2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/crc32.h>
16 #include <linux/gfs2_ondisk.h>
17 #include <linux/bio.h>
18 #include <linux/lm_interface.h>
36 static const u32 gfs2_old_fs_formats[] = {
40 static const u32 gfs2_old_multihost_formats[] = {
45 * gfs2_tune_init - Fill a gfs2_tune structure with default values
50 void gfs2_tune_init(struct gfs2_tune *gt)
52 spin_lock_init(>->gt_spin);
55 gt->gt_ilimit_tries = 3;
56 gt->gt_ilimit_min = 1;
57 gt->gt_demote_secs = 300;
58 gt->gt_incore_log_blocks = 1024;
59 gt->gt_log_flush_secs = 60;
60 gt->gt_jindex_refresh_secs = 60;
61 gt->gt_scand_secs = 15;
62 gt->gt_recoverd_secs = 60;
64 gt->gt_quotad_secs = 5;
65 gt->gt_quota_simul_sync = 64;
66 gt->gt_quota_warn_period = 10;
67 gt->gt_quota_scale_num = 1;
68 gt->gt_quota_scale_den = 1;
69 gt->gt_quota_cache_secs = 300;
70 gt->gt_quota_quantum = 60;
71 gt->gt_atime_quantum = 3600;
72 gt->gt_new_files_jdata = 0;
73 gt->gt_new_files_directio = 0;
74 gt->gt_max_readahead = 1 << 18;
75 gt->gt_lockdump_size = 131072;
76 gt->gt_stall_secs = 600;
77 gt->gt_complain_secs = 10;
78 gt->gt_reclaim_limit = 5000;
79 gt->gt_statfs_quantum = 30;
80 gt->gt_statfs_slow = 0;
84 * gfs2_check_sb - Check superblock
85 * @sdp: the filesystem
87 * @silent: Don't print a message if the check fails
89 * Checks the version code of the FS is one that we understand how to
90 * read and that the sizes of the various on-disk structures have not
94 int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb_host *sb, int silent)
98 if (sb->sb_magic != GFS2_MAGIC ||
99 sb->sb_type != GFS2_METATYPE_SB) {
101 printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n");
105 /* If format numbers match exactly, we're done. */
107 if (sb->sb_fs_format == GFS2_FORMAT_FS &&
108 sb->sb_multihost_format == GFS2_FORMAT_MULTI)
111 if (sb->sb_fs_format != GFS2_FORMAT_FS) {
112 for (x = 0; gfs2_old_fs_formats[x]; x++)
113 if (gfs2_old_fs_formats[x] == sb->sb_fs_format)
116 if (!gfs2_old_fs_formats[x]) {
118 "GFS2: code version (%u, %u) is incompatible "
119 "with ondisk format (%u, %u)\n",
120 GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
121 sb->sb_fs_format, sb->sb_multihost_format);
123 "GFS2: I don't know how to upgrade this FS\n");
128 if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) {
129 for (x = 0; gfs2_old_multihost_formats[x]; x++)
130 if (gfs2_old_multihost_formats[x] ==
131 sb->sb_multihost_format)
134 if (!gfs2_old_multihost_formats[x]) {
136 "GFS2: code version (%u, %u) is incompatible "
137 "with ondisk format (%u, %u)\n",
138 GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
139 sb->sb_fs_format, sb->sb_multihost_format);
141 "GFS2: I don't know how to upgrade this FS\n");
146 if (!sdp->sd_args.ar_upgrade) {
148 "GFS2: code version (%u, %u) is incompatible "
149 "with ondisk format (%u, %u)\n",
150 GFS2_FORMAT_FS, GFS2_FORMAT_MULTI,
151 sb->sb_fs_format, sb->sb_multihost_format);
153 "GFS2: Use the \"upgrade\" mount option to upgrade "
155 printk(KERN_INFO "GFS2: See the manual for more details\n");
163 static void end_bio_io_page(struct bio *bio, int error)
165 struct page *page = bio->bi_private;
168 SetPageUptodate(page);
170 printk(KERN_WARNING "gfs2: error %d reading superblock\n", error);
174 static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf)
176 const struct gfs2_sb *str = buf;
178 sb->sb_magic = be32_to_cpu(str->sb_header.mh_magic);
179 sb->sb_type = be32_to_cpu(str->sb_header.mh_type);
180 sb->sb_format = be32_to_cpu(str->sb_header.mh_format);
181 sb->sb_fs_format = be32_to_cpu(str->sb_fs_format);
182 sb->sb_multihost_format = be32_to_cpu(str->sb_multihost_format);
183 sb->sb_bsize = be32_to_cpu(str->sb_bsize);
184 sb->sb_bsize_shift = be32_to_cpu(str->sb_bsize_shift);
185 sb->sb_master_dir.no_addr = be64_to_cpu(str->sb_master_dir.no_addr);
186 sb->sb_master_dir.no_formal_ino = be64_to_cpu(str->sb_master_dir.no_formal_ino);
187 sb->sb_root_dir.no_addr = be64_to_cpu(str->sb_root_dir.no_addr);
188 sb->sb_root_dir.no_formal_ino = be64_to_cpu(str->sb_root_dir.no_formal_ino);
190 memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
191 memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
195 * gfs2_read_super - Read the gfs2 super block from disk
196 * @sdp: The GFS2 super block
197 * @sector: The location of the super block
198 * @error: The error code to return
200 * This uses the bio functions to read the super block from disk
201 * because we want to be 100% sure that we never read cached data.
202 * A super block is read twice only during each GFS2 mount and is
203 * never written to by the filesystem. The first time its read no
204 * locks are held, and the only details which are looked at are those
205 * relating to the locking protocol. Once locking is up and working,
206 * the sb is read again under the lock to establish the location of
207 * the master directory (contains pointers to journals etc) and the
210 * Returns: 0 on success or error
213 int gfs2_read_super(struct gfs2_sbd *sdp, sector_t sector)
215 struct super_block *sb = sdp->sd_vfs;
220 page = alloc_page(GFP_KERNEL);
224 ClearPageUptodate(page);
225 ClearPageDirty(page);
228 bio = bio_alloc(GFP_KERNEL, 1);
229 if (unlikely(!bio)) {
234 bio->bi_sector = sector * (sb->s_blocksize >> 9);
235 bio->bi_bdev = sb->s_bdev;
236 bio_add_page(bio, page, PAGE_SIZE, 0);
238 bio->bi_end_io = end_bio_io_page;
239 bio->bi_private = page;
240 submit_bio(READ_SYNC | (1 << BIO_RW_META), bio);
241 wait_on_page_locked(page);
243 if (!PageUptodate(page)) {
248 gfs2_sb_in(&sdp->sd_sb, p);
255 * gfs2_read_sb - Read super block
256 * @sdp: The GFS2 superblock
257 * @gl: the glock for the superblock (assumed to be held)
258 * @silent: Don't print message if mount fails
262 int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent)
264 u32 hash_blocks, ind_blocks, leaf_blocks;
269 error = gfs2_read_super(sdp, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift);
272 fs_err(sdp, "can't read superblock\n");
276 error = gfs2_check_sb(sdp, &sdp->sd_sb, silent);
280 sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift -
281 GFS2_BASIC_BLOCK_SHIFT;
282 sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
283 sdp->sd_diptrs = (sdp->sd_sb.sb_bsize -
284 sizeof(struct gfs2_dinode)) / sizeof(u64);
285 sdp->sd_inptrs = (sdp->sd_sb.sb_bsize -
286 sizeof(struct gfs2_meta_header)) / sizeof(u64);
287 sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header);
288 sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2;
289 sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1;
290 sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(u64);
291 sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize -
292 sizeof(struct gfs2_meta_header)) /
293 sizeof(struct gfs2_quota_change);
295 /* Compute maximum reservation required to add a entry to a directory */
297 hash_blocks = DIV_ROUND_UP(sizeof(u64) * (1 << GFS2_DIR_MAX_DEPTH),
301 for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) {
302 tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs);
303 ind_blocks += tmp_blocks;
306 leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH;
308 sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks;
310 sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize -
311 sizeof(struct gfs2_dinode);
312 sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs;
317 space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs;
319 m = do_div(d, sdp->sd_inptrs);
321 if (d != sdp->sd_heightsize[x - 1] || m)
323 sdp->sd_heightsize[x] = space;
325 sdp->sd_max_height = x;
326 gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
328 sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
329 sizeof(struct gfs2_dinode);
330 sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
335 space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
337 m = do_div(d, sdp->sd_inptrs);
339 if (d != sdp->sd_jheightsize[x - 1] || m)
341 sdp->sd_jheightsize[x] = space;
343 sdp->sd_max_jheight = x;
344 gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
350 * gfs2_jindex_hold - Grab a lock on the jindex
351 * @sdp: The GFS2 superblock
352 * @ji_gh: the holder for the jindex glock
354 * This is very similar to the gfs2_rindex_hold() function, except that
355 * in general we hold the jindex lock for longer periods of time and
356 * we grab it far less frequently (in general) then the rgrp lock.
361 int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh)
363 struct gfs2_inode *dip = GFS2_I(sdp->sd_jindex);
366 struct gfs2_jdesc *jd;
371 mutex_lock(&sdp->sd_jindex_mutex);
374 error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, ji_gh);
378 name.len = sprintf(buf, "journal%u", sdp->sd_journals);
379 name.hash = gfs2_disk_hash(name.name, name.len);
381 error = gfs2_dir_check(sdp->sd_jindex, &name, NULL);
382 if (error == -ENOENT) {
387 gfs2_glock_dq_uninit(ji_gh);
393 jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL);
397 jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL);
398 if (!jd->jd_inode || IS_ERR(jd->jd_inode)) {
402 error = PTR_ERR(jd->jd_inode);
407 spin_lock(&sdp->sd_jindex_spin);
408 jd->jd_jid = sdp->sd_journals++;
409 list_add_tail(&jd->jd_list, &sdp->sd_jindex_list);
410 spin_unlock(&sdp->sd_jindex_spin);
413 mutex_unlock(&sdp->sd_jindex_mutex);
419 * gfs2_jindex_free - Clear all the journal index information
420 * @sdp: The GFS2 superblock
424 void gfs2_jindex_free(struct gfs2_sbd *sdp)
426 struct list_head list;
427 struct gfs2_jdesc *jd;
429 spin_lock(&sdp->sd_jindex_spin);
430 list_add(&list, &sdp->sd_jindex_list);
431 list_del_init(&sdp->sd_jindex_list);
432 sdp->sd_journals = 0;
433 spin_unlock(&sdp->sd_jindex_spin);
435 while (!list_empty(&list)) {
436 jd = list_entry(list.next, struct gfs2_jdesc, jd_list);
437 list_del(&jd->jd_list);
443 static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid)
445 struct gfs2_jdesc *jd;
448 list_for_each_entry(jd, head, jd_list) {
449 if (jd->jd_jid == jid) {
461 struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid)
463 struct gfs2_jdesc *jd;
465 spin_lock(&sdp->sd_jindex_spin);
466 jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
467 spin_unlock(&sdp->sd_jindex_spin);
472 void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid)
474 struct gfs2_jdesc *jd;
476 spin_lock(&sdp->sd_jindex_spin);
477 jd = jdesc_find_i(&sdp->sd_jindex_list, jid);
480 spin_unlock(&sdp->sd_jindex_spin);
483 struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp)
485 struct gfs2_jdesc *jd;
488 spin_lock(&sdp->sd_jindex_spin);
490 list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
497 spin_unlock(&sdp->sd_jindex_spin);
505 int gfs2_jdesc_check(struct gfs2_jdesc *jd)
507 struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
508 struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
512 if (ip->i_di.di_size < (8 << 20) || ip->i_di.di_size > (1 << 30) ||
513 (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) {
514 gfs2_consist_inode(ip);
517 jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift;
519 error = gfs2_write_alloc_required(ip, 0, ip->i_di.di_size, &ar);
521 gfs2_consist_inode(ip);
529 * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one
530 * @sdp: the filesystem
535 int gfs2_make_fs_rw(struct gfs2_sbd *sdp)
537 struct gfs2_inode *ip = GFS2_I(sdp->sd_jdesc->jd_inode);
538 struct gfs2_glock *j_gl = ip->i_gl;
539 struct gfs2_holder t_gh;
540 struct gfs2_log_header_host head;
543 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, 0, &t_gh);
547 gfs2_meta_cache_flush(ip);
548 j_gl->gl_ops->go_inval(j_gl, DIO_METADATA);
550 error = gfs2_find_jhead(sdp->sd_jdesc, &head);
554 if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
560 /* Initialize some head of the log stuff */
561 sdp->sd_log_sequence = head.lh_sequence + 1;
562 gfs2_log_pointers_init(sdp, head.lh_blkno);
564 error = gfs2_quota_init(sdp);
568 set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
570 gfs2_glock_dq_uninit(&t_gh);
575 t_gh.gh_flags |= GL_NOCACHE;
576 gfs2_glock_dq_uninit(&t_gh);
582 * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one
583 * @sdp: the filesystem
588 int gfs2_make_fs_ro(struct gfs2_sbd *sdp)
590 struct gfs2_holder t_gh;
593 gfs2_quota_sync(sdp);
594 gfs2_statfs_sync(sdp);
596 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, GL_NOCACHE,
598 if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags))
601 gfs2_meta_syncfs(sdp);
602 gfs2_log_shutdown(sdp);
604 clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
607 gfs2_glock_dq_uninit(&t_gh);
609 gfs2_quota_cleanup(sdp);
614 static void gfs2_statfs_change_in(struct gfs2_statfs_change_host *sc, const void *buf)
616 const struct gfs2_statfs_change *str = buf;
618 sc->sc_total = be64_to_cpu(str->sc_total);
619 sc->sc_free = be64_to_cpu(str->sc_free);
620 sc->sc_dinodes = be64_to_cpu(str->sc_dinodes);
623 static void gfs2_statfs_change_out(const struct gfs2_statfs_change_host *sc, void *buf)
625 struct gfs2_statfs_change *str = buf;
627 str->sc_total = cpu_to_be64(sc->sc_total);
628 str->sc_free = cpu_to_be64(sc->sc_free);
629 str->sc_dinodes = cpu_to_be64(sc->sc_dinodes);
632 int gfs2_statfs_init(struct gfs2_sbd *sdp)
634 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
635 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
636 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
637 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
638 struct buffer_head *m_bh, *l_bh;
639 struct gfs2_holder gh;
642 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
647 error = gfs2_meta_inode_buffer(m_ip, &m_bh);
651 if (sdp->sd_args.ar_spectator) {
652 spin_lock(&sdp->sd_statfs_spin);
653 gfs2_statfs_change_in(m_sc, m_bh->b_data +
654 sizeof(struct gfs2_dinode));
655 spin_unlock(&sdp->sd_statfs_spin);
657 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
661 spin_lock(&sdp->sd_statfs_spin);
662 gfs2_statfs_change_in(m_sc, m_bh->b_data +
663 sizeof(struct gfs2_dinode));
664 gfs2_statfs_change_in(l_sc, l_bh->b_data +
665 sizeof(struct gfs2_dinode));
666 spin_unlock(&sdp->sd_statfs_spin);
674 gfs2_glock_dq_uninit(&gh);
678 void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
681 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
682 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
683 struct buffer_head *l_bh;
686 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
690 mutex_lock(&sdp->sd_statfs_mutex);
691 gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
692 mutex_unlock(&sdp->sd_statfs_mutex);
694 spin_lock(&sdp->sd_statfs_spin);
695 l_sc->sc_total += total;
696 l_sc->sc_free += free;
697 l_sc->sc_dinodes += dinodes;
698 gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
699 spin_unlock(&sdp->sd_statfs_spin);
704 int gfs2_statfs_sync(struct gfs2_sbd *sdp)
706 struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
707 struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
708 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
709 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
710 struct gfs2_holder gh;
711 struct buffer_head *m_bh, *l_bh;
714 error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE,
719 error = gfs2_meta_inode_buffer(m_ip, &m_bh);
723 spin_lock(&sdp->sd_statfs_spin);
724 gfs2_statfs_change_in(m_sc, m_bh->b_data +
725 sizeof(struct gfs2_dinode));
726 if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) {
727 spin_unlock(&sdp->sd_statfs_spin);
730 spin_unlock(&sdp->sd_statfs_spin);
732 error = gfs2_meta_inode_buffer(l_ip, &l_bh);
736 error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0);
740 mutex_lock(&sdp->sd_statfs_mutex);
741 gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1);
742 mutex_unlock(&sdp->sd_statfs_mutex);
744 spin_lock(&sdp->sd_statfs_spin);
745 m_sc->sc_total += l_sc->sc_total;
746 m_sc->sc_free += l_sc->sc_free;
747 m_sc->sc_dinodes += l_sc->sc_dinodes;
748 memset(l_sc, 0, sizeof(struct gfs2_statfs_change));
749 memset(l_bh->b_data + sizeof(struct gfs2_dinode),
750 0, sizeof(struct gfs2_statfs_change));
751 spin_unlock(&sdp->sd_statfs_spin);
753 gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1);
754 gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode));
763 gfs2_glock_dq_uninit(&gh);
768 * gfs2_statfs_i - Do a statfs
769 * @sdp: the filesystem
770 * @sg: the sg structure
775 int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
777 struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
778 struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
780 spin_lock(&sdp->sd_statfs_spin);
783 sc->sc_total += l_sc->sc_total;
784 sc->sc_free += l_sc->sc_free;
785 sc->sc_dinodes += l_sc->sc_dinodes;
787 spin_unlock(&sdp->sd_statfs_spin);
791 if (sc->sc_free > sc->sc_total)
792 sc->sc_free = sc->sc_total;
793 if (sc->sc_dinodes < 0)
800 * statfs_fill - fill in the sg for a given RG
802 * @sc: the sc structure
804 * Returns: 0 on success, -ESTALE if the LVB is invalid
807 static int statfs_slow_fill(struct gfs2_rgrpd *rgd,
808 struct gfs2_statfs_change_host *sc)
810 gfs2_rgrp_verify(rgd);
811 sc->sc_total += rgd->rd_data;
812 sc->sc_free += rgd->rd_rg.rg_free;
813 sc->sc_dinodes += rgd->rd_rg.rg_dinodes;
818 * gfs2_statfs_slow - Stat a filesystem using asynchronous locking
819 * @sdp: the filesystem
820 * @sc: the sc info that will be returned
822 * Any error (other than a signal) will cause this routine to fall back
823 * to the synchronous version.
825 * FIXME: This really shouldn't busy wait like this.
830 int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change_host *sc)
832 struct gfs2_holder ri_gh;
833 struct gfs2_rgrpd *rgd_next;
834 struct gfs2_holder *gha, *gh;
835 unsigned int slots = 64;
840 memset(sc, 0, sizeof(struct gfs2_statfs_change_host));
841 gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL);
845 error = gfs2_rindex_hold(sdp, &ri_gh);
849 rgd_next = gfs2_rgrpd_get_first(sdp);
854 for (x = 0; x < slots; x++) {
857 if (gh->gh_gl && gfs2_glock_poll(gh)) {
858 err = gfs2_glock_wait(gh);
860 gfs2_holder_uninit(gh);
864 error = statfs_slow_fill(
865 gh->gh_gl->gl_object, sc);
866 gfs2_glock_dq_uninit(gh);
872 else if (rgd_next && !error) {
873 error = gfs2_glock_nq_init(rgd_next->rd_gl,
877 rgd_next = gfs2_rgrpd_get_next(rgd_next);
881 if (signal_pending(current))
882 error = -ERESTARTSYS;
891 gfs2_glock_dq_uninit(&ri_gh);
899 struct list_head list;
900 struct gfs2_holder gh;
904 * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all
906 * @sdp: the file system
907 * @state: the state to put the transaction lock into
908 * @t_gh: the hold on the transaction lock
913 static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp,
914 struct gfs2_holder *t_gh)
916 struct gfs2_inode *ip;
917 struct gfs2_holder ji_gh;
918 struct gfs2_jdesc *jd;
921 struct gfs2_log_header_host lh;
924 error = gfs2_jindex_hold(sdp, &ji_gh);
928 list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
929 lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL);
934 ip = GFS2_I(jd->jd_inode);
935 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &lfcc->gh);
940 list_add(&lfcc->list, &list);
943 error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED,
944 LM_FLAG_PRIORITY | GL_NOCACHE,
947 list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) {
948 error = gfs2_jdesc_check(jd);
951 error = gfs2_find_jhead(jd, &lh);
954 if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
961 gfs2_glock_dq_uninit(t_gh);
964 while (!list_empty(&list)) {
965 lfcc = list_entry(list.next, struct lfcc, list);
966 list_del(&lfcc->list);
967 gfs2_glock_dq_uninit(&lfcc->gh);
970 gfs2_glock_dq_uninit(&ji_gh);
975 * gfs2_freeze_fs - freezes the file system
976 * @sdp: the file system
978 * This function flushes data and meta data for all machines by
979 * aquiring the transaction log exclusively. All journals are
980 * ensured to be in a clean state as well.
985 int gfs2_freeze_fs(struct gfs2_sbd *sdp)
989 mutex_lock(&sdp->sd_freeze_lock);
991 if (!sdp->sd_freeze_count++) {
992 error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh);
994 sdp->sd_freeze_count--;
997 mutex_unlock(&sdp->sd_freeze_lock);
1003 * gfs2_unfreeze_fs - unfreezes the file system
1004 * @sdp: the file system
1006 * This function allows the file system to proceed by unlocking
1007 * the exclusively held transaction lock. Other GFS2 nodes are
1008 * now free to acquire the lock shared and go on with their lives.
1012 void gfs2_unfreeze_fs(struct gfs2_sbd *sdp)
1014 mutex_lock(&sdp->sd_freeze_lock);
1016 if (sdp->sd_freeze_count && !--sdp->sd_freeze_count)
1017 gfs2_glock_dq_uninit(&sdp->sd_freeze_gh);
1019 mutex_unlock(&sdp->sd_freeze_lock);