/* * Called inside transaction, so use GFP_NOFS */ static struct inode *ext4_alloc_inode(struct super_block *sb) { struct ext4_inode_info *ei; ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS); if (!ei) return NULL; ei->vfs_inode.i_version = 1; spin_lock_init(&ei->i_raw_lock); INIT_LIST_HEAD(&ei->i_prealloc_list); spin_lock_init(&ei->i_prealloc_lock); ext4_es_init_tree(&ei->i_es_tree); rwlock_init(&ei->i_es_lock); INIT_LIST_HEAD(&ei->i_es_list); ei->i_es_all_nr = 0; ei->i_es_shk_nr = 0; ei->i_es_shrink_lblk = 0; ei->i_reserved_data_blocks = 0; ei->i_reserved_meta_blocks = 0; ei->i_allocated_meta_blocks = 0; ei->i_da_metadata_calc_len = 0; ei->i_da_metadata_calc_last_lblock = 0; spin_lock_init(&(ei->i_block_reservation_lock)); #ifdef CONFIG_QUOTA ei->i_reserved_quota = 0; memset(&ei->i_dquot, 0, sizeof(ei->i_dquot)); #endif ei->jinode = NULL; INIT_LIST_HEAD(&ei->i_rsv_conversion_list); spin_lock_init(&ei->i_completed_io_lock); ei->i_sync_tid = 0; ei->i_datasync_tid = 0; atomic_set(&ei->i_unwritten, 0); INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); return &ei->vfs_inode; } /* * fourth extended file system inode data in memory */ struct ext4_inode_info { __le32 i_data[15]; /* unconverted */ __u32 i_dtime; ext4_fsblk_t i_file_acl; /* * i_block_group is the number of the block group which contains * this file's inode. Constant across the lifetime of the inode, * it is ued for making block allocation decisions - we try to * place a file's data blocks near its inode block, and new inodes * near to their parent directory's inode. */ ext4_group_t i_block_group; ext4_lblk_t i_dir_start_lookup; #if (BITS_PER_LONG < 64) unsigned long i_state_flags; /* Dynamic state flags */ #endif unsigned long i_flags; /* * Extended attributes can be read independently of the main file * data. Taking i_mutex even when reading would cause contention * between readers of EAs and writers of regular file data, so * instead we synchronize on xattr_sem when reading or changing * EAs. */ struct rw_semaphore xattr_sem; struct list_head i_orphan; /* unlinked but open inodes */ /* * i_disksize keeps track of what the inode size is ON DISK, not * in memory. During truncate, i_size is set to the new size by * the VFS prior to calling ext4_truncate(), but the filesystem won't * set i_disksize to 0 until the truncate is actually under way. * * The intent is that i_disksize always represents the blocks which * are used by this file. This allows recovery to restart truncate * on orphans if we crash during truncate. We actually write i_disksize * into the on-disk inode when writing inodes out, instead of i_size. * * The only time when i_disksize and i_size may be different is when * a truncate is in progress. The only things which change i_disksize * are ext4_get_block (growth) and ext4_truncate (shrinkth). */ loff_t i_disksize; /* * i_data_sem is for serialising ext4_truncate() against * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's * data tree are chopped off during truncate. We can't do that in * ext4 because whenever we perform intermediate commits during * truncate, the inode and all the metadata blocks *must* be in a * consistent state which allows truncation of the orphans to restart * during recovery. Hence we must fix the get_block-vs-truncate race * by other means, so we have i_data_sem. */ struct rw_semaphore i_data_sem; /* * i_mmap_sem is for serializing page faults with truncate / punch hole * operations. We have to make sure that new page cannot be faulted in * a section of the inode that is being punched. We cannot easily use * i_data_sem for this since we need protection for the whole punch * operation and i_data_sem ranks below transaction start so we have * to occasionally drop it. */ struct rw_semaphore i_mmap_sem; struct inode vfs_inode; struct jbd2_inode *jinode; spinlock_t i_raw_lock; /* protects updates to the raw inode */ /* * File creation time. Its function is same as that of * struct timespec i_{a,c,m}time in the generic inode. */ struct timespec i_crtime; /* mballoc */ struct list_head i_prealloc_list; spinlock_t i_prealloc_lock; /* extents status tree */ struct ext4_es_tree i_es_tree; rwlock_t i_es_lock; struct list_head i_es_list; unsigned int i_es_all_nr; /* protected by i_es_lock */ unsigned int i_es_shk_nr; /* protected by i_es_lock */ ext4_lblk_t i_es_shrink_lblk; /* Offset where we start searching for extents to shrink. Protected by i_es_lock */ /* ialloc */ ext4_group_t i_last_alloc_group; /* allocation reservation info for delalloc */ /* In case of bigalloc, these refer to clusters rather than blocks */ unsigned int i_reserved_data_blocks; unsigned int i_reserved_meta_blocks; unsigned int i_allocated_meta_blocks; ext4_lblk_t i_da_metadata_calc_last_lblock; int i_da_metadata_calc_len; /* on-disk additional length */ __u16 i_extra_isize; /* Indicate the inline data space. */ u16 i_inline_off; u16 i_inline_size; #ifdef CONFIG_QUOTA /* quota space reservation, managed internally by quota code */ qsize_t i_reserved_quota; #endif /* Lock protecting lists below */ spinlock_t i_completed_io_lock; /* * Completed IOs that need unwritten extents handling and have * transaction reserved */ struct list_head i_rsv_conversion_list; struct work_struct i_rsv_conversion_work; atomic_t i_unwritten; /* Nr. of inflight conversions pending */ spinlock_t i_block_reservation_lock; /* * Transactions that contain inode's metadata needed to complete * fsync and fdatasync, respectively. */ tid_t i_sync_tid; tid_t i_datasync_tid; #ifdef CONFIG_QUOTA struct dquot *i_dquot[MAXQUOTAS]; #endif /* Precomputed uuid+inum+igen checksum for seeding inode checksums */ __u32 i_csum_seed; kprojid_t i_projid; };
ext4 分配節點ext4_alloc_inode
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