/* * 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/slab.h> #include <linux/spinlock.h> #include <linux/completion.h> #include <linux/buffer_head.h> #include <linux/gfs2_ondisk.h> #include <linux/crc32.h> #include <linux/lm_interface.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 "trans.h" #include "dir.h" #include "util.h" #include "ops_address.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 { __u16 mp_list[GFS2_MAX_META_HEIGHT]; }; typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh, struct buffer_head *bh, __be64 *top, __be64 *bottom, unsigned int height, void *data); 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 * @private: any locked page held by the caller process * * Returns: errno */ static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, u64 block, struct page *page) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct inode *inode = &ip->i_inode; struct buffer_head *bh; int release = 0; if (!page || page->index) { page = grab_cache_page(inode->i_mapping, 0); if (!page) return -ENOMEM; release = 1; } if (!PageUptodate(page)) { void *kaddr = kmap(page); memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), ip->i_di.di_size); memset(kaddr + ip->i_di.di_size, 0, PAGE_CACHE_SIZE - ip->i_di.di_size); 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 (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) gfs2_trans_add_bh(ip->i_gl, bh, 0); mark_buffer_dirty(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 * @unstuffer: the routine that handles unstuffing a non-zero length file * @private: private data for the unstuffer * * 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 (ip->i_di.di_size) { /* Get a free block, fill it with the stuffed data, and write it out to disk */ if (isdir) { block = gfs2_alloc_meta(ip); 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 { block = gfs2_alloc_data(ip); 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 (ip->i_di.di_size) { *(__be64 *)(di + 1) = cpu_to_be64(block); ip->i_di.di_blocks++; gfs2_set_inode_blocks(&ip->i_inode); di->di_blocks = cpu_to_be64(ip->i_di.di_blocks); } ip->i_di.di_height = 1; di->di_height = cpu_to_be16(1); out_brelse: brelse(dibh); out: up_write(&ip->i_rw_mutex); return error; } /** * calc_tree_height - Calculate the height of a metadata tree * @ip: The GFS2 inode * @size: The proposed size of the file * * Work out how tall a metadata tree needs to be in order to accommodate a * file of a particular size. If size is less than the current size of * the inode, then the current size of the inode is used instead of the * supplied one. * * Returns: the height the tree should be */ static unsigned int calc_tree_height(struct gfs2_inode *ip, u64 size) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); u64 *arr; unsigned int max, height; if (ip->i_di.di_size > size) size = ip->i_di.di_size; if (gfs2_is_dir(ip)) { arr = sdp->sd_jheightsize; max = sdp->sd_max_jheight; } else { arr = sdp->sd_heightsize; max = sdp->sd_max_height; } for (height = 0; height < max; height++) if (arr[height] >= size) break; return height; } /** * build_height - Build a metadata tree of the requested height * @ip: The GFS2 inode * @height: The height to build to * * * Returns: errno */ static int build_height(struct inode *inode, unsigned height) { struct gfs2_inode *ip = GFS2_I(inode); unsigned new_height = height - ip->i_di.di_height; struct buffer_head *dibh; struct buffer_head *blocks[GFS2_MAX_META_HEIGHT]; struct gfs2_dinode *di; int error; __be64 *bp; u64 bn; unsigned n; if (height <= ip->i_di.di_height) return 0; error = gfs2_meta_inode_buffer(ip, &dibh); if (error) return error; for(n = 0; n < new_height; n++) { bn = gfs2_alloc_meta(ip); blocks[n] = gfs2_meta_new(ip->i_gl, bn); gfs2_trans_add_bh(ip->i_gl, blocks[n], 1); } n = 0; bn = blocks[0]->b_blocknr; if (new_height > 1) { for(; n < new_height-1; n++) { gfs2_metatype_set(blocks[n], GFS2_METATYPE_IN, GFS2_FORMAT_IN); gfs2_buffer_clear_tail(blocks[n], sizeof(struct gfs2_meta_header)); bp = (__be64 *)(blocks[n]->b_data + sizeof(struct gfs2_meta_header)); *bp = cpu_to_be64(blocks[n+1]->b_blocknr); brelse(blocks[n]); blocks[n] = NULL; } } gfs2_metatype_set(blocks[n], GFS2_METATYPE_IN, GFS2_FORMAT_IN); gfs2_buffer_copy_tail(blocks[n], sizeof(struct gfs2_meta_header), dibh, sizeof(struct gfs2_dinode)); brelse(blocks[n]); 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)); *(__be64 *)(di + 1) = cpu_to_be64(bn); ip->i_di.di_height += new_height; ip->i_di.di_blocks += new_height; gfs2_set_inode_blocks(&ip->i_inode); di->di_height = cpu_to_be16(ip->i_di.di_height); di->di_blocks = cpu_to_be64(ip->i_di.di_blocks); brelse(dibh); return error; } /** * find_metapath - Find path through the metadata tree * @ip: The inode pointer * @mp: The metapath to return the result in * @block: The disk block to look up * * 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(struct gfs2_inode *ip, u64 block, struct metapath *mp) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); u64 b = block; unsigned int i; for (i = ip->i_di.di_height; i--;) mp->mp_list[i] = do_div(b, sdp->sd_inptrs); } /** * metapointer - Return pointer to start of metadata in a buffer * @bh: The 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(struct buffer_head *bh, int *boundary, unsigned int height, const struct metapath *mp) { unsigned int head_size = (height > 0) ? sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode); __be64 *ptr; *boundary = 0; ptr = ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height]; if (ptr + 1 == (__be64 *)(bh->b_data + bh->b_size)) *boundary = 1; return ptr; } /** * lookup_block - Get the next metadata block in metadata tree * @ip: The GFS2 inode * @bh: Buffer containing the pointers to metadata blocks * @height: The height of the tree (0 = dinode) * @mp: The metapath * @create: Non-zero if we may create a new meatdata block * @new: Used to indicate if we did create a new metadata block * @block: the returned disk block number * * Given a metatree, complete to a particular height, checks to see if the next * height of the tree exists. If not the next height of the tree is created. * The block number of the next height of the metadata tree is returned. * */ static int lookup_block(struct gfs2_inode *ip, struct buffer_head *bh, unsigned int height, struct metapath *mp, int create, int *new, u64 *block) { int boundary; __be64 *ptr = metapointer(bh, &boundary, height, mp); if (*ptr) { *block = be64_to_cpu(*ptr); return boundary; } *block = 0; if (!create) return 0; if (height == ip->i_di.di_height - 1 && !gfs2_is_dir(ip)) *block = gfs2_alloc_data(ip); else *block = gfs2_alloc_meta(ip); gfs2_trans_add_bh(ip->i_gl, bh, 1); *ptr = cpu_to_be64(*block); ip->i_di.di_blocks++; gfs2_set_inode_blocks(&ip->i_inode); *new = 1; return 0; } static inline void bmap_lock(struct inode *inode, int create) { struct gfs2_inode *ip = GFS2_I(inode); if (create) down_write(&ip->i_rw_mutex); else down_read(&ip->i_rw_mutex); } static inline void bmap_unlock(struct inode *inode, int create) { struct gfs2_inode *ip = GFS2_I(inode); if (create) up_write(&ip->i_rw_mutex); else up_read(&ip->i_rw_mutex); } /** * 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 * * Find the block number on the current device which corresponds to an * inode's block. If the block had to be created, "new" will be set. * * Returns: errno */ int gfs2_block_map(struct inode *inode, u64 lblock, int create, struct buffer_head *bh_map) { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); struct buffer_head *bh; unsigned int bsize; unsigned int height; unsigned int end_of_metadata; unsigned int x; int error = 0; int new = 0; u64 dblock = 0; int boundary; unsigned int maxlen = bh_map->b_size >> inode->i_blkbits; struct metapath mp; u64 size; BUG_ON(maxlen == 0); if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip))) return 0; bmap_lock(inode, create); clear_buffer_mapped(bh_map); clear_buffer_new(bh_map); clear_buffer_boundary(bh_map); bsize = gfs2_is_dir(ip) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize; size = (lblock + 1) * bsize; if (size > ip->i_di.di_size) { height = calc_tree_height(ip, size); if (ip->i_di.di_height < height) { if (!create) goto out_ok; error = build_height(inode, height); if (error) goto out_fail; } } find_metapath(ip, lblock, &mp); end_of_metadata = ip->i_di.di_height - 1; error = gfs2_meta_inode_buffer(ip, &bh); if (error) goto out_fail; for (x = 0; x < end_of_metadata; x++) { lookup_block(ip, bh, x, &mp, create, &new, &dblock); brelse(bh); if (!dblock) goto out_ok; error = gfs2_meta_indirect_buffer(ip, x+1, dblock, new, &bh); if (error) goto out_fail; } boundary = lookup_block(ip, bh, end_of_metadata, &mp, create, &new, &dblock); if (dblock) { map_bh(bh_map, inode->i_sb, dblock); if (boundary) set_buffer_boundary(bh_map); if (new) { struct buffer_head *dibh; error = gfs2_meta_inode_buffer(ip, &dibh); if (!error) { gfs2_trans_add_bh(ip->i_gl, dibh, 1); gfs2_dinode_out(ip, dibh->b_data); brelse(dibh); } set_buffer_new(bh_map); goto out_brelse; } while(--maxlen && !buffer_boundary(bh_map)) { u64 eblock; mp.mp_list[end_of_metadata]++; boundary = lookup_block(ip, bh, end_of_metadata, &mp, 0, &new, &eblock); if (eblock != ++dblock) break; bh_map->b_size += (1 << inode->i_blkbits); if (boundary) set_buffer_boundary(bh_map); } } out_brelse: brelse(bh); out_ok: error = 0; out_fail: bmap_unlock(inode, create); return error; } 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 + 5); ret = gfs2_block_map(inode, lblock, create, &bh); *extlen = bh.b_size >> inode->i_blkbits; *dblock = bh.b_blocknr; if (buffer_new(&bh)) *new = 1; else *new = 0; return ret; } /** * 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 * @bc: the call to make for each piece of metadata * @data: 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, block_call_t bc, void *data) { 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, 0, &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 = bc(ip, dibh, bh, top, bottom, height, data); if (error) goto out; if (height < ip->i_di.di_height - 1) for (; top < bottom; top++, first = 0) { if (!*top) continue; bn = be64_to_cpu(*top); error = recursive_scan(ip, dibh, mp, height + 1, bn, first, bc, data); if (error) break; } out: brelse(bh); return error; } /** * 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, void *data) { struct strip_mine *sm = data; struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrp_list rlist; u64 bn, bstart; u32 blen; __be64 *p; unsigned int rg_blocks = 0; int metadata; unsigned int revokes = 0; int x; int 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_di.di_height - 1); if (metadata) revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs; error = gfs2_rindex_hold(sdp, &ip->i_alloc.al_ri_gh); if (error) return error; 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(sdp, &rlist, bstart); bstart = bn; blen = 1; } } if (bstart) gfs2_rlist_add(sdp, &rlist, bstart); else goto out; /* Nothing to do */ gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE, 0); 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; 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; for (p = top; p < bottom; p++) { if (!*p) continue; bn = be64_to_cpu(*p); if (bstart + blen == bn) blen++; else { if (bstart) { if (metadata) gfs2_free_meta(ip, bstart, blen); else gfs2_free_data(ip, bstart, blen); } bstart = bn; blen = 1; } *p = 0; if (!ip->i_di.di_blocks) gfs2_consist_inode(ip); ip->i_di.di_blocks--; gfs2_set_inode_blocks(&ip->i_inode); } if (bstart) { if (metadata) gfs2_free_meta(ip, bstart, blen); else gfs2_free_data(ip, bstart, blen); } 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: gfs2_glock_dq_uninit(&ip->i_alloc.al_ri_gh); return error; } /** * do_grow - Make a file look bigger than it is * @ip: the inode * @size: the size to set the file to * * Called with an exclusive lock on @ip. * * Returns: errno */ static int do_grow(struct gfs2_inode *ip, u64 size) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_alloc *al; struct buffer_head *dibh; unsigned int h; int error; al = gfs2_alloc_get(ip); error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); if (error) goto out; error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid); if (error) goto out_gunlock_q; al->al_requested = sdp->sd_max_height + RES_DATA; error = gfs2_inplace_reserve(ip); if (error) goto out_gunlock_q; error = gfs2_trans_begin(sdp, sdp->sd_max_height + al->al_rgd->rd_length + RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0); if (error) goto out_ipres; if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { if (gfs2_is_stuffed(ip)) { error = gfs2_unstuff_dinode(ip, NULL); if (error) goto out_end_trans; } h = calc_tree_height(ip, size); if (ip->i_di.di_height < h) { down_write(&ip->i_rw_mutex); error = build_height(&ip->i_inode, h); up_write(&ip->i_rw_mutex); if (error) goto out_end_trans; } } ip->i_di.di_size = size; ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; error = gfs2_meta_inode_buffer(ip, &dibh); if (error) goto out_end_trans; gfs2_trans_add_bh(ip->i_gl, dibh, 1); gfs2_dinode_out(ip, dibh->b_data); brelse(dibh); out_end_trans: gfs2_trans_end(sdp); out_ipres: gfs2_inplace_release(ip); out_gunlock_q: gfs2_quota_unlock(ip); out: gfs2_alloc_put(ip); 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) { struct inode *inode = mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); loff_t from = inode->i_size; 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 = grab_cache_page(mapping, index); 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_get_block(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 (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) gfs2_trans_add_bh(ip->i_gl, bh, 0); zero_user_page(page, offset, length, KM_USER0); unlock: unlock_page(page); page_cache_release(page); return err; } static int trunc_start(struct gfs2_inode *ip, u64 size) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); 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; if (gfs2_is_stuffed(ip)) { ip->i_di.di_size = 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); gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size); error = 1; } else { if (size & (u64)(sdp->sd_sb.sb_bsize - 1)) error = gfs2_block_truncate_page(ip->i_inode.i_mapping); if (!error) { ip->i_di.di_size = size; ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG; gfs2_trans_add_bh(ip->i_gl, dibh, 1); gfs2_dinode_out(ip, dibh->b_data); } } brelse(dibh); out: gfs2_trans_end(sdp); return error; } static int trunc_dealloc(struct gfs2_inode *ip, u64 size) { unsigned int height = ip->i_di.di_height; u64 lblock; struct metapath mp; int error; if (!size) lblock = 0; else lblock = (size - 1) >> GFS2_SB(&ip->i_inode)->sd_sb.sb_bsize_shift; find_metapath(ip, lblock, &mp); gfs2_alloc_get(ip); error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); if (error) goto out; while (height--) { struct strip_mine sm; sm.sm_first = !!size; sm.sm_height = height; error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm); if (error) break; } gfs2_quota_unhold(ip); out: gfs2_alloc_put(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 (!ip->i_di.di_size) { ip->i_di.di_height = 0; ip->i_di.di_goal_meta = ip->i_di.di_goal_data = 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_di.di_flags &= ~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 * @ip: the inode * @size: the size to make the file * @truncator: function to truncate the last partial block * * Called with an exclusive lock on @ip. * * Returns: errno */ static int do_shrink(struct gfs2_inode *ip, u64 size) { int error; error = trunc_start(ip, size); if (error < 0) return error; if (error > 0) return 0; error = trunc_dealloc(ip, size); if (!error) error = trunc_end(ip); return error; } /** * gfs2_truncatei - make a file a given size * @ip: the inode * @size: the size to make the file * @truncator: function to truncate the last partial block * * The file size can grow, shrink, or stay the same size. * * Returns: errno */ int gfs2_truncatei(struct gfs2_inode *ip, u64 size) { int error; if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), S_ISREG(ip->i_inode.i_mode))) return -EINVAL; if (size > ip->i_di.di_size) error = do_grow(ip, size); else error = do_shrink(ip, size); return error; } int gfs2_truncatei_resume(struct gfs2_inode *ip) { int error; error = trunc_dealloc(ip, ip->i_di.di_size); if (!error) error = trunc_end(ip); return error; } int gfs2_file_dealloc(struct gfs2_inode *ip) { return trunc_dealloc(ip, 0); } /** * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file * @ip: the file * @len: the number of bytes to be written to the file * @data_blocks: returns the number of data blocks required * @ind_blocks: returns the number of indirect blocks required * */ void gfs2_write_calc_reserv(struct gfs2_inode *ip, unsigned int len, unsigned int *data_blocks, unsigned int *ind_blocks) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); unsigned int tmp; if (gfs2_is_dir(ip)) { *data_blocks = DIV_ROUND_UP(len, sdp->sd_jbsize) + 2; *ind_blocks = 3 * (sdp->sd_max_jheight - 1); } else { *data_blocks = (len >> sdp->sd_sb.sb_bsize_shift) + 3; *ind_blocks = 3 * (sdp->sd_max_height - 1); } for (tmp = *data_blocks; tmp > sdp->sd_diptrs;) { tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs); *ind_blocks += tmp; } } /** * 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 * @alloc_required: set to 1 if an alloc is required, 0 otherwise * * Returns: errno */ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, unsigned int len, int *alloc_required) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); u64 lblock, lblock_stop, dblock; u32 extlen; int new = 0; int error = 0; *alloc_required = 0; if (!len) return 0; if (gfs2_is_stuffed(ip)) { if (offset + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) *alloc_required = 1; return 0; } if (gfs2_is_dir(ip)) { unsigned int bsize = sdp->sd_jbsize; lblock = offset; do_div(lblock, bsize); lblock_stop = offset + len + bsize - 1; do_div(lblock_stop, bsize); } else { unsigned int shift = sdp->sd_sb.sb_bsize_shift; lblock = offset >> shift; lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; } for (; lblock < lblock_stop; lblock += extlen) { error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, &extlen); if (error) return error; if (!dblock) { *alloc_required = 1; return 0; } } return 0; }