fs/zfs/dbuf.c

33 #include <sys/dbuf.h>
56  * Global data structures and functions for the dbuf cache.
84  * dbuf hash table routines
111 #define	DBUF_EQUAL(dbuf, os, obj, level, blkid)		\
112 	((dbuf)->db.db_object == (obj) &&		\
113 	(dbuf)->db_objset == (os) &&			\
114 	(dbuf)->db_level == (level) &&			\
115 	(dbuf)->db_blkid == (blkid))
492 	 * All reads are synchronous, so we must have a hold on the dbuf
651 		 * Another reader came in while the dbuf was in flight
653 		 * writing the buffer (sending the dbuf to CACHED) or the
655 		 * and send the dbuf to CACHED.  Otherwise, a failure
656 		 * occurred and the dbuf went to UNCACHED.
720  * dbuf list for the dnode.
738 	 * If the last dirty record for this dbuf has not yet synced
739 	 * and its referencing the dbuf data, either:
843 			/* mutex has been dropped and dbuf destroyed */
865 		/* The dbuf is referenced */
882 				 * This dbuf is not dirty in the open context.
1212 		 * This is only a guess -- if the dbuf is dirty
1287  * transaction.  Return whether this evicted the dbuf.
1439  * Directly assign a provided arc buf to a given dbuf if it's not referenced
1440  * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf.
1502  * "Clear" the contents of this dbuf.  This will mark the dbuf
1552 		 * Decrementing the dbuf count means that the hold corresponding
1553 		 * to the removed dbuf is no longer discounted in dnode_move(),
1572 	 * If this dbuf is referenced from an indirect dbuf,
1573 	 * decrement the ref count on the indirect dbuf.
1681 		/* the bonus dbuf is not placed in the hash table */
1696 	 * Hold the dn_dbufs_mtx while we get the new dbuf
1699 	 * trying to look up this dbuf before its added to the
1761 		 * If this dbuf is still on the dn_dbufs list,
1775 			 * Decrementing the dbuf count means that the hold
1776 			 * corresponding to the removed dbuf is no longer
1813 		 * This dbuf is already in the cache.  We assume that
2001  * dnode's parent dbuf evicting its dnode handles.
2017  * dbuf_rele() for an already-locked dbuf.  This is necessary to allow
2029 	 * Remove the reference to the dbuf before removing its hold on the
2067 			 * dbuf with any data allocated from the ARC.
2075 			 * This dbuf has anonymous data associated with it.
2084 			 * A dbuf will be eligible for eviction if either the
2170 dmu_buf_freeable(dmu_buf_t *dbuf)
2173 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
2412 		 * zio_nowait() invalidates the dbuf.