linux.git/fs/mpage.c, branch v6.18.21

mpage: convert do_mpage_readpage() to return void type

2025-09-21T21:22:16+00:00

The return value of do_mpage_readpage() is arg->bio, which is already set
in the arg structure.  Returning it again is redundant.

This patch changes the return type to void since the caller doesn't care
about the return value.

Link: https://lkml.kernel.org/r/20250829023659.688649-2-chizhiling@163.com
Signed-off-by: Chi Zhiling 
Reviewed-by: Jan Kara 
Cc: Al Viro 
Cc: Christian Brauner 
Cc: Matthew Wilcox (Oracle) 
Cc: Namjae Jeon 
Cc: Sungjong Seo 
Cc: Yuezhang Mo 
Signed-off-by: Andrew Morton

mpage: terminate read-ahead on read error

2025-09-21T21:22:16+00:00

For exFAT filesystems with 4MB read_ahead_size, removing the storage
device during read operations can delay EIO error reporting by several
minutes.  This occurs because the read-ahead implementation in mpage
doesn't handle errors.

Another reason for the delay is that the filesystem requires metadata to
issue file read request.  When the storage device is removed, the metadata
buffers are invalidated, causing mpage to repeatedly attempt to fetch
metadata during each get_block call.

The original purpose of this patch is terminate read ahead when we fail to
get metadata, to make the patch more generic, implement it by checking
folio status, instead of checking the return of get_block().

So, if a folio is synchronously unlocked and non-uptodate, should we quit
the read ahead?

I think it depends on whether the error is permanent or temporary, and
whether further read ahead might succeed.  A device being unplugged is one
reason for returning such a folio, but we could return it for many other
reasons (e.g., metadata errors).  I think most errors won't be restored in
a short time, so we should quit read ahead when they occur.

Link: https://lkml.kernel.org/r/20250829023659.688649-1-chizhiling@163.com
Signed-off-by: Chi Zhiling 
Reviewed-by: Jan Kara 
Cc: Al Viro 
Cc: Christian Brauner 
Cc: Matthew Wilcox (Oracle) 
Cc: Namjae Jeon 
Cc: Sungjong Seo 
Cc: Yuezhang Mo 
Signed-off-by: Andrew Morton

fs: use writeback_iter directly in mpage_writepages

2025-05-09T10:37:48+00:00

Stop using write_cache_pages and use writeback_iter directly.  This
removes an indirect call per written folio and makes the code easier
to follow.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/20250507062124.3933305-1-hch@lst.de
Reviewed-by: Jan Kara 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christian Brauner

fs/buffer fs/mpage: remove large folio restriction

2025-02-24T10:44:44+00:00

Now that buffer-heads has been converted over to support large folios
we can remove the built-in VM_BUG_ON_FOLIO() checks which prevents
their use.

Reviewed-by: Hannes Reinecke 
Reviewed-by: "Matthew Wilcox (Oracle)" 
Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20250221223823.1680616-6-mcgrof@kernel.org
Reviewed-by: John Garry 
Signed-off-by: Christian Brauner

fs/mpage: use blocks_per_folio instead of blocks_per_page

2025-02-24T10:44:43+00:00

Convert mpage to folios and adjust accounting for the number of blocks
within a folio instead of a single page. This also adjusts the number
of pages we should process to be the size of the folio to ensure we
always read a full folio.

Note that the page cache code already ensures do_mpage_readpage() will
work with folios respecting the address space min order, this ensures
that so long as folio_size() is used for our requirements mpage will
also now be able to process block sizes larger than the page size.

Originally-by: Hannes Reinecke 
Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20250221223823.1680616-5-mcgrof@kernel.org
Reviewed-by: Hannes Reinecke 
Signed-off-by: Christian Brauner

fs/mpage: avoid negative shift for large blocksize

2025-02-24T10:44:43+00:00

For large blocksizes the number of block bits is larger than PAGE_SHIFT,
so calculate the sector number from the byte offset instead. This is
required to enable large folios with buffer-heads.

Reviewed-by: "Matthew Wilcox (Oracle)" 
Signed-off-by: Luis Chamberlain 
Signed-off-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20250221223823.1680616-4-mcgrof@kernel.org
Reviewed-by: Hannes Reinecke 
Signed-off-by: Christian Brauner

fs/writeback: convert wbc_account_cgroup_owner to take a folio

2024-10-28T12:26:54+00:00

Most of the callers of wbc_account_cgroup_owner() are converting a folio
to page before calling the function. wbc_account_cgroup_owner() is
converting the page back to a folio to call mem_cgroup_css_from_folio().

Convert wbc_account_cgroup_owner() to take a folio instead of a page,
and convert all callers to pass a folio directly except f2fs.

Convert the page to folio for all the callers from f2fs as they were the
only callers calling wbc_account_cgroup_owner() with a page. As f2fs is
already in the process of converting to folios, these call sites might
also soon be calling wbc_account_cgroup_owner() with a folio directly in
the future.

No functional changes. Only compile tested.

Signed-off-by: Pankaj Raghav 
Link: https://lore.kernel.org/r/20240926140121.203821-1-kernel@pankajraghav.com
Acked-by: David Sterba 
Acked-by: Tejun Heo 
Signed-off-by: Christian Brauner

buffer: Remove calls to set and clear the folio error flag

2024-05-31T10:31:43+00:00

The folio error flag is not tested anywhere, so we can stop setting
and clearing it.

Signed-off-by: Matthew Wilcox (Oracle) 
Link: https://lore.kernel.org/r/20240530202110.2653630-17-willy@infradead.org
Signed-off-by: Christian Brauner

block, fs: Restore the per-bio/request data lifetime fields

2024-02-06T13:31:05+00:00

Restore support for passing data lifetime information from filesystems to
block drivers. This patch reverts commit b179c98f7697 ("block: Remove
request.write_hint") and commit c75e707fe1aa ("block: remove the
per-bio/request write hint").

This patch does not modify the size of struct bio because the new
bi_write_hint member fills a hole in struct bio. pahole reports the
following for struct bio on an x86_64 system with this patch applied:

        /* size: 112, cachelines: 2, members: 20 */
        /* sum members: 110, holes: 1, sum holes: 2 */
        /* last cacheline: 48 bytes */

Reviewed-by: Kanchan Joshi 
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20240202203926.2478590-7-bvanassche@acm.org
Signed-off-by: Christian Brauner

fs: convert block_write_full_page to block_write_full_folio

2023-12-29T19:58:35+00:00

Convert the function to be compatible with writepage_t so that it can be
passed to write_cache_pages() by blkdev.  This removes a call to
compound_head().  We can also remove the function export as both callers
are built-in.

Link: https://lkml.kernel.org/r/20231215200245.748418-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Jens Axboe 
Signed-off-by: Andrew Morton