From: Andiry Xu <[email protected]> Search the file radix tree to find hold or data.
Signed-off-by: Andiry Xu <[email protected]> --- fs/nova/file.c | 47 +++++++++++++++++++++++ fs/nova/inode.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nova/inode.h | 1 + fs/nova/nova.h | 1 + 4 files changed, 162 insertions(+) diff --git a/fs/nova/file.c b/fs/nova/file.c index b46d4bd..ecaf20a 100644 --- a/fs/nova/file.c +++ b/fs/nova/file.c @@ -23,6 +23,53 @@ #include "nova.h" #include "inode.h" +static loff_t nova_llseek(struct file *file, loff_t offset, int origin) +{ + struct inode *inode = file->f_path.dentry->d_inode; + struct nova_inode_info *si = NOVA_I(inode); + struct nova_inode_info_header *sih = &si->header; + int retval; + + if (origin != SEEK_DATA && origin != SEEK_HOLE) + return generic_file_llseek(file, offset, origin); + + sih_lock_shared(sih); + switch (origin) { + case SEEK_DATA: + retval = nova_find_region(inode, &offset, 0); + if (retval) { + sih_unlock_shared(sih); + return retval; + } + break; + case SEEK_HOLE: + retval = nova_find_region(inode, &offset, 1); + if (retval) { + sih_unlock_shared(sih); + return retval; + } + break; + } + + if ((offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) || + offset > inode->i_sb->s_maxbytes) { + sih_unlock_shared(sih); + return -ENXIO; + } + + if (offset != file->f_pos) { + file->f_pos = offset; + file->f_version = 0; + } + + sih_unlock_shared(sih); + return offset; +} + + +const struct file_operations nova_dax_file_operations = { + .llseek = nova_llseek, +}; const struct inode_operations nova_file_inode_operations = { .setattr = nova_notify_change, diff --git a/fs/nova/inode.c b/fs/nova/inode.c index 6fcc5e7..a6d74cb 100644 --- a/fs/nova/inode.c +++ b/fs/nova/inode.c @@ -193,6 +193,52 @@ static void nova_truncate_file_blocks(struct inode *inode, loff_t start, } +/* search the radix tree to find hole or data + * in the specified range + * Input: + * first_blocknr: first block in the specified range + * last_blocknr: last_blocknr in the specified range + * @data_found: indicates whether data blocks were found + * @hole_found: indicates whether a hole was found + * hole: whether we are looking for a hole or data + */ +static int nova_lookup_hole_in_range(struct super_block *sb, + struct nova_inode_info_header *sih, + unsigned long first_blocknr, unsigned long last_blocknr, + int *data_found, int *hole_found, int hole) +{ + struct nova_file_write_entry *entry; + unsigned long blocks = 0; + unsigned long pgoff, old_pgoff; + + pgoff = first_blocknr; + while (pgoff <= last_blocknr) { + old_pgoff = pgoff; + entry = radix_tree_lookup(&sih->tree, pgoff); + if (entry) { + *data_found = 1; + if (!hole) + goto done; + pgoff++; + } else { + *hole_found = 1; + entry = nova_find_next_entry(sb, sih, pgoff); + pgoff++; + if (entry) { + pgoff = pgoff > entry->pgoff ? + pgoff : entry->pgoff; + if (pgoff > last_blocknr) + pgoff = last_blocknr + 1; + } + } + + if (!*hole_found || !hole) + blocks += pgoff - old_pgoff; + } +done: + return blocks; +} + /* copy persistent state to struct inode */ static int nova_read_inode(struct super_block *sb, struct inode *inode, u64 pi_addr) @@ -232,6 +278,7 @@ static int nova_read_inode(struct super_block *sb, struct inode *inode, switch (inode->i_mode & S_IFMT) { case S_IFREG: inode->i_op = &nova_file_inode_operations; + inode->i_fop = &nova_dax_file_operations; break; case S_IFDIR: inode->i_op = &nova_dir_inode_operations; @@ -929,6 +976,7 @@ struct inode *nova_new_vfs_inode(enum nova_new_inode_type type, case TYPE_CREATE: inode->i_op = &nova_file_inode_operations; inode->i_mapping->a_ops = &nova_aops_dax; + inode->i_fop = &nova_dax_file_operations; break; case TYPE_MKNOD: init_special_inode(inode, mode, rdev); @@ -1170,6 +1218,71 @@ int nova_notify_change(struct dentry *dentry, struct iattr *attr) return ret; } +/* + * find the file offset for SEEK_DATA/SEEK_HOLE + */ +unsigned long nova_find_region(struct inode *inode, loff_t *offset, int hole) +{ + struct nova_inode_info *si = NOVA_I(inode); + struct nova_inode_info_header *sih = &si->header; + unsigned int data_bits = blk_type_to_shift[sih->i_blk_type]; + unsigned long first_blocknr, last_blocknr; + unsigned long blocks = 0, offset_in_block; + int data_found = 0, hole_found = 0; + + if (*offset >= inode->i_size) + return -ENXIO; + + if (!inode->i_blocks || !sih->i_size) { + if (hole) + return inode->i_size; + else + return -ENXIO; + } + + offset_in_block = *offset & ((1UL << data_bits) - 1); + + first_blocknr = *offset >> data_bits; + last_blocknr = inode->i_size >> data_bits; + + nova_dbgv("find_region offset %llx, first_blocknr %lx, last_blocknr %lx hole %d\n", + *offset, first_blocknr, last_blocknr, hole); + + blocks = nova_lookup_hole_in_range(inode->i_sb, sih, + first_blocknr, last_blocknr, &data_found, &hole_found, hole); + + /* Searching data but only hole found till the end */ + if (!hole && !data_found && hole_found) + return -ENXIO; + + if (data_found && !hole_found) { + /* Searching data but we are already into them */ + if (hole) + /* Searching hole but only data found, go to the end */ + *offset = inode->i_size; + return 0; + } + + /* Searching for hole, hole found and starting inside an hole */ + if (hole && hole_found && !blocks) { + /* we found data after it */ + if (!data_found) + /* last hole */ + *offset = inode->i_size; + return 0; + } + + if (offset_in_block) { + blocks--; + *offset += (blocks << data_bits) + + ((1 << data_bits) - offset_in_block); + } else { + *offset += blocks << data_bits; + } + + return 0; +} + static ssize_t nova_direct_IO(struct kiocb *iocb, struct iov_iter *iter) { /* DAX does not support direct IO */ diff --git a/fs/nova/inode.h b/fs/nova/inode.h index 48403cf..693aa90 100644 --- a/fs/nova/inode.h +++ b/fs/nova/inode.h @@ -264,6 +264,7 @@ int nova_delete_file_tree(struct super_block *sb, struct nova_inode_info_header *sih, unsigned long start_blocknr, unsigned long last_blocknr, bool delete_nvmm, bool delete_dead, u64 epoch_id); +unsigned long nova_find_region(struct inode *inode, loff_t *offset, int hole); extern void nova_evict_inode(struct inode *inode); extern int nova_write_inode(struct inode *inode, struct writeback_control *wbc); extern void nova_dirty_inode(struct inode *inode, int flags); diff --git a/fs/nova/nova.h b/fs/nova/nova.h index 601e082..b2831f6 100644 --- a/fs/nova/nova.h +++ b/fs/nova/nova.h @@ -485,6 +485,7 @@ int nova_remove_dentry(struct dentry *dentry, int dec_link, struct nova_inode_update *update, u64 epoch_id); /* file.c */ +extern const struct file_operations nova_dax_file_operations; extern const struct inode_operations nova_file_inode_operations; /* namei.c */ -- 2.7.4
