// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2003-2006, Cluster File Systems, Inc, [email protected] * Written by Alex Tomas <[email protected]> * * Architecture independence: * Copyright (c) 2005, Bull S.A. * Written by Pierre Peiffer <[email protected]> */ /* * Extents support for EXT4 * * TODO: * - ext4*_error() should be used in some situations * - analyze all BUG()/BUG_ON(), use -EIO where appropriate * - smart tree reduction */ #include <linux/fs.h> #include <linux/time.h> #include <linux/jbd2.h> #include <linux/highuid.h> #include <linux/pagemap.h> #include <linux/quotaops.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/fiemap.h> #include <linux/iomap.h> #include <linux/sched/mm.h> #include "ext4_jbd2.h" #include "ext4_extents.h" #include "xattr.h" #include <trace/events/ext4.h> /* * used by extent splitting. */ #define EXT4_EXT_MAY_ZEROOUT … #define EXT4_EXT_MARK_UNWRIT1 … #define EXT4_EXT_MARK_UNWRIT2 … #define EXT4_EXT_DATA_VALID1 … #define EXT4_EXT_DATA_VALID2 … static __le32 ext4_extent_block_csum(struct inode *inode, struct ext4_extent_header *eh) { … } static int ext4_extent_block_csum_verify(struct inode *inode, struct ext4_extent_header *eh) { … } static void ext4_extent_block_csum_set(struct inode *inode, struct ext4_extent_header *eh) { … } static int ext4_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t split, int split_flag, int flags); static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped) { … } static void ext4_ext_drop_refs(struct ext4_ext_path *path) { … } void ext4_free_ext_path(struct ext4_ext_path *path) { … } /* * Make sure 'handle' has at least 'check_cred' credits. If not, restart * transaction with 'restart_cred' credits. The function drops i_data_sem * when restarting transaction and gets it after transaction is restarted. * * The function returns 0 on success, 1 if transaction had to be restarted, * and < 0 in case of fatal error. */ int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode, int check_cred, int restart_cred, int revoke_cred) { … } /* * could return: * - EROFS * - ENOMEM */ static int ext4_ext_get_access(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { … } /* * could return: * - EROFS * - ENOMEM * - EIO */ static int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { … } #define ext4_ext_dirty(handle, inode, path) … static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { … } /* * Allocation for a meta data block */ static ext4_fsblk_t ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex, int *err, unsigned int flags) { … } static inline int ext4_ext_space_block(struct inode *inode, int check) { … } static inline int ext4_ext_space_block_idx(struct inode *inode, int check) { … } static inline int ext4_ext_space_root(struct inode *inode, int check) { … } static inline int ext4_ext_space_root_idx(struct inode *inode, int check) { … } static inline int ext4_force_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t lblk, int nofail) { … } static int ext4_ext_max_entries(struct inode *inode, int depth) { … } static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) { … } static int ext4_valid_extent_idx(struct inode *inode, struct ext4_extent_idx *ext_idx) { … } static int ext4_valid_extent_entries(struct inode *inode, struct ext4_extent_header *eh, ext4_lblk_t lblk, ext4_fsblk_t *pblk, int depth) { … } static int __ext4_ext_check(const char *function, unsigned int line, struct inode *inode, struct ext4_extent_header *eh, int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk) { … } #define ext4_ext_check(inode, eh, depth, pblk) … int ext4_ext_check_inode(struct inode *inode) { … } static void ext4_cache_extents(struct inode *inode, struct ext4_extent_header *eh) { … } static struct buffer_head * __read_extent_tree_block(const char *function, unsigned int line, struct inode *inode, struct ext4_extent_idx *idx, int depth, int flags) { … } #define read_extent_tree_block(inode, idx, depth, flags) … /* * This function is called to cache a file's extent information in the * extent status tree */ int ext4_ext_precache(struct inode *inode) { … } #ifdef EXT_DEBUG static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) { int k, l = path->p_depth; ext_debug(inode, "path:"); for (k = 0; k <= l; k++, path++) { if (path->p_idx) { ext_debug(inode, " %d->%llu", le32_to_cpu(path->p_idx->ei_block), ext4_idx_pblock(path->p_idx)); } else if (path->p_ext) { ext_debug(inode, " %d:[%d]%d:%llu ", le32_to_cpu(path->p_ext->ee_block), ext4_ext_is_unwritten(path->p_ext), ext4_ext_get_actual_len(path->p_ext), ext4_ext_pblock(path->p_ext)); } else ext_debug(inode, " []"); } ext_debug(inode, "\n"); } static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) { int depth = ext_depth(inode); struct ext4_extent_header *eh; struct ext4_extent *ex; int i; if (!path) return; eh = path[depth].p_hdr; ex = EXT_FIRST_EXTENT(eh); ext_debug(inode, "Displaying leaf extents\n"); for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); } ext_debug(inode, "\n"); } static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path, ext4_fsblk_t newblock, int level) { int depth = ext_depth(inode); struct ext4_extent *ex; if (depth != level) { struct ext4_extent_idx *idx; idx = path[level].p_idx; while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) { ext_debug(inode, "%d: move %d:%llu in new index %llu\n", level, le32_to_cpu(idx->ei_block), ext4_idx_pblock(idx), newblock); idx++; } return; } ex = path[depth].p_ext; while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) { ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n", le32_to_cpu(ex->ee_block), ext4_ext_pblock(ex), ext4_ext_is_unwritten(ex), ext4_ext_get_actual_len(ex), newblock); ex++; } } #else #define ext4_ext_show_path(inode, path) … #define ext4_ext_show_leaf(inode, path) … #define ext4_ext_show_move(inode, path, newblock, level) … #endif /* * ext4_ext_binsearch_idx: * binary search for the closest index of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { … } /* * ext4_ext_binsearch: * binary search for closest extent of the given block * the header must be checked before calling this */ static void ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t block) { … } void ext4_ext_tree_init(handle_t *handle, struct inode *inode) { … } struct ext4_ext_path * ext4_find_extent(struct inode *inode, ext4_lblk_t block, struct ext4_ext_path **orig_path, int flags) { … } /* * ext4_ext_insert_index: * insert new index [@logical;@ptr] into the block at @curp; * check where to insert: before @curp or after @curp */ static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, struct ext4_ext_path *curp, int logical, ext4_fsblk_t ptr) { … } /* * ext4_ext_split: * inserts new subtree into the path, using free index entry * at depth @at: * - allocates all needed blocks (new leaf and all intermediate index blocks) * - makes decision where to split * - moves remaining extents and index entries (right to the split point) * into the newly allocated blocks * - initializes subtree */ static int ext4_ext_split(handle_t *handle, struct inode *inode, unsigned int flags, struct ext4_ext_path *path, struct ext4_extent *newext, int at) { … } /* * ext4_ext_grow_indepth: * implements tree growing procedure: * - allocates new block * - moves top-level data (index block or leaf) into the new block * - initializes new top-level, creating index that points to the * just created block */ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, unsigned int flags) { … } /* * ext4_ext_create_new_leaf: * finds empty index and adds new leaf. * if no free index is found, then it requests in-depth growing. */ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, unsigned int mb_flags, unsigned int gb_flags, struct ext4_ext_path **ppath, struct ext4_extent *newext) { … } /* * search the closest allocated block to the left for *logical * and returns it at @logical + it's physical address at @phys * if *logical is the smallest allocated block, the function * returns 0 at @phys * return value contains 0 (success) or error code */ static int ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys) { … } /* * Search the closest allocated block to the right for *logical * and returns it at @logical + it's physical address at @phys. * If not exists, return 0 and @phys is set to 0. We will return * 1 which means we found an allocated block and ret_ex is valid. * Or return a (< 0) error code. */ static int ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *logical, ext4_fsblk_t *phys, struct ext4_extent *ret_ex) { … } /* * ext4_ext_next_allocated_block: * returns allocated block in subsequent extent or EXT_MAX_BLOCKS. * NOTE: it considers block number from index entry as * allocated block. Thus, index entries have to be consistent * with leaves. */ ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path) { … } /* * ext4_ext_next_leaf_block: * returns first allocated block from next leaf or EXT_MAX_BLOCKS */ static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path) { … } /* * ext4_ext_correct_indexes: * if leaf gets modified and modified extent is first in the leaf, * then we have to correct all indexes above. * TODO: do we need to correct tree in all cases? */ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { … } static int ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, struct ext4_extent *ex2) { … } /* * This function tries to merge the "ex" extent to the next extent in the tree. * It always tries to merge towards right. If you want to merge towards * left, pass "ex - 1" as argument instead of "ex". * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns * 1 if they got merged. */ static int ext4_ext_try_to_merge_right(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { … } /* * This function does a very simple check to see if we can collapse * an extent tree with a single extent tree leaf block into the inode. */ static void ext4_ext_try_to_merge_up(handle_t *handle, struct inode *inode, struct ext4_ext_path *path) { … } /* * This function tries to merge the @ex extent to neighbours in the tree, then * tries to collapse the extent tree into the inode. */ static void ext4_ext_try_to_merge(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { … } /* * check if a portion of the "newext" extent overlaps with an * existing extent. * * If there is an overlap discovered, it updates the length of the newext * such that there will be no overlap, and then returns 1. * If there is no overlap found, it returns 0. */ static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi, struct inode *inode, struct ext4_extent *newext, struct ext4_ext_path *path) { … } /* * ext4_ext_insert_extent: * tries to merge requested extent into the existing extent or * inserts requested extent as new one into the tree, * creating new leaf in the no-space case. */ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, struct ext4_extent *newext, int gb_flags) { … } static int ext4_fill_es_cache_info(struct inode *inode, ext4_lblk_t block, ext4_lblk_t num, struct fiemap_extent_info *fieinfo) { … } /* * ext4_ext_find_hole - find hole around given block according to the given path * @inode: inode we lookup in * @path: path in extent tree to @lblk * @lblk: pointer to logical block around which we want to determine hole * * Determine hole length (and start if easily possible) around given logical * block. We don't try too hard to find the beginning of the hole but @path * actually points to extent before @lblk, we provide it. * * The function returns the length of a hole starting at @lblk. We update @lblk * to the beginning of the hole if we managed to find it. */ static ext4_lblk_t ext4_ext_find_hole(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t *lblk) { … } /* * ext4_ext_rm_idx: * removes index from the index block. */ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, int depth) { … } /* * ext4_ext_calc_credits_for_single_extent: * This routine returns max. credits that needed to insert an extent * to the extent tree. * When pass the actual path, the caller should calculate credits * under i_data_sem. */ int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, struct ext4_ext_path *path) { … } /* * How many index/leaf blocks need to change/allocate to add @extents extents? * * If we add a single extent, then in the worse case, each tree level * index/leaf need to be changed in case of the tree split. * * If more extents are inserted, they could cause the whole tree split more * than once, but this is really rare. */ int ext4_ext_index_trans_blocks(struct inode *inode, int extents) { … } static inline int get_default_free_blocks_flags(struct inode *inode) { … } /* * ext4_rereserve_cluster - increment the reserved cluster count when * freeing a cluster with a pending reservation * * @inode - file containing the cluster * @lblk - logical block in cluster to be reserved * * Increments the reserved cluster count and adjusts quota in a bigalloc * file system when freeing a partial cluster containing at least one * delayed and unwritten block. A partial cluster meeting that * requirement will have a pending reservation. If so, the * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to * defer reserved and allocated space accounting to a subsequent call * to this function. */ static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk) { … } static int ext4_remove_blocks(handle_t *handle, struct inode *inode, struct ext4_extent *ex, struct partial_cluster *partial, ext4_lblk_t from, ext4_lblk_t to) { … } /* * ext4_ext_rm_leaf() Removes the extents associated with the * blocks appearing between "start" and "end". Both "start" * and "end" must appear in the same extent or EIO is returned. * * @handle: The journal handle * @inode: The files inode * @path: The path to the leaf * @partial_cluster: The cluster which we'll have to free if all extents * has been released from it. However, if this value is * negative, it's a cluster just to the right of the * punched region and it must not be freed. * @start: The first block to remove * @end: The last block to remove */ static int ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, struct partial_cluster *partial, ext4_lblk_t start, ext4_lblk_t end) { … } /* * ext4_ext_more_to_rm: * returns 1 if current index has to be freed (even partial) */ static int ext4_ext_more_to_rm(struct ext4_ext_path *path) { … } int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, ext4_lblk_t end) { … } /* * called at mount time */ void ext4_ext_init(struct super_block *sb) { … } /* * called at umount time */ void ext4_ext_release(struct super_block *sb) { … } static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex) { … } /* FIXME!! we need to try to merge to left or right after zero-out */ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) { … } /* * ext4_split_extent_at() splits an extent at given block. * * @handle: the journal handle * @inode: the file inode * @path: the path to the extent * @split: the logical block where the extent is splitted. * @split_flags: indicates if the extent could be zeroout if split fails, and * the states(init or unwritten) of new extents. * @flags: flags used to insert new extent to extent tree. * * * Splits extent [a, b] into two extents [a, @split) and [@split, b], states * of which are determined by split_flag. * * There are two cases: * a> the extent are splitted into two extent. * b> split is not needed, and just mark the extent. * * return 0 on success. */ static int ext4_split_extent_at(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, ext4_lblk_t split, int split_flag, int flags) { … } /* * ext4_split_extents() splits an extent and mark extent which is covered * by @map as split_flags indicates * * It may result in splitting the extent into multiple extents (up to three) * There are three possibilities: * a> There is no split required * b> Splits in two extents: Split is happening at either end of the extent * c> Splits in three extents: Somone is splitting in middle of the extent * */ static int ext4_split_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path **ppath, struct ext4_map_blocks *map, int split_flag, int flags) { … } /* * This function is called by ext4_ext_map_blocks() if someone tries to write * to an unwritten extent. It may result in splitting the unwritten * extent into multiple extents (up to three - one initialized and two * unwritten). * There are three possibilities: * a> There is no split required: Entire extent should be initialized * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent * * Pre-conditions: * - The extent pointed to by 'path' is unwritten. * - The extent pointed to by 'path' contains a superset * of the logical span [map->m_lblk, map->m_lblk + map->m_len). * * Post-conditions on success: * - the returned value is the number of blocks beyond map->l_lblk * that are allocated and initialized. * It is guaranteed to be >= map->m_len. */ static int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags) { … } /* * This function is called by ext4_ext_map_blocks() from * ext4_get_blocks_dio_write() when DIO to write * to an unwritten extent. * * Writing to an unwritten extent may result in splitting the unwritten * extent into multiple initialized/unwritten extents (up to three) * There are three possibilities: * a> There is no split required: Entire extent should be unwritten * b> Splits in two extents: Write is happening at either end of the extent * c> Splits in three extents: Somone is writing in middle of the extent * * This works the same way in the case of initialized -> unwritten conversion. * * One of more index blocks maybe needed if the extent tree grow after * the unwritten extent split. To prevent ENOSPC occur at the IO * complete, we need to split the unwritten extent before DIO submit * the IO. The unwritten extent called at this time will be split * into three unwritten extent(at most). After IO complete, the part * being filled will be convert to initialized by the end_io callback function * via ext4_convert_unwritten_extents(). * * Returns the size of unwritten extent to be written on success. */ static int ext4_split_convert_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags) { … } static int ext4_convert_unwritten_extents_endio(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath) { … } static int convert_initialized_extent(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, unsigned int *allocated) { … } static int ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, struct ext4_ext_path **ppath, int flags, unsigned int allocated, ext4_fsblk_t newblock) { … } /* * get_implied_cluster_alloc - check to see if the requested * allocation (in the map structure) overlaps with a cluster already * allocated in an extent. * @sb The filesystem superblock structure * @map The requested lblk->pblk mapping * @ex The extent structure which might contain an implied * cluster allocation * * This function is called by ext4_ext_map_blocks() after we failed to * find blocks that were already in the inode's extent tree. Hence, * we know that the beginning of the requested region cannot overlap * the extent from the inode's extent tree. There are three cases we * want to catch. The first is this case: * * |--- cluster # N--| * |--- extent ---| |---- requested region ---| * |==========| * * The second case that we need to test for is this one: * * |--------- cluster # N ----------------| * |--- requested region --| |------- extent ----| * |=======================| * * The third case is when the requested region lies between two extents * within the same cluster: * |------------- cluster # N-------------| * |----- ex -----| |---- ex_right ----| * |------ requested region ------| * |================| * * In each of the above cases, we need to set the map->m_pblk and * map->m_len so it corresponds to the return the extent labelled as * "|====|" from cluster #N, since it is already in use for data in * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to * signal to ext4_ext_map_blocks() that map->m_pblk should be treated * as a new "allocated" block region. Otherwise, we will return 0 and * ext4_ext_map_blocks() will then allocate one or more new clusters * by calling ext4_mb_new_blocks(). */ static int get_implied_cluster_alloc(struct super_block *sb, struct ext4_map_blocks *map, struct ext4_extent *ex, struct ext4_ext_path *path) { … } /* * Determine hole length around the given logical block, first try to * locate and expand the hole from the given @path, and then adjust it * if it's partially or completely converted to delayed extents, insert * it into the extent cache tree if it's indeed a hole, finally return * the length of the determined extent. */ static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode, struct ext4_ext_path *path, ext4_lblk_t lblk) { … } /* * Block allocation/map/preallocation routine for extents based files * * * Need to be called with * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block * (ie, flags is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) * * return > 0, number of blocks already mapped/allocated * if flags doesn't contain EXT4_GET_BLOCKS_CREATE and these are pre-allocated blocks * buffer head is unmapped * otherwise blocks are mapped * * return = 0, if plain look up failed (blocks have not been allocated) * buffer head is unmapped * * return < 0, error case. */ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags) { … } int ext4_ext_truncate(handle_t *handle, struct inode *inode) { … } static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, ext4_lblk_t len, loff_t new_size, int flags) { … } static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len); static int ext4_insert_range(struct file *file, loff_t offset, loff_t len); static long ext4_zero_range(struct file *file, loff_t offset, loff_t len, int mode) { … } /* * preallocate space for a file. This implements ext4's fallocate file * operation, which gets called from sys_fallocate system call. * For block-mapped files, posix_fallocate should fall back to the method * of writing zeroes to the required new blocks (the same behavior which is * expected for file systems which do not support fallocate() system call). */ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { … } /* * This function convert a range of blocks to written extents * The caller of this function will pass the start offset and the size. * all unwritten extents within this range will be converted to * written extents. * * This function is called from the direct IO end io call back * function, to convert the fallocated extents after IO is completed. * Returns 0 on success. */ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode, loff_t offset, ssize_t len) { … } int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end) { … } static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap) { … } static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap, struct iomap *srcmap) { … } static const struct iomap_ops ext4_iomap_xattr_ops = …; static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len) { … } int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, u64 start, u64 len) { … } int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { … } /* * ext4_ext_shift_path_extents: * Shift the extents of a path structure lying between path[depth].p_ext * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells * if it is right shift or left shift operation. */ static int ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, struct inode *inode, handle_t *handle, enum SHIFT_DIRECTION SHIFT) { … } /* * ext4_ext_shift_extents: * All the extents which lies in the range from @start to the last allocated * block for the @inode are shifted either towards left or right (depending * upon @SHIFT) by @shift blocks. * On success, 0 is returned, error otherwise. */ static int ext4_ext_shift_extents(struct inode *inode, handle_t *handle, ext4_lblk_t start, ext4_lblk_t shift, enum SHIFT_DIRECTION SHIFT) { … } /* * ext4_collapse_range: * This implements the fallocate's collapse range functionality for ext4 * Returns: 0 and non-zero on error. */ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len) { … } /* * ext4_insert_range: * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate. * The data blocks starting from @offset to the EOF are shifted by @len * towards right to create a hole in the @inode. Inode size is increased * by len bytes. * Returns 0 on success, error otherwise. */ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) { … } /** * ext4_swap_extents() - Swap extents between two inodes * @handle: handle for this transaction * @inode1: First inode * @inode2: Second inode * @lblk1: Start block for first inode * @lblk2: Start block for second inode * @count: Number of blocks to swap * @unwritten: Mark second inode's extents as unwritten after swap * @erp: Pointer to save error value * * This helper routine does exactly what is promise "swap extents". All other * stuff such as page-cache locking consistency, bh mapping consistency or * extent's data copying must be performed by caller. * Locking: * i_rwsem is held for both inodes * i_data_sem is locked for write for both inodes * Assumptions: * All pages from requested range are locked for both inodes */ int ext4_swap_extents(handle_t *handle, struct inode *inode1, struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2, ext4_lblk_t count, int unwritten, int *erp) { … } /* * ext4_clu_mapped - determine whether any block in a logical cluster has * been mapped to a physical cluster * * @inode - file containing the logical cluster * @lclu - logical cluster of interest * * Returns 1 if any block in the logical cluster is mapped, signifying * that a physical cluster has been allocated for it. Otherwise, * returns 0. Can also return negative error codes. Derived from * ext4_ext_map_blocks(). */ int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu) { … } /* * Updates physical block address and unwritten status of extent * starting at lblk start and of len. If such an extent doesn't exist, * this function splits the extent tree appropriately to create an * extent like this. This function is called in the fast commit * replay path. Returns 0 on success and error on failure. */ int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start, int len, int unwritten, ext4_fsblk_t pblk) { … } /* Try to shrink the extent tree */ void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end) { … } /* Check if *cur is a hole and if it is, skip it */ static int skip_hole(struct inode *inode, ext4_lblk_t *cur) { … } /* Count number of blocks used by this inode and update i_blocks */ int ext4_ext_replay_set_iblocks(struct inode *inode) { … } int ext4_ext_clear_bb(struct inode *inode) { … }
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