class LockedPage

class LockedPage

Defined at line 202 of file ../../src/storage/f2fs/file_cache.h

LockedPage is a wrapper class for f2fs::Page lock management.

When LockedPage holds "fbl::RefPtr<Page> page" and the page is not nullptr, it guarantees that

the page is locked.

The syntax looks something like...

fbl::RefPtr

<Page

> unlocked_page;

{

LockedPage locked_page(unlocked_page);

do something requiring page lock...

}

When Page is used as a function parameter, you should use `LockedPage

&

` type for locked page.

Public Methods

void LockedPage ()

Defined at line 204 of file ../../src/storage/f2fs/file_cache.h

void LockedPage (const LockedPage & )

Defined at line 206 of file ../../src/storage/f2fs/file_cache.h

LockedPage & operator= (const LockedPage & )

Defined at line 207 of file ../../src/storage/f2fs/file_cache.h

zx::result<> SetVmoDirty ()

It works only for paged vmo. When f2fs needs to update the contents of a page without

triggering Vnode::VmoDirty(), it calls this method before the modification. If its page is

present, kernel pre-dirties the page. If not, it returns zx::error(ZX_ERR_NOT_FOUND), and the

caller have to supply a vmo.

Defined at line 215 of file ../../src/storage/f2fs/file_cache.cc

bool ClearDirtyForIo ()

Defined at line 67 of file ../../src/storage/f2fs/file_cache.cc

bool SetDirty ()

Defined at line 37 of file ../../src/storage/f2fs/file_cache.cc

void Zero (size_t start, size_t end)

Defined at line 209 of file ../../src/storage/f2fs/file_cache.cc

void Invalidate ()

It invalidates |this| for truncate and punch-a-hole operations. A caller should call

WaitOnWriteback() before it.

Defined at line 99 of file ../../src/storage/f2fs/file_cache.cc

void WaitOnWriteback ()

It waits for the writeback flag of |page_| to be cleared. So, it should not be called with

FileCache::page_lock_ acquired. It acquires LockedPage::lock_ during waiting.

TODO(b/293975446): Consider releasing |lock_| during waiting.

Defined at line 121 of file ../../src/storage/f2fs/file_cache.cc

bool SetWriteback (block_t addr)

Defined at line 128 of file ../../src/storage/f2fs/file_cache.cc

void LockedPage (LockedPage && p)

Defined at line 209 of file ../../src/storage/f2fs/file_cache.h

LockedPage & operator= (LockedPage && p)

Defined at line 215 of file ../../src/storage/f2fs/file_cache.h

void LockedPage (fbl::RefPtr<Page> page, std::try_to_lock_t t)

If it fails to acquire |page->mutex_|, it doesn't own |page|, and LockedPage::bool returns

false.

Defined at line 225 of file ../../src/storage/f2fs/file_cache.h

void LockedPage (fbl::RefPtr<Page> page)

Defined at line 232 of file ../../src/storage/f2fs/file_cache.h

void ~LockedPage ()

Defined at line 237 of file ../../src/storage/f2fs/file_cache.h

void reset ()

Defined at line 239 of file ../../src/storage/f2fs/file_cache.h

fbl::RefPtr<Page> release ()

It returns the ownership of unlocked |page_|.

Defined at line 266 of file ../../src/storage/f2fs/file_cache.h

fbl::RefPtr<Page> CopyRefPtr ()

CopyRefPtr() returns a RefPtr of locked |page_|.

Defined at line 275 of file ../../src/storage/f2fs/file_cache.h

template <typename T = Page>
T & GetPage ()

Defined at line 278 of file ../../src/storage/f2fs/file_cache.h

Page * get ()

Defined at line 282 of file ../../src/storage/f2fs/file_cache.h

Page & operator* ()

Defined at line 283 of file ../../src/storage/f2fs/file_cache.h

Page * operator-> ()

Defined at line 284 of file ../../src/storage/f2fs/file_cache.h

bool operator bool ()

Defined at line 285 of file ../../src/storage/f2fs/file_cache.h

bool operator== (decltype(nullptr) )

Comparison against nullptr operators (of the form, myptr == nullptr).

Defined at line 288 of file ../../src/storage/f2fs/file_cache.h

bool operator!= (decltype(nullptr) )

Defined at line 289 of file ../../src/storage/f2fs/file_cache.h