diff options
Diffstat (limited to 'fs/gfs2/super.c')
| -rw-r--r-- | fs/gfs2/super.c | 945 |
1 files changed, 945 insertions, 0 deletions
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c new file mode 100644 index 000000000000..a943a505bc5a --- /dev/null +++ b/fs/gfs2/super.c @@ -0,0 +1,945 @@ +/* + * 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 v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/crc32.h> +#include <linux/gfs2_ondisk.h> + +#include "gfs2.h" +#include "lm_interface.h" +#include "incore.h" +#include "bmap.h" +#include "dir.h" +#include "format.h" +#include "glock.h" +#include "glops.h" +#include "inode.h" +#include "log.h" +#include "meta_io.h" +#include "quota.h" +#include "recovery.h" +#include "rgrp.h" +#include "super.h" +#include "trans.h" +#include "unlinked.h" +#include "util.h" + +/** + * gfs2_tune_init - Fill a gfs2_tune structure with default values + * @gt: tune + * + */ + +void gfs2_tune_init(struct gfs2_tune *gt) +{ + spin_lock_init(>->gt_spin); + + gt->gt_ilimit = 100; + gt->gt_ilimit_tries = 3; + gt->gt_ilimit_min = 1; + gt->gt_demote_secs = 300; + gt->gt_incore_log_blocks = 1024; + gt->gt_log_flush_secs = 60; + gt->gt_jindex_refresh_secs = 60; + gt->gt_scand_secs = 15; + gt->gt_recoverd_secs = 60; + gt->gt_logd_secs = 1; + gt->gt_quotad_secs = 5; + gt->gt_inoded_secs = 15; + gt->gt_quota_simul_sync = 64; + gt->gt_quota_warn_period = 10; + gt->gt_quota_scale_num = 1; + gt->gt_quota_scale_den = 1; + gt->gt_quota_cache_secs = 300; + gt->gt_quota_quantum = 60; + gt->gt_atime_quantum = 3600; + gt->gt_new_files_jdata = 0; + gt->gt_new_files_directio = 0; + gt->gt_max_atomic_write = 4 << 20; + gt->gt_max_readahead = 1 << 18; + gt->gt_lockdump_size = 131072; + gt->gt_stall_secs = 600; + gt->gt_complain_secs = 10; + gt->gt_reclaim_limit = 5000; + gt->gt_entries_per_readdir = 32; + gt->gt_prefetch_secs = 10; + gt->gt_greedy_default = HZ / 10; + gt->gt_greedy_quantum = HZ / 40; + gt->gt_greedy_max = HZ / 4; + gt->gt_statfs_quantum = 30; + gt->gt_statfs_slow = 0; +} + +/** + * gfs2_check_sb - Check superblock + * @sdp: the filesystem + * @sb: The superblock + * @silent: Don't print a message if the check fails + * + * Checks the version code of the FS is one that we understand how to + * read and that the sizes of the various on-disk structures have not + * changed. + */ + +int gfs2_check_sb(struct gfs2_sbd *sdp, struct gfs2_sb *sb, int silent) +{ + unsigned int x; + + if (sb->sb_header.mh_magic != GFS2_MAGIC || + sb->sb_header.mh_type != GFS2_METATYPE_SB) { + if (!silent) + printk(KERN_WARNING "GFS2: not a GFS2 filesystem\n"); + return -EINVAL; + } + + /* If format numbers match exactly, we're done. */ + + if (sb->sb_fs_format == GFS2_FORMAT_FS && + sb->sb_multihost_format == GFS2_FORMAT_MULTI) + return 0; + + if (sb->sb_fs_format != GFS2_FORMAT_FS) { + for (x = 0; gfs2_old_fs_formats[x]; x++) + if (gfs2_old_fs_formats[x] == sb->sb_fs_format) + break; + + if (!gfs2_old_fs_formats[x]) { + printk(KERN_WARNING + "GFS2: code version (%u, %u) is incompatible " + "with ondisk format (%u, %u)\n", + GFS2_FORMAT_FS, GFS2_FORMAT_MULTI, + sb->sb_fs_format, sb->sb_multihost_format); + printk(KERN_WARNING + "GFS2: I don't know how to upgrade this FS\n"); + return -EINVAL; + } + } + + if (sb->sb_multihost_format != GFS2_FORMAT_MULTI) { + for (x = 0; gfs2_old_multihost_formats[x]; x++) + if (gfs2_old_multihost_formats[x] == + sb->sb_multihost_format) + break; + + if (!gfs2_old_multihost_formats[x]) { + printk(KERN_WARNING + "GFS2: code version (%u, %u) is incompatible " + "with ondisk format (%u, %u)\n", + GFS2_FORMAT_FS, GFS2_FORMAT_MULTI, + sb->sb_fs_format, sb->sb_multihost_format); + printk(KERN_WARNING + "GFS2: I don't know how to upgrade this FS\n"); + return -EINVAL; + } + } + + if (!sdp->sd_args.ar_upgrade) { + printk(KERN_WARNING + "GFS2: code version (%u, %u) is incompatible " + "with ondisk format (%u, %u)\n", + GFS2_FORMAT_FS, GFS2_FORMAT_MULTI, + sb->sb_fs_format, sb->sb_multihost_format); + printk(KERN_INFO + "GFS2: Use the \"upgrade\" mount option to upgrade " + "the FS\n"); + printk(KERN_INFO "GFS2: See the manual for more details\n"); + return -EINVAL; + } + + return 0; +} + +/** + * gfs2_read_sb - Read super block + * @sdp: The GFS2 superblock + * @gl: the glock for the superblock (assumed to be held) + * @silent: Don't print message if mount fails + * + */ + +int gfs2_read_sb(struct gfs2_sbd *sdp, struct gfs2_glock *gl, int silent) +{ + struct buffer_head *bh; + uint32_t hash_blocks, ind_blocks, leaf_blocks; + uint32_t tmp_blocks; + unsigned int x; + int error; + + error = gfs2_meta_read(gl, GFS2_SB_ADDR >> sdp->sd_fsb2bb_shift, + DIO_FORCE | DIO_START | DIO_WAIT, &bh); + if (error) { + if (!silent) + fs_err(sdp, "can't read superblock\n"); + return error; + } + + gfs2_assert(sdp, sizeof(struct gfs2_sb) <= bh->b_size); + gfs2_sb_in(&sdp->sd_sb, bh->b_data); + brelse(bh); + + error = gfs2_check_sb(sdp, &sdp->sd_sb, silent); + if (error) + return error; + + sdp->sd_fsb2bb_shift = sdp->sd_sb.sb_bsize_shift - + GFS2_BASIC_BLOCK_SHIFT; + sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift; + sdp->sd_diptrs = (sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_dinode)) / sizeof(uint64_t); + sdp->sd_inptrs = (sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_meta_header)) / sizeof(uint64_t); + sdp->sd_jbsize = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header); + sdp->sd_hash_bsize = sdp->sd_sb.sb_bsize / 2; + sdp->sd_hash_bsize_shift = sdp->sd_sb.sb_bsize_shift - 1; + sdp->sd_hash_ptrs = sdp->sd_hash_bsize / sizeof(uint64_t); + sdp->sd_ut_per_block = (sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_meta_header)) / + sizeof(struct gfs2_unlinked_tag); + sdp->sd_qc_per_block = (sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_meta_header)) / + sizeof(struct gfs2_quota_change); + + /* Compute maximum reservation required to add a entry to a directory */ + + hash_blocks = DIV_ROUND_UP(sizeof(uint64_t) * (1 << GFS2_DIR_MAX_DEPTH), + sdp->sd_jbsize); + + ind_blocks = 0; + for (tmp_blocks = hash_blocks; tmp_blocks > sdp->sd_diptrs;) { + tmp_blocks = DIV_ROUND_UP(tmp_blocks, sdp->sd_inptrs); + ind_blocks += tmp_blocks; + } + + leaf_blocks = 2 + GFS2_DIR_MAX_DEPTH; + + sdp->sd_max_dirres = hash_blocks + ind_blocks + leaf_blocks; + + sdp->sd_heightsize[0] = sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_dinode); + sdp->sd_heightsize[1] = sdp->sd_sb.sb_bsize * sdp->sd_diptrs; + for (x = 2;; x++) { + uint64_t space, d; + uint32_t m; + + space = sdp->sd_heightsize[x - 1] * sdp->sd_inptrs; + d = space; + m = do_div(d, sdp->sd_inptrs); + + if (d != sdp->sd_heightsize[x - 1] || m) + break; + sdp->sd_heightsize[x] = space; + } + sdp->sd_max_height = x; + gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT); + + sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize - + sizeof(struct gfs2_dinode); + sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs; + for (x = 2;; x++) { + uint64_t space, d; + uint32_t m; + + space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs; + d = space; + m = do_div(d, sdp->sd_inptrs); + + if (d != sdp->sd_jheightsize[x - 1] || m) + break; + sdp->sd_jheightsize[x] = space; + } + sdp->sd_max_jheight = x; + gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT); + + return 0; +} + +/** + * gfs2_jindex_hold - Grab a lock on the jindex + * @sdp: The GFS2 superblock + * @ji_gh: the holder for the jindex glock + * + * This is very similar to the gfs2_rindex_hold() function, except that + * in general we hold the jindex lock for longer periods of time and + * we grab it far less frequently (in general) then the rgrp lock. + * + * Returns: errno + */ + +int gfs2_jindex_hold(struct gfs2_sbd *sdp, struct gfs2_holder *ji_gh) +{ + struct gfs2_inode *dip = sdp->sd_jindex->u.generic_ip; + struct qstr name; + char buf[20]; + struct gfs2_jdesc *jd; + int error; + + name.name = buf; + + mutex_lock(&sdp->sd_jindex_mutex); + + for (;;) { + error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, + GL_LOCAL_EXCL, ji_gh); + if (error) + break; + + name.len = sprintf(buf, "journal%u", sdp->sd_journals); + name.hash = gfs2_disk_hash(name.name, name.len); + + error = gfs2_dir_search(sdp->sd_jindex, + &name, NULL, NULL); + if (error == -ENOENT) { + error = 0; + break; + } + + gfs2_glock_dq_uninit(ji_gh); + + if (error) + break; + + error = -ENOMEM; + jd = kzalloc(sizeof(struct gfs2_jdesc), GFP_KERNEL); + if (!jd) + break; + + jd->jd_inode = gfs2_lookupi(sdp->sd_jindex, &name, 1, NULL); + if (!jd->jd_inode || IS_ERR(jd->jd_inode)) { + if (!jd->jd_inode) + error = -ENOENT; + else + error = PTR_ERR(jd->jd_inode); + kfree(jd); + break; + } + + spin_lock(&sdp->sd_jindex_spin); + jd->jd_jid = sdp->sd_journals++; + list_add_tail(&jd->jd_list, &sdp->sd_jindex_list); + spin_unlock(&sdp->sd_jindex_spin); + } + + mutex_unlock(&sdp->sd_jindex_mutex); + + return error; +} + +/** + * gfs2_jindex_free - Clear all the journal index information + * @sdp: The GFS2 superblock + * + */ + +void gfs2_jindex_free(struct gfs2_sbd *sdp) +{ + struct list_head list; + struct gfs2_jdesc *jd; + + spin_lock(&sdp->sd_jindex_spin); + list_add(&list, &sdp->sd_jindex_list); + list_del_init(&sdp->sd_jindex_list); + sdp->sd_journals = 0; + spin_unlock(&sdp->sd_jindex_spin); + + while (!list_empty(&list)) { + jd = list_entry(list.next, struct gfs2_jdesc, jd_list); + list_del(&jd->jd_list); + iput(jd->jd_inode); + kfree(jd); + } +} + +static struct gfs2_jdesc *jdesc_find_i(struct list_head *head, unsigned int jid) +{ + struct gfs2_jdesc *jd; + int found = 0; + + list_for_each_entry(jd, head, jd_list) { + if (jd->jd_jid == jid) { + found = 1; + break; + } + } + + if (!found) + jd = NULL; + + return jd; +} + +struct gfs2_jdesc *gfs2_jdesc_find(struct gfs2_sbd *sdp, unsigned int jid) +{ + struct gfs2_jdesc *jd; + + spin_lock(&sdp->sd_jindex_spin); + jd = jdesc_find_i(&sdp->sd_jindex_list, jid); + spin_unlock(&sdp->sd_jindex_spin); + + return jd; +} + +void gfs2_jdesc_make_dirty(struct gfs2_sbd *sdp, unsigned int jid) +{ + struct gfs2_jdesc *jd; + + spin_lock(&sdp->sd_jindex_spin); + jd = jdesc_find_i(&sdp->sd_jindex_list, jid); + if (jd) + jd->jd_dirty = 1; + spin_unlock(&sdp->sd_jindex_spin); +} + +struct gfs2_jdesc *gfs2_jdesc_find_dirty(struct gfs2_sbd *sdp) +{ + struct gfs2_jdesc *jd; + int found = 0; + + spin_lock(&sdp->sd_jindex_spin); + + list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) { + if (jd->jd_dirty) { + jd->jd_dirty = 0; + found = 1; + break; + } + } + spin_unlock(&sdp->sd_jindex_spin); + + if (!found) + jd = NULL; + + return jd; +} + +int gfs2_jdesc_check(struct gfs2_jdesc *jd) +{ + struct gfs2_inode *ip = jd->jd_inode->u.generic_ip; + struct gfs2_sbd *sdp = ip->i_sbd; + int ar; + int error; + + if (ip->i_di.di_size < (8 << 20) || + ip->i_di.di_size > (1 << 30) || + (ip->i_di.di_size & (sdp->sd_sb.sb_bsize - 1))) { + gfs2_consist_inode(ip); + return -EIO; + } + jd->jd_blocks = ip->i_di.di_size >> sdp->sd_sb.sb_bsize_shift; + + error = gfs2_write_alloc_required(ip, + 0, ip->i_di.di_size, + &ar); + if (!error && ar) { + gfs2_consist_inode(ip); + error = -EIO; + } + + return error; +} + +/** + * gfs2_make_fs_rw - Turn a Read-Only FS into a Read-Write one + * @sdp: the filesystem + * + * Returns: errno + */ + +int gfs2_make_fs_rw(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *ip = sdp->sd_jdesc->jd_inode->u.generic_ip; + struct gfs2_glock *j_gl = ip->i_gl; + struct gfs2_holder t_gh; + struct gfs2_log_header head; + int error; + + error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, + GL_LOCAL_EXCL, &t_gh); + if (error) + return error; + + gfs2_meta_cache_flush(ip); + j_gl->gl_ops->go_inval(j_gl, DIO_METADATA | DIO_DATA); + + error = gfs2_find_jhead(sdp->sd_jdesc, &head); + if (error) + goto fail; + + if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) { + gfs2_consist(sdp); + error = -EIO; + goto fail; + } + + /* Initialize some head of the log stuff */ + sdp->sd_log_sequence = head.lh_sequence + 1; + gfs2_log_pointers_init(sdp, head.lh_blkno); + + error = gfs2_unlinked_init(sdp); + if (error) + goto fail; + error = gfs2_quota_init(sdp); + if (error) + goto fail_unlinked; + + set_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); + + gfs2_glock_dq_uninit(&t_gh); + + return 0; + + fail_unlinked: + gfs2_unlinked_cleanup(sdp); + + fail: + t_gh.gh_flags |= GL_NOCACHE; + gfs2_glock_dq_uninit(&t_gh); + + return error; +} + +/** + * gfs2_make_fs_ro - Turn a Read-Write FS into a Read-Only one + * @sdp: the filesystem + * + * Returns: errno + */ + +int gfs2_make_fs_ro(struct gfs2_sbd *sdp) +{ + struct gfs2_holder t_gh; + int error; + + gfs2_unlinked_dealloc(sdp); + gfs2_quota_sync(sdp); + gfs2_statfs_sync(sdp); + + error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_SHARED, + GL_LOCAL_EXCL | GL_NOCACHE, + &t_gh); + if (error && !test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) + return error; + + gfs2_meta_syncfs(sdp); + gfs2_log_shutdown(sdp); + + clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); + + if (t_gh.gh_gl) + gfs2_glock_dq_uninit(&t_gh); + + gfs2_unlinked_cleanup(sdp); + gfs2_quota_cleanup(sdp); + + return error; +} + +int gfs2_statfs_init(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *m_ip = sdp->sd_statfs_inode->u.generic_ip; + struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master; + struct gfs2_inode *l_ip = sdp->sd_sc_inode->u.generic_ip; + struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local; + struct buffer_head *m_bh, *l_bh; + struct gfs2_holder gh; + int error; + + error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE, + &gh); + if (error) + return error; + + error = gfs2_meta_inode_buffer(m_ip, &m_bh); + if (error) + goto out; + + if (sdp->sd_args.ar_spectator) { + spin_lock(&sdp->sd_statfs_spin); + gfs2_statfs_change_in(m_sc, m_bh->b_data + + sizeof(struct gfs2_dinode)); + spin_unlock(&sdp->sd_statfs_spin); + } else { + error = gfs2_meta_inode_buffer(l_ip, &l_bh); + if (error) + goto out_m_bh; + + spin_lock(&sdp->sd_statfs_spin); + gfs2_statfs_change_in(m_sc, m_bh->b_data + + sizeof(struct gfs2_dinode)); + gfs2_statfs_change_in(l_sc, l_bh->b_data + + sizeof(struct gfs2_dinode)); + spin_unlock(&sdp->sd_statfs_spin); + + brelse(l_bh); + } + + out_m_bh: + brelse(m_bh); + + out: + gfs2_glock_dq_uninit(&gh); + + return 0; +} + +void gfs2_statfs_change(struct gfs2_sbd *sdp, int64_t total, int64_t free, + int64_t dinodes) +{ + struct gfs2_inode *l_ip = sdp->sd_sc_inode->u.generic_ip; + struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local; + struct buffer_head *l_bh; + int error; + + error = gfs2_meta_inode_buffer(l_ip, &l_bh); + if (error) + return; + + mutex_lock(&sdp->sd_statfs_mutex); + gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1); + mutex_unlock(&sdp->sd_statfs_mutex); + + spin_lock(&sdp->sd_statfs_spin); + l_sc->sc_total += total; + l_sc->sc_free += free; + l_sc->sc_dinodes += dinodes; + gfs2_statfs_change_out(l_sc, l_bh->b_data + + sizeof(struct gfs2_dinode)); + spin_unlock(&sdp->sd_statfs_spin); + + brelse(l_bh); +} + +int gfs2_statfs_sync(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *m_ip = sdp->sd_statfs_inode->u.generic_ip; + struct gfs2_inode *l_ip = sdp->sd_sc_inode->u.generic_ip; + struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master; + struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local; + struct gfs2_holder gh; + struct buffer_head *m_bh, *l_bh; + int error; + + error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE, GL_NOCACHE, + &gh); + if (error) + return error; + + error = gfs2_meta_inode_buffer(m_ip, &m_bh); + if (error) + goto out; + + spin_lock(&sdp->sd_statfs_spin); + gfs2_statfs_change_in(m_sc, m_bh->b_data + + sizeof(struct gfs2_dinode)); + if (!l_sc->sc_total && !l_sc->sc_free && !l_sc->sc_dinodes) { + spin_unlock(&sdp->sd_statfs_spin); + goto out_bh; + } + spin_unlock(&sdp->sd_statfs_spin); + + error = gfs2_meta_inode_buffer(l_ip, &l_bh); + if (error) + goto out_bh; + + error = gfs2_trans_begin(sdp, 2 * RES_DINODE, 0); + if (error) + goto out_bh2; + + mutex_lock(&sdp->sd_statfs_mutex); + gfs2_trans_add_bh(l_ip->i_gl, l_bh, 1); + mutex_unlock(&sdp->sd_statfs_mutex); + + spin_lock(&sdp->sd_statfs_spin); + m_sc->sc_total += l_sc->sc_total; + m_sc->sc_free += l_sc->sc_free; + m_sc->sc_dinodes += l_sc->sc_dinodes; + memset(l_sc, 0, sizeof(struct gfs2_statfs_change)); + memset(l_bh->b_data + sizeof(struct gfs2_dinode), + 0, sizeof(struct gfs2_statfs_change)); + spin_unlock(&sdp->sd_statfs_spin); + + gfs2_trans_add_bh(m_ip->i_gl, m_bh, 1); + gfs2_statfs_change_out(m_sc, m_bh->b_data + sizeof(struct gfs2_dinode)); + + gfs2_trans_end(sdp); + + out_bh2: + brelse(l_bh); + + out_bh: + brelse(m_bh); + + out: + gfs2_glock_dq_uninit(&gh); + + return error; +} + +/** + * gfs2_statfs_i - Do a statfs + * @sdp: the filesystem + * @sg: the sg structure + * + * Returns: errno + */ + +int gfs2_statfs_i(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc) +{ + struct gfs2_statfs_change *m_sc = &sdp->sd_statfs_master; + struct gfs2_statfs_change *l_sc = &sdp->sd_statfs_local; + + spin_lock(&sdp->sd_statfs_spin); + + *sc = *m_sc; + sc->sc_total += l_sc->sc_total; + sc->sc_free += l_sc->sc_free; + sc->sc_dinodes += l_sc->sc_dinodes; + + spin_unlock(&sdp->sd_statfs_spin); + + if (sc->sc_free < 0) + sc->sc_free = 0; + if (sc->sc_free > sc->sc_total) + sc->sc_free = sc->sc_total; + if (sc->sc_dinodes < 0) + sc->sc_dinodes = 0; + + return 0; +} + +/** + * statfs_fill - fill in the sg for a given RG + * @rgd: the RG + * @sc: the sc structure + * + * Returns: 0 on success, -ESTALE if the LVB is invalid + */ + +static int statfs_slow_fill(struct gfs2_rgrpd *rgd, + struct gfs2_statfs_change *sc) +{ + gfs2_rgrp_verify(rgd); + sc->sc_total += rgd->rd_ri.ri_data; + sc->sc_free += rgd->rd_rg.rg_free; + sc->sc_dinodes += rgd->rd_rg.rg_dinodes; + return 0; +} + +/** + * gfs2_statfs_slow - Stat a filesystem using asynchronous locking + * @sdp: the filesystem + * @sc: the sc info that will be returned + * + * Any error (other than a signal) will cause this routine to fall back + * to the synchronous version. + * + * FIXME: This really shouldn't busy wait like this. + * + * Returns: errno + */ + +int gfs2_statfs_slow(struct gfs2_sbd *sdp, struct gfs2_statfs_change *sc) +{ + struct gfs2_holder ri_gh; + struct gfs2_rgrpd *rgd_next; + struct gfs2_holder *gha, *gh; + unsigned int slots = 64; + unsigned int x; + int done; + int error = 0, err; + + memset(sc, 0, sizeof(struct gfs2_statfs_change)); + gha = kcalloc(slots, sizeof(struct gfs2_holder), GFP_KERNEL); + if (!gha) + return -ENOMEM; + + error = gfs2_rindex_hold(sdp, &ri_gh); + if (error) + goto out; + + rgd_next = gfs2_rgrpd_get_first(sdp); + + for (;;) { + done = 1; + + for (x = 0; x < slots; x++) { + gh = gha + x; + + if (gh->gh_gl && gfs2_glock_poll(gh)) { + err = gfs2_glock_wait(gh); + if (err) { + gfs2_holder_uninit(gh); + error = err; + } else { + if (!error) + error = statfs_slow_fill( + gh->gh_gl->gl_object, sc); + gfs2_glock_dq_uninit(gh); + } + } + + if (gh->gh_gl) + done = 0; + else if (rgd_next && !error) { + error = gfs2_glock_nq_init(rgd_next->rd_gl, + LM_ST_SHARED, + GL_ASYNC, + gh); + rgd_next = gfs2_rgrpd_get_next(rgd_next); + done = 0; + } + + if (signal_pending(current)) + error = -ERESTARTSYS; + } + + if (done) + break; + + yield(); + } + + gfs2_glock_dq_uninit(&ri_gh); + + out: + kfree(gha); + + return error; +} + +struct lfcc { + struct list_head list; + struct gfs2_holder gh; +}; + +/** + * gfs2_lock_fs_check_clean - Stop all writes to the FS and check that all + * journals are clean + * @sdp: the file system + * @state: the state to put the transaction lock into + * @t_gh: the hold on the transaction lock + * + * Returns: errno + */ + +static int gfs2_lock_fs_check_clean(struct gfs2_sbd *sdp, + struct gfs2_holder *t_gh) +{ + struct gfs2_inode *ip; + struct gfs2_holder ji_gh; + struct gfs2_jdesc *jd; + struct lfcc *lfcc; + LIST_HEAD(list); + struct gfs2_log_header lh; + int error; + + error = gfs2_jindex_hold(sdp, &ji_gh); + if (error) + return error; + + list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) { + lfcc = kmalloc(sizeof(struct lfcc), GFP_KERNEL); + if (!lfcc) { + error = -ENOMEM; + goto out; + } + ip = jd->jd_inode->u.generic_ip; + error = gfs2_glock_nq_init(ip->i_gl, + LM_ST_SHARED, 0, + &lfcc->gh); + if (error) { + kfree(lfcc); + goto out; + } + list_add(&lfcc->list, &list); + } + + error = gfs2_glock_nq_init(sdp->sd_trans_gl, LM_ST_DEFERRED, + LM_FLAG_PRIORITY | GL_NOCACHE, + t_gh); + + list_for_each_entry(jd, &sdp->sd_jindex_list, jd_list) { + error = gfs2_jdesc_check(jd); + if (error) + break; + error = gfs2_find_jhead(jd, &lh); + if (error) + break; + if (!(lh.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) { + error = -EBUSY; + break; + } + } + + if (error) + gfs2_glock_dq_uninit(t_gh); + + out: + while (!list_empty(&list)) { + lfcc = list_entry(list.next, struct lfcc, list); + list_del(&lfcc->list); + gfs2_glock_dq_uninit(&lfcc->gh); + kfree(lfcc); + } + gfs2_glock_dq_uninit(&ji_gh); + + return error; +} + +/** + * gfs2_freeze_fs - freezes the file system + * @sdp: the file system + * + * This function flushes data and meta data for all machines by + * aquiring the transaction log exclusively. All journals are + * ensured to be in a clean state as well. + * + * Returns: errno + */ + +int gfs2_freeze_fs(struct gfs2_sbd *sdp) +{ + int error = 0; + + mutex_lock(&sdp->sd_freeze_lock); + + if (!sdp->sd_freeze_count++) { + error = gfs2_lock_fs_check_clean(sdp, &sdp->sd_freeze_gh); + if (error) + sdp->sd_freeze_count--; + } + + mutex_unlock(&sdp->sd_freeze_lock); + + return error; +} + +/** + * gfs2_unfreeze_fs - unfreezes the file system + * @sdp: the file system + * + * This function allows the file system to proceed by unlocking + * the exclusively held transaction lock. Other GFS2 nodes are + * now free to acquire the lock shared and go on with their lives. + * + */ + +void gfs2_unfreeze_fs(struct gfs2_sbd *sdp) +{ + mutex_lock(&sdp->sd_freeze_lock); + + if (sdp->sd_freeze_count && !--sdp->sd_freeze_count) + gfs2_glock_dq_uninit(&sdp->sd_freeze_gh); + + mutex_unlock(&sdp->sd_freeze_lock); +} + |