Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\filemap.c Create Date:2022-07-28 14:02:02
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:d_get_pages_contig - gang contiguous pagecache lookup*@mapping: The address_space to search*@index: The starting page index*@nr_pages: The maximum number of pages*@pages: Where the resulting pages are placed* find_get_pages_contig() works exactly like

Proto:unsigned find_get_pages_contig(struct address_space *mapping, unsigned long index, unsigned int nr_pages, struct page **pages)

Type:unsigned

Parameter:

TypeParameterName
struct address_space *mapping
unsigned longindex
unsigned intnr_pages
struct page **pages
1860  XA_STATE() - Declare an XArray operation state.*@name: Name of this operation state (usually xas).*@array: Array to operate on.*@index: Initial index of interest.* Declare and initialise an xa_state on the stack.(xas, & i_pages, index)
1862  ret = 0
1864  If Value for the false possibility is greater at compile time(!nr_pages) Then Return 0
1867  _read_lock() - mark the beginning of an RCU read-side critical section* When synchronize_rcu() is invoked on one CPU while other CPUs* are within RCU read-side critical sections, then the* synchronize_rcu() is guaranteed to block until after all the other
1868  When page cycle
1869  If xas_retry() - Retry the operation if appropriate.*@xas: XArray operation state.*@entry: Entry from xarray.* The advanced functions may sometimes return an internal entry, such as* a retry entry or a zero entry. This function sets up the @xas to restart Then Continue
1875  If xa_is_value() - Determine if an entry is a value.*@entry: XArray entry.* Context: Any context.* Return: True if the entry is a value, false if it is a pointer. Then Break
1878  If Not page_cache_get_speculative(page) Then Go to retry
1882  If Value for the false possibility is greater at compile time(page != xas_reload() - Refetch an entry from the xarray) Then Go to put_page
1885  pages[ret] = find_subpage(page, xa_index)
1886  If ++ret == nr_pages Then Break
1888  Continue
1889  put_page :
1890  put_page(page)
1891  retry :
1892  xas_reset() - Reset an XArray operation state.*@xas: XArray operation state.* Resets the error or walk state of the @xas so future walks of the* array will start from the root. Use this if you have dropped the* xarray lock and want to reuse the xa_state.
1894  _read_unlock() - marks the end of an RCU read-side critical section.* In most situations, rcu_read_unlock() is immune from deadlock.* However, in kernels built with CONFIG_RCU_BOOST, rcu_read_unlock()
1895  Return ret