| /* |
| * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
| * |
| * This copyrighted material is made available to anyone wishing to use, |
| * modify, copy, or redistribute it subject to the terms and conditions |
| * of the GNU General Public License version 2. |
| */ |
| |
| #include <linux/spinlock.h> |
| #include <linux/completion.h> |
| #include <linux/buffer_head.h> |
| #include <linux/blkdev.h> |
| #include <linux/gfs2_ondisk.h> |
| #include <linux/crc32.h> |
| |
| #include "gfs2.h" |
| #include "incore.h" |
| #include "bmap.h" |
| #include "glock.h" |
| #include "inode.h" |
| #include "meta_io.h" |
| #include "quota.h" |
| #include "rgrp.h" |
| #include "super.h" |
| #include "trans.h" |
| #include "dir.h" |
| #include "util.h" |
| #include "trace_gfs2.h" |
| |
| /* This doesn't need to be that large as max 64 bit pointers in a 4k |
| * block is 512, so __u16 is fine for that. It saves stack space to |
| * keep it small. |
| */ |
| struct metapath { |
| struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT]; |
| __u16 mp_list[GFS2_MAX_META_HEIGHT]; |
| }; |
| |
| struct strip_mine { |
| int sm_first; |
| unsigned int sm_height; |
| }; |
| |
| /** |
| * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page |
| * @ip: the inode |
| * @dibh: the dinode buffer |
| * @block: the block number that was allocated |
| * @page: The (optional) page. This is looked up if @page is NULL |
| * |
| * Returns: errno |
| */ |
| |
| static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, |
| u64 block, struct page *page) |
| { |
| struct inode *inode = &ip->i_inode; |
| struct buffer_head *bh; |
| int release = 0; |
| |
| if (!page || page->index) { |
| page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS); |
| if (!page) |
| return -ENOMEM; |
| release = 1; |
| } |
| |
| if (!PageUptodate(page)) { |
| void *kaddr = kmap(page); |
| u64 dsize = i_size_read(inode); |
| |
| if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode))) |
| dsize = dibh->b_size - sizeof(struct gfs2_dinode); |
| |
| memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize); |
| memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize); |
| kunmap(page); |
| |
| SetPageUptodate(page); |
| } |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, 1 << inode->i_blkbits, |
| (1 << BH_Uptodate)); |
| |
| bh = page_buffers(page); |
| |
| if (!buffer_mapped(bh)) |
| map_bh(bh, inode->i_sb, block); |
| |
| set_buffer_uptodate(bh); |
| if (!gfs2_is_jdata(ip)) |
| mark_buffer_dirty(bh); |
| if (!gfs2_is_writeback(ip)) |
| gfs2_trans_add_bh(ip->i_gl, bh, 0); |
| |
| if (release) { |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big |
| * @ip: The GFS2 inode to unstuff |
| * @page: The (optional) page. This is looked up if the @page is NULL |
| * |
| * This routine unstuffs a dinode and returns it to a "normal" state such |
| * that the height can be grown in the traditional way. |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page) |
| { |
| struct buffer_head *bh, *dibh; |
| struct gfs2_dinode *di; |
| u64 block = 0; |
| int isdir = gfs2_is_dir(ip); |
| int error; |
| |
| down_write(&ip->i_rw_mutex); |
| |
| error = gfs2_meta_inode_buffer(ip, &dibh); |
| if (error) |
| goto out; |
| |
| if (i_size_read(&ip->i_inode)) { |
| /* Get a free block, fill it with the stuffed data, |
| and write it out to disk */ |
| |
| unsigned int n = 1; |
| error = gfs2_alloc_blocks(ip, &block, &n, 0, NULL); |
| if (error) |
| goto out_brelse; |
| if (isdir) { |
| gfs2_trans_add_unrevoke(GFS2_SB(&ip->i_inode), block, 1); |
| error = gfs2_dir_get_new_buffer(ip, block, &bh); |
| if (error) |
| goto out_brelse; |
| gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header), |
| dibh, sizeof(struct gfs2_dinode)); |
| brelse(bh); |
| } else { |
| error = gfs2_unstuffer_page(ip, dibh, block, page); |
| if (error) |
| goto out_brelse; |
| } |
| } |
| |
| /* Set up the pointer to the new block */ |
| |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| di = (struct gfs2_dinode *)dibh->b_data; |
| gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); |
| |
| if (i_size_read(&ip->i_inode)) { |
| *(__be64 *)(di + 1) = cpu_to_be64(block); |
| gfs2_add_inode_blocks(&ip->i_inode, 1); |
| di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode)); |
| } |
| |
| ip->i_height = 1; |
| di->di_height = cpu_to_be16(1); |
| |
| out_brelse: |
| brelse(dibh); |
| out: |
| up_write(&ip->i_rw_mutex); |
| return error; |
| } |
| |
| |
| /** |
| * find_metapath - Find path through the metadata tree |
| * @sdp: The superblock |
| * @mp: The metapath to return the result in |
| * @block: The disk block to look up |
| * @height: The pre-calculated height of the metadata tree |
| * |
| * This routine returns a struct metapath structure that defines a path |
| * through the metadata of inode "ip" to get to block "block". |
| * |
| * Example: |
| * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a |
| * filesystem with a blocksize of 4096. |
| * |
| * find_metapath() would return a struct metapath structure set to: |
| * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48, |
| * and mp_list[2] = 165. |
| * |
| * That means that in order to get to the block containing the byte at |
| * offset 101342453, we would load the indirect block pointed to by pointer |
| * 0 in the dinode. We would then load the indirect block pointed to by |
| * pointer 48 in that indirect block. We would then load the data block |
| * pointed to by pointer 165 in that indirect block. |
| * |
| * ---------------------------------------- |
| * | Dinode | | |
| * | | 4| |
| * | |0 1 2 3 4 5 9| |
| * | | 6| |
| * ---------------------------------------- |
| * | |
| * | |
| * V |
| * ---------------------------------------- |
| * | Indirect Block | |
| * | 5| |
| * | 4 4 4 4 4 5 5 1| |
| * |0 5 6 7 8 9 0 1 2| |
| * ---------------------------------------- |
| * | |
| * | |
| * V |
| * ---------------------------------------- |
| * | Indirect Block | |
| * | 1 1 1 1 1 5| |
| * | 6 6 6 6 6 1| |
| * |0 3 4 5 6 7 2| |
| * ---------------------------------------- |
| * | |
| * | |
| * V |
| * ---------------------------------------- |
| * | Data block containing offset | |
| * | 101342453 | |
| * | | |
| * | | |
| * ---------------------------------------- |
| * |
| */ |
| |
| static void find_metapath(const struct gfs2_sbd *sdp, u64 block, |
| struct metapath *mp, unsigned int height) |
| { |
| unsigned int i; |
| |
| for (i = height; i--;) |
| mp->mp_list[i] = do_div(block, sdp->sd_inptrs); |
| |
| } |
| |
| static inline unsigned int metapath_branch_start(const struct metapath *mp) |
| { |
| if (mp->mp_list[0] == 0) |
| return 2; |
| return 1; |
| } |
| |
| /** |
| * metapointer - Return pointer to start of metadata in a buffer |
| * @height: The metadata height (0 = dinode) |
| * @mp: The metapath |
| * |
| * Return a pointer to the block number of the next height of the metadata |
| * tree given a buffer containing the pointer to the current height of the |
| * metadata tree. |
| */ |
| |
| static inline __be64 *metapointer(unsigned int height, const struct metapath *mp) |
| { |
| struct buffer_head *bh = mp->mp_bh[height]; |
| unsigned int head_size = (height > 0) ? |
| sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode); |
| return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height]; |
| } |
| |
| static void gfs2_metapath_ra(struct gfs2_glock *gl, |
| const struct buffer_head *bh, const __be64 *pos) |
| { |
| struct buffer_head *rabh; |
| const __be64 *endp = (const __be64 *)(bh->b_data + bh->b_size); |
| const __be64 *t; |
| |
| for (t = pos; t < endp; t++) { |
| if (!*t) |
| continue; |
| |
| rabh = gfs2_getbuf(gl, be64_to_cpu(*t), CREATE); |
| if (trylock_buffer(rabh)) { |
| if (!buffer_uptodate(rabh)) { |
| rabh->b_end_io = end_buffer_read_sync; |
| submit_bh(READA | REQ_META, rabh); |
| continue; |
| } |
| unlock_buffer(rabh); |
| } |
| brelse(rabh); |
| } |
| } |
| |
| /** |
| * lookup_metapath - Walk the metadata tree to a specific point |
| * @ip: The inode |
| * @mp: The metapath |
| * |
| * Assumes that the inode's buffer has already been looked up and |
| * hooked onto mp->mp_bh[0] and that the metapath has been initialised |
| * by find_metapath(). |
| * |
| * If this function encounters part of the tree which has not been |
| * allocated, it returns the current height of the tree at the point |
| * at which it found the unallocated block. Blocks which are found are |
| * added to the mp->mp_bh[] list. |
| * |
| * Returns: error or height of metadata tree |
| */ |
| |
| static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp) |
| { |
| unsigned int end_of_metadata = ip->i_height - 1; |
| unsigned int x; |
| __be64 *ptr; |
| u64 dblock; |
| int ret; |
| |
| for (x = 0; x < end_of_metadata; x++) { |
| ptr = metapointer(x, mp); |
| dblock = be64_to_cpu(*ptr); |
| if (!dblock) |
| return x + 1; |
| |
| ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, &mp->mp_bh[x+1]); |
| if (ret) |
| return ret; |
| } |
| |
| return ip->i_height; |
| } |
| |
| static inline void release_metapath(struct metapath *mp) |
| { |
| int i; |
| |
| for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) { |
| if (mp->mp_bh[i] == NULL) |
| break; |
| brelse(mp->mp_bh[i]); |
| } |
| } |
| |
| /** |
| * gfs2_extent_length - Returns length of an extent of blocks |
| * @start: Start of the buffer |
| * @len: Length of the buffer in bytes |
| * @ptr: Current position in the buffer |
| * @limit: Max extent length to return (0 = unlimited) |
| * @eob: Set to 1 if we hit "end of block" |
| * |
| * If the first block is zero (unallocated) it will return the number of |
| * unallocated blocks in the extent, otherwise it will return the number |
| * of contiguous blocks in the extent. |
| * |
| * Returns: The length of the extent (minimum of one block) |
| */ |
| |
| static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, unsigned limit, int *eob) |
| { |
| const __be64 *end = (start + len); |
| const __be64 *first = ptr; |
| u64 d = be64_to_cpu(*ptr); |
| |
| *eob = 0; |
| do { |
| ptr++; |
| if (ptr >= end) |
| break; |
| if (limit && --limit == 0) |
| break; |
| if (d) |
| d++; |
| } while(be64_to_cpu(*ptr) == d); |
| if (ptr >= end) |
| *eob = 1; |
| return (ptr - first); |
| } |
| |
| static inline void bmap_lock(struct gfs2_inode *ip, int create) |
| { |
| if (create) |
| down_write(&ip->i_rw_mutex); |
| else |
| down_read(&ip->i_rw_mutex); |
| } |
| |
| static inline void bmap_unlock(struct gfs2_inode *ip, int create) |
| { |
| if (create) |
| up_write(&ip->i_rw_mutex); |
| else |
| up_read(&ip->i_rw_mutex); |
| } |
| |
| static inline __be64 *gfs2_indirect_init(struct metapath *mp, |
| struct gfs2_glock *gl, unsigned int i, |
| unsigned offset, u64 bn) |
| { |
| __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data + |
| ((i > 1) ? sizeof(struct gfs2_meta_header) : |
| sizeof(struct gfs2_dinode))); |
| BUG_ON(i < 1); |
| BUG_ON(mp->mp_bh[i] != NULL); |
| mp->mp_bh[i] = gfs2_meta_new(gl, bn); |
| gfs2_trans_add_bh(gl, mp->mp_bh[i], 1); |
| gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN); |
| gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header)); |
| ptr += offset; |
| *ptr = cpu_to_be64(bn); |
| return ptr; |
| } |
| |
| enum alloc_state { |
| ALLOC_DATA = 0, |
| ALLOC_GROW_DEPTH = 1, |
| ALLOC_GROW_HEIGHT = 2, |
| /* ALLOC_UNSTUFF = 3, TBD and rather complicated */ |
| }; |
| |
| /** |
| * gfs2_bmap_alloc - Build a metadata tree of the requested height |
| * @inode: The GFS2 inode |
| * @lblock: The logical starting block of the extent |
| * @bh_map: This is used to return the mapping details |
| * @mp: The metapath |
| * @sheight: The starting height (i.e. whats already mapped) |
| * @height: The height to build to |
| * @maxlen: The max number of data blocks to alloc |
| * |
| * In this routine we may have to alloc: |
| * i) Indirect blocks to grow the metadata tree height |
| * ii) Indirect blocks to fill in lower part of the metadata tree |
| * iii) Data blocks |
| * |
| * The function is in two parts. The first part works out the total |
| * number of blocks which we need. The second part does the actual |
| * allocation asking for an extent at a time (if enough contiguous free |
| * blocks are available, there will only be one request per bmap call) |
| * and uses the state machine to initialise the blocks in order. |
| * |
| * Returns: errno on error |
| */ |
| |
| static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock, |
| struct buffer_head *bh_map, struct metapath *mp, |
| const unsigned int sheight, |
| const unsigned int height, |
| const unsigned int maxlen) |
| { |
| struct gfs2_inode *ip = GFS2_I(inode); |
| struct gfs2_sbd *sdp = GFS2_SB(inode); |
| struct super_block *sb = sdp->sd_vfs; |
| struct buffer_head *dibh = mp->mp_bh[0]; |
| u64 bn, dblock = 0; |
| unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0; |
| unsigned dblks = 0; |
| unsigned ptrs_per_blk; |
| const unsigned end_of_metadata = height - 1; |
| int ret; |
| int eob = 0; |
| enum alloc_state state; |
| __be64 *ptr; |
| __be64 zero_bn = 0; |
| |
| BUG_ON(sheight < 1); |
| BUG_ON(dibh == NULL); |
| |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| |
| if (height == sheight) { |
| struct buffer_head *bh; |
| /* Bottom indirect block exists, find unalloced extent size */ |
| ptr = metapointer(end_of_metadata, mp); |
| bh = mp->mp_bh[end_of_metadata]; |
| dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, |
| &eob); |
| BUG_ON(dblks < 1); |
| state = ALLOC_DATA; |
| } else { |
| /* Need to allocate indirect blocks */ |
| ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs; |
| dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]); |
| if (height == ip->i_height) { |
| /* Writing into existing tree, extend tree down */ |
| iblks = height - sheight; |
| state = ALLOC_GROW_DEPTH; |
| } else { |
| /* Building up tree height */ |
| state = ALLOC_GROW_HEIGHT; |
| iblks = height - ip->i_height; |
| branch_start = metapath_branch_start(mp); |
| iblks += (height - branch_start); |
| } |
| } |
| |
| /* start of the second part of the function (state machine) */ |
| |
| blks = dblks + iblks; |
| i = sheight; |
| do { |
| int error; |
| n = blks - alloced; |
| error = gfs2_alloc_blocks(ip, &bn, &n, 0, NULL); |
| if (error) |
| return error; |
| alloced += n; |
| if (state != ALLOC_DATA || gfs2_is_jdata(ip)) |
| gfs2_trans_add_unrevoke(sdp, bn, n); |
| switch (state) { |
| /* Growing height of tree */ |
| case ALLOC_GROW_HEIGHT: |
| if (i == 1) { |
| ptr = (__be64 *)(dibh->b_data + |
| sizeof(struct gfs2_dinode)); |
| zero_bn = *ptr; |
| } |
| for (; i - 1 < height - ip->i_height && n > 0; i++, n--) |
| gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++); |
| if (i - 1 == height - ip->i_height) { |
| i--; |
| gfs2_buffer_copy_tail(mp->mp_bh[i], |
| sizeof(struct gfs2_meta_header), |
| dibh, sizeof(struct gfs2_dinode)); |
| gfs2_buffer_clear_tail(dibh, |
| sizeof(struct gfs2_dinode) + |
| sizeof(__be64)); |
| ptr = (__be64 *)(mp->mp_bh[i]->b_data + |
| sizeof(struct gfs2_meta_header)); |
| *ptr = zero_bn; |
| state = ALLOC_GROW_DEPTH; |
| for(i = branch_start; i < height; i++) { |
| if (mp->mp_bh[i] == NULL) |
| break; |
| brelse(mp->mp_bh[i]); |
| mp->mp_bh[i] = NULL; |
| } |
| i = branch_start; |
| } |
| if (n == 0) |
| break; |
| /* Branching from existing tree */ |
| case ALLOC_GROW_DEPTH: |
| if (i > 1 && i < height) |
| gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[i-1], 1); |
| for (; i < height && n > 0; i++, n--) |
| gfs2_indirect_init(mp, ip->i_gl, i, |
| mp->mp_list[i-1], bn++); |
| if (i == height) |
| state = ALLOC_DATA; |
| if (n == 0) |
| break; |
| /* Tree complete, adding data blocks */ |
| case ALLOC_DATA: |
| BUG_ON(n > dblks); |
| BUG_ON(mp->mp_bh[end_of_metadata] == NULL); |
| gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[end_of_metadata], 1); |
| dblks = n; |
| ptr = metapointer(end_of_metadata, mp); |
| dblock = bn; |
| while (n-- > 0) |
| *ptr++ = cpu_to_be64(bn++); |
| if (buffer_zeronew(bh_map)) { |
| ret = sb_issue_zeroout(sb, dblock, dblks, |
| GFP_NOFS); |
| if (ret) { |
| fs_err(sdp, |
| "Failed to zero data buffers\n"); |
| clear_buffer_zeronew(bh_map); |
| } |
| } |
| break; |
| } |
| } while ((state != ALLOC_DATA) || !dblock); |
| |
| ip->i_height = height; |
| gfs2_add_inode_blocks(&ip->i_inode, alloced); |
| gfs2_dinode_out(ip, mp->mp_bh[0]->b_data); |
| map_bh(bh_map, inode->i_sb, dblock); |
| bh_map->b_size = dblks << inode->i_blkbits; |
| set_buffer_new(bh_map); |
| return 0; |
| } |
| |
| /** |
| * gfs2_block_map - Map a block from an inode to a disk block |
| * @inode: The inode |
| * @lblock: The logical block number |
| * @bh_map: The bh to be mapped |
| * @create: True if its ok to alloc blocks to satify the request |
| * |
| * Sets buffer_mapped() if successful, sets buffer_boundary() if a |
| * read of metadata will be required before the next block can be |
| * mapped. Sets buffer_new() if new blocks were allocated. |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_block_map(struct inode *inode, sector_t lblock, |
| struct buffer_head *bh_map, int create) |
| { |
| struct gfs2_inode *ip = GFS2_I(inode); |
| struct gfs2_sbd *sdp = GFS2_SB(inode); |
| unsigned int bsize = sdp->sd_sb.sb_bsize; |
| const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits; |
| const u64 *arr = sdp->sd_heightsize; |
| __be64 *ptr; |
| u64 size; |
| struct metapath mp; |
| int ret; |
| int eob; |
| unsigned int len; |
| struct buffer_head *bh; |
| u8 height; |
| |
| BUG_ON(maxlen == 0); |
| |
| memset(mp.mp_bh, 0, sizeof(mp.mp_bh)); |
| bmap_lock(ip, create); |
| clear_buffer_mapped(bh_map); |
| clear_buffer_new(bh_map); |
| clear_buffer_boundary(bh_map); |
| trace_gfs2_bmap(ip, bh_map, lblock, create, 1); |
| if (gfs2_is_dir(ip)) { |
| bsize = sdp->sd_jbsize; |
| arr = sdp->sd_jheightsize; |
| } |
| |
| ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]); |
| if (ret) |
| goto out; |
| |
| height = ip->i_height; |
| size = (lblock + 1) * bsize; |
| while (size > arr[height]) |
| height++; |
| find_metapath(sdp, lblock, &mp, height); |
| ret = 1; |
| if (height > ip->i_height || gfs2_is_stuffed(ip)) |
| goto do_alloc; |
| ret = lookup_metapath(ip, &mp); |
| if (ret < 0) |
| goto out; |
| if (ret != ip->i_height) |
| goto do_alloc; |
| ptr = metapointer(ip->i_height - 1, &mp); |
| if (*ptr == 0) |
| goto do_alloc; |
| map_bh(bh_map, inode->i_sb, be64_to_cpu(*ptr)); |
| bh = mp.mp_bh[ip->i_height - 1]; |
| len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, &eob); |
| bh_map->b_size = (len << inode->i_blkbits); |
| if (eob) |
| set_buffer_boundary(bh_map); |
| ret = 0; |
| out: |
| release_metapath(&mp); |
| trace_gfs2_bmap(ip, bh_map, lblock, create, ret); |
| bmap_unlock(ip, create); |
| return ret; |
| |
| do_alloc: |
| /* All allocations are done here, firstly check create flag */ |
| if (!create) { |
| BUG_ON(gfs2_is_stuffed(ip)); |
| ret = 0; |
| goto out; |
| } |
| |
| /* At this point ret is the tree depth of already allocated blocks */ |
| ret = gfs2_bmap_alloc(inode, lblock, bh_map, &mp, ret, height, maxlen); |
| goto out; |
| } |
| |
| /* |
| * Deprecated: do not use in new code |
| */ |
| int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen) |
| { |
| struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 }; |
| int ret; |
| int create = *new; |
| |
| BUG_ON(!extlen); |
| BUG_ON(!dblock); |
| BUG_ON(!new); |
| |
| bh.b_size = 1 << (inode->i_blkbits + (create ? 0 : 5)); |
| ret = gfs2_block_map(inode, lblock, &bh, create); |
| *extlen = bh.b_size >> inode->i_blkbits; |
| *dblock = bh.b_blocknr; |
| if (buffer_new(&bh)) |
| *new = 1; |
| else |
| *new = 0; |
| return ret; |
| } |
| |
| /** |
| * do_strip - Look for a layer a particular layer of the file and strip it off |
| * @ip: the inode |
| * @dibh: the dinode buffer |
| * @bh: A buffer of pointers |
| * @top: The first pointer in the buffer |
| * @bottom: One more than the last pointer |
| * @height: the height this buffer is at |
| * @data: a pointer to a struct strip_mine |
| * |
| * Returns: errno |
| */ |
| |
| static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh, |
| struct buffer_head *bh, __be64 *top, __be64 *bottom, |
| unsigned int height, struct strip_mine *sm) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct gfs2_rgrp_list rlist; |
| u64 bn, bstart; |
| u32 blen, btotal; |
| __be64 *p; |
| unsigned int rg_blocks = 0; |
| int metadata; |
| unsigned int revokes = 0; |
| int x; |
| int error; |
| |
| error = gfs2_rindex_update(sdp); |
| if (error) |
| return error; |
| |
| if (!*top) |
| sm->sm_first = 0; |
| |
| if (height != sm->sm_height) |
| return 0; |
| |
| if (sm->sm_first) { |
| top++; |
| sm->sm_first = 0; |
| } |
| |
| metadata = (height != ip->i_height - 1); |
| if (metadata) |
| revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs; |
| else if (ip->i_depth) |
| revokes = sdp->sd_inptrs; |
| |
| memset(&rlist, 0, sizeof(struct gfs2_rgrp_list)); |
| bstart = 0; |
| blen = 0; |
| |
| for (p = top; p < bottom; p++) { |
| if (!*p) |
| continue; |
| |
| bn = be64_to_cpu(*p); |
| |
| if (bstart + blen == bn) |
| blen++; |
| else { |
| if (bstart) |
| gfs2_rlist_add(ip, &rlist, bstart); |
| |
| bstart = bn; |
| blen = 1; |
| } |
| } |
| |
| if (bstart) |
| gfs2_rlist_add(ip, &rlist, bstart); |
| else |
| goto out; /* Nothing to do */ |
| |
| gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE); |
| |
| for (x = 0; x < rlist.rl_rgrps; x++) { |
| struct gfs2_rgrpd *rgd; |
| rgd = rlist.rl_ghs[x].gh_gl->gl_object; |
| rg_blocks += rgd->rd_length; |
| } |
| |
| error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs); |
| if (error) |
| goto out_rlist; |
| |
| if (gfs2_rs_active(ip->i_res)) /* needs to be done with the rgrp glock held */ |
| gfs2_rs_deltree(ip, ip->i_res); |
| |
| error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + |
| RES_INDIRECT + RES_STATFS + RES_QUOTA, |
| revokes); |
| if (error) |
| goto out_rg_gunlock; |
| |
| down_write(&ip->i_rw_mutex); |
| |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| gfs2_trans_add_bh(ip->i_gl, bh, 1); |
| |
| bstart = 0; |
| blen = 0; |
| btotal = 0; |
| |
| for (p = top; p < bottom; p++) { |
| if (!*p) |
| continue; |
| |
| bn = be64_to_cpu(*p); |
| |
| if (bstart + blen == bn) |
| blen++; |
| else { |
| if (bstart) { |
| __gfs2_free_blocks(ip, bstart, blen, metadata); |
| btotal += blen; |
| } |
| |
| bstart = bn; |
| blen = 1; |
| } |
| |
| *p = 0; |
| gfs2_add_inode_blocks(&ip->i_inode, -1); |
| } |
| if (bstart) { |
| __gfs2_free_blocks(ip, bstart, blen, metadata); |
| btotal += blen; |
| } |
| |
| gfs2_statfs_change(sdp, 0, +btotal, 0); |
| gfs2_quota_change(ip, -(s64)btotal, ip->i_inode.i_uid, |
| ip->i_inode.i_gid); |
| |
| ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
| |
| gfs2_dinode_out(ip, dibh->b_data); |
| |
| up_write(&ip->i_rw_mutex); |
| |
| gfs2_trans_end(sdp); |
| |
| out_rg_gunlock: |
| gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs); |
| out_rlist: |
| gfs2_rlist_free(&rlist); |
| out: |
| return error; |
| } |
| |
| /** |
| * recursive_scan - recursively scan through the end of a file |
| * @ip: the inode |
| * @dibh: the dinode buffer |
| * @mp: the path through the metadata to the point to start |
| * @height: the height the recursion is at |
| * @block: the indirect block to look at |
| * @first: 1 if this is the first block |
| * @sm: data opaque to this function to pass to @bc |
| * |
| * When this is first called @height and @block should be zero and |
| * @first should be 1. |
| * |
| * Returns: errno |
| */ |
| |
| static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh, |
| struct metapath *mp, unsigned int height, |
| u64 block, int first, struct strip_mine *sm) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct buffer_head *bh = NULL; |
| __be64 *top, *bottom; |
| u64 bn; |
| int error; |
| int mh_size = sizeof(struct gfs2_meta_header); |
| |
| if (!height) { |
| error = gfs2_meta_inode_buffer(ip, &bh); |
| if (error) |
| return error; |
| dibh = bh; |
| |
| top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0]; |
| bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs; |
| } else { |
| error = gfs2_meta_indirect_buffer(ip, height, block, &bh); |
| if (error) |
| return error; |
| |
| top = (__be64 *)(bh->b_data + mh_size) + |
| (first ? mp->mp_list[height] : 0); |
| |
| bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs; |
| } |
| |
| error = do_strip(ip, dibh, bh, top, bottom, height, sm); |
| if (error) |
| goto out; |
| |
| if (height < ip->i_height - 1) { |
| |
| gfs2_metapath_ra(ip->i_gl, bh, top); |
| |
| for (; top < bottom; top++, first = 0) { |
| if (!*top) |
| continue; |
| |
| bn = be64_to_cpu(*top); |
| |
| error = recursive_scan(ip, dibh, mp, height + 1, bn, |
| first, sm); |
| if (error) |
| break; |
| } |
| } |
| out: |
| brelse(bh); |
| return error; |
| } |
| |
| |
| /** |
| * gfs2_block_truncate_page - Deal with zeroing out data for truncate |
| * |
| * This is partly borrowed from ext3. |
| */ |
| static int gfs2_block_truncate_page(struct address_space *mapping, loff_t from) |
| { |
| struct inode *inode = mapping->host; |
| struct gfs2_inode *ip = GFS2_I(inode); |
| unsigned long index = from >> PAGE_CACHE_SHIFT; |
| unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| unsigned blocksize, iblock, length, pos; |
| struct buffer_head *bh; |
| struct page *page; |
| int err; |
| |
| page = find_or_create_page(mapping, index, GFP_NOFS); |
| if (!page) |
| return 0; |
| |
| blocksize = inode->i_sb->s_blocksize; |
| length = blocksize - (offset & (blocksize - 1)); |
| iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, blocksize, 0); |
| |
| /* Find the buffer that contains "offset" */ |
| bh = page_buffers(page); |
| pos = blocksize; |
| while (offset >= pos) { |
| bh = bh->b_this_page; |
| iblock++; |
| pos += blocksize; |
| } |
| |
| err = 0; |
| |
| if (!buffer_mapped(bh)) { |
| gfs2_block_map(inode, iblock, bh, 0); |
| /* unmapped? It's a hole - nothing to do */ |
| if (!buffer_mapped(bh)) |
| goto unlock; |
| } |
| |
| /* Ok, it's mapped. Make sure it's up-to-date */ |
| if (PageUptodate(page)) |
| set_buffer_uptodate(bh); |
| |
| if (!buffer_uptodate(bh)) { |
| err = -EIO; |
| ll_rw_block(READ, 1, &bh); |
| wait_on_buffer(bh); |
| /* Uhhuh. Read error. Complain and punt. */ |
| if (!buffer_uptodate(bh)) |
| goto unlock; |
| err = 0; |
| } |
| |
| if (!gfs2_is_writeback(ip)) |
| gfs2_trans_add_bh(ip->i_gl, bh, 0); |
| |
| zero_user(page, offset, length); |
| mark_buffer_dirty(bh); |
| unlock: |
| unlock_page(page); |
| page_cache_release(page); |
| return err; |
| } |
| |
| static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize) |
| { |
| struct gfs2_inode *ip = GFS2_I(inode); |
| struct gfs2_sbd *sdp = GFS2_SB(inode); |
| struct address_space *mapping = inode->i_mapping; |
| struct buffer_head *dibh; |
| int journaled = gfs2_is_jdata(ip); |
| int error; |
| |
| error = gfs2_trans_begin(sdp, |
| RES_DINODE + (journaled ? RES_JDATA : 0), 0); |
| if (error) |
| return error; |
| |
| error = gfs2_meta_inode_buffer(ip, &dibh); |
| if (error) |
| goto out; |
| |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| |
| if (gfs2_is_stuffed(ip)) { |
| gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize); |
| } else { |
| if (newsize & (u64)(sdp->sd_sb.sb_bsize - 1)) { |
| error = gfs2_block_truncate_page(mapping, newsize); |
| if (error) |
| goto out_brelse; |
| } |
| ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; |
| } |
| |
| i_size_write(inode, newsize); |
| ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
| gfs2_dinode_out(ip, dibh->b_data); |
| |
| truncate_pagecache(inode, oldsize, newsize); |
| out_brelse: |
| brelse(dibh); |
| out: |
| gfs2_trans_end(sdp); |
| return error; |
| } |
| |
| static int trunc_dealloc(struct gfs2_inode *ip, u64 size) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| unsigned int height = ip->i_height; |
| u64 lblock; |
| struct metapath mp; |
| int error; |
| |
| if (!size) |
| lblock = 0; |
| else |
| lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift; |
| |
| find_metapath(sdp, lblock, &mp, ip->i_height); |
| error = gfs2_rindex_update(sdp); |
| if (error) |
| return error; |
| |
| error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); |
| if (error) |
| return error; |
| |
| while (height--) { |
| struct strip_mine sm; |
| sm.sm_first = !!size; |
| sm.sm_height = height; |
| |
| error = recursive_scan(ip, NULL, &mp, 0, 0, 1, &sm); |
| if (error) |
| break; |
| } |
| |
| gfs2_quota_unhold(ip); |
| |
| return error; |
| } |
| |
| static int trunc_end(struct gfs2_inode *ip) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct buffer_head *dibh; |
| int error; |
| |
| error = gfs2_trans_begin(sdp, RES_DINODE, 0); |
| if (error) |
| return error; |
| |
| down_write(&ip->i_rw_mutex); |
| |
| error = gfs2_meta_inode_buffer(ip, &dibh); |
| if (error) |
| goto out; |
| |
| if (!i_size_read(&ip->i_inode)) { |
| ip->i_height = 0; |
| ip->i_goal = ip->i_no_addr; |
| gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); |
| } |
| ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
| ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG; |
| |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| gfs2_dinode_out(ip, dibh->b_data); |
| brelse(dibh); |
| |
| out: |
| up_write(&ip->i_rw_mutex); |
| gfs2_trans_end(sdp); |
| return error; |
| } |
| |
| /** |
| * do_shrink - make a file smaller |
| * @inode: the inode |
| * @oldsize: the current inode size |
| * @newsize: the size to make the file |
| * |
| * Called with an exclusive lock on @inode. The @size must |
| * be equal to or smaller than the current inode size. |
| * |
| * Returns: errno |
| */ |
| |
| static int do_shrink(struct inode *inode, u64 oldsize, u64 newsize) |
| { |
| struct gfs2_inode *ip = GFS2_I(inode); |
| int error; |
| |
| error = trunc_start(inode, oldsize, newsize); |
| if (error < 0) |
| return error; |
| if (gfs2_is_stuffed(ip)) |
| return 0; |
| |
| error = trunc_dealloc(ip, newsize); |
| if (error == 0) |
| error = trunc_end(ip); |
| |
| return error; |
| } |
| |
| void gfs2_trim_blocks(struct inode *inode) |
| { |
| u64 size = inode->i_size; |
| int ret; |
| |
| ret = do_shrink(inode, size, size); |
| WARN_ON(ret != 0); |
| } |
| |
| /** |
| * do_grow - Touch and update inode size |
| * @inode: The inode |
| * @size: The new size |
| * |
| * This function updates the timestamps on the inode and |
| * may also increase the size of the inode. This function |
| * must not be called with @size any smaller than the current |
| * inode size. |
| * |
| * Although it is not strictly required to unstuff files here, |
| * earlier versions of GFS2 have a bug in the stuffed file reading |
| * code which will result in a buffer overrun if the size is larger |
| * than the max stuffed file size. In order to prevent this from |
| * occurring, such files are unstuffed, but in other cases we can |
| * just update the inode size directly. |
| * |
| * Returns: 0 on success, or -ve on error |
| */ |
| |
| static int do_grow(struct inode *inode, u64 size) |
| { |
| struct gfs2_inode *ip = GFS2_I(inode); |
| struct gfs2_sbd *sdp = GFS2_SB(inode); |
| struct buffer_head *dibh; |
| int error; |
| int unstuff = 0; |
| |
| if (gfs2_is_stuffed(ip) && |
| (size > (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)))) { |
| error = gfs2_quota_lock_check(ip); |
| if (error) |
| return error; |
| |
| error = gfs2_inplace_reserve(ip, 1, 0); |
| if (error) |
| goto do_grow_qunlock; |
| unstuff = 1; |
| } |
| |
| error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT, 0); |
| if (error) |
| goto do_grow_release; |
| |
| if (unstuff) { |
| error = gfs2_unstuff_dinode(ip, NULL); |
| if (error) |
| goto do_end_trans; |
| } |
| |
| error = gfs2_meta_inode_buffer(ip, &dibh); |
| if (error) |
| goto do_end_trans; |
| |
| i_size_write(inode, size); |
| ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
| gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
| gfs2_dinode_out(ip, dibh->b_data); |
| brelse(dibh); |
| |
| do_end_trans: |
| gfs2_trans_end(sdp); |
| do_grow_release: |
| if (unstuff) { |
| gfs2_inplace_release(ip); |
| do_grow_qunlock: |
| gfs2_quota_unlock(ip); |
| } |
| return error; |
| } |
| |
| /** |
| * gfs2_setattr_size - make a file a given size |
| * @inode: the inode |
| * @newsize: the size to make the file |
| * |
| * The file size can grow, shrink, or stay the same size. This |
| * is called holding i_mutex and an exclusive glock on the inode |
| * in question. |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_setattr_size(struct inode *inode, u64 newsize) |
| { |
| int ret; |
| u64 oldsize; |
| |
| BUG_ON(!S_ISREG(inode->i_mode)); |
| |
| ret = inode_newsize_ok(inode, newsize); |
| if (ret) |
| return ret; |
| |
| inode_dio_wait(inode); |
| |
| oldsize = inode->i_size; |
| if (newsize >= oldsize) |
| return do_grow(inode, newsize); |
| |
| return do_shrink(inode, oldsize, newsize); |
| } |
| |
| int gfs2_truncatei_resume(struct gfs2_inode *ip) |
| { |
| int error; |
| error = trunc_dealloc(ip, i_size_read(&ip->i_inode)); |
| if (!error) |
| error = trunc_end(ip); |
| return error; |
| } |
| |
| int gfs2_file_dealloc(struct gfs2_inode *ip) |
| { |
| return trunc_dealloc(ip, 0); |
| } |
| |
| /** |
| * gfs2_write_alloc_required - figure out if a write will require an allocation |
| * @ip: the file being written to |
| * @offset: the offset to write to |
| * @len: the number of bytes being written |
| * |
| * Returns: 1 if an alloc is required, 0 otherwise |
| */ |
| |
| int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, |
| unsigned int len) |
| { |
| struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
| struct buffer_head bh; |
| unsigned int shift; |
| u64 lblock, lblock_stop, size; |
| u64 end_of_file; |
| |
| if (!len) |
| return 0; |
| |
| if (gfs2_is_stuffed(ip)) { |
| if (offset + len > |
| sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) |
| return 1; |
| return 0; |
| } |
| |
| shift = sdp->sd_sb.sb_bsize_shift; |
| BUG_ON(gfs2_is_dir(ip)); |
| end_of_file = (i_size_read(&ip->i_inode) + sdp->sd_sb.sb_bsize - 1) >> shift; |
| lblock = offset >> shift; |
| lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; |
| if (lblock_stop > end_of_file) |
| return 1; |
| |
| size = (lblock_stop - lblock) << shift; |
| do { |
| bh.b_state = 0; |
| bh.b_size = size; |
| gfs2_block_map(&ip->i_inode, lblock, &bh, 0); |
| if (!buffer_mapped(&bh)) |
| return 1; |
| size -= bh.b_size; |
| lblock += (bh.b_size >> ip->i_inode.i_blkbits); |
| } while(size > 0); |
| |
| return 0; |
| } |
| |