From: Matthew Wilcox <willy@infradead.org>
To: unlisted-recipients:; (no To-header on input)
Cc: Matthew Wilcox <mawilcox@microsoft.com>,
Ross Zwisler <ross.zwisler@linux.intel.com>,
Jens Axboe <axboe@kernel.dk>, Rehas Sachdeva <aquannie@gmail.com>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net,
linux-nilfs@vger.kernel.org, linux-btrfs@vger.kernel.org,
linux-xfs@vger.kernel.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v4 23/73] page cache: Add page_cache_range_empty function
Date: Tue, 5 Dec 2017 16:41:09 -0800 [thread overview]
Message-ID: <20171206004159.3755-24-willy@infradead.org> (raw)
In-Reply-To: <20171206004159.3755-1-willy@infradead.org>
From: Matthew Wilcox <mawilcox@microsoft.com>
btrfs has its own custom function for determining whether the page cache
has any pages in a particular range. Move this functionality to the
page cache, and call it from btrfs.
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
---
fs/btrfs/btrfs_inode.h | 7 ++++-
fs/btrfs/inode.c | 70 -------------------------------------------------
include/linux/pagemap.h | 2 ++
mm/filemap.c | 26 ++++++++++++++++++
4 files changed, 34 insertions(+), 71 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index 63f0ccc92a71..a48bd6e0a0bb 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -365,6 +365,11 @@ static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
logical_start, csum, csum_expected, mirror_num);
}
-bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end);
+static inline bool btrfs_page_exists_in_range(struct inode *inode,
+ loff_t start, loff_t end)
+{
+ return page_cache_range_empty(inode->i_mapping, start >> PAGE_SHIFT,
+ end >> PAGE_SHIFT);
+}
#endif
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 72f763c56127..a2692bceaa98 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7539,76 +7539,6 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
return ret;
}
-bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
-{
- struct radix_tree_root *root = &inode->i_mapping->pages;
- bool found = false;
- void **pagep = NULL;
- struct page *page = NULL;
- unsigned long start_idx;
- unsigned long end_idx;
-
- start_idx = start >> PAGE_SHIFT;
-
- /*
- * end is the last byte in the last page. end == start is legal
- */
- end_idx = end >> PAGE_SHIFT;
-
- rcu_read_lock();
-
- /* Most of the code in this while loop is lifted from
- * find_get_page. It's been modified to begin searching from a
- * page and return just the first page found in that range. If the
- * found idx is less than or equal to the end idx then we know that
- * a page exists. If no pages are found or if those pages are
- * outside of the range then we're fine (yay!) */
- while (page == NULL &&
- radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
- page = radix_tree_deref_slot(pagep);
- if (unlikely(!page))
- break;
-
- if (radix_tree_exception(page)) {
- if (radix_tree_deref_retry(page)) {
- page = NULL;
- continue;
- }
- /*
- * Otherwise, shmem/tmpfs must be storing a swap entry
- * here so return it without attempting to raise page
- * count.
- */
- page = NULL;
- break; /* TODO: Is this relevant for this use case? */
- }
-
- if (!page_cache_get_speculative(page)) {
- page = NULL;
- continue;
- }
-
- /*
- * Has the page moved?
- * This is part of the lockless pagecache protocol. See
- * include/linux/pagemap.h for details.
- */
- if (unlikely(page != *pagep)) {
- put_page(page);
- page = NULL;
- }
- }
-
- if (page) {
- if (page->index <= end_idx)
- found = true;
- put_page(page);
- }
-
- rcu_read_unlock();
- return found;
-}
-
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state, int writing)
{
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 0db127c3ccac..34d4fa3ad1c5 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -245,6 +245,8 @@ pgoff_t page_cache_next_gap(struct address_space *mapping,
pgoff_t index, unsigned long max_scan);
pgoff_t page_cache_prev_gap(struct address_space *mapping,
pgoff_t index, unsigned long max_scan);
+bool page_cache_range_empty(struct address_space *mapping,
+ pgoff_t index, pgoff_t max);
#define FGP_ACCESSED 0x00000001
#define FGP_LOCK 0x00000002
diff --git a/mm/filemap.c b/mm/filemap.c
index 650624f7b79d..51f88ffc5319 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1397,6 +1397,32 @@ pgoff_t page_cache_prev_gap(struct address_space *mapping,
}
EXPORT_SYMBOL(page_cache_prev_gap);
+bool page_cache_range_empty(struct address_space *mapping, pgoff_t index,
+ pgoff_t max)
+{
+ struct page *page;
+ XA_STATE(xas, &mapping->pages, index);
+
+ rcu_read_lock();
+ do {
+ page = xas_find(&xas, max);
+ if (xas_retry(&xas, page))
+ continue;
+ /* Shadow entries don't count */
+ if (xa_is_value(page))
+ continue;
+ /*
+ * We don't need to try to pin this page; we're about to
+ * release the RCU lock anyway. It is enough to know that
+ * there was a page here recently.
+ */
+ } while (0);
+ rcu_read_unlock();
+
+ return page != NULL;
+}
+EXPORT_SYMBOL_GPL(page_cache_range_empty);
+
/**
* find_get_entry - find and get a page cache entry
* @mapping: the address_space to search
--
2.15.0
next prev parent reply other threads:[~2017-12-06 1:00 UTC|newest]
Thread overview: 127+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-06 0:40 [PATCH v4 00/73] XArray version 4 Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 01/73] xfs: Rename xa_ elements to ail_ Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 02/73] xarray: Add the xa_lock to the radix_tree_root Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 03/73] page cache: Use xa_lock Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 04/73] xarray: Replace exceptional entries Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 05/73] xarray: Change definition of sibling entries Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 06/73] xarray: Add definition of struct xarray Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 07/73] xarray: Define struct xa_node Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 08/73] xarray: Add documentation Matthew Wilcox
2017-12-11 23:10 ` Randy Dunlap
2017-12-15 4:22 ` Matthew Wilcox
2017-12-15 12:34 ` Naming of tag operations in the XArray Matthew Wilcox
2017-12-19 0:16 ` Randy Dunlap
2017-12-15 17:10 ` Storing errors " Matthew Wilcox
2017-12-19 0:27 ` Randy Dunlap
2017-12-06 0:40 ` [PATCH v4 09/73] xarray: Add xa_load Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 10/73] xarray: Add xa_get_tag, xa_set_tag and xa_clear_tag Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 11/73] xarray: Add xa_store Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 12/73] xarray: Add xa_cmpxchg Matthew Wilcox
2017-12-06 0:40 ` [PATCH v4 13/73] xarray: Add xa_for_each Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 14/73] xarray: Add xas_for_each_tag Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 15/73] xarray: Add xa_get_entries, xa_get_tagged and xa_get_maybe_tag Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 16/73] xarray: Add xa_destroy Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 17/73] xarray: Add xas_next and xas_prev Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 18/73] xarray: Add xas_create_range Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 19/73] xarray: Add MAINTAINERS entry Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 20/73] idr: Convert to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 21/73] ida: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 22/73] page cache: Convert hole search " Matthew Wilcox
2017-12-06 0:41 ` Matthew Wilcox [this message]
2017-12-06 0:41 ` [PATCH v4 24/73] page cache: Add and replace pages using the XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 25/73] page cache: Convert page deletion to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 26/73] page cache: Convert page cache lookups " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 27/73] page cache: Convert delete_batch " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 28/73] page cache: Remove stray radix comment Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 29/73] mm: Convert page-writeback to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 30/73] mm: Convert workingset " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 31/73] mm: Convert truncate " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 32/73] mm: Convert add_to_swap_cache " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 33/73] mm: Convert delete_from_swap_cache " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 34/73] mm: Convert cgroup writeback " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 35/73] mm: Convert __do_page_cache_readahead " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 36/73] mm: Convert page migration " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 37/73] mm: Convert huge_memory " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 38/73] mm: Convert collapse_shmem " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 39/73] mm: Convert khugepaged_scan_shmem " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 40/73] pagevec: Use xa_tag_t Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 41/73] shmem: Convert replace to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 42/73] shmem: Convert shmem_confirm_swap " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 43/73] shmem: Convert find_swap_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 44/73] shmem: Convert shmem_tag_pins " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 45/73] shmem: Convert shmem_wait_for_pins " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 46/73] shmem: Convert shmem_add_to_page_cache " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 47/73] shmem: Convert shmem_alloc_hugepage " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 48/73] shmem: Convert shmem_free_swap " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 49/73] shmem: Convert shmem_partial_swap_usage " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 50/73] shmem: Comment fixups Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 51/73] btrfs: Convert page cache to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 52/73] fs: Convert buffer " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 53/73] fs: Convert writeback " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 54/73] nilfs2: Convert " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 55/73] f2fs: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 56/73] lustre: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 57/73] dax: Convert dax_unlock_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 58/73] dax: Convert lock_slot " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 59/73] dax: More XArray conversion Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 60/73] dax: Convert __dax_invalidate_mapping_entry to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 61/73] dax: Convert dax_writeback_one " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 62/73] dax: Convert dax_insert_pfn_mkwrite " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 63/73] dax: Convert dax_insert_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 64/73] dax: Convert grab_mapping_entry " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 65/73] dax: Fix sparse warning Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 66/73] page cache: Finish XArray conversion Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 67/73] vmalloc: Convert to XArray Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 68/73] brd: " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 69/73] xfs: Convert m_perag_tree " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 70/73] xfs: Convert pag_ici_root " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 71/73] xfs: Convert xfs dquot " Matthew Wilcox
2017-12-06 0:41 ` [PATCH v4 72/73] xfs: Convert mru cache " Matthew Wilcox
2017-12-06 1:36 ` Dave Chinner
2017-12-06 2:02 ` Matthew Wilcox
2017-12-06 3:14 ` Dave Chinner
2017-12-06 4:45 ` Matthew Wilcox
2017-12-06 4:52 ` Matthew Wilcox
2017-12-06 8:44 ` Dave Chinner
2017-12-06 14:06 ` Matthew Wilcox
2017-12-07 0:38 ` Dave Chinner
2017-12-08 23:01 ` Matthew Wilcox
2017-12-10 23:57 ` Dave Chinner
2017-12-11 4:23 ` Matthew Wilcox
2017-12-11 21:55 ` Dave Chinner
2017-12-07 16:06 ` Theodore Ts'o
2017-12-07 22:22 ` Dave Chinner
2017-12-08 4:45 ` Byungchul Park
2017-12-08 7:25 ` Dave Chinner
2017-12-08 9:27 ` Byungchul Park
2017-12-08 17:35 ` Alan Stern
2017-12-08 22:36 ` Dave Chinner
2017-12-09 17:00 ` Joe Perches
2017-12-11 21:43 ` Dave Chinner
2017-12-11 22:12 ` Joe Perches
2017-12-11 22:43 ` Matthew Wilcox
2017-12-11 23:46 ` Joe Perches
2017-12-12 15:51 ` Alan Stern
2017-12-14 18:23 ` Joe Perches
2017-12-17 1:26 ` [RFC patch] checkpatch: Add a test for long function definitions (>200 lines) Joe Perches
2017-12-17 21:46 ` Linus Torvalds
2017-12-17 22:22 ` Joe Perches
2017-12-17 22:33 ` Luc Van Oostenryck
2017-12-11 23:38 ` [PATCH v4 72/73] xfs: Convert mru cache to XArray Dave Chinner
2017-12-21 12:05 ` Knut Omang
2017-12-07 22:38 ` Lockdep is less useful than it was Matthew Wilcox
2017-12-07 22:39 ` Matthew Wilcox
2017-12-08 0:14 ` Dave Chinner
2017-12-08 15:27 ` Theodore Ts'o
2017-12-08 18:14 ` Matthew Wilcox
2017-12-08 22:47 ` Dave Chinner
2017-12-06 0:41 ` [PATCH v4 73/73] usb: Convert xhci-mem to XArray Matthew Wilcox
2017-12-06 1:45 ` [PATCH v4 00/73] XArray version 4 Dave Chinner
2017-12-06 1:51 ` Dave Chinner
2017-12-06 1:53 ` Matthew Wilcox
2017-12-06 2:17 ` Dave Chinner
2017-12-06 2:27 ` Matthew Wilcox
2017-12-06 2:05 ` Matthew Wilcox
2017-12-06 2:38 ` Dave Chinner
2017-12-06 23:58 ` Ross Zwisler
2017-12-07 0:13 ` Matthew Wilcox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171206004159.3755-24-willy@infradead.org \
--to=willy@infradead.org \
--cc=aquannie@gmail.com \
--cc=axboe@kernel.dk \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nilfs@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=mawilcox@microsoft.com \
--cc=ross.zwisler@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).