diff options
| -rw-r--r-- | fs/xfs/xfs_iget.c | 348 |
1 files changed, 191 insertions, 157 deletions
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index 58865fe4780..b2539b17c95 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -40,161 +40,119 @@ #include "xfs_utils.h" /* - * Look up an inode by number in the given file system. - * The inode is looked up in the cache held in each AG. - * If the inode is found in the cache, attach it to the provided - * vnode. - * - * If it is not in core, read it in from the file system's device, - * add it to the cache and attach the provided vnode. - * - * The inode is locked according to the value of the lock_flags parameter. - * This flag parameter indicates how and if the inode's IO lock and inode lock - * should be taken. - * - * mp -- the mount point structure for the current file system. It points - * to the inode hash table. - * tp -- a pointer to the current transaction if there is one. This is - * simply passed through to the xfs_iread() call. - * ino -- the number of the inode desired. This is the unique identifier - * within the file system for the inode being requested. - * lock_flags -- flags indicating how to lock the inode. See the comment - * for xfs_ilock() for a list of valid values. - * bno -- the block number starting the buffer containing the inode, - * if known (as by bulkstat), else 0. + * Check the validity of the inode we just found it the cache */ -STATIC int -xfs_iget_core( - struct inode *inode, - xfs_mount_t *mp, - xfs_trans_t *tp, - xfs_ino_t ino, - uint flags, - uint lock_flags, - xfs_inode_t **ipp, - xfs_daddr_t bno) +static int +xfs_iget_cache_hit( + struct inode *inode, + struct xfs_perag *pag, + struct xfs_inode *ip, + int flags, + int lock_flags) __releases(pag->pag_ici_lock) { - struct inode *old_inode; - xfs_inode_t *ip; - int error; - unsigned long first_index, mask; - xfs_perag_t *pag; - xfs_agino_t agino; + struct xfs_mount *mp = ip->i_mount; + struct inode *old_inode; + int error = 0; - /* the radix tree exists only in inode capable AGs */ - if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi) - return EINVAL; - - /* get the perag structure and ensure that it's inode capable */ - pag = xfs_get_perag(mp, ino); - if (!pag->pagi_inodeok) - return EINVAL; - ASSERT(pag->pag_ici_init); - agino = XFS_INO_TO_AGINO(mp, ino); - -again: - read_lock(&pag->pag_ici_lock); - ip = radix_tree_lookup(&pag->pag_ici_root, agino); + /* + * If INEW is set this inode is being set up + * Pause and try again. + */ + if (xfs_iflags_test(ip, XFS_INEW)) { + error = EAGAIN; + XFS_STATS_INC(xs_ig_frecycle); + goto out_error; + } - if (ip != NULL) { + old_inode = ip->i_vnode; + if (old_inode == NULL) { /* - * If INEW is set this inode is being set up + * If IRECLAIM is set this inode is + * on its way out of the system, * we need to pause and try again. */ - if (xfs_iflags_test(ip, XFS_INEW)) { - read_unlock(&pag->pag_ici_lock); - delay(1); + if (xfs_iflags_test(ip, XFS_IRECLAIM)) { + error = EAGAIN; XFS_STATS_INC(xs_ig_frecycle); + goto out_error; + } + ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE)); - goto again; + /* + * If lookup is racing with unlink, then we + * should return an error immediately so we + * don't remove it from the reclaim list and + * potentially leak the inode. + */ + if ((ip->i_d.di_mode == 0) && + !(flags & XFS_IGET_CREATE)) { + error = ENOENT; + goto out_error; } + xfs_itrace_exit_tag(ip, "xfs_iget.alloc"); - old_inode = ip->i_vnode; - if (old_inode == NULL) { - /* - * If IRECLAIM is set this inode is - * on its way out of the system, - * we need to pause and try again. - */ - if (xfs_iflags_test(ip, XFS_IRECLAIM)) { - read_unlock(&pag->pag_ici_lock); - delay(1); - XFS_STATS_INC(xs_ig_frecycle); - - goto again; - } - ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE)); - - /* - * If lookup is racing with unlink, then we - * should return an error immediately so we - * don't remove it from the reclaim list and - * potentially leak the inode. - */ - if ((ip->i_d.di_mode == 0) && - !(flags & XFS_IGET_CREATE)) { - read_unlock(&pag->pag_ici_lock); - xfs_put_perag(mp, pag); - return ENOENT; - } - - xfs_itrace_exit_tag(ip, "xfs_iget.alloc"); - - XFS_STATS_INC(xs_ig_found); - xfs_iflags_clear(ip, XFS_IRECLAIMABLE); - read_unlock(&pag->pag_ici_lock); - - XFS_MOUNT_ILOCK(mp); - list_del_init(&ip->i_reclaim); - XFS_MOUNT_IUNLOCK(mp); - - goto finish_inode; - - } else if (inode != old_inode) { - /* The inode is being torn down, pause and - * try again. - */ - if (old_inode->i_state & (I_FREEING | I_CLEAR)) { - read_unlock(&pag->pag_ici_lock); - delay(1); - XFS_STATS_INC(xs_ig_frecycle); - - goto again; - } + xfs_iflags_clear(ip, XFS_IRECLAIMABLE); + read_unlock(&pag->pag_ici_lock); + + XFS_MOUNT_ILOCK(mp); + list_del_init(&ip->i_reclaim); + XFS_MOUNT_IUNLOCK(mp); + + } else if (inode != old_inode) { + /* The inode is being torn down, pause and + * try again. + */ + if (old_inode->i_state & (I_FREEING | I_CLEAR)) { + error = EAGAIN; + XFS_STATS_INC(xs_ig_frecycle); + goto out_error; + } /* Chances are the other vnode (the one in the inode) is being torn * down right now, and we landed on top of it. Question is, what do * we do? Unhook the old inode and hook up the new one? */ - cmn_err(CE_PANIC, - "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p", - old_inode, inode); - } - - /* - * Inode cache hit - */ + cmn_err(CE_PANIC, + "xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p", + old_inode, inode); + } else { read_unlock(&pag->pag_ici_lock); - XFS_STATS_INC(xs_ig_found); + } -finish_inode: - if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) { - xfs_put_perag(mp, pag); - return ENOENT; - } + if (ip->i_d.di_mode == 0 && !(flags & XFS_IGET_CREATE)) { + error = ENOENT; + goto out; + } - if (lock_flags != 0) - xfs_ilock(ip, lock_flags); + if (lock_flags != 0) + xfs_ilock(ip, lock_flags); - xfs_iflags_clear(ip, XFS_ISTALE); - xfs_itrace_exit_tag(ip, "xfs_iget.found"); - goto return_ip; - } + xfs_iflags_clear(ip, XFS_ISTALE); + xfs_itrace_exit_tag(ip, "xfs_iget.found"); + XFS_STATS_INC(xs_ig_found); + return 0; - /* - * Inode cache miss - */ +out_error: read_unlock(&pag->pag_ici_lock); - XFS_STATS_INC(xs_ig_missed); +out: + return error; +} + + +static int +xfs_iget_cache_miss( + struct xfs_mount *mp, + struct xfs_perag *pag, + xfs_trans_t *tp, + xfs_ino_t ino, + struct xfs_inode **ipp, + xfs_daddr_t bno, + int flags, + int lock_flags) __releases(pag->pag_ici_lock) +{ + struct xfs_inode *ip; + int error; + unsigned long first_index, mask; + xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino); /* * Read the disk inode attributes into a new inode structure and get @@ -202,17 +160,14 @@ finish_inode: */ error = xfs_iread(mp, tp, ino, &ip, bno, (flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0); - if (error) { - xfs_put_perag(mp, pag); + if (error) return error; - } xfs_itrace_exit_tag(ip, "xfs_iget.alloc"); if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) { - xfs_idestroy(ip); - xfs_put_perag(mp, pag); - return ENOENT; + error = ENOENT; + goto out_destroy; } /* @@ -220,9 +175,8 @@ finish_inode: * write spinlock. */ if (radix_tree_preload(GFP_KERNEL)) { - xfs_idestroy(ip); - delay(1); - goto again; + error = EAGAIN; + goto out_destroy; } if (lock_flags) @@ -231,32 +185,104 @@ finish_inode: mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1); first_index = agino & mask; write_lock(&pag->pag_ici_lock); - /* - * insert the new inode - */ + + /* insert the new inode */ error = radix_tree_insert(&pag->pag_ici_root, agino, ip); if (unlikely(error)) { - BUG_ON(error != -EEXIST); - write_unlock(&pag->pag_ici_lock); - radix_tree_preload_end(); - if (lock_flags) - xfs_iunlock(ip, lock_flags); - xfs_idestroy(ip); + WARN_ON(error != -EEXIST); XFS_STATS_INC(xs_ig_dup); - goto again; + error = EAGAIN; + goto out_unlock; } - /* - * These values _must_ be set before releasing the radix tree lock! - */ + /* These values _must_ be set before releasing the radix tree lock! */ ip->i_udquot = ip->i_gdquot = NULL; xfs_iflags_set(ip, XFS_INEW); write_unlock(&pag->pag_ici_lock); radix_tree_preload_end(); + *ipp = ip; + return 0; + +out_unlock: + write_unlock(&pag->pag_ici_lock); + radix_tree_preload_end(); +out_destroy: + xfs_idestroy(ip); + return error; +} + +/* + * Look up an inode by number in the given file system. + * The inode is looked up in the cache held in each AG. + * If the inode is found in the cache, attach it to the provided + * vnode. + * + * If it is not in core, read it in from the file system's device, + * add it to the cache and attach the provided vnode. + * + * The inode is locked according to the value of the lock_flags parameter. + * This flag parameter indicates how and if the inode's IO lock and inode lock + * should be taken. + * + * mp -- the mount point structure for the current file system. It points + * to the inode hash table. + * tp -- a pointer to the current transaction if there is one. This is + * simply passed through to the xfs_iread() call. + * ino -- the number of the inode desired. This is the unique identifier + * within the file system for the inode being requested. + * lock_flags -- flags indicating how to lock the inode. See the comment + * for xfs_ilock() for a list of valid values. + * bno -- the block number starting the buffer containing the inode, + * if known (as by bulkstat), else 0. + */ +STATIC int +xfs_iget_core( + struct inode *inode, + xfs_mount_t *mp, + xfs_trans_t *tp, + xfs_ino_t ino, + uint flags, + uint lock_flags, + xfs_inode_t **ipp, + xfs_daddr_t bno) +{ + xfs_inode_t *ip; + int error; + xfs_perag_t *pag; + xfs_agino_t agino; + + /* the radix tree exists only in inode capable AGs */ + if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi) + return EINVAL; + + /* get the perag structure and ensure that it's inode capable */ + pag = xfs_get_perag(mp, ino); + if (!pag->pagi_inodeok) + return EINVAL; + ASSERT(pag->pag_ici_init); + agino = XFS_INO_TO_AGINO(mp, ino); + +again: + error = 0; + read_lock(&pag->pag_ici_lock); + ip = radix_tree_lookup(&pag->pag_ici_root, agino); + + if (ip) { + error = xfs_iget_cache_hit(inode, pag, ip, flags, lock_flags); + if (error) + goto out_error_or_again; + } else { + read_unlock(&pag->pag_ici_lock); + XFS_STATS_INC(xs_ig_missed); + + error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip, bno, + flags, lock_flags); + if (error) + goto out_error_or_again; + } xfs_put_perag(mp, pag); - return_ip: ASSERT(ip->i_df.if_ext_max == XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t)); @@ -276,6 +302,14 @@ finish_inode: if (ip->i_d.di_mode != 0) xfs_setup_inode(ip); return 0; + +out_error_or_again: + if (error == EAGAIN) { + delay(1); + goto again; + } + xfs_put_perag(mp, pag); + return error; } |