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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-04-29 08:45:43 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-05-09 16:21:44 -0400
commit08830c8bc6cc7047d2cc8a136849a15fcb977044 (patch)
tree1508259225849278114543f831a9083e8a137fd4 /Documentation/filesystems
parent5efe7448a1426250b5747c10ad438517f44f1e51 (diff)
fs: Add read_folio documentation
Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/fscrypt.rst2
-rw-r--r--Documentation/filesystems/fsverity.rst2
-rw-r--r--Documentation/filesystems/locking.rst10
-rw-r--r--Documentation/filesystems/netfs_library.rst8
-rw-r--r--Documentation/filesystems/vfs.rst20
5 files changed, 21 insertions, 21 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst
index 6ccd5efb25b7..2e9aaa295125 100644
--- a/Documentation/filesystems/fscrypt.rst
+++ b/Documentation/filesystems/fscrypt.rst
@@ -1256,7 +1256,7 @@ inline encryption hardware will encrypt/decrypt the file contents.
When inline encryption isn't used, filesystems must encrypt/decrypt
the file contents themselves, as described below:
-For the read path (->readpage()) of regular files, filesystems can
+For the read path (->read_folio()) of regular files, filesystems can
read the ciphertext into the page cache and decrypt it in-place. The
page lock must be held until decryption has finished, to prevent the
page from becoming visible to userspace prematurely.
diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst
index 8cc536d08f51..36290530e194 100644
--- a/Documentation/filesystems/fsverity.rst
+++ b/Documentation/filesystems/fsverity.rst
@@ -548,7 +548,7 @@ already verified). Below, we describe how filesystems implement this.
Pagecache
~~~~~~~~~
-For filesystems using Linux's pagecache, the ``->readpage()`` and
+For filesystems using Linux's pagecache, the ``->read_folio()`` and
``->readahead()`` methods must be modified to verify pages before they
are marked Uptodate. Merely hooking ``->read_iter()`` would be
insufficient, since ``->read_iter()`` is not used for memory maps.
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index fd9d9caf09ab..aeba2475a53c 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -237,7 +237,7 @@ address_space_operations
prototypes::
int (*writepage)(struct page *page, struct writeback_control *wbc);
- int (*readpage)(struct file *, struct page *);
+ int (*read_folio)(struct file *, struct folio *);
int (*writepages)(struct address_space *, struct writeback_control *);
bool (*dirty_folio)(struct address_space *, struct folio *folio);
void (*readahead)(struct readahead_control *);
@@ -268,7 +268,7 @@ locking rules:
ops PageLocked(page) i_rwsem invalidate_lock
====================== ======================== ========= ===============
writepage: yes, unlocks (see below)
-readpage: yes, unlocks shared
+read_folio: yes, unlocks shared
writepages:
dirty_folio maybe
readahead: yes, unlocks shared
@@ -289,13 +289,13 @@ swap_activate: no
swap_deactivate: no
====================== ======================== ========= ===============
-->write_begin(), ->write_end() and ->readpage() may be called from
+->write_begin(), ->write_end() and ->read_folio() may be called from
the request handler (/dev/loop).
-->readpage() unlocks the page, either synchronously or via I/O
+->read_folio() unlocks the folio, either synchronously or via I/O
completion.
-->readahead() unlocks the pages that I/O is attempted on like ->readpage().
+->readahead() unlocks the folios that I/O is attempted on like ->read_folio().
->writepage() is used for two purposes: for "memory cleansing" and for
"sync". These are quite different operations and the behaviour may differ
diff --git a/Documentation/filesystems/netfs_library.rst b/Documentation/filesystems/netfs_library.rst
index d51c2a5ccf57..a80a59941d2f 100644
--- a/Documentation/filesystems/netfs_library.rst
+++ b/Documentation/filesystems/netfs_library.rst
@@ -96,7 +96,7 @@ attached to an inode (or NULL if fscache is disabled)::
Buffered Read Helpers
=====================
-The library provides a set of read helpers that handle the ->readpage(),
+The library provides a set of read helpers that handle the ->read_folio(),
->readahead() and much of the ->write_begin() VM operations and translate them
into a common call framework.
@@ -136,8 +136,8 @@ Read Helper Functions
Three read helpers are provided::
void netfs_readahead(struct readahead_control *ractl);
- int netfs_readpage(struct file *file,
- struct page *page);
+ int netfs_read_folio(struct file *file,
+ struct folio *folio);
int netfs_write_begin(struct file *file,
struct address_space *mapping,
loff_t pos,
@@ -148,7 +148,7 @@ Three read helpers are provided::
Each corresponds to a VM address space operation. These operations use the
state in the per-inode context.
-For ->readahead() and ->readpage(), the network filesystem just point directly
+For ->readahead() and ->read_folio(), the network filesystem just point directly
at the corresponding read helper; whereas for ->write_begin(), it may be a
little more complicated as the network filesystem might want to flush
conflicting writes or track dirty data and needs to put the acquired folio if
diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index 469882f72fc1..0919a4ad973a 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -656,7 +656,7 @@ by memory-mapping the page. Data is written into the address space by
the application, and then written-back to storage typically in whole
pages, however the address_space has finer control of write sizes.
-The read process essentially only requires 'readpage'. The write
+The read process essentially only requires 'read_folio'. The write
process is more complicated and uses write_begin/write_end or
dirty_folio to write data into the address_space, and writepage and
writepages to writeback data to storage.
@@ -722,7 +722,7 @@ cache in your filesystem. The following members are defined:
struct address_space_operations {
int (*writepage)(struct page *page, struct writeback_control *wbc);
- int (*readpage)(struct file *, struct page *);
+ int (*read_folio)(struct file *, struct folio *);
int (*writepages)(struct address_space *, struct writeback_control *);
bool (*dirty_folio)(struct address_space *, struct folio *);
void (*readahead)(struct readahead_control *);
@@ -772,14 +772,14 @@ cache in your filesystem. The following members are defined:
See the file "Locking" for more details.
-``readpage``
- called by the VM to read a page from backing store. The page
- will be Locked when readpage is called, and should be unlocked
- and marked uptodate once the read completes. If ->readpage
- discovers that it needs to unlock the page for some reason, it
- can do so, and then return AOP_TRUNCATED_PAGE. In this case,
- the page will be relocated, relocked and if that all succeeds,
- ->readpage will be called again.
+``read_folio``
+ called by the VM to read a folio from backing store. The folio
+ will be locked when read_folio is called, and should be unlocked
+ and marked uptodate once the read completes. If ->read_folio
+ discovers that it cannot perform the I/O at this time, it can
+ unlock the folio and return AOP_TRUNCATED_PAGE. In this case,
+ the folio will be looked up again, relocked and if that all succeeds,
+ ->read_folio will be called again.
``writepages``
called by the VM to write out pages associated with the