[PATCH v3 1/8] ext4/xfs: add page refcount helper
From: Alex Sierra <hidden>
Date: 2021-06-19 18:32:04
Also in:
amd-gfx, dri-devel, linux-mm, linux-xfs
Subsystem:
ext4 file system, filesystem direct access (dax), filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
"Theodore Ts'o", Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
From: Ralph Campbell <redacted> There are several places where ZONE_DEVICE struct pages assume a reference count == 1 means the page is idle and free. Instead of open coding this, add a helper function to hide this detail. v3: [AS]: rename dax_layout_is_idle_page func to dax_page_unused Signed-off-by: Ralph Campbell <redacted> Signed-off-by: Alex Sierra <redacted> --- fs/dax.c | 4 ++-- fs/ext4/inode.c | 5 +---- fs/xfs/xfs_file.c | 4 +--- include/linux/dax.h | 10 ++++++++++ 4 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 26d5dcd2d69e..4820bb511d68 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); + WARN_ON_ONCE(trunc && !dax_page_unused(page)); WARN_ON_ONCE(page->mapping && page->mapping != mapping); page->mapping = NULL; page->index = 0;
@@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - if (page_ref_count(page) > 1) + if (!dax_page_unused(page)) return page; } return NULL;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c173c8405856..9ee00186412f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -3972,10 +3972,7 @@ int ext4_break_layouts(struct inode *inode) if (!page) return 0; - error = ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, - TASK_INTERRUPTIBLE, 0, 0, - ext4_wait_dax_page(ei)); + error = dax_wait_page(ei, page, ext4_wait_dax_page); } while (error == 0); return error;
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 5b0f93f73837..39565fe5f817 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c@@ -782,9 +782,7 @@ xfs_break_dax_layouts( return 0; *retry = true; - return ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, - 0, 0, xfs_wait_dax_page(inode)); + return dax_wait_page(inode, page, xfs_wait_dax_page); } int
diff --git a/include/linux/dax.h b/include/linux/dax.h
index b52f084aa643..8b5da1d60dbc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h@@ -243,6 +243,16 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } +static inline bool dax_page_unused(struct page *page) +{ + return page_ref_count(page) == 1; +} + +#define dax_wait_page(_inode, _page, _wait_cb) \ + ___wait_var_event(&(_page)->_refcount, \ + dax_page_unused(_page), \ + TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode)) + #ifdef CONFIG_DEV_DAX_HMEM_DEVICES void hmem_register_device(int target_nid, struct resource *r); #else
--
2.32.0