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author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-04-29 14:45:43 +0200 |
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committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-05-09 22:21:44 +0200 |
commit | 08830c8bc6cc7047d2cc8a136849a15fcb977044 (patch) | |
tree | 1508259225849278114543f831a9083e8a137fd4 | |
parent | fs: Introduce aops->read_folio (diff) | |
download | linux-08830c8bc6cc7047d2cc8a136849a15fcb977044.tar.xz linux-08830c8bc6cc7047d2cc8a136849a15fcb977044.zip |
fs: Add read_folio documentation
Convert all the ->readpage documentation to ->read_folio.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
-rw-r--r-- | Documentation/filesystems/fscrypt.rst | 2 | ||||
-rw-r--r-- | Documentation/filesystems/fsverity.rst | 2 | ||||
-rw-r--r-- | Documentation/filesystems/locking.rst | 10 | ||||
-rw-r--r-- | Documentation/filesystems/netfs_library.rst | 8 | ||||
-rw-r--r-- | Documentation/filesystems/vfs.rst | 20 |
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 |