return error;
}
-/**
- * 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, struct metapath *mp, unsigned height)
-{
- struct gfs2_inode *ip = GFS2_I(inode);
- unsigned new_height = height - ip->i_height;
- struct buffer_head *dibh = mp->mp_bh[0];
- struct gfs2_dinode *di;
- __be64 *bp;
- u64 bn;
- unsigned n, i = 0;
-
- BUG_ON(height <= ip->i_height);
-
- do {
- n = new_height - i;
- bn = gfs2_alloc_block(ip, &n);
- gfs2_trans_add_unrevoke(GFS2_SB(inode), bn, n);
- do {
- mp->mp_bh[i + 1] = gfs2_meta_new(ip->i_gl, bn++);
- gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[i + 1], 1);
- i++;
- } while(i < n);
- } while(i < new_height);
-
- n = 0;
- bn = mp->mp_bh[1]->b_blocknr;
- if (new_height > 1) {
- for(; n < new_height-1; n++) {
- gfs2_metatype_set(mp->mp_bh[n + 1], GFS2_METATYPE_IN,
- GFS2_FORMAT_IN);
- gfs2_buffer_clear_tail(mp->mp_bh[n + 1],
- sizeof(struct gfs2_meta_header));
- bp = (__be64 *)(mp->mp_bh[n + 1]->b_data +
- sizeof(struct gfs2_meta_header));
- *bp = cpu_to_be64(mp->mp_bh[n+2]->b_blocknr);
- brelse(mp->mp_bh[n+1]);
- mp->mp_bh[n+1] = NULL;
- }
- }
- gfs2_metatype_set(mp->mp_bh[n+1], GFS2_METATYPE_IN, GFS2_FORMAT_IN);
- gfs2_buffer_copy_tail(mp->mp_bh[n+1], sizeof(struct gfs2_meta_header),
- dibh, sizeof(struct gfs2_dinode));
- brelse(mp->mp_bh[n+1]);
- mp->mp_bh[n+1] = NULL;
- 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_height += new_height;
- gfs2_add_inode_blocks(&ip->i_inode, new_height);
- di->di_height = cpu_to_be16(ip->i_height);
- di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode));
- return 0;
-}
/**
* find_metapath - Find path through the metadata tree
- * @ip: The inode pointer
+ * @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".
*
*/
-static void find_metapath(struct gfs2_inode *ip, u64 block,
- struct metapath *mp)
+static void find_metapath(const struct gfs2_sbd *sdp, u64 block,
+ struct metapath *mp, unsigned int height)
{
- struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
unsigned int i;
- for (i = ip->i_height; i--;)
+ for (i = height; i--;)
mp->mp_list[i] = do_div(block, sdp->sd_inptrs);
}
+static inline unsigned int zero_metapath_length(const struct metapath *mp,
+ unsigned height)
+{
+ unsigned int i;
+ for (i = 0; i < height - 1; i++) {
+ if (mp->mp_list[i] != 0)
+ return i;
+ }
+ return height;
+}
+
/**
* metapointer - Return pointer to start of metadata in a buffer
* @height: The metadata height (0 = dinode)
* metadata tree.
*/
-static inline __be64 *metapointer(int *boundary, unsigned int height,
- const struct metapath *mp)
+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);
- __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;
+ return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height];
}
/**
- * lookup_block - Get the next metadata block in metadata tree
- * @ip: The GFS2 inode
- * @height: The height of the tree (0 = dinode)
+ * lookup_metapath - Walk the metadata tree to a specific point
+ * @ip: The inode
* @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.
+ * 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_block(struct gfs2_inode *ip, unsigned int height,
- struct metapath *mp, int create,
- int *new, u64 *block)
+static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp)
{
- int boundary;
- __be64 *ptr = metapointer(&boundary, height, mp);
- unsigned int n = 1;
-
- if (*ptr) {
- *block = be64_to_cpu(*ptr);
- return boundary;
- }
-
- *block = 0;
-
- if (!create)
- return 0;
-
- *block = gfs2_alloc_block(ip, &n);
- if (height != ip->i_height - 1 || gfs2_is_dir(ip))
- gfs2_trans_add_unrevoke(GFS2_SB(&ip->i_inode), *block, 1);
-
- gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[height], 1);
-
- *ptr = cpu_to_be64(*block);
- gfs2_add_inode_blocks(&ip->i_inode, 1);
-
- *new = 1;
- return 0;
-}
-
-static int lookup_metapath(struct inode *inode, struct metapath *mp,
- int create, int *new, u64 *dblock)
-{
- struct buffer_head *bh;
- struct gfs2_inode *ip = GFS2_I(inode);
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++) {
- lookup_block(ip, x, mp, create, new, dblock);
- if (!*dblock)
- return 0;
+ ptr = metapointer(x, mp);
+ dblock = be64_to_cpu(*ptr);
+ if (!dblock)
+ return x + 1;
- ret = gfs2_meta_indirect_buffer(ip, x+1, *dblock, *new, &mp->mp_bh[x+1]);
+ ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, 0, &mp->mp_bh[x+1]);
if (ret)
return ret;
}
- return lookup_block(ip, end_of_metadata, mp, create, new, dblock);
+ return ip->i_height;
}
-static void release_metapath(struct metapath *mp)
+static inline void release_metapath(struct metapath *mp)
{
int i;
- for (i = 0; i < GFS2_MAX_META_HEIGHT; i++)
- if (mp->mp_bh[i])
- brelse(mp->mp_bh[i]);
+ for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) {
+ if (mp->mp_bh[i] == NULL)
+ break;
+ brelse(mp->mp_bh[i]);
+ }
}
/**
return (ptr - first);
}
-static inline void bmap_lock(struct inode *inode, int create)
+static inline void bmap_lock(struct gfs2_inode *ip, 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)
+static inline void bmap_unlock(struct gfs2_inode *ip, int create)
{
- struct gfs2_inode *ip = GFS2_I(inode);
if (create)
up_write(&ip->i_rw_mutex);
else
up_read(&ip->i_rw_mutex);
}
+static inline __be64 *gfs2_indirect_init(struct metapath *mp,
+ struct gfs2_glock *gl, unsigned int i,
+ unsigned offset, u64 bn)
+{
+ __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data +
+ ((i > 1) ? sizeof(struct gfs2_meta_header) :
+ sizeof(struct gfs2_dinode)));
+ BUG_ON(i < 1);
+ BUG_ON(mp->mp_bh[i] != NULL);
+ mp->mp_bh[i] = gfs2_meta_new(gl, bn);
+ gfs2_trans_add_bh(gl, mp->mp_bh[i], 1);
+ gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN);
+ gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header));
+ ptr += offset;
+ *ptr = cpu_to_be64(bn);
+ return ptr;
+}
+
+enum alloc_state {
+ ALLOC_DATA = 0,
+ ALLOC_GROW_DEPTH = 1,
+ ALLOC_GROW_HEIGHT = 2,
+ /* ALLOC_UNSTUFF = 3, TBD and rather complicated */
+};
+
+/**
+ * gfs2_bmap_alloc - Build a metadata tree of the requested height
+ * @inode: The GFS2 inode
+ * @lblock: The logical starting block of the extent
+ * @bh_map: This is used to return the mapping details
+ * @mp: The metapath
+ * @sheight: The starting height (i.e. whats already mapped)
+ * @height: The height to build to
+ * @maxlen: The max number of data blocks to alloc
+ *
+ * In this routine we may have to alloc:
+ * i) Indirect blocks to grow the metadata tree height
+ * ii) Indirect blocks to fill in lower part of the metadata tree
+ * iii) Data blocks
+ *
+ * The function is in two parts. The first part works out the total
+ * number of blocks which we need. The second part does the actual
+ * allocation asking for an extent at a time (if enough contiguous free
+ * blocks are available, there will only be one request per bmap call)
+ * and uses the state machine to initialise the blocks in order.
+ *
+ * Returns: errno on error
+ */
+
+static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock,
+ struct buffer_head *bh_map, struct metapath *mp,
+ const unsigned int sheight,
+ const unsigned int height,
+ const unsigned int maxlen)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct buffer_head *dibh = mp->mp_bh[0];
+ u64 bn, dblock = 0;
+ unsigned n, i, blks, alloced = 0, iblks = 0, zmpl = 0;
+ unsigned dblks = 0;
+ unsigned ptrs_per_blk;
+ const unsigned end_of_metadata = height - 1;
+ int eob = 0;
+ enum alloc_state state;
+ __be64 *ptr;
+ __be64 zero_bn = 0;
+
+ BUG_ON(sheight < 1);
+ BUG_ON(dibh == NULL);
+
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+
+ if (height == sheight) {
+ struct buffer_head *bh;
+ /* Bottom indirect block exists, find unalloced extent size */
+ ptr = metapointer(end_of_metadata, mp);
+ bh = mp->mp_bh[end_of_metadata];
+ dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen,
+ &eob);
+ BUG_ON(dblks < 1);
+ state = ALLOC_DATA;
+ } else {
+ /* Need to allocate indirect blocks */
+ ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs;
+ dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]);
+ if (height == ip->i_height) {
+ /* Writing into existing tree, extend tree down */
+ iblks = height - sheight;
+ state = ALLOC_GROW_DEPTH;
+ } else {
+ /* Building up tree height */
+ state = ALLOC_GROW_HEIGHT;
+ iblks = height - ip->i_height;
+ zmpl = zero_metapath_length(mp, height);
+ iblks -= zmpl;
+ iblks += height;
+ }
+ }
+
+ /* start of the second part of the function (state machine) */
+
+ blks = dblks + iblks;
+ i = sheight;
+ do {
+ n = blks - alloced;
+ bn = gfs2_alloc_block(ip, &n);
+ 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 = zmpl; i < height; i++) {
+ if (mp->mp_bh[i] == NULL)
+ break;
+ brelse(mp->mp_bh[i]);
+ mp->mp_bh[i] = NULL;
+ }
+ i = zmpl;
+ }
+ if (n == 0)
+ break;
+ /* Branching from existing tree */
+ case ALLOC_GROW_DEPTH:
+ if (i > 1 && i < height)
+ gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[i-1], 1);
+ for (; i < height && n > 0; i++, n--)
+ gfs2_indirect_init(mp, ip->i_gl, i,
+ mp->mp_list[i-1], bn++);
+ if (i == height)
+ state = ALLOC_DATA;
+ if (n == 0)
+ break;
+ /* Tree complete, adding data blocks */
+ case ALLOC_DATA:
+ BUG_ON(n > dblks);
+ BUG_ON(mp->mp_bh[end_of_metadata] == NULL);
+ gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[end_of_metadata], 1);
+ dblks = n;
+ ptr = metapointer(end_of_metadata, mp);
+ dblock = bn;
+ while (n-- > 0)
+ *ptr++ = cpu_to_be64(bn++);
+ break;
+ }
+ } while (state != ALLOC_DATA);
+
+ 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
*
- * 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.
+ * 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
*/
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
unsigned int bsize = sdp->sd_sb.sb_bsize;
- 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;
+ const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits;
const u64 *arr = sdp->sd_heightsize;
- BUG_ON(maxlen == 0);
+ __be64 *ptr;
+ u64 size;
+ struct metapath mp;
+ int ret;
+ int eob;
+ unsigned int len;
+ struct buffer_head *bh;
+ u8 height;
- if (gfs2_assert_warn(sdp, !gfs2_is_stuffed(ip)))
- return 0;
+ BUG_ON(maxlen == 0);
memset(mp.mp_bh, 0, sizeof(mp.mp_bh));
- bmap_lock(inode, create);
+ bmap_lock(ip, create);
clear_buffer_mapped(bh_map);
clear_buffer_new(bh_map);
clear_buffer_boundary(bh_map);
bsize = sdp->sd_jbsize;
arr = sdp->sd_jheightsize;
}
- size = (lblock + 1) * bsize;
- error = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
- if (error)
- goto out_fail;
-
- if (size > arr[ip->i_height]) {
- u8 height = ip->i_height;
- if (!create)
- goto out_ok;
- while (size > arr[height])
- height++;
- error = build_height(inode, &mp, height);
- if (error)
- goto out_fail;
- }
+ ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
+ if (ret)
+ goto out;
- find_metapath(ip, lblock, &mp);
- error = lookup_metapath(inode, &mp, create, &new, &dblock);
- if (error < 0)
- goto out_fail;
- boundary = error;
-
- if (new) {
- map_bh(bh_map, inode->i_sb, dblock);
- if (boundary)
- set_buffer_boundary(bh_map);
- gfs2_trans_add_bh(ip->i_gl, mp.mp_bh[0], 1);
- gfs2_dinode_out(ip, mp.mp_bh[0]->b_data);
- set_buffer_new(bh_map);
- goto out_ok;
- }
+ 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);
+ bmap_unlock(ip, create);
+ return ret;
- if (dblock) {
- unsigned int len;
- struct buffer_head *bh = mp.mp_bh[ip->i_height - 1];
- __be64 *ptr = metapointer(&boundary, ip->i_height - 1, &mp);
- map_bh(bh_map, inode->i_sb, dblock);
- len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen,
- &boundary);
- bh_map->b_size = (len << inode->i_blkbits);
- if (boundary)
- set_buffer_boundary(bh_map);
+do_alloc:
+ /* All allocations are done here, firstly check create flag */
+ if (!create) {
+ BUG_ON(gfs2_is_stuffed(ip));
+ ret = 0;
+ goto out;
}
-out_ok:
- error = 0;
-out_fail:
- release_metapath(&mp);
- bmap_unlock(inode, create);
- return error;
+
+ /* 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;
}
/*
BUG_ON(!dblock);
BUG_ON(!new);
- bh.b_size = 1 << (inode->i_blkbits + 5);
+ 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 (error)
goto out_ipres;
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (error)
+ goto out_end_trans;
+
if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
- const u64 *arr = sdp->sd_heightsize;
if (gfs2_is_stuffed(ip)) {
error = gfs2_unstuff_dinode(ip, NULL);
if (error)
- goto out_end_trans;
- }
-
- down_write(&ip->i_rw_mutex);
- if (size > arr[ip->i_height]) {
- struct metapath mp;
- u8 height = ip->i_height;
- while(size > arr[height])
- height++;
- error = build_height(&ip->i_inode, &mp, height);
+ goto out_brelse;
}
- 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_brelse:
+ brelse(dibh);
out_end_trans:
gfs2_trans_end(sdp);
out_ipres:
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;
if (!size)
lblock = 0;
else
- lblock = (size - 1) >> GFS2_SB(&ip->i_inode)->sd_sb.sb_bsize_shift;
+ lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift;
- find_metapath(ip, lblock, &mp);
+ find_metapath(sdp, lblock, &mp, ip->i_height);
gfs2_alloc_get(ip);
error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
projects / linux-2.6 / commitdiff