| Message ID | 20170721223956.29485-3-ross.zwisler@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 21-07-17 16:39:52, Ross Zwisler wrote: > dax_load_hole() will soon need to call dax_insert_mapping_entry(), so it > needs to be moved lower in dax.c so the definition exists. > > dax_wake_mapping_entry_waiter() will soon be removed from dax.h and be made > static to dax.c, so we need to move its definition above all its callers. > > Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/dax.c | 138 +++++++++++++++++++++++++++++++-------------------------------- > 1 file changed, 69 insertions(+), 69 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index c844a51..779dc5e 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -121,6 +121,31 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo > } > > /* > + * We do not necessarily hold the mapping->tree_lock when we call this > + * function so it is possible that 'entry' is no longer a valid item in the > + * radix tree. This is okay because all we really need to do is to find the > + * correct waitqueue where tasks might be waiting for that old 'entry' and > + * wake them. > + */ > +void dax_wake_mapping_entry_waiter(struct address_space *mapping, > + pgoff_t index, void *entry, bool wake_all) > +{ > + struct exceptional_entry_key key; > + wait_queue_head_t *wq; > + > + wq = dax_entry_waitqueue(mapping, index, entry, &key); > + > + /* > + * Checking for locked entry and prepare_to_wait_exclusive() happens > + * under mapping->tree_lock, ditto for entry handling in our callers. > + * So at this point all tasks that could have seen our entry locked > + * must be in the waitqueue and the following check will see them. > + */ > + if (waitqueue_active(wq)) > + __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); > +} > + > +/* > * Check whether the given slot is locked. The function must be called with > * mapping->tree_lock held > */ > @@ -392,31 +417,6 @@ static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, > return entry; > } > > -/* > - * We do not necessarily hold the mapping->tree_lock when we call this > - * function so it is possible that 'entry' is no longer a valid item in the > - * radix tree. This is okay because all we really need to do is to find the > - * correct waitqueue where tasks might be waiting for that old 'entry' and > - * wake them. > - */ > -void dax_wake_mapping_entry_waiter(struct address_space *mapping, > - pgoff_t index, void *entry, bool wake_all) > -{ > - struct exceptional_entry_key key; > - wait_queue_head_t *wq; > - > - wq = dax_entry_waitqueue(mapping, index, entry, &key); > - > - /* > - * Checking for locked entry and prepare_to_wait_exclusive() happens > - * under mapping->tree_lock, ditto for entry handling in our callers. > - * So at this point all tasks that could have seen our entry locked > - * must be in the waitqueue and the following check will see them. > - */ > - if (waitqueue_active(wq)) > - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); > -} > - > static int __dax_invalidate_mapping_entry(struct address_space *mapping, > pgoff_t index, bool trunc) > { > @@ -468,50 +468,6 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, > return __dax_invalidate_mapping_entry(mapping, index, false); > } > > -/* > - * The user has performed a load from a hole in the file. Allocating > - * a new page in the file would cause excessive storage usage for > - * workloads with sparse files. We allocate a page cache page instead. > - * We'll kick it out of the page cache if it's ever written to, > - * otherwise it will simply fall out of the page cache under memory > - * pressure without ever having been dirtied. > - */ > -static int dax_load_hole(struct address_space *mapping, void **entry, > - struct vm_fault *vmf) > -{ > - struct inode *inode = mapping->host; > - struct page *page; > - int ret; > - > - /* Hole page already exists? Return it... */ > - if (!radix_tree_exceptional_entry(*entry)) { > - page = *entry; > - goto finish_fault; > - } > - > - /* This will replace locked radix tree entry with a hole page */ > - page = find_or_create_page(mapping, vmf->pgoff, > - vmf->gfp_mask | __GFP_ZERO); > - if (!page) { > - ret = VM_FAULT_OOM; > - goto out; > - } > - > -finish_fault: > - vmf->page = page; > - ret = finish_fault(vmf); > - vmf->page = NULL; > - *entry = page; > - if (!ret) { > - /* Grab reference for PTE that is now referencing the page */ > - get_page(page); > - ret = VM_FAULT_NOPAGE; > - } > -out: > - trace_dax_load_hole(inode, vmf, ret); > - return ret; > -} > - > static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, > sector_t sector, size_t size, struct page *to, > unsigned long vaddr) > @@ -938,6 +894,50 @@ int dax_pfn_mkwrite(struct vm_fault *vmf) > } > EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); > > +/* > + * The user has performed a load from a hole in the file. Allocating > + * a new page in the file would cause excessive storage usage for > + * workloads with sparse files. We allocate a page cache page instead. > + * We'll kick it out of the page cache if it's ever written to, > + * otherwise it will simply fall out of the page cache under memory > + * pressure without ever having been dirtied. > + */ > +static int dax_load_hole(struct address_space *mapping, void **entry, > + struct vm_fault *vmf) > +{ > + struct inode *inode = mapping->host; > + struct page *page; > + int ret; > + > + /* Hole page already exists? Return it... */ > + if (!radix_tree_exceptional_entry(*entry)) { > + page = *entry; > + goto finish_fault; > + } > + > + /* This will replace locked radix tree entry with a hole page */ > + page = find_or_create_page(mapping, vmf->pgoff, > + vmf->gfp_mask | __GFP_ZERO); > + if (!page) { > + ret = VM_FAULT_OOM; > + goto out; > + } > + > +finish_fault: > + vmf->page = page; > + ret = finish_fault(vmf); > + vmf->page = NULL; > + *entry = page; > + if (!ret) { > + /* Grab reference for PTE that is now referencing the page */ > + get_page(page); > + ret = VM_FAULT_NOPAGE; > + } > +out: > + trace_dax_load_hole(inode, vmf, ret); > + return ret; > +} > + > static bool dax_range_is_aligned(struct block_device *bdev, > unsigned int offset, unsigned int length) > { > -- > 2.9.4 >
diff --git a/fs/dax.c b/fs/dax.c index c844a51..779dc5e 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -121,6 +121,31 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mo } /* + * We do not necessarily hold the mapping->tree_lock when we call this + * function so it is possible that 'entry' is no longer a valid item in the + * radix tree. This is okay because all we really need to do is to find the + * correct waitqueue where tasks might be waiting for that old 'entry' and + * wake them. + */ +void dax_wake_mapping_entry_waiter(struct address_space *mapping, + pgoff_t index, void *entry, bool wake_all) +{ + struct exceptional_entry_key key; + wait_queue_head_t *wq; + + wq = dax_entry_waitqueue(mapping, index, entry, &key); + + /* + * Checking for locked entry and prepare_to_wait_exclusive() happens + * under mapping->tree_lock, ditto for entry handling in our callers. + * So at this point all tasks that could have seen our entry locked + * must be in the waitqueue and the following check will see them. + */ + if (waitqueue_active(wq)) + __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); +} + +/* * Check whether the given slot is locked. The function must be called with * mapping->tree_lock held */ @@ -392,31 +417,6 @@ static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, return entry; } -/* - * We do not necessarily hold the mapping->tree_lock when we call this - * function so it is possible that 'entry' is no longer a valid item in the - * radix tree. This is okay because all we really need to do is to find the - * correct waitqueue where tasks might be waiting for that old 'entry' and - * wake them. - */ -void dax_wake_mapping_entry_waiter(struct address_space *mapping, - pgoff_t index, void *entry, bool wake_all) -{ - struct exceptional_entry_key key; - wait_queue_head_t *wq; - - wq = dax_entry_waitqueue(mapping, index, entry, &key); - - /* - * Checking for locked entry and prepare_to_wait_exclusive() happens - * under mapping->tree_lock, ditto for entry handling in our callers. - * So at this point all tasks that could have seen our entry locked - * must be in the waitqueue and the following check will see them. - */ - if (waitqueue_active(wq)) - __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); -} - static int __dax_invalidate_mapping_entry(struct address_space *mapping, pgoff_t index, bool trunc) { @@ -468,50 +468,6 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping, return __dax_invalidate_mapping_entry(mapping, index, false); } -/* - * The user has performed a load from a hole in the file. Allocating - * a new page in the file would cause excessive storage usage for - * workloads with sparse files. We allocate a page cache page instead. - * We'll kick it out of the page cache if it's ever written to, - * otherwise it will simply fall out of the page cache under memory - * pressure without ever having been dirtied. - */ -static int dax_load_hole(struct address_space *mapping, void **entry, - struct vm_fault *vmf) -{ - struct inode *inode = mapping->host; - struct page *page; - int ret; - - /* Hole page already exists? Return it... */ - if (!radix_tree_exceptional_entry(*entry)) { - page = *entry; - goto finish_fault; - } - - /* This will replace locked radix tree entry with a hole page */ - page = find_or_create_page(mapping, vmf->pgoff, - vmf->gfp_mask | __GFP_ZERO); - if (!page) { - ret = VM_FAULT_OOM; - goto out; - } - -finish_fault: - vmf->page = page; - ret = finish_fault(vmf); - vmf->page = NULL; - *entry = page; - if (!ret) { - /* Grab reference for PTE that is now referencing the page */ - get_page(page); - ret = VM_FAULT_NOPAGE; - } -out: - trace_dax_load_hole(inode, vmf, ret); - return ret; -} - static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, sector_t sector, size_t size, struct page *to, unsigned long vaddr) @@ -938,6 +894,50 @@ int dax_pfn_mkwrite(struct vm_fault *vmf) } EXPORT_SYMBOL_GPL(dax_pfn_mkwrite); +/* + * The user has performed a load from a hole in the file. Allocating + * a new page in the file would cause excessive storage usage for + * workloads with sparse files. We allocate a page cache page instead. + * We'll kick it out of the page cache if it's ever written to, + * otherwise it will simply fall out of the page cache under memory + * pressure without ever having been dirtied. + */ +static int dax_load_hole(struct address_space *mapping, void **entry, + struct vm_fault *vmf) +{ + struct inode *inode = mapping->host; + struct page *page; + int ret; + + /* Hole page already exists? Return it... */ + if (!radix_tree_exceptional_entry(*entry)) { + page = *entry; + goto finish_fault; + } + + /* This will replace locked radix tree entry with a hole page */ + page = find_or_create_page(mapping, vmf->pgoff, + vmf->gfp_mask | __GFP_ZERO); + if (!page) { + ret = VM_FAULT_OOM; + goto out; + } + +finish_fault: + vmf->page = page; + ret = finish_fault(vmf); + vmf->page = NULL; + *entry = page; + if (!ret) { + /* Grab reference for PTE that is now referencing the page */ + get_page(page); + ret = VM_FAULT_NOPAGE; + } +out: + trace_dax_load_hole(inode, vmf, ret); + return ret; +} + static bool dax_range_is_aligned(struct block_device *bdev, unsigned int offset, unsigned int length) {
dax_load_hole() will soon need to call dax_insert_mapping_entry(), so it needs to be moved lower in dax.c so the definition exists. dax_wake_mapping_entry_waiter() will soon be removed from dax.h and be made static to dax.c, so we need to move its definition above all its callers. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> --- fs/dax.c | 138 +++++++++++++++++++++++++++++++-------------------------------- 1 file changed, 69 insertions(+), 69 deletions(-)