84  * Returns if the folio has dirty or writeback buffers. If all the buffers
86  * any of the buffers are locked, it is assumed they are locked for IO.
181  * But it's the page lock which protects the buffers.  To get around this,
223 	/* we might be here because some of the buffers on this page are  in __find_get_block_slow()
226 	 * elsewhere, don't buffer_error if we had some unmapped buffers  in __find_get_block_slow()
420  * If a page's buffers are under async readin (end_buffer_async_read
422  * control could lock one of the buffers after it has completed
423  * but while some of the other buffers have not completed.  This
428  * The page comes unlocked when it has no locked buffer_async buffers
432  * the buffers.
469  * management of a list of dependent buffers at ->i_mapping->i_private_list.
471  * Locking is a little subtle: try_to_free_buffers() will remove buffers
474  * at the time, not against the S_ISREG file which depends on those buffers.
476  * which backs the buffers.  Which is different from the address_space 
477  * against which the buffers are listed.  So for a particular address_space,
482  * Which introduces a requirement: all buffers on an address_space's
485  * address_spaces which do not place buffers at ->i_private_list via these
496  * mark_buffer_dirty_fsync() to clearly define why those buffers are being
503  * that buffers are taken *off* the old inode's list when they are freed
530  * as you dirty the buffers, and then use osync_inode_buffers to wait for
531  * completion.  Any other dirty buffers which are not yet queued for
560  * sync_mapping_buffers - write out & wait upon a mapping's "associated" buffers
561  * @mapping: the mapping which wants those buffers written
563  * Starts I/O against the buffers at mapping->i_private_list, and waits upon
567  * @mapping is a file or directory which needs those buffers to be written for
592  * filesystems which track all non-inode metadata in the buffers list
617 	/* check and advance again to catch errors after syncing out buffers */  in generic_buffers_fsync_noflush()
635  * filesystems which track all non-inode metadata in the buffers list
696  * If the page has buffers, the uptodate buffers are set dirty, to preserve
697  * dirty-state coherency between the page and the buffers.  It the page does
698  * not have buffers then when they are later attached they will all be set
701  * The buffers are dirtied before the page is dirtied.  There's a small race
704  * before the buffers, a concurrent writepage caller could clear the page dirty
705  * bit, see a bunch of clean buffers and we'd end up with dirty buffers/clean
709  * page's buffer list.  Also use this to protect against clean buffers being
751  * Write out and wait upon a list of buffers.
754  * initially dirty buffers get waited on, but that any subsequently
755  * dirtied buffers don't.  After all, we don't want fsync to last
758  * Do this in two main stages: first we copy dirty buffers to a
766  * the osync code to catch these locked, dirty buffers without requeuing
767  * any newly dirty buffers for write.
849  * Invalidate any and all dirty buffers on a given inode.  We are
851  * done a sync().  Just drop the buffers from the inode list.
854  * assumes that all the buffers are against the blockdev.  Not true
873  * Remove any clean buffers from the inode's buffer list.  This is called
874  * when we're trying to free the inode itself.  Those buffers can pin it.
876  * Returns true if all buffers were removed.
902  * Create the appropriate buffers when given a folio for data area and
904  * follow the buffers created.  Return NULL if unable to create more
905  * buffers.
994  * Initialise the state of a blockdev folio's buffers.
1056 		 * writeback, or buffers may be cleaned.  This should not  in grow_dev_folio()
1057 		 * happen very often; maybe we have old buffers attached to  in grow_dev_folio()
1072 	 * Link the folio to the buffers and initialise them.  Take the  in grow_dev_folio()
1087  * Create buffers for the specified block device block's folio.  If
1088  * that folio was dirty, the buffers are set dirty also.  Returns false
1107 	/* Create a folio with the proper size buffers */  in grow_buffers()
1140  * The relationship between dirty buffers and dirty pages:
1142  * Whenever a page has any dirty buffers, the page's dirty bit is set, and
1145  * At all times, the dirtiness of the buffers represents the dirtiness of
1146  * subsections of the page.  If the page has buffers, the page dirty bit is
1149  * When a page is set dirty in its entirety, all its buffers are marked dirty
1150  * (if the page has buffers).
1153  * buffers are not.
1155  * Also.  When blockdev buffers are explicitly read with bread(), they
1157  * uptodate - even if all of its buffers are uptodate.  A subsequent
1159  * buffers, will set the folio uptodate and will perform no I/O.
1223  * Decrement a buffer_head's reference count.  If all buffers against a page
1225  * and unlocked then try_to_free_buffers() may strip the buffers from the page
1226  * in preparation for freeing it (sometimes, rarely, buffers are removed from
1227  * a page but it ends up not being freed, and buffers may later be reattached).
1278  * The bhs[] array is sorted - newest buffer is at bhs[0].  Buffers have their
1584  * block_invalidate_folio() does not have to release all buffers, but it must
1628 	 * We release buffers only if the entire folio is being invalidated.  in block_invalidate_folio()
1640  * We attach and possibly dirty the buffers atomically wrt
1678  * clean_bdev_aliases: clean a range of buffers in block device
1679  * @bdev: Block device to clean buffers in
1693  * writeout I/O going on against recently-freed buffers.  We don't wait on that
1719 			 * to pin buffers here since we can afford to sleep and  in clean_bdev_aliases()
1780  * While block_write_full_folio is writing back the dirty buffers under
1781  * the page lock, whoever dirtied the buffers may decide to clean them
1811 	 * here, and the (potentially unmapped) buffers may become dirty at  in __block_write_full_folio()
1815 	 * Buffers outside i_size may be dirtied by block_dirty_folio;  in __block_write_full_folio()
1826 	 * Get all the dirty buffers mapped to disk addresses and  in __block_write_full_folio()
1832 			 * mapped buffers outside i_size will occur, because  in __block_write_full_folio()
1883 	 * The folio and its buffers are protected by the writeback flag,  in __block_write_full_folio()
1903 		 * The folio was marked dirty, but the buffers were  in __block_write_full_folio()
1924 	/* Recovery: lock and submit the mapped buffers */  in __block_write_full_folio()
1958  * If a folio has any new buffers, zero them out here, and mark them uptodate
2185 	 * If this is a partial write which happened to make all buffers  in __block_commit_write()
2232 		 * The buffers that were written will now be uptodate, so  in block_write_end()
2297  * block_is_partially_uptodate checks whether buffers within a folio are
2300  * Returns true if all buffers which correspond to the specified part
2410 		 * All buffers are uptodate or get_block() returned an  in block_read_full_folio()
2417 	/* Stage two: lock the buffers */  in block_read_full_folio()
2861  * try_to_free_buffers() checks if all the buffers on this particular folio
2867  * If the folio is dirty but all the buffers are clean then we need to
2869  * may be against a block device, and a later reattachment of buffers
2870  * to a dirty folio will set *all* buffers dirty.  Which would corrupt
2873  * The same applies to regular filesystem folios: if all the buffers are
2932 	 * If the filesystem writes its buffers by hand (eg ext3)  in try_to_free_buffers()
2933 	 * then we can have clean buffers against a dirty folio.  We  in try_to_free_buffers()
2938 	 * the folio's buffers clean.  We discover that here and clean  in try_to_free_buffers()
3081  * __bh_read_batch - Submit read for a batch of unlocked buffers