fs/xfs/xfs_fsops.c

218 		 * Reserve AG metadata blocks. ENOSPC here does not mean there  in xfs_growfs_data_private()
350  * Reserve the requested number of blocks if available. Otherwise return
372 	 * retry if we end up trying to reserve more space than is available.  in xfs_reserve_blocks()
399 	 * If the request is larger than the current reservation, reserve the  in xfs_reserve_blocks()
400 	 * blocks before we update the reserve counters. Sample m_fdblocks and  in xfs_reserve_blocks()
404 	 * fdblocks to stash in the reserve pool.  This is a classic TOCTOU  in xfs_reserve_blocks()
406 	 * m_sb_lock.  Set the reserve size even if there's not enough free  in xfs_reserve_blocks()
408 	 * reserve when it can.  in xfs_reserve_blocks()
418 		 * here - we don't want to reserve the extra reserve blocks  in xfs_reserve_blocks()
419 		 * from the reserve.  in xfs_reserve_blocks()
421 		 * The desired reserve size can change after we drop the lock.  in xfs_reserve_blocks()
422 		 * Use mod_fdblocks to put the space into the reserve or into  in xfs_reserve_blocks()
525  * Reserve free space for per-AG metadata.
545 	"Error %d reserving per-AG metadata reserve pool.", error);  in xfs_fs_reserve_ag_blocks()