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-rw-r--r--fs/gfs2/bmap.c1221
1 files changed, 1221 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
new file mode 100644
index 00000000000..cc57f2ecd21
--- /dev/null
+++ b/fs/gfs2/bmap.c
@@ -0,0 +1,1221 @@
+/*
+ * 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/sched.h>
+#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, u64 *top,
+ u64 *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++;
+ 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;
+ u64 *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 = (u64 *)(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;
+ 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 u64 *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);
+ u64 *ptr;
+ *boundary = 0;
+ ptr = ((u64 *)(bh->b_data + head_size)) + mp->mp_list[height];
+ if (ptr + 1 == (u64 *)(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;
+ u64 *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++;
+
+ *new = 1;
+ return 0;
+}
+
+/**
+ * gfs2_block_pointers - Map a block from an inode to a disk block
+ * @inode: The inode
+ * @lblock: The logical block number
+ * @map_bh: The bh to be mapped
+ * @mp: metapath to use
+ *
+ * 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
+ */
+
+static int gfs2_block_pointers(struct inode *inode, u64 lblock, int create,
+ struct buffer_head *bh_map, struct metapath *mp,
+ unsigned int maxlen)
+{
+ 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;
+
+ BUG_ON(maxlen == 0);
+
+ if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
+ return 0;
+
+ bsize = gfs2_is_dir(ip) ? sdp->sd_jbsize : sdp->sd_sb.sb_bsize;
+
+ height = calc_tree_height(ip, (lblock + 1) * bsize);
+ if (ip->i_di.di_height < height) {
+ if (!create)
+ return 0;
+
+ error = build_height(inode, height);
+ if (error)
+ return error;
+ }
+
+ find_metapath(ip, lblock, mp);
+ end_of_metadata = ip->i_di.di_height - 1;
+
+ error = gfs2_meta_inode_buffer(ip, &bh);
+ if (error)
+ return error;
+
+ for (x = 0; x < end_of_metadata; x++) {
+ lookup_block(ip, bh, x, mp, create, &new, &dblock);
+ brelse(bh);
+ if (!dblock)
+ return 0;
+
+ error = gfs2_meta_indirect_buffer(ip, x+1, dblock, new, &bh);
+ if (error)
+ return error;
+ }
+
+ boundary = lookup_block(ip, bh, end_of_metadata, mp, create, &new, &dblock);
+ clear_buffer_mapped(bh_map);
+ clear_buffer_new(bh_map);
+ clear_buffer_boundary(bh_map);
+
+ if (dblock) {
+ map_bh(bh_map, inode->i_sb, dblock);
+ if (boundary)
+ set_buffer_boundary(bh);
+ 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->i_di, 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);
+ 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);
+}
+
+int gfs2_block_map(struct inode *inode, u64 lblock, int create,
+ struct buffer_head *bh, unsigned int maxlen)
+{
+ struct metapath mp;
+ int ret;
+
+ bmap_lock(inode, create);
+ ret = gfs2_block_pointers(inode, lblock, create, bh, &mp, maxlen);
+ bmap_unlock(inode, create);
+ return ret;
+}
+
+int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen)
+{
+ struct metapath mp;
+ struct buffer_head bh = { .b_state = 0, .b_blocknr = 0, .b_size = 0 };
+ int ret;
+ int create = *new;
+
+ BUG_ON(!extlen);
+ BUG_ON(!dblock);
+ BUG_ON(!new);
+
+ bmap_lock(inode, create);
+ ret = gfs2_block_pointers(inode, lblock, create, &bh, &mp, 32);
+ bmap_unlock(inode, create);
+ *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;
+ u64 *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 = (u64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0];
+ bottom = (u64 *)(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 = (u64 *)(bh->b_data + mh_size) +
+ (first ? mp->mp_list[height] : 0);
+
+ bottom = (u64 *)(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, u64 *top, u64 *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;
+ u64 *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_ri.ri_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--;
+ }
+ if (bstart) {
+ if (metadata)
+ gfs2_free_meta(ip, bstart, blen);
+ else
+ gfs2_free_data(ip, bstart, blen);
+ }
+
+ ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+
+ gfs2_dinode_out(&ip->i_di, 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_di.di_uid, ip->i_di.di_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_ri.ri_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_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+
+ 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->i_di, 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;
+ void *kaddr;
+ 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;
+ }
+
+ if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip))
+ gfs2_trans_add_bh(ip->i_gl, bh, 0);
+
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + offset, 0, length);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, 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_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+ gfs2_dinode_out(&ip->i_di, 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_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+ ip->i_di.di_flags |= GFS2_DIF_TRUNC_IN_PROG;
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+ gfs2_dinode_out(&ip->i_di, 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_num.no_addr;
+ gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
+ }
+ ip->i_di.di_mtime = ip->i_di.di_ctime = get_seconds();
+ ip->i_di.di_flags &= ~GFS2_DIF_TRUNC_IN_PROG;
+
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+ gfs2_dinode_out(&ip->i_di, 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_di.di_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;
+}
+
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 03:09:05 +0000