// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) International Business Machines Corp., 2000-2004 */ /* * jfs_imap.c: inode allocation map manager * * Serialization: * Each AG has a simple lock which is used to control the serialization of * the AG level lists. This lock should be taken first whenever an AG * level list will be modified or accessed. * * Each IAG is locked by obtaining the buffer for the IAG page. * * There is also a inode lock for the inode map inode. A read lock needs to * be taken whenever an IAG is read from the map or the global level * information is read. A write lock needs to be taken whenever the global * level information is modified or an atomic operation needs to be used. * * If more than one IAG is read at one time, the read lock may not * be given up until all of the IAG's are read. Otherwise, a deadlock * may occur when trying to obtain the read lock while another thread * holding the read lock is waiting on the IAG already being held. * * The control page of the inode map is read into memory by diMount(). * Thereafter it should only be modified in memory and then it will be * written out when the filesystem is unmounted by diUnmount(). */ #include <linux/fs.h> #include <linux/buffer_head.h> #include <linux/pagemap.h> #include <linux/quotaops.h> #include <linux/slab.h> #include "jfs_incore.h" #include "jfs_inode.h" #include "jfs_filsys.h" #include "jfs_dinode.h" #include "jfs_dmap.h" #include "jfs_imap.h" #include "jfs_metapage.h" #include "jfs_superblock.h" #include "jfs_debug.h" /* * imap locks */ /* iag free list lock */ #define IAGFREE_LOCK_INIT(imap) … #define IAGFREE_LOCK(imap) … #define IAGFREE_UNLOCK(imap) … /* per ag iag list locks */ #define AG_LOCK_INIT(imap,index) … #define AG_LOCK(imap,agno) … #define AG_UNLOCK(imap,agno) … /* * forward references */ static int diAllocAG(struct inomap *, int, bool, struct inode *); static int diAllocAny(struct inomap *, int, bool, struct inode *); static int diAllocBit(struct inomap *, struct iag *, int); static int diAllocExt(struct inomap *, int, struct inode *); static int diAllocIno(struct inomap *, int, struct inode *); static int diFindFree(u32, int); static int diNewExt(struct inomap *, struct iag *, int); static int diNewIAG(struct inomap *, int *, int, struct metapage **); static void duplicateIXtree(struct super_block *, s64, int, s64 *); static int diIAGRead(struct inomap * imap, int, struct metapage **); static int copy_from_dinode(struct dinode *, struct inode *); static void copy_to_dinode(struct dinode *, struct inode *); /* * NAME: diMount() * * FUNCTION: initialize the incore inode map control structures for * a fileset or aggregate init time. * * the inode map's control structure (dinomap) is * brought in from disk and placed in virtual memory. * * PARAMETERS: * ipimap - pointer to inode map inode for the aggregate or fileset. * * RETURN VALUES: * 0 - success * -ENOMEM - insufficient free virtual memory. * -EIO - i/o error. */ int diMount(struct inode *ipimap) { … } /* * NAME: diUnmount() * * FUNCTION: write to disk the incore inode map control structures for * a fileset or aggregate at unmount time. * * PARAMETERS: * ipimap - pointer to inode map inode for the aggregate or fileset. * * RETURN VALUES: * 0 - success * -ENOMEM - insufficient free virtual memory. * -EIO - i/o error. */ int diUnmount(struct inode *ipimap, int mounterror) { … } /* * diSync() */ int diSync(struct inode *ipimap) { … } /* * NAME: diRead() * * FUNCTION: initialize an incore inode from disk. * * on entry, the specifed incore inode should itself * specify the disk inode number corresponding to the * incore inode (i.e. i_number should be initialized). * * this routine handles incore inode initialization for * both "special" and "regular" inodes. special inodes * are those required early in the mount process and * require special handling since much of the file system * is not yet initialized. these "special" inodes are * identified by a NULL inode map inode pointer and are * actually initialized by a call to diReadSpecial(). * * for regular inodes, the iag describing the disk inode * is read from disk to determine the inode extent address * for the disk inode. with the inode extent address in * hand, the page of the extent that contains the disk * inode is read and the disk inode is copied to the * incore inode. * * PARAMETERS: * ip - pointer to incore inode to be initialized from disk. * * RETURN VALUES: * 0 - success * -EIO - i/o error. * -ENOMEM - insufficient memory * */ int diRead(struct inode *ip) { … } /* * NAME: diReadSpecial() * * FUNCTION: initialize a 'special' inode from disk. * * this routines handles aggregate level inodes. The * inode cache cannot differentiate between the * aggregate inodes and the filesystem inodes, so we * handle these here. We don't actually use the aggregate * inode map, since these inodes are at a fixed location * and in some cases the aggregate inode map isn't initialized * yet. * * PARAMETERS: * sb - filesystem superblock * inum - aggregate inode number * secondary - 1 if secondary aggregate inode table * * RETURN VALUES: * new inode - success * NULL - i/o error. */ struct inode *diReadSpecial(struct super_block *sb, ino_t inum, int secondary) { … } /* * NAME: diWriteSpecial() * * FUNCTION: Write the special inode to disk * * PARAMETERS: * ip - special inode * secondary - 1 if secondary aggregate inode table * * RETURN VALUES: none */ void diWriteSpecial(struct inode *ip, int secondary) { … } /* * NAME: diFreeSpecial() * * FUNCTION: Free allocated space for special inode */ void diFreeSpecial(struct inode *ip) { … } /* * NAME: diWrite() * * FUNCTION: write the on-disk inode portion of the in-memory inode * to its corresponding on-disk inode. * * on entry, the specifed incore inode should itself * specify the disk inode number corresponding to the * incore inode (i.e. i_number should be initialized). * * the inode contains the inode extent address for the disk * inode. with the inode extent address in hand, the * page of the extent that contains the disk inode is * read and the disk inode portion of the incore inode * is copied to the disk inode. * * PARAMETERS: * tid - transacation id * ip - pointer to incore inode to be written to the inode extent. * * RETURN VALUES: * 0 - success * -EIO - i/o error. */ int diWrite(tid_t tid, struct inode *ip) { … } /* * NAME: diFree(ip) * * FUNCTION: free a specified inode from the inode working map * for a fileset or aggregate. * * if the inode to be freed represents the first (only) * free inode within the iag, the iag will be placed on * the ag free inode list. * * freeing the inode will cause the inode extent to be * freed if the inode is the only allocated inode within * the extent. in this case all the disk resource backing * up the inode extent will be freed. in addition, the iag * will be placed on the ag extent free list if the extent * is the first free extent in the iag. if freeing the * extent also means that no free inodes will exist for * the iag, the iag will also be removed from the ag free * inode list. * * the iag describing the inode will be freed if the extent * is to be freed and it is the only backed extent within * the iag. in this case, the iag will be removed from the * ag free extent list and ag free inode list and placed on * the inode map's free iag list. * * a careful update approach is used to provide consistency * in the face of updates to multiple buffers. under this * approach, all required buffers are obtained before making * any updates and are held until all updates are complete. * * PARAMETERS: * ip - inode to be freed. * * RETURN VALUES: * 0 - success * -EIO - i/o error. */ int diFree(struct inode *ip) { … } /* * There are several places in the diAlloc* routines where we initialize * the inode. */ static inline void diInitInode(struct inode *ip, int iagno, int ino, int extno, struct iag * iagp) { … } /* * NAME: diAlloc(pip,dir,ip) * * FUNCTION: allocate a disk inode from the inode working map * for a fileset or aggregate. * * PARAMETERS: * pip - pointer to incore inode for the parent inode. * dir - 'true' if the new disk inode is for a directory. * ip - pointer to a new inode * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ int diAlloc(struct inode *pip, bool dir, struct inode *ip) { … } /* * NAME: diAllocAG(imap,agno,dir,ip) * * FUNCTION: allocate a disk inode from the allocation group. * * this routine first determines if a new extent of free * inodes should be added for the allocation group, with * the current request satisfied from this extent. if this * is the case, an attempt will be made to do just that. if * this attempt fails or it has been determined that a new * extent should not be added, an attempt is made to satisfy * the request by allocating an existing (backed) free inode * from the allocation group. * * PRE CONDITION: Already have the AG lock for this AG. * * PARAMETERS: * imap - pointer to inode map control structure. * agno - allocation group to allocate from. * dir - 'true' if the new disk inode is for a directory. * ip - pointer to the new inode to be filled in on successful return * with the disk inode number allocated, its extent address * and the start of the ag. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diAllocAG(struct inomap * imap, int agno, bool dir, struct inode *ip) { … } /* * NAME: diAllocAny(imap,agno,dir,iap) * * FUNCTION: allocate a disk inode from any other allocation group. * * this routine is called when an allocation attempt within * the primary allocation group has failed. if attempts to * allocate an inode from any allocation group other than the * specified primary group. * * PARAMETERS: * imap - pointer to inode map control structure. * agno - primary allocation group (to avoid). * dir - 'true' if the new disk inode is for a directory. * ip - pointer to a new inode to be filled in on successful return * with the disk inode number allocated, its extent address * and the start of the ag. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diAllocAny(struct inomap * imap, int agno, bool dir, struct inode *ip) { … } /* * NAME: diAllocIno(imap,agno,ip) * * FUNCTION: allocate a disk inode from the allocation group's free * inode list, returning an error if this free list is * empty (i.e. no iags on the list). * * allocation occurs from the first iag on the list using * the iag's free inode summary map to find the leftmost * free inode in the iag. * * PRE CONDITION: Already have AG lock for this AG. * * PARAMETERS: * imap - pointer to inode map control structure. * agno - allocation group. * ip - pointer to new inode to be filled in on successful return * with the disk inode number allocated, its extent address * and the start of the ag. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diAllocIno(struct inomap * imap, int agno, struct inode *ip) { … } /* * NAME: diAllocExt(imap,agno,ip) * * FUNCTION: add a new extent of free inodes to an iag, allocating * an inode from this extent to satisfy the current allocation * request. * * this routine first tries to find an existing iag with free * extents through the ag free extent list. if list is not * empty, the head of the list will be selected as the home * of the new extent of free inodes. otherwise (the list is * empty), a new iag will be allocated for the ag to contain * the extent. * * once an iag has been selected, the free extent summary map * is used to locate a free extent within the iag and diNewExt() * is called to initialize the extent, with initialization * including the allocation of the first inode of the extent * for the purpose of satisfying this request. * * PARAMETERS: * imap - pointer to inode map control structure. * agno - allocation group number. * ip - pointer to new inode to be filled in on successful return * with the disk inode number allocated, its extent address * and the start of the ag. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diAllocExt(struct inomap * imap, int agno, struct inode *ip) { … } /* * NAME: diAllocBit(imap,iagp,ino) * * FUNCTION: allocate a backed inode from an iag. * * this routine performs the mechanics of allocating a * specified inode from a backed extent. * * if the inode to be allocated represents the last free * inode within the iag, the iag will be removed from the * ag free inode list. * * a careful update approach is used to provide consistency * in the face of updates to multiple buffers. under this * approach, all required buffers are obtained before making * any updates and are held all are updates are complete. * * PRE CONDITION: Already have buffer lock on iagp. Already have AG lock on * this AG. Must have read lock on imap inode. * * PARAMETERS: * imap - pointer to inode map control structure. * iagp - pointer to iag. * ino - inode number to be allocated within the iag. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diAllocBit(struct inomap * imap, struct iag * iagp, int ino) { … } /* * NAME: diNewExt(imap,iagp,extno) * * FUNCTION: initialize a new extent of inodes for an iag, allocating * the first inode of the extent for use for the current * allocation request. * * disk resources are allocated for the new extent of inodes * and the inodes themselves are initialized to reflect their * existence within the extent (i.e. their inode numbers and * inode extent addresses are set) and their initial state * (mode and link count are set to zero). * * if the iag is new, it is not yet on an ag extent free list * but will now be placed on this list. * * if the allocation of the new extent causes the iag to * have no free extent, the iag will be removed from the * ag extent free list. * * if the iag has no free backed inodes, it will be placed * on the ag free inode list, since the addition of the new * extent will now cause it to have free inodes. * * a careful update approach is used to provide consistency * (i.e. list consistency) in the face of updates to multiple * buffers. under this approach, all required buffers are * obtained before making any updates and are held until all * updates are complete. * * PRE CONDITION: Already have buffer lock on iagp. Already have AG lock on * this AG. Must have read lock on imap inode. * * PARAMETERS: * imap - pointer to inode map control structure. * iagp - pointer to iag. * extno - extent number. * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. */ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno) { … } /* * NAME: diNewIAG(imap,iagnop,agno) * * FUNCTION: allocate a new iag for an allocation group. * * first tries to allocate the iag from the inode map * iagfree list: * if the list has free iags, the head of the list is removed * and returned to satisfy the request. * if the inode map's iag free list is empty, the inode map * is extended to hold a new iag. this new iag is initialized * and returned to satisfy the request. * * PARAMETERS: * imap - pointer to inode map control structure. * iagnop - pointer to an iag number set with the number of the * newly allocated iag upon successful return. * agno - allocation group number. * bpp - Buffer pointer to be filled in with new IAG's buffer * * RETURN VALUES: * 0 - success. * -ENOSPC - insufficient disk resources. * -EIO - i/o error. * * serialization: * AG lock held on entry/exit; * write lock on the map is held inside; * read lock on the map is held on successful completion; * * note: new iag transaction: * . synchronously write iag; * . write log of xtree and inode of imap; * . commit; * . synchronous write of xtree (right to left, bottom to top); * . at start of logredo(): init in-memory imap with one additional iag page; * . at end of logredo(): re-read imap inode to determine * new imap size; */ static int diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp) { … } /* * NAME: diIAGRead() * * FUNCTION: get the buffer for the specified iag within a fileset * or aggregate inode map. * * PARAMETERS: * imap - pointer to inode map control structure. * iagno - iag number. * bpp - point to buffer pointer to be filled in on successful * exit. * * SERIALIZATION: * must have read lock on imap inode * (When called by diExtendFS, the filesystem is quiesced, therefore * the read lock is unnecessary.) * * RETURN VALUES: * 0 - success. * -EIO - i/o error. */ static int diIAGRead(struct inomap * imap, int iagno, struct metapage ** mpp) { … } /* * NAME: diFindFree() * * FUNCTION: find the first free bit in a word starting at * the specified bit position. * * PARAMETERS: * word - word to be examined. * start - starting bit position. * * RETURN VALUES: * bit position of first free bit in the word or 32 if * no free bits were found. */ static int diFindFree(u32 word, int start) { … } /* * NAME: diUpdatePMap() * * FUNCTION: Update the persistent map in an IAG for the allocation or * freeing of the specified inode. * * PRE CONDITIONS: Working map has already been updated for allocate. * * PARAMETERS: * ipimap - Incore inode map inode * inum - Number of inode to mark in permanent map * is_free - If 'true' indicates inode should be marked freed, otherwise * indicates inode should be marked allocated. * * RETURN VALUES: * 0 for success */ int diUpdatePMap(struct inode *ipimap, unsigned long inum, bool is_free, struct tblock * tblk) { … } /* * diExtendFS() * * function: update imap for extendfs(); * * note: AG size has been increased s.t. each k old contiguous AGs are * coalesced into a new AG; */ int diExtendFS(struct inode *ipimap, struct inode *ipbmap) { … } /* * duplicateIXtree() * * serialization: IWRITE_LOCK held on entry/exit * * note: shadow page with regular inode (rel.2); */ static void duplicateIXtree(struct super_block *sb, s64 blkno, int xlen, s64 *xaddr) { … } /* * NAME: copy_from_dinode() * * FUNCTION: Copies inode info from disk inode to in-memory inode * * RETURN VALUES: * 0 - success * -ENOMEM - insufficient memory */ static int copy_from_dinode(struct dinode * dip, struct inode *ip) { … } /* * NAME: copy_to_dinode() * * FUNCTION: Copies inode info from in-memory inode to disk inode */ static void copy_to_dinode(struct dinode * dip, struct inode *ip) { … }
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