read Matthew Wilcox (Oracle)
2020-11-17 16:00 ` Zi Yan
2020-11-17 16:07 ` Matthew Wilcox
2020-11-10 3:36 ` [PATCH v3 05/18] mm/filemap: Pass a sleep state to put_and_wait_on_page_locked Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 06/18] mm/filemap: Support readpage splitting a page Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 07/18] mm/filemap: Inline __wait_on_page_locked_async into caller Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 08/18] mm/filemap: Don't call ->readpage if IOCB_WAITQ is set Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 09/18] mm/filemap: Change filemap_read_page calling conventions Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 10/18] mm/filemap: Change filemap_create_page " Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 11/18] mm/filemap: Convert filemap_update_page to return an errno Matthew Wilcox (Oracle)
2020-11-10 18:22 ` Christoph Hellwig
2020-11-10 3:36 ` [PATCH v3 12/18] mm/filemap: Move the iocb checks into filemap_update_page Matthew Wilcox (Oracle)
2020-11-10 3:36 ` [PATCH v3 13/18] mm/filemap: Add filemap_range_uptodate Matthew Wilcox (Oracle)
2020-11-10 18:22 ` Christoph Hellwig
2020-11-10 3:36 ` [PATCH v3 14/18] mm/filemap: Split filemap_readahead out of filemap_get_pages Matthew Wilcox (Oracle)
2020-11-10 18:23 ` Christoph Hellwig
2020-11-10 3:37 ` [PATCH v3 15/18] mm/filemap: Restructure filemap_get_pages Matthew Wilcox (Oracle)
2020-11-10 18:24 ` Christoph Hellwig
2020-11-10 3:37 ` [PATCH v3 16/18] mm/filemap: Don't relock the page after calling readpage Matthew Wilcox (Oracle)
2020-11-10 18:24 ` Christoph Hellwig
2020-11-10 3:37 ` Matthew Wilcox (Oracle) [this message]
2020-11-10 3:37 ` [PATCH v3 18/18] mm/filemap: Simplify generic_file_read_iter Matthew Wilcox (Oracle)
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