Commit cd856db6 authored by Carlos Maiolino's avatar Carlos Maiolino Committed by Ben Myers
Browse files

xfs: Update inode alloc comments 



I found some out of date comments while studying the inode allocation
code, so I believe it's worth to have these comments updated.

It basically rewrites the comment regarding to "call_again" variable,
which is not used anymore, but instead, callers of xfs_ialloc() decides
if it needs to be called again relying only if ialloc_context is NULL or
not.

Also did some small changes in another comment that I thought to be
pertinent to the current behaviour of these functions and some alignment
on both comments.

Signed-off-by: default avatarCarlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarBen Myers <bpm@sgi.com>
parent 531c3bdc

fs/xfs/xfs_ialloc.c

+3 −3
Original line number Diff line number Diff line
@@ -877,9 +877,9 @@ error0: 
 * This function is designed to be called twice if it has to do an allocation

 * to make more free inodes.  On the first call, *IO_agbp should be set to NULL.

 * If an inode is available without having to performn an allocation, an inode

 * number is returned.  In this case, *IO_agbp would be NULL.  If an allocation

 * needes to be done, xfs_dialloc would return the current AGI buffer in

 * *IO_agbp.  The caller should then commit the current transaction, allocate a

 * number is returned.  In this case, *IO_agbp is set to NULL.  If an allocation

 * needs to be done, xfs_dialloc returns the current AGI buffer in *IO_agbp.

 * The caller should then commit the current transaction, allocate a

 * new transaction, and call xfs_dialloc() again, passing in the previous value

 * of *IO_agbp.  IO_agbp should be held across the transactions. Since the AGI

 * buffer is locked across the two calls, the second call is guaranteed to have

fs/xfs/xfs_inode.c

+9 −9
Original line number Diff line number Diff line
@@ -1104,16 +1104,16 @@ xfs_iread_extents( 
 * set according to the contents of the given cred structure.

 *

 * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()

 * has a free inode available, call xfs_iget()

 * to obtain the in-core version of the allocated inode.  Finally,

 * fill in the inode and log its initial contents.  In this case,

 * ialloc_context would be set to NULL and call_again set to false.

 * has a free inode available, call xfs_iget() to obtain the in-core

 * version of the allocated inode.  Finally, fill in the inode and

 * log its initial contents.  In this case, ialloc_context would be

 * set to NULL.

 *

 * If xfs_dialloc() does not have an available inode,

 * it will replenish its supply by doing an allocation. Since we can

 * only do one allocation within a transaction without deadlocks, we

 * must commit the current transaction before returning the inode itself.

 * In this case, therefore, we will set call_again to true and return.

 * If xfs_dialloc() does not have an available inode, it will replenish

 * its supply by doing an allocation. Since we can only do one

 * allocation within a transaction without deadlocks, we must commit

 * the current transaction before returning the inode itself.

 * In this case, therefore, we will set ialloc_context and return.

 * The caller should then commit the current transaction, start a new

 * transaction, and call xfs_ialloc() again to actually get the inode.

 *

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