diff options
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/ext4.h | 3 | ||||
| -rw-r--r-- | fs/ext4/extents.c | 307 | ||||
| -rw-r--r-- | fs/ext4/move_extent.c | 2 |
3 files changed, 310 insertions, 2 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index b7207db3107c..beec42750a8c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2758,6 +2758,7 @@ extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk); extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len); extern int ext4_ext_precache(struct inode *inode); +extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len); /* move_extent.c */ extern void ext4_double_down_write_data_sem(struct inode *first, @@ -2767,6 +2768,8 @@ extern void ext4_double_up_write_data_sem(struct inode *orig_inode, extern int ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 start_orig, __u64 start_donor, __u64 len, __u64 *moved_len); +extern int mext_next_extent(struct inode *inode, struct ext4_ext_path *path, + struct ext4_extent **extent); /* page-io.c */ extern int __init ext4_init_pageio(void); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 2e0608e3be6e..bbba1ef5417d 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4581,12 +4581,16 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) unsigned int credits, blkbits = inode->i_blkbits; /* Return error if mode is not supported */ - if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | + FALLOC_FL_COLLAPSE_RANGE)) return -EOPNOTSUPP; if (mode & FALLOC_FL_PUNCH_HOLE) return ext4_punch_hole(inode, offset, len); + if (mode & FALLOC_FL_COLLAPSE_RANGE) + return ext4_collapse_range(inode, offset, len); + ret = ext4_convert_inline_data(inode); if (ret) return ret; @@ -4885,3 +4889,304 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, ext4_es_lru_add(inode); return error; } + +/* + * ext4_access_path: + * Function to access the path buffer for marking it dirty. + * It also checks if there are sufficient credits left in the journal handle + * to update path. + */ +static int +ext4_access_path(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + int credits, err; + + if (!ext4_handle_valid(handle)) + return 0; + + /* + * Check if need to extend journal credits + * 3 for leaf, sb, and inode plus 2 (bmap and group + * descriptor) for each block group; assume two block + * groups + */ + if (handle->h_buffer_credits < 7) { + credits = ext4_writepage_trans_blocks(inode); + err = ext4_ext_truncate_extend_restart(handle, inode, credits); + /* EAGAIN is success */ + if (err && err != -EAGAIN) + return err; + } + + err = ext4_ext_get_access(handle, inode, path); + return err; +} + +/* + * 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) downwards, by subtracting shift + * from starting block for each extent. + */ +static int +ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift, + struct inode *inode, handle_t *handle, + ext4_lblk_t *start) +{ + int depth, err = 0; + struct ext4_extent *ex_start, *ex_last; + bool update = 0; + depth = path->p_depth; + + while (depth >= 0) { + if (depth == path->p_depth) { + ex_start = path[depth].p_ext; + if (!ex_start) + return -EIO; + + ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); + if (!ex_last) + return -EIO; + + err = ext4_access_path(handle, inode, path + depth); + if (err) + goto out; + + if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) + update = 1; + + *start = ex_last->ee_block + + ext4_ext_get_actual_len(ex_last); + + while (ex_start <= ex_last) { + ex_start->ee_block -= shift; + if (ex_start > + EXT_FIRST_EXTENT(path[depth].p_hdr)) { + if (ext4_ext_try_to_merge_right(inode, + path, ex_start - 1)) + ex_last--; + } + ex_start++; + } + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + if (--depth < 0 || !update) + break; + } + + /* Update index too */ + err = ext4_access_path(handle, inode, path + depth); + if (err) + goto out; + + path[depth].p_idx->ei_block -= shift; + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + /* we are done if current index is not a starting index */ + if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr)) + break; + + depth--; + } + +out: + return err; +} + +/* + * ext4_ext_shift_extents: + * All the extents which lies in the range from start to the last allocated + * block for the file are shifted downwards 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) +{ + struct ext4_ext_path *path; + int ret = 0, depth; + struct ext4_extent *extent; + ext4_lblk_t stop_block, current_block; + ext4_lblk_t ex_start, ex_end; + + /* Let path point to the last extent */ + path = ext4_ext_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0); + if (IS_ERR(path)) + return PTR_ERR(path); + + depth = path->p_depth; + extent = path[depth].p_ext; + if (!extent) { + ext4_ext_drop_refs(path); + kfree(path); + return ret; + } + + stop_block = extent->ee_block + ext4_ext_get_actual_len(extent); + ext4_ext_drop_refs(path); + kfree(path); + + /* Nothing to shift, if hole is at the end of file */ + if (start >= stop_block) + return ret; + + /* + * Don't start shifting extents until we make sure the hole is big + * enough to accomodate the shift. + */ + path = ext4_ext_find_extent(inode, start - 1, NULL, 0); + depth = path->p_depth; + extent = path[depth].p_ext; + ex_start = extent->ee_block; + ex_end = extent->ee_block + ext4_ext_get_actual_len(extent); + ext4_ext_drop_refs(path); + kfree(path); + + if ((start == ex_start && shift > ex_start) || + (shift > start - ex_end)) + return -EINVAL; + + /* Its safe to start updating extents */ + while (start < stop_block) { + path = ext4_ext_find_extent(inode, start, NULL, 0); + if (IS_ERR(path)) + return PTR_ERR(path); + depth = path->p_depth; + extent = path[depth].p_ext; + current_block = extent->ee_block; + if (start > current_block) { + /* Hole, move to the next extent */ + ret = mext_next_extent(inode, path, &extent); + if (ret != 0) { + ext4_ext_drop_refs(path); + kfree(path); + if (ret == 1) + ret = 0; + break; + } + } + ret = ext4_ext_shift_path_extents(path, shift, inode, + handle, &start); + ext4_ext_drop_refs(path); + kfree(path); + if (ret) + break; + } + + return ret; +} + +/* + * ext4_collapse_range: + * This implements the fallocate's collapse range functionality for ext4 + * Returns: 0 and non-zero on error. + */ +int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) +{ + struct super_block *sb = inode->i_sb; + ext4_lblk_t punch_start, punch_stop; + handle_t *handle; + unsigned int credits; + loff_t new_size; + int ret; + + BUG_ON(offset + len > i_size_read(inode)); + + /* Collapse range works only on fs block size aligned offsets. */ + if (offset & (EXT4_BLOCK_SIZE(sb) - 1) || + len & (EXT4_BLOCK_SIZE(sb) - 1)) + return -EINVAL; + + if (!S_ISREG(inode->i_mode)) + return -EOPNOTSUPP; + + trace_ext4_collapse_range(inode, offset, len); + + punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb); + punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb); + + /* Write out all dirty pages */ + ret = filemap_write_and_wait_range(inode->i_mapping, offset, -1); + if (ret) + return ret; + + /* Take mutex lock */ + mutex_lock(&inode->i_mutex); + + /* It's not possible punch hole on append only file */ + if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) { + ret = -EPERM; + goto out_mutex; + } + + if (IS_SWAPFILE(inode)) { + ret = -ETXTBSY; + goto out_mutex; + } + + /* Currently just for extent based files */ + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + ret = -EOPNOTSUPP; + goto out_mutex; + } + + truncate_pagecache_range(inode, offset, -1); + + /* Wait for existing dio to complete */ + ext4_inode_block_unlocked_dio(inode); + inode_dio_wait(inode); + + credits = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_dio; + } + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_discard_preallocations(inode); + + ret = ext4_es_remove_extent(inode, punch_start, + EXT_MAX_BLOCKS - punch_start - 1); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + ret = ext4_ext_shift_extents(inode, handle, punch_stop, + punch_stop - punch_start); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + new_size = i_size_read(inode) - len; + truncate_setsize(inode, new_size); + EXT4_I(inode)->i_disksize = new_size; + + ext4_discard_preallocations(inode); + up_write(&EXT4_I(inode)->i_data_sem); + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + inode->i_mtime = inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + +out_stop: + ext4_journal_stop(handle); +out_dio: + ext4_inode_resume_unlocked_dio(inode); +out_mutex: + mutex_unlock(&inode->i_mutex); + return ret; +} diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index f39a88abe32c..58ee7dc87669 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -76,7 +76,7 @@ copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest) * ext4_ext_path structure refers to the last extent, or a negative error * value on failure. */ -static int +int mext_next_extent(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent **extent) { |
