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Date: Fri, 15 Dec 2017 14:04:30 -0800 From: Matthew Wilcox <willy@...radead.org> To: linux-kernel@...r.kernel.org Cc: Matthew Wilcox <mawilcox@...rosoft.com>, Ross Zwisler <ross.zwisler@...ux.intel.com>, David Howells <dhowells@...hat.com>, Shaohua Li <shli@...nel.org>, Jens Axboe <axboe@...nel.dk>, Rehas Sachdeva <aquannie@...il.com>, Marc Zyngier <marc.zyngier@....com>, linux-mm@...ck.org, linux-fsdevel@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net, linux-nilfs@...r.kernel.org, linux-btrfs@...r.kernel.org, linux-xfs@...r.kernel.org, linux-usb@...r.kernel.org, linux-raid@...r.kernel.org Subject: [PATCH v5 58/78] dax: Convert dax_unlock_mapping_entry to XArray From: Matthew Wilcox <mawilcox@...rosoft.com> Replace slot_locked() with dax_locked() and inline unlock_slot() into its only caller. Signed-off-by: Matthew Wilcox <mawilcox@...rosoft.com> --- fs/dax.c | 48 ++++++++++++++++-------------------------------- 1 file changed, 16 insertions(+), 32 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 92693859efb5..dd4674ce48f5 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -73,6 +73,11 @@ fs_initcall(init_dax_wait_table); #define DAX_ZERO_PAGE (1UL << 2) #define DAX_EMPTY (1UL << 3) +static bool dax_locked(void *entry) +{ + return xa_to_value(entry) & DAX_ENTRY_LOCK; +} + static unsigned long dax_radix_sector(void *entry) { return xa_to_value(entry) >> DAX_SHIFT; @@ -180,16 +185,6 @@ static void dax_wake_mapping_entry_waiter(struct address_space *mapping, __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); } -/* - * Check whether the given slot is locked. Must be called with xa_lock held. - */ -static inline int slot_locked(struct address_space *mapping, void **slot) -{ - unsigned long entry = xa_to_value( - radix_tree_deref_slot_protected(slot, &mapping->pages.xa_lock)); - return entry & DAX_ENTRY_LOCK; -} - /* * Mark the given slot as locked. Must be called with xa_lock held. */ @@ -202,18 +197,6 @@ static inline void *lock_slot(struct address_space *mapping, void **slot) return entry; } -/* - * Mark the given slot as unlocked. Must be called with xa_lock held. - */ -static inline void *unlock_slot(struct address_space *mapping, void **slot) -{ - unsigned long v = xa_to_value( - radix_tree_deref_slot_protected(slot, &mapping->pages.xa_lock)); - void *entry = xa_mk_value(v & ~DAX_ENTRY_LOCK); - radix_tree_replace_slot(&mapping->pages, slot, entry); - return entry; -} - /* * Lookup entry in radix tree, wait for it to become unlocked if it is * a DAX entry and return it. The caller must call @@ -237,8 +220,7 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping, entry = __radix_tree_lookup(&mapping->pages, index, NULL, &slot); if (!entry || - WARN_ON_ONCE(!xa_is_value(entry)) || - !slot_locked(mapping, slot)) { + WARN_ON_ONCE(!xa_is_value(entry)) || !dax_locked(entry)) { if (slotp) *slotp = slot; return entry; @@ -257,17 +239,19 @@ static void *get_unlocked_mapping_entry(struct address_space *mapping, static void dax_unlock_mapping_entry(struct address_space *mapping, pgoff_t index) { - void *entry, **slot; + XA_STATE(xas, &mapping->pages, index); + void *entry; - xa_lock_irq(&mapping->pages); - entry = __radix_tree_lookup(&mapping->pages, index, NULL, &slot); - if (WARN_ON_ONCE(!entry || !xa_is_value(entry) || - !slot_locked(mapping, slot))) { - xa_unlock_irq(&mapping->pages); + xas_lock_irq(&xas); + entry = xas_load(&xas); + if (WARN_ON_ONCE(!entry || !xa_is_value(entry) || !dax_locked(entry))) { + xas_unlock_irq(&xas); return; } - unlock_slot(mapping, slot); - xa_unlock_irq(&mapping->pages); + entry = xa_mk_value(xa_to_value(entry) & ~DAX_ENTRY_LOCK); + xas_store(&xas, entry); + /* Safe to not call xas_pause here -- we don't touch the array after */ + xas_unlock_irq(&xas); dax_wake_mapping_entry_waiter(mapping, index, entry, false); } -- 2.15.1
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