ref: f881d4f67254359ef348376e092c779993f57ed6
dir: /sys/src/cmd/ext4srv/include/ext4_fs.h/
#pragma once
#include "ext4_config.h"
#include "ext4_types.h"
#include "ext4_misc.h"
struct ext4_fs {
bool read_only;
struct ext4_blockdev *bdev;
struct ext4_sblock sb;
u32int uuid_crc32c;
u64int inode_block_limits[4];
u64int inode_blocks_per_level[4];
u32int last_inode_bg_id;
struct jbd_fs *jbd_fs;
struct jbd_journal *jbd_journal;
struct jbd_trans *curr_trans;
};
struct ext4_block_group_ref {
struct ext4_block block;
struct ext4_bgroup *block_group;
struct ext4_fs *fs;
u32int index;
bool dirty;
};
struct ext4_inode_ref {
struct ext4_block block;
struct ext4_inode *inode;
struct ext4_fs *fs;
u32int index;
bool dirty;
};
#pragma incomplete struct ext4_fs
/**@brief Convert block address to relative index in block group.
* @param sb Superblock pointer
* @param baddr Block number to convert
* @return Relative number of block
*/
static inline u32int ext4_fs_addr_to_idx_bg(struct ext4_sblock *s,
ext4_fsblk_t baddr)
{
if (ext4_get32(s, first_data_block) && baddr)
baddr--;
return baddr % ext4_get32(s, blocks_per_group);
}
/**@brief Convert relative block address in group to absolute address.
* @param s Superblock pointer
* @param index Relative block address
* @param bgid Block group
* @return Absolute block address
*/
static inline ext4_fsblk_t ext4_fs_bg_idx_to_addr(struct ext4_sblock *s,
u32int index,
u32int bgid)
{
if (ext4_get32(s, first_data_block))
index++;
return ext4_get32(s, blocks_per_group) * bgid + index;
}
/**@brief TODO: */
static inline ext4_fsblk_t ext4_fs_first_bg_block_no(struct ext4_sblock *s,
u32int bgid)
{
return (u64int)bgid * ext4_get32(s, blocks_per_group) +
ext4_get32(s, first_data_block);
}
/**@brief Initialize filesystem and read all needed data.
* @param fs Filesystem instance to be initialized
* @param bdev Identifier if device with the filesystem
* @param read_only Mark the filesystem as read-only.
* @return Error code
*/
int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev,
bool read_only);
/**@brief Destroy filesystem instance (used by unmount operation).
* @param fs Filesystem to be destroyed
* @return Error code
*/
int ext4_fs_fini(struct ext4_fs *fs);
/**@brief Check filesystem's features, if supported by this driver
* Function can return 0 and set read_only flag. It mean's that
* there are some not-supported features, that can cause problems
* during some write operations.
* @param fs Filesystem to be checked
* @param read_only Flag if filesystem should be mounted only for reading
* @return Error code
*/
int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only);
/**@brief Get reference to block group specified by index.
* @param fs Filesystem to find block group on
* @param bgid Index of block group to load
* @param ref Output pointer for reference
* @return Error code
*/
int ext4_fs_get_block_group_ref(struct ext4_fs *fs, u32int bgid,
struct ext4_block_group_ref *ref);
/**@brief Put reference to block group.
* @param ref Pointer for reference to be put back
* @return Error code
*/
int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref);
/**@brief Get reference to i-node specified by index.
* @param fs Filesystem to find i-node on
* @param index Index of i-node to load
* @param ref Output pointer for reference
* @return Error code
*/
int ext4_fs_get_inode_ref(struct ext4_fs *fs, u32int index,
struct ext4_inode_ref *ref);
/**@brief Reset blocks field of i-node.
* @param fs Filesystem to reset blocks field of i-inode on
* @param inode_ref ref Pointer for inode to be operated on
*/
void ext4_fs_inode_blocks_init(struct ext4_fs *fs,
struct ext4_inode_ref *inode_ref);
/**@brief Put reference to i-node.
* @param ref Pointer for reference to be put back
* @return Error code
*/
int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref);
/**@brief Convert filetype to inode mode.
* @param filetype
* @return inode mode
*/
u32int ext4_fs_correspond_inode_mode(int filetype);
/**@brief Allocate new i-node in the filesystem.
* @param fs Filesystem to allocated i-node on
* @param inode_ref Output pointer to return reference to allocated i-node
* @param filetype File type of newly created i-node
* @return Error code
*/
int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
int filetype);
/**@brief Release i-node and mark it as free.
* @param inode_ref I-node to be released
* @return Error code
*/
int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref);
/**@brief Truncate i-node data blocks.
* @param inode_ref I-node to be truncated
* @param new_size New size of inode (must be < current size)
* @return Error code
*/
int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, u64int new_size);
/**@brief Compute 'goal' for inode index
* @param inode_ref Reference to inode, to allocate block for
* @return goal
*/
ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref);
/**@brief Compute 'goal' for allocation algorithm (For blockmap).
* @param inode_ref Reference to inode, to allocate block for
* @param goal
* @return error code
*/
int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t *goal);
/**@brief Get physical block address by logical index of the block.
* @param inode_ref I-node to read block address from
* @param iblock Logical index of block
* @param fblock Output pointer for return physical
* block address
* @param support_unwritten Indicate whether unwritten block range
* is supported under the current context
* @return Error code
*/
int ext4_fs_get_inode_dblk_idx(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t *fblock,
bool support_unwritten);
/**@brief Initialize a part of unwritten range of the inode.
* @param inode_ref I-node to proceed on.
* @param iblock Logical index of block
* @param fblock Output pointer for return physical block address
* @return Error code
*/
int ext4_fs_init_inode_dblk_idx(struct ext4_inode_ref *inode_ref,
ext4_lblk_t iblock, ext4_fsblk_t *fblock);
/**@brief Append following logical block to the i-node.
* @param inode_ref I-node to append block to
* @param fblock Output physical block address of newly allocated block
* @param iblock Output logical number of newly allocated block
* @return Error code
*/
int ext4_fs_append_inode_dblk(struct ext4_inode_ref *inode_ref,
ext4_fsblk_t *fblock, ext4_lblk_t *iblock);
/**@brief Increment inode link count.
* @param inode none handle
*/
void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref);
/**@brief Decrement inode link count.
* @param inode none handle
*/
void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref);