From b93b016313b3ba8003c3b8bb71f569af91f19fc7 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 10 Apr 2018 16:36:56 -0700 Subject: page cache: use xa_lock Remove the address_space ->tree_lock and use the xa_lock newly added to the radix_tree_root. Rename the address_space ->page_tree to ->i_pages, since we don't really care that it's a tree. [willy@infradead.org: fix nds32, fs/dax.c] Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org Signed-off-by: Matthew Wilcox Acked-by: Jeff Layton Cc: Darrick J. Wong Cc: Dave Chinner Cc: Ryusuke Konishi Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/backing-dev.h | 14 +++++++------- include/linux/fs.h | 8 ++++---- include/linux/mm.h | 2 +- include/linux/pagemap.h | 4 ++-- 4 files changed, 14 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index e6cbb915ee56..09da0f124699 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -329,7 +329,7 @@ static inline bool inode_to_wb_is_valid(struct inode *inode) * @inode: inode of interest * * Returns the wb @inode is currently associated with. The caller must be - * holding either @inode->i_lock, @inode->i_mapping->tree_lock, or the + * holding either @inode->i_lock, the i_pages lock, or the * associated wb's list_lock. */ static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) @@ -337,7 +337,7 @@ static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) #ifdef CONFIG_LOCKDEP WARN_ON_ONCE(debug_locks && (!lockdep_is_held(&inode->i_lock) && - !lockdep_is_held(&inode->i_mapping->tree_lock) && + !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) && !lockdep_is_held(&inode->i_wb->list_lock))); #endif return inode->i_wb; @@ -349,7 +349,7 @@ static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) * @lockedp: temp bool output param, to be passed to the end function * * The caller wants to access the wb associated with @inode but isn't - * holding inode->i_lock, mapping->tree_lock or wb->list_lock. This + * holding inode->i_lock, the i_pages lock or wb->list_lock. This * function determines the wb associated with @inode and ensures that the * association doesn't change until the transaction is finished with * unlocked_inode_to_wb_end(). @@ -370,11 +370,11 @@ unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) *lockedp = smp_load_acquire(&inode->i_state) & I_WB_SWITCH; if (unlikely(*lockedp)) - spin_lock_irq(&inode->i_mapping->tree_lock); + xa_lock_irq(&inode->i_mapping->i_pages); /* - * Protected by either !I_WB_SWITCH + rcu_read_lock() or tree_lock. - * inode_to_wb() will bark. Deref directly. + * Protected by either !I_WB_SWITCH + rcu_read_lock() or the i_pages + * lock. inode_to_wb() will bark. Deref directly. */ return inode->i_wb; } @@ -387,7 +387,7 @@ unlocked_inode_to_wb_begin(struct inode *inode, bool *lockedp) static inline void unlocked_inode_to_wb_end(struct inode *inode, bool locked) { if (unlikely(locked)) - spin_unlock_irq(&inode->i_mapping->tree_lock); + xa_unlock_irq(&inode->i_mapping->i_pages); rcu_read_unlock(); } diff --git a/include/linux/fs.h b/include/linux/fs.h index 2aa02cad94d4..92efaf1f8977 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -390,12 +391,11 @@ int pagecache_write_end(struct file *, struct address_space *mapping, struct address_space { struct inode *host; /* owner: inode, block_device */ - struct radix_tree_root page_tree; /* radix tree of all pages */ - spinlock_t tree_lock; /* and lock protecting it */ + struct radix_tree_root i_pages; /* cached pages */ atomic_t i_mmap_writable;/* count VM_SHARED mappings */ struct rb_root_cached i_mmap; /* tree of private and shared mappings */ struct rw_semaphore i_mmap_rwsem; /* protect tree, count, list */ - /* Protected by tree_lock together with the radix tree */ + /* Protected by the i_pages lock */ unsigned long nrpages; /* number of total pages */ /* number of shadow or DAX exceptional entries */ unsigned long nrexceptional; @@ -1989,7 +1989,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) * * I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to * synchronize competing switching instances and to tell - * wb stat updates to grab mapping->tree_lock. See + * wb stat updates to grab the i_pages lock. See * inode_switch_wb_work_fn() for details. * * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper diff --git a/include/linux/mm.h b/include/linux/mm.h index f13bc25f7a9f..1ac1f06a4be6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -747,7 +747,7 @@ int finish_mkwrite_fault(struct vm_fault *vmf); * refcount. The each user mapping also has a reference to the page. * * The pagecache pages are stored in a per-mapping radix tree, which is - * rooted at mapping->page_tree, and indexed by offset. + * rooted at mapping->i_pages, and indexed by offset. * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space * lists, we instead now tag pages as dirty/writeback in the radix tree. * diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 34ce3ebf97d5..b1bd2186e6d2 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -144,7 +144,7 @@ void release_pages(struct page **pages, int nr); * 3. check the page is still in pagecache (if no, goto 1) * * Remove-side that cares about stability of _refcount (eg. reclaim) has the - * following (with tree_lock held for write): + * following (with the i_pages lock held): * A. atomically check refcount is correct and set it to 0 (atomic_cmpxchg) * B. remove page from pagecache * C. free the page @@ -157,7 +157,7 @@ void release_pages(struct page **pages, int nr); * * It is possible that between 1 and 2, the page is removed then the exact same * page is inserted into the same position in pagecache. That's OK: the - * old find_get_page using tree_lock could equally have run before or after + * old find_get_page using a lock could equally have run before or after * such a re-insertion, depending on order that locks are granted. * * Lookups racing against pagecache insertion isn't a big problem: either 1 -- cgit v1.2.3