2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
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35 * @(#)ffs_alloc.c 8.8 (Berkeley) 2/21/94
39 #include <sys/param.h>
40 #include <sys/systm.h>
42 #include <sys/vnode.h>
44 #include <sys/mount.h>
45 #include <sys/syslog.h>
47 #include <gnu/fs/ext2fs/inode.h>
48 #include <gnu/fs/ext2fs/ext2_mount.h>
49 #include <gnu/fs/ext2fs/ext2_fs.h>
50 #include <gnu/fs/ext2fs/ext2_fs_sb.h>
51 #include <gnu/fs/ext2fs/fs.h>
52 #include <gnu/fs/ext2fs/ext2_extern.h>
54 static void ext2_fserr(struct ext2_sb_info *, u_int, char *);
57 * Linux calls this functions at the following locations:
58 * (1) the inode is freed
59 * (2) a preallocation miss occurs
60 * (3) truncate is called
61 * (4) release_file is called and f_mode & 2
63 * I call it in ext2_inactive, ext2_truncate, ext2_vfree and in (2)
64 * the call in vfree might be redundant
67 ext2_discard_prealloc(ip)
70 #ifdef EXT2_PREALLOCATE
71 if (ip->i_prealloc_count) {
72 int i = ip->i_prealloc_count;
73 ip->i_prealloc_count = 0;
74 ext2_free_blocks (ITOV(ip)->v_mount,
82 * Allocate a block in the file system.
84 * this takes the framework from ffs_alloc. To implement the
85 * actual allocation, it calls ext2_new_block, the ported version
86 * of the same Linux routine.
88 * we note that this is always called in connection with ext2_blkpref
90 * preallocation is done as Linux does it
93 ext2_alloc(ip, lbn, bpref, size, cred, bnp)
100 struct ext2_sb_info *fs;
106 if ((u_int)size > fs->s_blocksize || blkoff(fs, size) != 0) {
107 vn_printf(ip->i_devvp, "bsize = %lu, size = %d, fs = %s\n",
108 fs->s_blocksize, size, fs->fs_fsmnt);
109 panic("ext2_alloc: bad size");
112 panic("ext2_alloc: missing credential");
113 #endif /* DIAGNOSTIC */
114 if (size == fs->s_blocksize && fs->s_es->s_free_blocks_count == 0)
116 if (cred->cr_uid != 0 &&
117 fs->s_es->s_free_blocks_count < fs->s_es->s_r_blocks_count)
119 if (bpref >= fs->s_es->s_blocks_count)
121 /* call the Linux code */
122 #ifdef EXT2_PREALLOCATE
123 /* To have a preallocation hit, we must
124 * - have at least one block preallocated
125 * - and our preferred block must have that block number or one below
127 if (ip->i_prealloc_count &&
128 (bpref == ip->i_prealloc_block ||
129 bpref + 1 == ip->i_prealloc_block))
131 bno = ip->i_prealloc_block++;
132 ip->i_prealloc_count--;
133 /* ext2_debug ("preallocation hit (%lu/%lu).\n",
134 ++alloc_hits, ++alloc_attempts); */
136 /* Linux gets, clears, and releases the buffer at this
137 point - we don't have to that; we leave it to the caller
140 ext2_discard_prealloc (ip);
141 /* ext2_debug ("preallocation miss (%lu/%lu).\n",
142 alloc_hits, ++alloc_attempts); */
143 if (S_ISREG(ip->i_mode))
145 (ITOV(ip)->v_mount, bpref,
146 &ip->i_prealloc_count,
147 &ip->i_prealloc_block);
149 bno = (int32_t)ext2_new_block(ITOV(ip)->v_mount,
153 bno = (int32_t)ext2_new_block(ITOV(ip)->v_mount, bpref, 0, 0);
157 /* set next_alloc fields as done in block_getblk */
158 ip->i_next_alloc_block = lbn;
159 ip->i_next_alloc_goal = bno;
161 ip->i_blocks += btodb(size);
162 ip->i_flag |= IN_CHANGE | IN_UPDATE;
167 ext2_fserr(fs, cred->cr_uid, "file system full");
168 uprintf("\n%s: write failed, file system is full\n", fs->fs_fsmnt);
173 * Reallocate a sequence of blocks into a contiguous sequence of blocks.
175 * The vnode and an array of buffer pointers for a range of sequential
176 * logical blocks to be made contiguous is given. The allocator attempts
177 * to find a range of sequential blocks starting as close as possible to
178 * an fs_rotdelay offset from the end of the allocation for the logical
179 * block immediately preceding the current range. If successful, the
180 * physical block numbers in the buffer pointers and in the inode are
181 * changed to reflect the new allocation. If unsuccessful, the allocation
182 * is left unchanged. The success in doing the reallocation is returned.
183 * Note that the error return is not reflected back to the user. Rather
184 * the previous block allocation will be used.
188 #include <sys/sysctl.h>
189 static int doasyncfree = 1;
191 SYSCTL_INT(_debug, 14, doasyncfree, CTLFLAG_RW, &doasyncfree, 0, "");
192 #endif /* OPT_DEBUG */
197 struct vop_reallocblks_args /* {
199 struct cluster_save *a_buflist;
202 #ifndef FANCY_REALLOC
203 /* printf("ext2_reallocblks not implemented\n"); */
207 struct ext2_sb_info *fs;
210 struct buf *sbp, *ebp;
211 int32_t *bap, *sbap, *ebap;
212 struct cluster_save *buflist;
213 int32_t start_lbn, end_lbn, soff, eoff, newblk, blkno;
214 struct indir start_ap[NIADDR + 1], end_ap[NIADDR + 1], *idp;
215 int i, len, start_lvl, end_lvl, pref, ssize;
221 if (fs->fs_contigsumsize <= 0)
224 buflist = ap->a_buflist;
225 len = buflist->bs_nchildren;
226 start_lbn = buflist->bs_children[0]->b_lblkno;
227 end_lbn = start_lbn + len - 1;
229 for (i = 1; i < len; i++)
230 if (buflist->bs_children[i]->b_lblkno != start_lbn + i)
231 panic("ext2_reallocblks: non-cluster");
234 * If the latest allocation is in a new cylinder group, assume that
235 * the filesystem has decided to move and do not force it back to
236 * the previous cylinder group.
238 if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) !=
239 dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno)))
241 if (ufs_getlbns(vp, start_lbn, start_ap, &start_lvl) ||
242 ufs_getlbns(vp, end_lbn, end_ap, &end_lvl))
245 * Get the starting offset and block map for the first block.
247 if (start_lvl == 0) {
251 idp = &start_ap[start_lvl - 1];
252 if (bread(vp, idp->in_lbn, (int)fs->s_blocksize, NOCRED, &sbp)) {
256 sbap = (int32_t *)sbp->b_data;
260 * Find the preferred location for the cluster.
262 pref = ext2_blkpref(ip, start_lbn, soff, sbap);
264 * If the block range spans two block maps, get the second map.
266 if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
270 if (start_ap[start_lvl-1].in_lbn == idp->in_lbn)
271 panic("ext2_reallocblk: start == end");
273 ssize = len - (idp->in_off + 1);
274 if (bread(vp, idp->in_lbn, (int)fs->s_blocksize, NOCRED, &ebp))
276 ebap = (int32_t *)ebp->b_data;
279 * Search the block map looking for an allocation of the desired size.
281 if ((newblk = (int32_t)ext2_hashalloc(ip, dtog(fs, pref), (long)pref,
282 len, (u_long (*)())ext2_clusteralloc)) == 0)
285 * We have found a new contiguous block.
287 * First we have to replace the old block pointers with the new
288 * block pointers in the inode and indirect blocks associated
292 for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->s_frags_per_block) {
296 if (buflist->bs_children[i]->b_blkno != fsbtodb(fs, *bap))
297 panic("ext2_reallocblks: alloc mismatch");
302 * Next we must write out the modified inode and indirect blocks.
303 * For strict correctness, the writes should be synchronous since
304 * the old block values may have been written to disk. In practise
305 * they are almost never written, but if we are concerned about
306 * strict correctness, the `doasyncfree' flag should be set to zero.
308 * The test on `doasyncfree' should be changed to test a flag
309 * that shows whether the associated buffers and inodes have
310 * been written. The flag should be set when the cluster is
311 * started and cleared whenever the buffer or inode is flushed.
312 * We can then check below to see if it is set, and do the
313 * synchronous write only when it has been cleared.
315 if (sbap != &ip->i_db[0]) {
321 ip->i_flag |= IN_CHANGE | IN_UPDATE;
331 * Last, free the old blocks and assign the new blocks to the buffers.
333 for (blkno = newblk, i = 0; i < len; i++, blkno += fs->s_frags_per_block) {
334 ext2_blkfree(ip, dbtofsb(fs, buflist->bs_children[i]->b_blkno),
336 buflist->bs_children[i]->b_blkno = fsbtodb(fs, blkno);
343 if (sbap != &ip->i_db[0])
347 #endif /* FANCY_REALLOC */
351 * Allocate an inode in the file system.
353 * we leave the actual allocation strategy to the (modified)
354 * ext2_new_inode(), to make sure we get the policies right
357 ext2_valloc(pvp, mode, cred, vpp)
364 struct ext2_sb_info *fs;
372 if (fs->s_es->s_free_inodes_count == 0)
375 /* call the Linux routine - it returns the inode number only */
376 ino = ext2_new_inode(pip, mode);
380 error = VFS_VGET(pvp->v_mount, ino, LK_EXCLUSIVE, vpp);
382 ext2_vfree(pvp, ino, mode);
388 the question is whether using VGET was such good idea at all -
389 Linux doesn't read the old inode in when it's allocating a
390 new one. I will set at least i_size & i_blocks the zero.
396 /* now we want to make sure that the block pointers are zeroed out */
397 for (i = 0; i < NDADDR; i++)
399 for (i = 0; i < NIADDR; i++)
403 * Set up a new generation number for this inode.
404 * XXX check if this makes sense in ext2
406 if (ip->i_gen == 0 || ++ip->i_gen == 0)
407 ip->i_gen = random() / 2 + 1;
409 printf("ext2_valloc: allocated inode %d\n", ino);
413 ext2_fserr(fs, cred->cr_uid, "out of inodes");
414 uprintf("\n%s: create/symlink failed, no inodes free\n", fs->fs_fsmnt);
419 * Select the desired position for the next block in a file.
421 * we try to mimic what Remy does in inode_getblk/block_getblk
423 * we note: blocknr == 0 means that we're about to allocate either
424 * a direct block or a pointer block at the first level of indirection
425 * (In other words, stuff that will go in i_db[] or i_ib[])
427 * blocknr != 0 means that we're allocating a block that is none
428 * of the above. Then, blocknr tells us the number of the block
429 * that will hold the pointer
432 ext2_blkpref(ip, lbn, indx, bap, blocknr)
441 /* if the next block is actually what we thought it is,
442 then set the goal to what we thought it should be
444 if(ip->i_next_alloc_block == lbn)
445 return ip->i_next_alloc_goal;
447 /* now check whether we were provided with an array that basically
448 tells us previous blocks to which we want to stay closeby
451 for (tmp = indx - 1; tmp >= 0; tmp--)
455 /* else let's fall back to the blocknr, or, if there is none,
456 follow the rule that a block should be allocated near its inode
458 return blocknr ? blocknr :
459 (int32_t)(ip->i_block_group *
460 EXT2_BLOCKS_PER_GROUP(ip->i_e2fs)) +
461 ip->i_e2fs->s_es->s_first_data_block;
465 * Free a block or fragment.
467 * pass on to the Linux code
470 ext2_blkfree(ip, bno, size)
475 struct ext2_sb_info *fs;
479 * call Linux code with mount *, block number, count
481 ext2_free_blocks(ITOV(ip)->v_mount, bno, size / fs->s_frag_size);
487 * the maintenance of the actual bitmaps is again up to the linux code
490 ext2_vfree(pvp, ino, mode)
495 struct ext2_sb_info *fs;
501 if ((u_int)ino > fs->s_inodes_per_group * fs->s_groups_count)
502 panic("ext2_vfree: range: devvp = %p, ino = %d, fs = %s",
503 pip->i_devvp, ino, fs->fs_fsmnt);
505 /* ext2_debug("ext2_vfree (%d, %d) called\n", pip->i_number, mode);
507 ext2_discard_prealloc(pip);
509 /* we need to make sure that ext2_free_inode can adjust the
510 used_dir_counts in the group summary information - I'd
511 really like to know what the rationale behind this
512 'set i_mode to zero to denote an unused inode' is
514 save_i_mode = pip->i_mode;
516 ext2_free_inode(pip);
517 pip->i_mode = save_i_mode;
522 * Fserr prints the name of a file system with an error diagnostic.
524 * The form of the error message is:
528 ext2_fserr(fs, uid, cp)
529 struct ext2_sb_info *fs;
534 log(LOG_ERR, "uid %d on %s: %s\n", uid, fs->fs_fsmnt, cp);