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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357// SPDX-License-Identifier: GPL-2.0+/* * NILFS B-tree node cache * * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. * * Originally written by Seiji Kihara. * Fully revised by Ryusuke Konishi for stabilization and simplification. * */
#include <linux/types.h>#include <linux/buffer_head.h>#include <linux/mm.h>#include <linux/backing-dev.h>#include <linux/gfp.h>#include "nilfs.h"#include "mdt.h"#include "dat.h"#include "page.h"#include "btnode.h"
/** * nilfs_init_btnc_inode - initialize B-tree node cache inode * @btnc_inode: inode to be initialized * * nilfs_init_btnc_inode() sets up an inode for B-tree node cache. */void nilfs_init_btnc_inode(struct inode *btnc_inode){ struct nilfs_inode_info *ii = NILFS_I(btnc_inode);
btnc_inode->i_mode = S_IFREG; ii->i_flags = 0; memset(&ii->i_bmap_data, 0, sizeof(struct nilfs_bmap)); mapping_set_gfp_mask(btnc_inode->i_mapping, GFP_NOFS); btnc_inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;}
void nilfs_btnode_cache_clear(struct address_space *btnc){ invalidate_mapping_pages(btnc, 0, -1); truncate_inode_pages(btnc, 0);}
struct buffer_head *nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr){ struct inode *inode = btnc->host; struct buffer_head *bh;
bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); if (unlikely(!bh)) return ERR_PTR(-ENOMEM);
if (unlikely(buffer_mapped(bh) || buffer_uptodate(bh) || buffer_dirty(bh))) { /* * The block buffer at the specified new address was already * in use. This can happen if it is a virtual block number * and has been reallocated due to corruption of the bitmap * used to manage its allocation state (if not, the buffer * clearing of an abandoned b-tree node is missing somewhere). */ nilfs_error(inode->i_sb, "state inconsistency probably due to duplicate use of b-tree node block address %llu (ino=%llu)", (unsigned long long)blocknr, inode->i_ino); goto failed; } memset(bh->b_data, 0, i_blocksize(inode)); bh->b_blocknr = blocknr; set_buffer_mapped(bh); set_buffer_uptodate(bh);
folio_unlock(bh->b_folio); folio_put(bh->b_folio); return bh;
failed: folio_unlock(bh->b_folio); folio_put(bh->b_folio); brelse(bh); return ERR_PTR(-EIO);}
int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, sector_t pblocknr, blk_opf_t opf, struct buffer_head **pbh, sector_t *submit_ptr){ struct buffer_head *bh; struct inode *inode = btnc->host; struct folio *folio; int err;
bh = nilfs_grab_buffer(inode, btnc, blocknr, BIT(BH_NILFS_Node)); if (unlikely(!bh)) return -ENOMEM;
err = -EEXIST; /* internal code */ folio = bh->b_folio;
if (buffer_uptodate(bh) || buffer_dirty(bh)) goto found;
if (pblocknr == 0) { pblocknr = blocknr; if (inode->i_ino != NILFS_DAT_INO) { struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
/* blocknr is a virtual block number */ err = nilfs_dat_translate(nilfs->ns_dat, blocknr, &pblocknr); if (unlikely(err)) { brelse(bh); goto out_locked; } } }
if (opf & REQ_RAHEAD) { if (pblocknr != *submit_ptr + 1 || !trylock_buffer(bh)) { err = -EBUSY; /* internal code */ brelse(bh); goto out_locked; } } else { /* opf == REQ_OP_READ */ lock_buffer(bh); } if (buffer_uptodate(bh)) { unlock_buffer(bh); err = -EEXIST; /* internal code */ goto found; } set_buffer_mapped(bh); bh->b_blocknr = pblocknr; /* set block address for read */ bh_submit(bh, opf, bh_end_read); bh->b_blocknr = blocknr; /* set back to the given block address */ *submit_ptr = pblocknr; err = 0;found: *pbh = bh;
out_locked: folio_unlock(folio); folio_put(folio); return err;}
/** * nilfs_btnode_delete - delete B-tree node buffer * @bh: buffer to be deleted * * nilfs_btnode_delete() invalidates the specified buffer and delete the page * including the buffer if the page gets unbusy. */void nilfs_btnode_delete(struct buffer_head *bh){ struct address_space *mapping; struct folio *folio = bh->b_folio; pgoff_t index = folio->index; int still_dirty;
folio_get(folio); folio_lock(folio); folio_wait_writeback(folio);
nilfs_forget_buffer(bh); still_dirty = folio_test_dirty(folio); mapping = folio->mapping; folio_unlock(folio); folio_put(folio);
if (!still_dirty && mapping) invalidate_inode_pages2_range(mapping, index, index);}
/** * nilfs_btnode_prepare_change_key - prepare to change the search key of a * b-tree node block * @btnc: page cache in which the b-tree node block is buffered * @ctxt: structure for exchanging context information for key change * * nilfs_btnode_prepare_change_key() prepares to move the contents of the * b-tree node block of the old key given in the "oldkey" member of @ctxt to * the position of the new key given in the "newkey" member of @ctxt in the * page cache @btnc. Here, the key of the block is an index in units of * blocks, and if the page and block sizes match, it matches the page index * in the page cache. * * If the page size and block size match, this function attempts to move the * entire folio, and in preparation for this, inserts the original folio into * the new index of the cache. If this insertion fails or if the page size * and block size are different, it falls back to a copy preparation using * nilfs_btnode_create_block(), inserts a new block at the position * corresponding to "newkey", and stores the buffer head pointer in the * "newbh" member of @ctxt. * * Note that the current implementation does not support folio sizes larger * than the page size. * * Return: 0 on success, or one of the following negative error codes on * failure: * * %-EIO - I/O error (metadata corruption). * * %-ENOMEM - Insufficient memory available. */int nilfs_btnode_prepare_change_key(struct address_space *btnc, struct nilfs_btnode_chkey_ctxt *ctxt){ struct buffer_head *obh, *nbh; struct inode *inode = btnc->host; __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; int err;
if (oldkey == newkey) return 0;
obh = ctxt->bh; ctxt->newbh = NULL;
if (inode->i_blkbits == PAGE_SHIFT) { struct folio *ofolio = obh->b_folio; folio_lock(ofolio);retry: /* BUG_ON(oldkey != obh->b_folio->index); */ if (unlikely(oldkey != ofolio->index)) NILFS_FOLIO_BUG(ofolio, "invalid oldkey %lld (newkey=%lld)", (unsigned long long)oldkey, (unsigned long long)newkey);
xa_lock_irq(&btnc->i_pages); err = __xa_insert(&btnc->i_pages, newkey, ofolio, GFP_NOFS); xa_unlock_irq(&btnc->i_pages); /* * Note: folio->index will not change to newkey until * nilfs_btnode_commit_change_key() will be called. * To protect the folio in intermediate state, the folio lock * is held. */ if (!err) return 0; else if (err != -EBUSY) goto failed_unlock;
err = invalidate_inode_pages2_range(btnc, newkey, newkey); if (!err) goto retry; /* fallback to copy mode */ folio_unlock(ofolio); }
nbh = nilfs_btnode_create_block(btnc, newkey); if (IS_ERR(nbh)) return PTR_ERR(nbh);
BUG_ON(nbh == obh); ctxt->newbh = nbh; return 0;
failed_unlock: folio_unlock(obh->b_folio); return err;}
/** * nilfs_btnode_commit_change_key - commit the change of the search key of * a b-tree node block * @btnc: page cache in which the b-tree node block is buffered * @ctxt: structure for exchanging context information for key change * * nilfs_btnode_commit_change_key() executes the key change based on the * context @ctxt prepared by nilfs_btnode_prepare_change_key(). If no valid * block buffer is prepared in "newbh" of @ctxt (i.e., a full folio move), * this function removes the folio from the old index and completes the move. * Otherwise, it copies the block data and inherited flag states of "oldbh" * to "newbh" and clears the "oldbh" from the cache. In either case, the * relocated buffer is marked as dirty. * * As with nilfs_btnode_prepare_change_key(), the current implementation does * not support folio sizes larger than the page size. */void nilfs_btnode_commit_change_key(struct address_space *btnc, struct nilfs_btnode_chkey_ctxt *ctxt){ struct buffer_head *obh = ctxt->bh, *nbh = ctxt->newbh; __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey; struct folio *ofolio;
if (oldkey == newkey) return;
if (nbh == NULL) { /* blocksize == pagesize */ ofolio = obh->b_folio; if (unlikely(oldkey != ofolio->index)) NILFS_FOLIO_BUG(ofolio, "invalid oldkey %lld (newkey=%lld)", (unsigned long long)oldkey, (unsigned long long)newkey); mark_buffer_dirty(obh);
xa_lock_irq(&btnc->i_pages); __xa_erase(&btnc->i_pages, oldkey); __xa_set_mark(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY); xa_unlock_irq(&btnc->i_pages);
ofolio->index = obh->b_blocknr = newkey; folio_unlock(ofolio); } else { nilfs_copy_buffer(nbh, obh); mark_buffer_dirty(nbh);
nbh->b_blocknr = newkey; ctxt->bh = nbh; nilfs_btnode_delete(obh); /* will decrement bh->b_count */ }}
/** * nilfs_btnode_abort_change_key - abort the change of the search key of a * b-tree node block * @btnc: page cache in which the b-tree node block is buffered * @ctxt: structure for exchanging context information for key change * * nilfs_btnode_abort_change_key() cancels the key change associated with the * context @ctxt prepared via nilfs_btnode_prepare_change_key() and performs * any necessary cleanup. If no valid block buffer is prepared in "newbh" of * @ctxt, this function removes the folio from the destination index and aborts * the move. Otherwise, it clears "newbh" from the cache. * * As with nilfs_btnode_prepare_change_key(), the current implementation does * not support folio sizes larger than the page size. */void nilfs_btnode_abort_change_key(struct address_space *btnc, struct nilfs_btnode_chkey_ctxt *ctxt){ struct buffer_head *nbh = ctxt->newbh; __u64 oldkey = ctxt->oldkey, newkey = ctxt->newkey;
if (oldkey == newkey) return;
if (nbh == NULL) { /* blocksize == pagesize */ xa_erase_irq(&btnc->i_pages, newkey); folio_unlock(ctxt->bh->b_folio); } else { /* * When canceling a buffer that a prepare operation has * allocated to copy a node block to another location, use * nilfs_btnode_delete() to initialize and release the buffer * so that the buffer flags will not be in an inconsistent * state when it is reallocated. */ nilfs_btnode_delete(nbh); }}