Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:fs\aio.c Create Date:2022-07-28 20:21:13
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:ioctx_add_table

Proto:static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)

Type:int

Parameter:

TypeParameterName
struct kioctx *ctx
struct mm_struct *mm
639  spin_lock( & ioctx_lock)
640  table = Dependency order vs. p above. (ioctx_table)
642  When 1 cycle
643  If table Then When i < nr cycle
645  If Not cu_access_pointer() - fetch RCU pointer with no dereferencing*@p: The pointer to read* Return the value of the specified RCU-protected pointer, but omit the* lockdep checks for being in an RCU read-side critical section(table[i]) Then
646  id = i
647  cu_assign_pointer() - assign to RCU-protected pointer*@p: pointer to assign to*@v: value to assign (publish)* Assigns the specified value to the specified RCU-protected* pointer, ensuring that any concurrent RCU readers will see* any prior initialization(table[i], ctx)
648  spin_unlock( & ioctx_lock)
654  ring = kmap_atomic(ring_pages[0])
655  kernel internal index number = id
656  Prevent people trying to call kunmap_atomic() as if it were kunmap()* kunmap_atomic() should get the return value of kmap_atomic, not the page.(ring)
657  Return 0
660  new_nr = If table Then nr Else 1 * 4
661  spin_unlock( & ioctx_lock)
663  table = kzalloc - allocate memory. The memory is set to zero.*@size: how many bytes of memory are required.*@flags: the type of memory to allocate (see kmalloc).
665  If Not table Then Return -ENOMEM
668  nr = new_nr
670  spin_lock( & ioctx_lock)
671  old = Dependency order vs. p above. (ioctx_table)
673  If Not old Then
674  cu_assign_pointer() - assign to RCU-protected pointer*@p: pointer to assign to*@v: value to assign (publish)* Assigns the specified value to the specified RCU-protected* pointer, ensuring that any concurrent RCU readers will see* any prior initialization(ioctx_table, table)
675  Else if nr > nr Then
676  memcpy(table, table, nr * size of * )
679  cu_assign_pointer() - assign to RCU-protected pointer*@p: pointer to assign to*@v: value to assign (publish)* Assigns the specified value to the specified RCU-protected* pointer, ensuring that any concurrent RCU readers will see* any prior initialization(ioctx_table, table)
680  kfree_rcu() - kfree an object after a grace period(old, rcu)
681  Else
682  kfree(table)
683  table = old
Caller
NameDescribe
ioctx_allocx_alloc* Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.