From: Ira Weiny <[email protected]> ext4 must attempt to break a layout lease if it is held to know if the layout can be modified.
Split out the logic to determine if a mapping is DAX, export it, and then break layout leases if a mapping is DAX. Signed-off-by: Ira Weiny <[email protected]> --- Changes from RFC v1: Based on feedback from Dave Chinner, add support to fail all other layout breaks when a lease is held. fs/dax.c | 23 ++++++++++++++++------- fs/ext4/inode.c | 7 +++++++ include/linux/dax.h | 6 ++++++ 3 files changed, 29 insertions(+), 7 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index b64964ef44f6..a14ec32255d8 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -557,6 +557,21 @@ static void *grab_mapping_entry(struct xa_state *xas, return xa_mk_internal(VM_FAULT_FALLBACK); } +bool dax_mapping_is_dax(struct address_space *mapping) +{ + /* + * In the 'limited' case get_user_pages() for dax is disabled. + */ + if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) + return false; + + if (!dax_mapping(mapping) || !mapping_mapped(mapping)) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(dax_mapping_is_dax); + /** * dax_layout_busy_page - find first pinned page in @mapping * @mapping: address space to scan for a page with ref count > 1 @@ -579,13 +594,7 @@ struct page *dax_layout_busy_page(struct address_space *mapping) unsigned int scanned = 0; struct page *page = NULL; - /* - * In the 'limited' case get_user_pages() for dax is disabled. - */ - if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) - return NULL; - - if (!dax_mapping(mapping) || !mapping_mapped(mapping)) + if (!dax_mapping_is_dax(mapping)) return NULL; /* diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index b2c8d09acf65..f08f48de52c5 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4271,6 +4271,13 @@ int ext4_break_layouts(struct inode *inode) if (WARN_ON_ONCE(!rwsem_is_locked(&ei->i_mmap_sem))) return -EINVAL; + /* Break layout leases if active */ + if (dax_mapping_is_dax(inode->i_mapping)) { + error = break_layout(inode, true); + if (error) + return error; + } + do { page = dax_layout_busy_page(inode->i_mapping); if (!page) diff --git a/include/linux/dax.h b/include/linux/dax.h index 9bd8528bd305..da0768b34b48 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -143,6 +143,7 @@ struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); int dax_writeback_mapping_range(struct address_space *mapping, struct block_device *bdev, struct writeback_control *wbc); +bool dax_mapping_is_dax(struct address_space *mapping); struct page *dax_layout_busy_page(struct address_space *mapping); dax_entry_t dax_lock_page(struct page *page); void dax_unlock_page(struct page *page, dax_entry_t cookie); @@ -174,6 +175,11 @@ static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) return NULL; } +static inline bool dax_mapping_is_dax(struct address_space *mapping) +{ + return false; +} + static inline struct page *dax_layout_busy_page(struct address_space *mapping) { return NULL; -- 2.20.1
