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Diffstat (limited to 'fs/gfs2/bmap.c')
| -rw-r--r-- | fs/gfs2/bmap.c | 1495 |
1 files changed, 1495 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c new file mode 100644 index 000000000..61296ecbd --- /dev/null +++ b/fs/gfs2/bmap.c @@ -0,0 +1,1495 @@ +/* + * 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 "log.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_data(ip->i_gl, bh); + + 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_meta(ip->i_gl, dibh); + 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, size_t 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_meta(gl, mp->mp_bh[i]); + 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 size_t 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_meta(ip->i_gl, dibh); + + 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, (size_t)(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_meta(ip->i_gl, mp->mp_bh[i-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_meta(ip->i_gl, mp->mp_bh[end_of_metadata]); + 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 size_t 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 + * @sm: 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->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_meta(ip->i_gl, dibh); + gfs2_trans_add_meta(ip->i_gl, bh); + + 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_data(ip->i_gl, bh); + + zero_user(page, offset, length); + mark_buffer_dirty(bh); +unlock: + unlock_page(page); + page_cache_release(page); + return err; +} + +#define GFS2_JTRUNC_REVOKES 8192 + +/** + * gfs2_journaled_truncate - Wrapper for truncate_pagecache for jdata files + * @inode: The inode being truncated + * @oldsize: The original (larger) size + * @newsize: The new smaller size + * + * With jdata files, we have to journal a revoke for each block which is + * truncated. As a result, we need to split this into separate transactions + * if the number of pages being truncated gets too large. + */ + +static int gfs2_journaled_truncate(struct inode *inode, u64 oldsize, u64 newsize) +{ + struct gfs2_sbd *sdp = GFS2_SB(inode); + u64 max_chunk = GFS2_JTRUNC_REVOKES * sdp->sd_vfs->s_blocksize; + u64 chunk; + int error; + + while (oldsize != newsize) { + chunk = oldsize - newsize; + if (chunk > max_chunk) + chunk = max_chunk; + truncate_pagecache(inode, oldsize - chunk); + oldsize -= chunk; + gfs2_trans_end(sdp); + error = gfs2_trans_begin(sdp, RES_DINODE, GFS2_JTRUNC_REVOKES); + if (error) + return error; + } + + return 0; +} + +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; + + if (journaled) + error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES); + else + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + error = gfs2_meta_inode_buffer(ip, &dibh); + if (error) + goto out; + + gfs2_trans_add_meta(ip->i_gl, dibh); + + 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); + + if (journaled) + error = gfs2_journaled_truncate(inode, oldsize, newsize); + else + truncate_pagecache(inode, newsize); + + if (error) { + brelse(dibh); + return error; + } + +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_UID_QUOTA_CHANGE, NO_GID_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)); + gfs2_ordered_del_inode(ip); + } + ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; + ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG; + + gfs2_trans_add_meta(ip->i_gl, dibh); + 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 gfs2_alloc_parms ap = { .target = 1, }; + 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, &ap); + if (error) + return error; + + error = gfs2_inplace_reserve(ip, &ap); + if (error) + goto do_grow_qunlock; + unstuff = 1; + } + + error = gfs2_trans_begin(sdp, RES_DINODE + RES_STATFS + RES_RG_BIT + + (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF ? + 0 : RES_QUOTA), 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_meta(ip->i_gl, dibh); + 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) +{ + struct gfs2_inode *ip = GFS2_I(inode); + int ret; + u64 oldsize; + + BUG_ON(!S_ISREG(inode->i_mode)); + + ret = inode_newsize_ok(inode, newsize); + if (ret) + return ret; + + ret = get_write_access(inode); + if (ret) + return ret; + + inode_dio_wait(inode); + + ret = gfs2_rs_alloc(ip); + if (ret) + goto out; + + oldsize = inode->i_size; + if (newsize >= oldsize) { + ret = do_grow(inode, newsize); + goto out; + } + + gfs2_rs_deltree(ip->i_res); + ret = do_shrink(inode, oldsize, newsize); +out: + put_write_access(inode); + return ret; +} + +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_free_journal_extents - Free cached journal bmap info + * @jd: The journal + * + */ + +void gfs2_free_journal_extents(struct gfs2_jdesc *jd) +{ + struct gfs2_journal_extent *jext; + + while(!list_empty(&jd->extent_list)) { + jext = list_entry(jd->extent_list.next, struct gfs2_journal_extent, list); + list_del(&jext->list); + kfree(jext); + } +} + +/** + * gfs2_add_jextent - Add or merge a new extent to extent cache + * @jd: The journal descriptor + * @lblock: The logical block at start of new extent + * @dblock: The physical block at start of new extent + * @blocks: Size of extent in fs blocks + * + * Returns: 0 on success or -ENOMEM + */ + +static int gfs2_add_jextent(struct gfs2_jdesc *jd, u64 lblock, u64 dblock, u64 blocks) +{ + struct gfs2_journal_extent *jext; + + if (!list_empty(&jd->extent_list)) { + jext = list_entry(jd->extent_list.prev, struct gfs2_journal_extent, list); + if ((jext->dblock + jext->blocks) == dblock) { + jext->blocks += blocks; + return 0; + } + } + + jext = kzalloc(sizeof(struct gfs2_journal_extent), GFP_NOFS); + if (jext == NULL) + return -ENOMEM; + jext->dblock = dblock; + jext->lblock = lblock; + jext->blocks = blocks; + list_add_tail(&jext->list, &jd->extent_list); + jd->nr_extents++; + return 0; +} + +/** + * gfs2_map_journal_extents - Cache journal bmap info + * @sdp: The super block + * @jd: The journal to map + * + * Create a reusable "extent" mapping from all logical + * blocks to all physical blocks for the given journal. This will save + * us time when writing journal blocks. Most journals will have only one + * extent that maps all their logical blocks. That's because gfs2.mkfs + * arranges the journal blocks sequentially to maximize performance. + * So the extent would map the first block for the entire file length. + * However, gfs2_jadd can happen while file activity is happening, so + * those journals may not be sequential. Less likely is the case where + * the users created their own journals by mounting the metafs and + * laying it out. But it's still possible. These journals might have + * several extents. + * + * Returns: 0 on success, or error on failure + */ + +int gfs2_map_journal_extents(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd) +{ + u64 lblock = 0; + u64 lblock_stop; + struct gfs2_inode *ip = GFS2_I(jd->jd_inode); + struct buffer_head bh; + unsigned int shift = sdp->sd_sb.sb_bsize_shift; + u64 size; + int rc; + + lblock_stop = i_size_read(jd->jd_inode) >> shift; + size = (lblock_stop - lblock) << shift; + jd->nr_extents = 0; + WARN_ON(!list_empty(&jd->extent_list)); + + do { + bh.b_state = 0; + bh.b_blocknr = 0; + bh.b_size = size; + rc = gfs2_block_map(jd->jd_inode, lblock, &bh, 0); + if (rc || !buffer_mapped(&bh)) + goto fail; + rc = gfs2_add_jextent(jd, lblock, bh.b_blocknr, bh.b_size >> shift); + if (rc) + goto fail; + size -= bh.b_size; + lblock += (bh.b_size >> ip->i_inode.i_blkbits); + } while(size > 0); + + fs_info(sdp, "journal %d mapped with %u extents\n", jd->jd_jid, + jd->nr_extents); + return 0; + +fail: + fs_warn(sdp, "error %d mapping journal %u at offset %llu (extent %u)\n", + rc, jd->jd_jid, + (unsigned long long)(i_size_read(jd->jd_inode) - size), + jd->nr_extents); + fs_warn(sdp, "bmap=%d lblock=%llu block=%llu, state=0x%08lx, size=%llu\n", + rc, (unsigned long long)lblock, (unsigned long long)bh.b_blocknr, + bh.b_state, (unsigned long long)bh.b_size); + gfs2_free_journal_extents(jd); + return rc; +} + +/** + * 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; +} + |