1748de673SAkira Fujita /* 2748de673SAkira Fujita * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd. 3748de673SAkira Fujita * Written by Takashi Sato <t-sato@yk.jp.nec.com> 4748de673SAkira Fujita * Akira Fujita <a-fujita@rs.jp.nec.com> 5748de673SAkira Fujita * 6748de673SAkira Fujita * This program is free software; you can redistribute it and/or modify it 7748de673SAkira Fujita * under the terms of version 2.1 of the GNU Lesser General Public License 8748de673SAkira Fujita * as published by the Free Software Foundation. 9748de673SAkira Fujita * 10748de673SAkira Fujita * This program is distributed in the hope that it will be useful, 11748de673SAkira Fujita * but WITHOUT ANY WARRANTY; without even the implied warranty of 12748de673SAkira Fujita * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13748de673SAkira Fujita * GNU General Public License for more details. 14748de673SAkira Fujita */ 15748de673SAkira Fujita 16748de673SAkira Fujita #include <linux/fs.h> 17748de673SAkira Fujita #include <linux/quotaops.h> 185a0e3ad6STejun Heo #include <linux/slab.h> 19748de673SAkira Fujita #include "ext4_jbd2.h" 20748de673SAkira Fujita #include "ext4.h" 214a092d73STheodore Ts'o #include "ext4_extents.h" 22748de673SAkira Fujita 23e8505970SAkira Fujita /** 24e8505970SAkira Fujita * get_ext_path - Find an extent path for designated logical block number. 25e8505970SAkira Fujita * 26e8505970SAkira Fujita * @inode: an inode which is searched 27e8505970SAkira Fujita * @lblock: logical block number to find an extent path 28e8505970SAkira Fujita * @path: pointer to an extent path pointer (for output) 29e8505970SAkira Fujita * 30ed8a1a76STheodore Ts'o * ext4_find_extent wrapper. Return 0 on success, or a negative error value 31e8505970SAkira Fujita * on failure. 32e8505970SAkira Fujita */ 33e8505970SAkira Fujita static inline int 34e8505970SAkira Fujita get_ext_path(struct inode *inode, ext4_lblk_t lblock, 353bdf14b4STheodore Ts'o struct ext4_ext_path **ppath) 36e8505970SAkira Fujita { 370e401101SDmitry Monakhov struct ext4_ext_path *path; 38e8505970SAkira Fujita 39ed8a1a76STheodore Ts'o path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE); 400e401101SDmitry Monakhov if (IS_ERR(path)) 413bdf14b4STheodore Ts'o return PTR_ERR(path); 423bdf14b4STheodore Ts'o if (path[ext_depth(inode)].p_ext == NULL) { 433bdf14b4STheodore Ts'o ext4_ext_drop_refs(path); 443bdf14b4STheodore Ts'o kfree(path); 453bdf14b4STheodore Ts'o *ppath = NULL; 463bdf14b4STheodore Ts'o return -ENODATA; 473bdf14b4STheodore Ts'o } 483bdf14b4STheodore Ts'o *ppath = path; 493bdf14b4STheodore Ts'o return 0; 50e8505970SAkira Fujita } 51748de673SAkira Fujita 52748de673SAkira Fujita /** 53393d1d1dSDr. Tilmann Bubeck * ext4_double_down_write_data_sem - Acquire two inodes' write lock 54393d1d1dSDr. Tilmann Bubeck * of i_data_sem 55748de673SAkira Fujita * 5603bd8b9bSDmitry Monakhov * Acquire write lock of i_data_sem of the two inodes 57748de673SAkira Fujita */ 58393d1d1dSDr. Tilmann Bubeck void 59393d1d1dSDr. Tilmann Bubeck ext4_double_down_write_data_sem(struct inode *first, struct inode *second) 60748de673SAkira Fujita { 6103bd8b9bSDmitry Monakhov if (first < second) { 62748de673SAkira Fujita down_write(&EXT4_I(first)->i_data_sem); 6349bd22bcSAkira Fujita down_write_nested(&EXT4_I(second)->i_data_sem, SINGLE_DEPTH_NESTING); 6403bd8b9bSDmitry Monakhov } else { 6503bd8b9bSDmitry Monakhov down_write(&EXT4_I(second)->i_data_sem); 6603bd8b9bSDmitry Monakhov down_write_nested(&EXT4_I(first)->i_data_sem, SINGLE_DEPTH_NESTING); 6703bd8b9bSDmitry Monakhov 6803bd8b9bSDmitry Monakhov } 69748de673SAkira Fujita } 70748de673SAkira Fujita 71748de673SAkira Fujita /** 72393d1d1dSDr. Tilmann Bubeck * ext4_double_up_write_data_sem - Release two inodes' write lock of i_data_sem 73748de673SAkira Fujita * 74748de673SAkira Fujita * @orig_inode: original inode structure to be released its lock first 75748de673SAkira Fujita * @donor_inode: donor inode structure to be released its lock second 76fc04cb49SAkira Fujita * Release write lock of i_data_sem of two inodes (orig and donor). 77748de673SAkira Fujita */ 78393d1d1dSDr. Tilmann Bubeck void 79393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(struct inode *orig_inode, 80393d1d1dSDr. Tilmann Bubeck struct inode *donor_inode) 81748de673SAkira Fujita { 82748de673SAkira Fujita up_write(&EXT4_I(orig_inode)->i_data_sem); 83748de673SAkira Fujita up_write(&EXT4_I(donor_inode)->i_data_sem); 84748de673SAkira Fujita } 85748de673SAkira Fujita 86748de673SAkira Fujita /** 878c854473SDmitry Monakhov * mext_check_coverage - Check that all extents in range has the same type 888c854473SDmitry Monakhov * 898c854473SDmitry Monakhov * @inode: inode in question 908c854473SDmitry Monakhov * @from: block offset of inode 918c854473SDmitry Monakhov * @count: block count to be checked 92556615dcSLukas Czerner * @unwritten: extents expected to be unwritten 938c854473SDmitry Monakhov * @err: pointer to save error value 948c854473SDmitry Monakhov * 958c854473SDmitry Monakhov * Return 1 if all extents in range has expected type, and zero otherwise. 968c854473SDmitry Monakhov */ 978c854473SDmitry Monakhov static int 988c854473SDmitry Monakhov mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count, 99556615dcSLukas Czerner int unwritten, int *err) 1008c854473SDmitry Monakhov { 1018c854473SDmitry Monakhov struct ext4_ext_path *path = NULL; 1028c854473SDmitry Monakhov struct ext4_extent *ext; 1030e401101SDmitry Monakhov int ret = 0; 1048c854473SDmitry Monakhov ext4_lblk_t last = from + count; 1058c854473SDmitry Monakhov while (from < last) { 1068c854473SDmitry Monakhov *err = get_ext_path(inode, from, &path); 1078c854473SDmitry Monakhov if (*err) 1080e401101SDmitry Monakhov goto out; 1098c854473SDmitry Monakhov ext = path[ext_depth(inode)].p_ext; 110556615dcSLukas Czerner if (unwritten != ext4_ext_is_unwritten(ext)) 1110e401101SDmitry Monakhov goto out; 1128c854473SDmitry Monakhov from += ext4_ext_get_actual_len(ext); 1138c854473SDmitry Monakhov ext4_ext_drop_refs(path); 1148c854473SDmitry Monakhov } 1150e401101SDmitry Monakhov ret = 1; 1160e401101SDmitry Monakhov out: 1170e401101SDmitry Monakhov ext4_ext_drop_refs(path); 1180e401101SDmitry Monakhov kfree(path); 1190e401101SDmitry Monakhov return ret; 1208c854473SDmitry Monakhov } 1218c854473SDmitry Monakhov 1228c854473SDmitry Monakhov /** 123bb557488SDmitry Monakhov * mext_page_double_lock - Grab and lock pages on both @inode1 and @inode2 124bb557488SDmitry Monakhov * 125bb557488SDmitry Monakhov * @inode1: the inode structure 126bb557488SDmitry Monakhov * @inode2: the inode structure 12765dd8327SXiaoguang Wang * @index1: page index 12865dd8327SXiaoguang Wang * @index2: page index 129bb557488SDmitry Monakhov * @page: result page vector 130bb557488SDmitry Monakhov * 131bb557488SDmitry Monakhov * Grab two locked pages for inode's by inode order 132bb557488SDmitry Monakhov */ 133bb557488SDmitry Monakhov static int 134bb557488SDmitry Monakhov mext_page_double_lock(struct inode *inode1, struct inode *inode2, 135fcf6b1b7SDmitry Monakhov pgoff_t index1, pgoff_t index2, struct page *page[2]) 136bb557488SDmitry Monakhov { 137bb557488SDmitry Monakhov struct address_space *mapping[2]; 138bb557488SDmitry Monakhov unsigned fl = AOP_FLAG_NOFS; 139bb557488SDmitry Monakhov 140bb557488SDmitry Monakhov BUG_ON(!inode1 || !inode2); 141bb557488SDmitry Monakhov if (inode1 < inode2) { 142bb557488SDmitry Monakhov mapping[0] = inode1->i_mapping; 143bb557488SDmitry Monakhov mapping[1] = inode2->i_mapping; 144bb557488SDmitry Monakhov } else { 145fcf6b1b7SDmitry Monakhov pgoff_t tmp = index1; 146fcf6b1b7SDmitry Monakhov index1 = index2; 147fcf6b1b7SDmitry Monakhov index2 = tmp; 148bb557488SDmitry Monakhov mapping[0] = inode2->i_mapping; 149bb557488SDmitry Monakhov mapping[1] = inode1->i_mapping; 150bb557488SDmitry Monakhov } 151bb557488SDmitry Monakhov 152fcf6b1b7SDmitry Monakhov page[0] = grab_cache_page_write_begin(mapping[0], index1, fl); 153bb557488SDmitry Monakhov if (!page[0]) 154bb557488SDmitry Monakhov return -ENOMEM; 155bb557488SDmitry Monakhov 156fcf6b1b7SDmitry Monakhov page[1] = grab_cache_page_write_begin(mapping[1], index2, fl); 157bb557488SDmitry Monakhov if (!page[1]) { 158bb557488SDmitry Monakhov unlock_page(page[0]); 159bb557488SDmitry Monakhov page_cache_release(page[0]); 160bb557488SDmitry Monakhov return -ENOMEM; 161bb557488SDmitry Monakhov } 1627e8b12c6SDmitry Monakhov /* 1637e8b12c6SDmitry Monakhov * grab_cache_page_write_begin() may not wait on page's writeback if 1647e8b12c6SDmitry Monakhov * BDI not demand that. But it is reasonable to be very conservative 1657e8b12c6SDmitry Monakhov * here and explicitly wait on page's writeback 1667e8b12c6SDmitry Monakhov */ 1677e8b12c6SDmitry Monakhov wait_on_page_writeback(page[0]); 1687e8b12c6SDmitry Monakhov wait_on_page_writeback(page[1]); 169bb557488SDmitry Monakhov if (inode1 > inode2) { 170bb557488SDmitry Monakhov struct page *tmp; 171bb557488SDmitry Monakhov tmp = page[0]; 172bb557488SDmitry Monakhov page[0] = page[1]; 173bb557488SDmitry Monakhov page[1] = tmp; 174bb557488SDmitry Monakhov } 175bb557488SDmitry Monakhov return 0; 176bb557488SDmitry Monakhov } 177bb557488SDmitry Monakhov 178bb557488SDmitry Monakhov /* Force page buffers uptodate w/o dropping page's lock */ 179bb557488SDmitry Monakhov static int 180bb557488SDmitry Monakhov mext_page_mkuptodate(struct page *page, unsigned from, unsigned to) 181bb557488SDmitry Monakhov { 182bb557488SDmitry Monakhov struct inode *inode = page->mapping->host; 183bb557488SDmitry Monakhov sector_t block; 184bb557488SDmitry Monakhov struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE]; 185bb557488SDmitry Monakhov unsigned int blocksize, block_start, block_end; 186bb557488SDmitry Monakhov int i, err, nr = 0, partial = 0; 187bb557488SDmitry Monakhov BUG_ON(!PageLocked(page)); 188bb557488SDmitry Monakhov BUG_ON(PageWriteback(page)); 189bb557488SDmitry Monakhov 190bb557488SDmitry Monakhov if (PageUptodate(page)) 191bb557488SDmitry Monakhov return 0; 192bb557488SDmitry Monakhov 193bb557488SDmitry Monakhov blocksize = 1 << inode->i_blkbits; 194bb557488SDmitry Monakhov if (!page_has_buffers(page)) 195bb557488SDmitry Monakhov create_empty_buffers(page, blocksize, 0); 196bb557488SDmitry Monakhov 197bb557488SDmitry Monakhov head = page_buffers(page); 198bb557488SDmitry Monakhov block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); 199bb557488SDmitry Monakhov for (bh = head, block_start = 0; bh != head || !block_start; 200bb557488SDmitry Monakhov block++, block_start = block_end, bh = bh->b_this_page) { 201bb557488SDmitry Monakhov block_end = block_start + blocksize; 202bb557488SDmitry Monakhov if (block_end <= from || block_start >= to) { 203bb557488SDmitry Monakhov if (!buffer_uptodate(bh)) 204bb557488SDmitry Monakhov partial = 1; 205bb557488SDmitry Monakhov continue; 206bb557488SDmitry Monakhov } 207bb557488SDmitry Monakhov if (buffer_uptodate(bh)) 208bb557488SDmitry Monakhov continue; 209bb557488SDmitry Monakhov if (!buffer_mapped(bh)) { 210bb557488SDmitry Monakhov err = ext4_get_block(inode, block, bh, 0); 211bb557488SDmitry Monakhov if (err) { 212bb557488SDmitry Monakhov SetPageError(page); 213bb557488SDmitry Monakhov return err; 214bb557488SDmitry Monakhov } 215bb557488SDmitry Monakhov if (!buffer_mapped(bh)) { 216bb557488SDmitry Monakhov zero_user(page, block_start, blocksize); 217bb557488SDmitry Monakhov set_buffer_uptodate(bh); 218bb557488SDmitry Monakhov continue; 219bb557488SDmitry Monakhov } 220bb557488SDmitry Monakhov } 221bb557488SDmitry Monakhov BUG_ON(nr >= MAX_BUF_PER_PAGE); 222bb557488SDmitry Monakhov arr[nr++] = bh; 223bb557488SDmitry Monakhov } 224bb557488SDmitry Monakhov /* No io required */ 225bb557488SDmitry Monakhov if (!nr) 226bb557488SDmitry Monakhov goto out; 227bb557488SDmitry Monakhov 228bb557488SDmitry Monakhov for (i = 0; i < nr; i++) { 229bb557488SDmitry Monakhov bh = arr[i]; 230bb557488SDmitry Monakhov if (!bh_uptodate_or_lock(bh)) { 231bb557488SDmitry Monakhov err = bh_submit_read(bh); 232bb557488SDmitry Monakhov if (err) 233bb557488SDmitry Monakhov return err; 234bb557488SDmitry Monakhov } 235bb557488SDmitry Monakhov } 236bb557488SDmitry Monakhov out: 237bb557488SDmitry Monakhov if (!partial) 238bb557488SDmitry Monakhov SetPageUptodate(page); 239bb557488SDmitry Monakhov return 0; 240bb557488SDmitry Monakhov } 241bb557488SDmitry Monakhov 242bb557488SDmitry Monakhov /** 243748de673SAkira Fujita * move_extent_per_page - Move extent data per page 244748de673SAkira Fujita * 245748de673SAkira Fujita * @o_filp: file structure of original file 246748de673SAkira Fujita * @donor_inode: donor inode 247748de673SAkira Fujita * @orig_page_offset: page index on original file 24865dd8327SXiaoguang Wang * @donor_page_offset: page index on donor file 249748de673SAkira Fujita * @data_offset_in_page: block index where data swapping starts 250748de673SAkira Fujita * @block_len_in_page: the number of blocks to be swapped 251556615dcSLukas Czerner * @unwritten: orig extent is unwritten or not 252f868a48dSAkira Fujita * @err: pointer to save return value 253748de673SAkira Fujita * 254748de673SAkira Fujita * Save the data in original inode blocks and replace original inode extents 25565dd8327SXiaoguang Wang * with donor inode extents by calling ext4_swap_extents(). 256f868a48dSAkira Fujita * Finally, write out the saved data in new original inode blocks. Return 257f868a48dSAkira Fujita * replaced block count. 258748de673SAkira Fujita */ 259748de673SAkira Fujita static int 26044fc48f7SAkira Fujita move_extent_per_page(struct file *o_filp, struct inode *donor_inode, 261fcf6b1b7SDmitry Monakhov pgoff_t orig_page_offset, pgoff_t donor_page_offset, 262fcf6b1b7SDmitry Monakhov int data_offset_in_page, 263556615dcSLukas Czerner int block_len_in_page, int unwritten, int *err) 264748de673SAkira Fujita { 265496ad9aaSAl Viro struct inode *orig_inode = file_inode(o_filp); 266bb557488SDmitry Monakhov struct page *pagep[2] = {NULL, NULL}; 267748de673SAkira Fujita handle_t *handle; 268fcf6b1b7SDmitry Monakhov ext4_lblk_t orig_blk_offset, donor_blk_offset; 269748de673SAkira Fujita unsigned long blocksize = orig_inode->i_sb->s_blocksize; 270748de673SAkira Fujita unsigned int w_flags = 0; 271f868a48dSAkira Fujita unsigned int tmp_data_size, data_size, replaced_size; 272bb557488SDmitry Monakhov int err2, jblocks, retries = 0; 273f868a48dSAkira Fujita int replaced_count = 0; 274bb557488SDmitry Monakhov int from = data_offset_in_page << orig_inode->i_blkbits; 275748de673SAkira Fujita int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; 276748de673SAkira Fujita 277748de673SAkira Fujita /* 278748de673SAkira Fujita * It needs twice the amount of ordinary journal buffers because 279748de673SAkira Fujita * inode and donor_inode may change each different metadata blocks. 280748de673SAkira Fujita */ 281bb557488SDmitry Monakhov again: 282bb557488SDmitry Monakhov *err = 0; 283748de673SAkira Fujita jblocks = ext4_writepage_trans_blocks(orig_inode) * 2; 2849924a92aSTheodore Ts'o handle = ext4_journal_start(orig_inode, EXT4_HT_MOVE_EXTENTS, jblocks); 285748de673SAkira Fujita if (IS_ERR(handle)) { 286f868a48dSAkira Fujita *err = PTR_ERR(handle); 287f868a48dSAkira Fujita return 0; 288748de673SAkira Fujita } 289748de673SAkira Fujita 290748de673SAkira Fujita if (segment_eq(get_fs(), KERNEL_DS)) 291748de673SAkira Fujita w_flags |= AOP_FLAG_UNINTERRUPTIBLE; 292748de673SAkira Fujita 293748de673SAkira Fujita orig_blk_offset = orig_page_offset * blocks_per_page + 294748de673SAkira Fujita data_offset_in_page; 295748de673SAkira Fujita 296fcf6b1b7SDmitry Monakhov donor_blk_offset = donor_page_offset * blocks_per_page + 297fcf6b1b7SDmitry Monakhov data_offset_in_page; 298fcf6b1b7SDmitry Monakhov 299f868a48dSAkira Fujita /* Calculate data_size */ 300748de673SAkira Fujita if ((orig_blk_offset + block_len_in_page - 1) == 301748de673SAkira Fujita ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) { 302748de673SAkira Fujita /* Replace the last block */ 303f868a48dSAkira Fujita tmp_data_size = orig_inode->i_size & (blocksize - 1); 304748de673SAkira Fujita /* 305f868a48dSAkira Fujita * If data_size equal zero, it shows data_size is multiples of 306748de673SAkira Fujita * blocksize. So we set appropriate value. 307748de673SAkira Fujita */ 308f868a48dSAkira Fujita if (tmp_data_size == 0) 309f868a48dSAkira Fujita tmp_data_size = blocksize; 310748de673SAkira Fujita 311f868a48dSAkira Fujita data_size = tmp_data_size + 312748de673SAkira Fujita ((block_len_in_page - 1) << orig_inode->i_blkbits); 313f868a48dSAkira Fujita } else 314f868a48dSAkira Fujita data_size = block_len_in_page << orig_inode->i_blkbits; 315748de673SAkira Fujita 316f868a48dSAkira Fujita replaced_size = data_size; 317f868a48dSAkira Fujita 318bb557488SDmitry Monakhov *err = mext_page_double_lock(orig_inode, donor_inode, orig_page_offset, 319fcf6b1b7SDmitry Monakhov donor_page_offset, pagep); 320f868a48dSAkira Fujita if (unlikely(*err < 0)) 321bb557488SDmitry Monakhov goto stop_journal; 3228c854473SDmitry Monakhov /* 323556615dcSLukas Czerner * If orig extent was unwritten it can become initialized 3248c854473SDmitry Monakhov * at any time after i_data_sem was dropped, in order to 3258c854473SDmitry Monakhov * serialize with delalloc we have recheck extent while we 3268c854473SDmitry Monakhov * hold page's lock, if it is still the case data copy is not 3278c854473SDmitry Monakhov * necessary, just swap data blocks between orig and donor. 3288c854473SDmitry Monakhov */ 329556615dcSLukas Czerner if (unwritten) { 330393d1d1dSDr. Tilmann Bubeck ext4_double_down_write_data_sem(orig_inode, donor_inode); 3318c854473SDmitry Monakhov /* If any of extents in range became initialized we have to 3328c854473SDmitry Monakhov * fallback to data copying */ 333556615dcSLukas Czerner unwritten = mext_check_coverage(orig_inode, orig_blk_offset, 3348c854473SDmitry Monakhov block_len_in_page, 1, err); 3358c854473SDmitry Monakhov if (*err) 3368c854473SDmitry Monakhov goto drop_data_sem; 337748de673SAkira Fujita 338fcf6b1b7SDmitry Monakhov unwritten &= mext_check_coverage(donor_inode, donor_blk_offset, 3398c854473SDmitry Monakhov block_len_in_page, 1, err); 3408c854473SDmitry Monakhov if (*err) 3418c854473SDmitry Monakhov goto drop_data_sem; 3428c854473SDmitry Monakhov 343556615dcSLukas Czerner if (!unwritten) { 344393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(orig_inode, donor_inode); 3458c854473SDmitry Monakhov goto data_copy; 3468c854473SDmitry Monakhov } 3478c854473SDmitry Monakhov if ((page_has_private(pagep[0]) && 3488c854473SDmitry Monakhov !try_to_release_page(pagep[0], 0)) || 3498c854473SDmitry Monakhov (page_has_private(pagep[1]) && 3508c854473SDmitry Monakhov !try_to_release_page(pagep[1], 0))) { 3518c854473SDmitry Monakhov *err = -EBUSY; 3528c854473SDmitry Monakhov goto drop_data_sem; 3538c854473SDmitry Monakhov } 354fcf6b1b7SDmitry Monakhov replaced_count = ext4_swap_extents(handle, orig_inode, 3558c854473SDmitry Monakhov donor_inode, orig_blk_offset, 356fcf6b1b7SDmitry Monakhov donor_blk_offset, 357fcf6b1b7SDmitry Monakhov block_len_in_page, 1, err); 3588c854473SDmitry Monakhov drop_data_sem: 359393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(orig_inode, donor_inode); 3608c854473SDmitry Monakhov goto unlock_pages; 3618c854473SDmitry Monakhov } 3628c854473SDmitry Monakhov data_copy: 363bb557488SDmitry Monakhov *err = mext_page_mkuptodate(pagep[0], from, from + replaced_size); 364bb557488SDmitry Monakhov if (*err) 365bb557488SDmitry Monakhov goto unlock_pages; 366bb557488SDmitry Monakhov 367bb557488SDmitry Monakhov /* At this point all buffers in range are uptodate, old mapping layout 368bb557488SDmitry Monakhov * is no longer required, try to drop it now. */ 369bb557488SDmitry Monakhov if ((page_has_private(pagep[0]) && !try_to_release_page(pagep[0], 0)) || 370bb557488SDmitry Monakhov (page_has_private(pagep[1]) && !try_to_release_page(pagep[1], 0))) { 371bb557488SDmitry Monakhov *err = -EBUSY; 372bb557488SDmitry Monakhov goto unlock_pages; 373748de673SAkira Fujita } 3746e263146SDmitry Monakhov ext4_double_down_write_data_sem(orig_inode, donor_inode); 375fcf6b1b7SDmitry Monakhov replaced_count = ext4_swap_extents(handle, orig_inode, donor_inode, 376fcf6b1b7SDmitry Monakhov orig_blk_offset, donor_blk_offset, 377fcf6b1b7SDmitry Monakhov block_len_in_page, 1, err); 3786e263146SDmitry Monakhov ext4_double_up_write_data_sem(orig_inode, donor_inode); 379bb557488SDmitry Monakhov if (*err) { 380f868a48dSAkira Fujita if (replaced_count) { 381f868a48dSAkira Fujita block_len_in_page = replaced_count; 382f868a48dSAkira Fujita replaced_size = 383f868a48dSAkira Fujita block_len_in_page << orig_inode->i_blkbits; 384ac48b0a1SAkira Fujita } else 385bb557488SDmitry Monakhov goto unlock_pages; 386f868a48dSAkira Fujita } 387bb557488SDmitry Monakhov /* Perform all necessary steps similar write_begin()/write_end() 388bb557488SDmitry Monakhov * but keeping in mind that i_size will not change */ 3897e8b12c6SDmitry Monakhov *err = __block_write_begin(pagep[0], from, replaced_size, 390bb557488SDmitry Monakhov ext4_get_block); 391bb557488SDmitry Monakhov if (!*err) 392bb557488SDmitry Monakhov *err = block_commit_write(pagep[0], from, from + replaced_size); 393fc04cb49SAkira Fujita 394bb557488SDmitry Monakhov if (unlikely(*err < 0)) 395bb557488SDmitry Monakhov goto repair_branches; 396748de673SAkira Fujita 397bb557488SDmitry Monakhov /* Even in case of data=writeback it is reasonable to pin 398bb557488SDmitry Monakhov * inode to transaction, to prevent unexpected data loss */ 399bb557488SDmitry Monakhov *err = ext4_jbd2_file_inode(handle, orig_inode); 400748de673SAkira Fujita 401bb557488SDmitry Monakhov unlock_pages: 402bb557488SDmitry Monakhov unlock_page(pagep[0]); 403bb557488SDmitry Monakhov page_cache_release(pagep[0]); 404bb557488SDmitry Monakhov unlock_page(pagep[1]); 405bb557488SDmitry Monakhov page_cache_release(pagep[1]); 406bb557488SDmitry Monakhov stop_journal: 40791cc219aSPeng Tao ext4_journal_stop(handle); 408bb557488SDmitry Monakhov /* Buffer was busy because probably is pinned to journal transaction, 409bb557488SDmitry Monakhov * force transaction commit may help to free it. */ 410bb557488SDmitry Monakhov if (*err == -EBUSY && ext4_should_retry_alloc(orig_inode->i_sb, 411bb557488SDmitry Monakhov &retries)) 412bb557488SDmitry Monakhov goto again; 413f868a48dSAkira Fujita return replaced_count; 414bb557488SDmitry Monakhov 415bb557488SDmitry Monakhov repair_branches: 416bb557488SDmitry Monakhov /* 417bb557488SDmitry Monakhov * This should never ever happen! 418bb557488SDmitry Monakhov * Extents are swapped already, but we are not able to copy data. 419bb557488SDmitry Monakhov * Try to swap extents to it's original places 420bb557488SDmitry Monakhov */ 421393d1d1dSDr. Tilmann Bubeck ext4_double_down_write_data_sem(orig_inode, donor_inode); 422fcf6b1b7SDmitry Monakhov replaced_count = ext4_swap_extents(handle, donor_inode, orig_inode, 423fcf6b1b7SDmitry Monakhov orig_blk_offset, donor_blk_offset, 424fcf6b1b7SDmitry Monakhov block_len_in_page, 0, &err2); 425393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(orig_inode, donor_inode); 426bb557488SDmitry Monakhov if (replaced_count != block_len_in_page) { 427bb557488SDmitry Monakhov EXT4_ERROR_INODE_BLOCK(orig_inode, (sector_t)(orig_blk_offset), 428bb557488SDmitry Monakhov "Unable to copy data block," 429bb557488SDmitry Monakhov " data will be lost."); 430bb557488SDmitry Monakhov *err = -EIO; 431bb557488SDmitry Monakhov } 432bb557488SDmitry Monakhov replaced_count = 0; 433bb557488SDmitry Monakhov goto unlock_pages; 434748de673SAkira Fujita } 435748de673SAkira Fujita 436748de673SAkira Fujita /** 437c437b273SAkira Fujita * mext_check_arguments - Check whether move extent can be done 438748de673SAkira Fujita * 439748de673SAkira Fujita * @orig_inode: original inode 440748de673SAkira Fujita * @donor_inode: donor inode 441748de673SAkira Fujita * @orig_start: logical start offset in block for orig 442748de673SAkira Fujita * @donor_start: logical start offset in block for donor 443748de673SAkira Fujita * @len: the number of blocks to be moved 444748de673SAkira Fujita * 445748de673SAkira Fujita * Check the arguments of ext4_move_extents() whether the files can be 446748de673SAkira Fujita * exchanged with each other. 447748de673SAkira Fujita * Return 0 on success, or a negative error value on failure. 448748de673SAkira Fujita */ 449748de673SAkira Fujita static int 450748de673SAkira Fujita mext_check_arguments(struct inode *orig_inode, 451748de673SAkira Fujita struct inode *donor_inode, __u64 orig_start, 452446aaa6eSKazuya Mio __u64 donor_start, __u64 *len) 453748de673SAkira Fujita { 454fcf6b1b7SDmitry Monakhov __u64 orig_eof, donor_eof; 45570d5d3dcSAkira Fujita unsigned int blkbits = orig_inode->i_blkbits; 45670d5d3dcSAkira Fujita unsigned int blocksize = 1 << blkbits; 45770d5d3dcSAkira Fujita 458fcf6b1b7SDmitry Monakhov orig_eof = (i_size_read(orig_inode) + blocksize - 1) >> blkbits; 459fcf6b1b7SDmitry Monakhov donor_eof = (i_size_read(donor_inode) + blocksize - 1) >> blkbits; 460fcf6b1b7SDmitry Monakhov 461fcf6b1b7SDmitry Monakhov 4624a58579bSAkira Fujita if (donor_inode->i_mode & (S_ISUID|S_ISGID)) { 4634a58579bSAkira Fujita ext4_debug("ext4 move extent: suid or sgid is set" 4644a58579bSAkira Fujita " to donor file [ino:orig %lu, donor %lu]\n", 4654a58579bSAkira Fujita orig_inode->i_ino, donor_inode->i_ino); 4664a58579bSAkira Fujita return -EINVAL; 4674a58579bSAkira Fujita } 4684a58579bSAkira Fujita 4691f5a81e4STheodore Ts'o if (IS_IMMUTABLE(donor_inode) || IS_APPEND(donor_inode)) 4701f5a81e4STheodore Ts'o return -EPERM; 4711f5a81e4STheodore Ts'o 472748de673SAkira Fujita /* Ext4 move extent does not support swapfile */ 473748de673SAkira Fujita if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) { 474748de673SAkira Fujita ext4_debug("ext4 move extent: The argument files should " 475748de673SAkira Fujita "not be swapfile [ino:orig %lu, donor %lu]\n", 476748de673SAkira Fujita orig_inode->i_ino, donor_inode->i_ino); 477fcf6b1b7SDmitry Monakhov return -EBUSY; 478748de673SAkira Fujita } 479748de673SAkira Fujita 480748de673SAkira Fujita /* Ext4 move extent supports only extent based file */ 48112e9b892SDmitry Monakhov if (!(ext4_test_inode_flag(orig_inode, EXT4_INODE_EXTENTS))) { 482748de673SAkira Fujita ext4_debug("ext4 move extent: orig file is not extents " 483748de673SAkira Fujita "based file [ino:orig %lu]\n", orig_inode->i_ino); 484748de673SAkira Fujita return -EOPNOTSUPP; 48512e9b892SDmitry Monakhov } else if (!(ext4_test_inode_flag(donor_inode, EXT4_INODE_EXTENTS))) { 486748de673SAkira Fujita ext4_debug("ext4 move extent: donor file is not extents " 487748de673SAkira Fujita "based file [ino:donor %lu]\n", donor_inode->i_ino); 488748de673SAkira Fujita return -EOPNOTSUPP; 489748de673SAkira Fujita } 490748de673SAkira Fujita 491748de673SAkira Fujita if ((!orig_inode->i_size) || (!donor_inode->i_size)) { 492748de673SAkira Fujita ext4_debug("ext4 move extent: File size is 0 byte\n"); 493748de673SAkira Fujita return -EINVAL; 494748de673SAkira Fujita } 495748de673SAkira Fujita 496748de673SAkira Fujita /* Start offset should be same */ 497fcf6b1b7SDmitry Monakhov if ((orig_start & ~(PAGE_MASK >> orig_inode->i_blkbits)) != 498fcf6b1b7SDmitry Monakhov (donor_start & ~(PAGE_MASK >> orig_inode->i_blkbits))) { 499748de673SAkira Fujita ext4_debug("ext4 move extent: orig and donor's start " 500fcf6b1b7SDmitry Monakhov "offset are not alligned [ino:orig %lu, donor %lu]\n", 501748de673SAkira Fujita orig_inode->i_ino, donor_inode->i_ino); 502748de673SAkira Fujita return -EINVAL; 503748de673SAkira Fujita } 504748de673SAkira Fujita 505f17722f9SLukas Czerner if ((orig_start >= EXT_MAX_BLOCKS) || 506fcf6b1b7SDmitry Monakhov (donor_start >= EXT_MAX_BLOCKS) || 507f17722f9SLukas Czerner (*len > EXT_MAX_BLOCKS) || 508fcf6b1b7SDmitry Monakhov (donor_start + *len >= EXT_MAX_BLOCKS) || 509f17722f9SLukas Czerner (orig_start + *len >= EXT_MAX_BLOCKS)) { 5100a80e986SEric Sandeen ext4_debug("ext4 move extent: Can't handle over [%u] blocks " 511f17722f9SLukas Czerner "[ino:orig %lu, donor %lu]\n", EXT_MAX_BLOCKS, 512748de673SAkira Fujita orig_inode->i_ino, donor_inode->i_ino); 513748de673SAkira Fujita return -EINVAL; 514748de673SAkira Fujita } 515fcf6b1b7SDmitry Monakhov if (orig_eof < orig_start + *len - 1) 516fcf6b1b7SDmitry Monakhov *len = orig_eof - orig_start; 517fcf6b1b7SDmitry Monakhov if (donor_eof < donor_start + *len - 1) 518fcf6b1b7SDmitry Monakhov *len = donor_eof - donor_start; 519748de673SAkira Fujita if (!*len) { 52092c28159SAkira Fujita ext4_debug("ext4 move extent: len should not be 0 " 521748de673SAkira Fujita "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino, 522748de673SAkira Fujita donor_inode->i_ino); 523748de673SAkira Fujita return -EINVAL; 524748de673SAkira Fujita } 525748de673SAkira Fujita 526748de673SAkira Fujita return 0; 527748de673SAkira Fujita } 528748de673SAkira Fujita 529748de673SAkira Fujita /** 530748de673SAkira Fujita * ext4_move_extents - Exchange the specified range of a file 531748de673SAkira Fujita * 532748de673SAkira Fujita * @o_filp: file structure of the original file 533748de673SAkira Fujita * @d_filp: file structure of the donor file 53465dd8327SXiaoguang Wang * @orig_blk: start offset in block for orig 53565dd8327SXiaoguang Wang * @donor_blk: start offset in block for donor 536748de673SAkira Fujita * @len: the number of blocks to be moved 537748de673SAkira Fujita * @moved_len: moved block length 538748de673SAkira Fujita * 539748de673SAkira Fujita * This function returns 0 and moved block length is set in moved_len 540748de673SAkira Fujita * if succeed, otherwise returns error value. 541748de673SAkira Fujita * 542748de673SAkira Fujita */ 543748de673SAkira Fujita int 544fcf6b1b7SDmitry Monakhov ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk, 545fcf6b1b7SDmitry Monakhov __u64 donor_blk, __u64 len, __u64 *moved_len) 546748de673SAkira Fujita { 547496ad9aaSAl Viro struct inode *orig_inode = file_inode(o_filp); 548496ad9aaSAl Viro struct inode *donor_inode = file_inode(d_filp); 549fcf6b1b7SDmitry Monakhov struct ext4_ext_path *path = NULL; 550748de673SAkira Fujita int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits; 551fcf6b1b7SDmitry Monakhov ext4_lblk_t o_end, o_start = orig_blk; 552fcf6b1b7SDmitry Monakhov ext4_lblk_t d_start = donor_blk; 553fcf6b1b7SDmitry Monakhov int ret; 554748de673SAkira Fujita 55503bd8b9bSDmitry Monakhov if (orig_inode->i_sb != donor_inode->i_sb) { 55603bd8b9bSDmitry Monakhov ext4_debug("ext4 move extent: The argument files " 55703bd8b9bSDmitry Monakhov "should be in same FS [ino:orig %lu, donor %lu]\n", 55803bd8b9bSDmitry Monakhov orig_inode->i_ino, donor_inode->i_ino); 55903bd8b9bSDmitry Monakhov return -EINVAL; 56003bd8b9bSDmitry Monakhov } 56103bd8b9bSDmitry Monakhov 56203bd8b9bSDmitry Monakhov /* orig and donor should be different inodes */ 56303bd8b9bSDmitry Monakhov if (orig_inode == donor_inode) { 564f3ce8064STheodore Ts'o ext4_debug("ext4 move extent: The argument files should not " 56503bd8b9bSDmitry Monakhov "be same inode [ino:orig %lu, donor %lu]\n", 566f3ce8064STheodore Ts'o orig_inode->i_ino, donor_inode->i_ino); 567f3ce8064STheodore Ts'o return -EINVAL; 568f3ce8064STheodore Ts'o } 569f3ce8064STheodore Ts'o 5707247c0caSAkira Fujita /* Regular file check */ 5717247c0caSAkira Fujita if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) { 5727247c0caSAkira Fujita ext4_debug("ext4 move extent: The argument files should be " 5737247c0caSAkira Fujita "regular file [ino:orig %lu, donor %lu]\n", 5747247c0caSAkira Fujita orig_inode->i_ino, donor_inode->i_ino); 5757247c0caSAkira Fujita return -EINVAL; 5767247c0caSAkira Fujita } 577f066055aSDmitry Monakhov /* TODO: This is non obvious task to swap blocks for inodes with full 578f066055aSDmitry Monakhov jornaling enabled */ 579f066055aSDmitry Monakhov if (ext4_should_journal_data(orig_inode) || 580f066055aSDmitry Monakhov ext4_should_journal_data(donor_inode)) { 581f066055aSDmitry Monakhov return -EINVAL; 582f066055aSDmitry Monakhov } 583fc04cb49SAkira Fujita /* Protect orig and donor inodes against a truncate */ 584375e289eSJ. Bruce Fields lock_two_nondirectories(orig_inode, donor_inode); 585748de673SAkira Fujita 58617335dccSDmitry Monakhov /* Wait for all existing dio workers */ 58717335dccSDmitry Monakhov ext4_inode_block_unlocked_dio(orig_inode); 58817335dccSDmitry Monakhov ext4_inode_block_unlocked_dio(donor_inode); 58917335dccSDmitry Monakhov inode_dio_wait(orig_inode); 59017335dccSDmitry Monakhov inode_dio_wait(donor_inode); 59117335dccSDmitry Monakhov 592fc04cb49SAkira Fujita /* Protect extent tree against block allocations via delalloc */ 593393d1d1dSDr. Tilmann Bubeck ext4_double_down_write_data_sem(orig_inode, donor_inode); 594748de673SAkira Fujita /* Check the filesystem environment whether move_extent can be done */ 595fcf6b1b7SDmitry Monakhov ret = mext_check_arguments(orig_inode, donor_inode, orig_blk, 596fcf6b1b7SDmitry Monakhov donor_blk, &len); 59703bd8b9bSDmitry Monakhov if (ret) 598347fa6f1SAkira Fujita goto out; 599fcf6b1b7SDmitry Monakhov o_end = o_start + len; 600748de673SAkira Fujita 601fcf6b1b7SDmitry Monakhov while (o_start < o_end) { 602fcf6b1b7SDmitry Monakhov struct ext4_extent *ex; 603fcf6b1b7SDmitry Monakhov ext4_lblk_t cur_blk, next_blk; 604fcf6b1b7SDmitry Monakhov pgoff_t orig_page_index, donor_page_index; 605fcf6b1b7SDmitry Monakhov int offset_in_page; 606fcf6b1b7SDmitry Monakhov int unwritten, cur_len; 607748de673SAkira Fujita 608fcf6b1b7SDmitry Monakhov ret = get_ext_path(orig_inode, o_start, &path); 60903bd8b9bSDmitry Monakhov if (ret) 610347fa6f1SAkira Fujita goto out; 611fcf6b1b7SDmitry Monakhov ex = path[path->p_depth].p_ext; 612fcf6b1b7SDmitry Monakhov next_blk = ext4_ext_next_allocated_block(path); 613fcf6b1b7SDmitry Monakhov cur_blk = le32_to_cpu(ex->ee_block); 614fcf6b1b7SDmitry Monakhov cur_len = ext4_ext_get_actual_len(ex); 615fcf6b1b7SDmitry Monakhov /* Check hole before the start pos */ 616fcf6b1b7SDmitry Monakhov if (cur_blk + cur_len - 1 < o_start) { 617fcf6b1b7SDmitry Monakhov if (next_blk == EXT_MAX_BLOCKS) { 618fcf6b1b7SDmitry Monakhov o_start = o_end; 619fcf6b1b7SDmitry Monakhov ret = -ENODATA; 620748de673SAkira Fujita goto out; 621748de673SAkira Fujita } 622fcf6b1b7SDmitry Monakhov d_start += next_blk - o_start; 623fcf6b1b7SDmitry Monakhov o_start = next_blk; 6243bdf14b4STheodore Ts'o continue; 625fcf6b1b7SDmitry Monakhov /* Check hole after the start pos */ 626fcf6b1b7SDmitry Monakhov } else if (cur_blk > o_start) { 627fcf6b1b7SDmitry Monakhov /* Skip hole */ 628fcf6b1b7SDmitry Monakhov d_start += cur_blk - o_start; 629fcf6b1b7SDmitry Monakhov o_start = cur_blk; 630fcf6b1b7SDmitry Monakhov /* Extent inside requested range ?*/ 631fcf6b1b7SDmitry Monakhov if (cur_blk >= o_end) 632748de673SAkira Fujita goto out; 633fcf6b1b7SDmitry Monakhov } else { /* in_range(o_start, o_blk, o_len) */ 634fcf6b1b7SDmitry Monakhov cur_len += cur_blk - o_start; 635748de673SAkira Fujita } 636fcf6b1b7SDmitry Monakhov unwritten = ext4_ext_is_unwritten(ex); 637fcf6b1b7SDmitry Monakhov if (o_end - o_start < cur_len) 638fcf6b1b7SDmitry Monakhov cur_len = o_end - o_start; 639748de673SAkira Fujita 640fcf6b1b7SDmitry Monakhov orig_page_index = o_start >> (PAGE_CACHE_SHIFT - 641fcf6b1b7SDmitry Monakhov orig_inode->i_blkbits); 642fcf6b1b7SDmitry Monakhov donor_page_index = d_start >> (PAGE_CACHE_SHIFT - 643fcf6b1b7SDmitry Monakhov donor_inode->i_blkbits); 644fcf6b1b7SDmitry Monakhov offset_in_page = o_start % blocks_per_page; 645fcf6b1b7SDmitry Monakhov if (cur_len > blocks_per_page- offset_in_page) 646fcf6b1b7SDmitry Monakhov cur_len = blocks_per_page - offset_in_page; 647fc04cb49SAkira Fujita /* 648fc04cb49SAkira Fujita * Up semaphore to avoid following problems: 649fc04cb49SAkira Fujita * a. transaction deadlock among ext4_journal_start, 650fc04cb49SAkira Fujita * ->write_begin via pagefault, and jbd2_journal_commit 651fc04cb49SAkira Fujita * b. racing with ->readpage, ->write_begin, and ext4_get_block 652fc04cb49SAkira Fujita * in move_extent_per_page 653fc04cb49SAkira Fujita */ 654393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(orig_inode, donor_inode); 655748de673SAkira Fujita /* Swap original branches with new branches */ 656fcf6b1b7SDmitry Monakhov move_extent_per_page(o_filp, donor_inode, 657fcf6b1b7SDmitry Monakhov orig_page_index, donor_page_index, 658fcf6b1b7SDmitry Monakhov offset_in_page, cur_len, 659556615dcSLukas Czerner unwritten, &ret); 660393d1d1dSDr. Tilmann Bubeck ext4_double_down_write_data_sem(orig_inode, donor_inode); 66103bd8b9bSDmitry Monakhov if (ret < 0) 662fc04cb49SAkira Fujita break; 663fcf6b1b7SDmitry Monakhov o_start += cur_len; 664fcf6b1b7SDmitry Monakhov d_start += cur_len; 665748de673SAkira Fujita } 666fcf6b1b7SDmitry Monakhov *moved_len = o_start - orig_blk; 667fcf6b1b7SDmitry Monakhov if (*moved_len > len) 668fcf6b1b7SDmitry Monakhov *moved_len = len; 669fcf6b1b7SDmitry Monakhov 670748de673SAkira Fujita out: 67194d7c16cSAkira Fujita if (*moved_len) { 67294d7c16cSAkira Fujita ext4_discard_preallocations(orig_inode); 67394d7c16cSAkira Fujita ext4_discard_preallocations(donor_inode); 67494d7c16cSAkira Fujita } 67594d7c16cSAkira Fujita 676fcf6b1b7SDmitry Monakhov ext4_ext_drop_refs(path); 677fcf6b1b7SDmitry Monakhov kfree(path); 678393d1d1dSDr. Tilmann Bubeck ext4_double_up_write_data_sem(orig_inode, donor_inode); 67917335dccSDmitry Monakhov ext4_inode_resume_unlocked_dio(orig_inode); 68017335dccSDmitry Monakhov ext4_inode_resume_unlocked_dio(donor_inode); 681375e289eSJ. Bruce Fields unlock_two_nondirectories(orig_inode, donor_inode); 682748de673SAkira Fujita 68303bd8b9bSDmitry Monakhov return ret; 684748de673SAkira Fujita } 685