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Commit 066a9be6 authored by Naohiro Aota's avatar Naohiro Aota Committed by Linus Torvalds
Browse files

idr: fix idr_pre_get() locking description 

Despite the idr_pre_get() kernel-doc, there are some cases where you can
call idr_pre_get() from within locked regions.  Add a description for such
cases.

See also: http://lkml.org/lkml/2010/9/16/462



[akpm@linux-foundation.org: cleanups, grammatical fixes]
Signed-off-by: default avatarNaohiro Aota <naota@elisp.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 66f1991b

lib/idr.c

+13 −11
Original line number Diff line number Diff line
@@ -110,9 +110,10 @@ static void idr_mark_full(struct idr_layer **pa, int id) 
 * @idp:	idr handle

 * @gfp_mask:	memory allocation flags

 *

 * This function should be called prior to locking and calling the

 * idr_get_new* functions. It preallocates enough memory to satisfy

 * the worst possible allocation.

 * This function should be called prior to calling the idr_get_new* functions.

 * It preallocates enough memory to satisfy the worst possible allocation. The

 * caller should pass in GFP_KERNEL if possible.  This of course requires that

 * no spinning locks be held.

 *

 * If the system is REALLY out of memory this function returns 0,

 * otherwise 1.
@@ -290,9 +291,11 @@ static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) 
 * This is the allocate id function.  It should be called with any

 * required locks.

 *

 * If memory is required, it will return -EAGAIN, you should unlock

 * and go back to the idr_pre_get() call.  If the idr is full, it will

 * return -ENOSPC.

 * If allocation from IDR's private freelist fails, idr_get_new_above() will

 * return -EAGAIN.  The caller should retry the idr_pre_get() call to refill

 * IDR's preallocation and then retry the idr_get_new_above() call.

 *

 * If the idr is full idr_get_new_above() will return -ENOSPC.

 *

 * @id returns a value in the range @starting_id ... 0x7fffffff

 */
@@ -318,12 +321,11 @@ EXPORT_SYMBOL(idr_get_new_above); 
 * @ptr: pointer you want associated with the id

 * @id: pointer to the allocated handle

 *

 * This is the allocate id function.  It should be called with any

 * required locks.

 * If allocation from IDR's private freelist fails, idr_get_new_above() will

 * return -EAGAIN.  The caller should retry the idr_pre_get() call to refill

 * IDR's preallocation and then retry the idr_get_new_above() call.

 *

 * If memory is required, it will return -EAGAIN, you should unlock

 * and go back to the idr_pre_get() call.  If the idr is full, it will

 * return -ENOSPC.

 * If the idr is full idr_get_new_above() will return -ENOSPC.

 *

 * @id returns a value in the range 0 ... 0x7fffffff

 */