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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-19 17:23:53 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-19 17:23:53 +0100 |
commit | e93b1cc8a8965da137ffea0b88e5f62fa1d2a9e6 (patch) | |
tree | 9757e9167daff086a314b031429d9b65a39b96bc /fs/quota | |
parent | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm (diff) | |
parent | quota: Fix bogus warning in dquot_disable() (diff) | |
download | linux-e93b1cc8a8965da137ffea0b88e5f62fa1d2a9e6.tar.xz linux-e93b1cc8a8965da137ffea0b88e5f62fa1d2a9e6.zip |
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota, fsnotify and ext2 updates from Jan Kara:
"Changes to locking of some quota operations from dedicated quota mutex
to s_umount semaphore, a fsnotify fix and a simple ext2 fix"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
quota: Fix bogus warning in dquot_disable()
fsnotify: Fix possible use-after-free in inode iteration on umount
ext2: reject inodes with negative size
quota: Remove dqonoff_mutex
ocfs2: Use s_umount for quota recovery protection
quota: Remove dqonoff_mutex from dquot_scan_active()
ocfs2: Protect periodic quota syncing with s_umount semaphore
quota: Use s_umount protection for quota operations
quota: Hold s_umount in exclusive mode when enabling / disabling quotas
fs: Provide function to get superblock with exclusive s_umount
Diffstat (limited to 'fs/quota')
-rw-r--r-- | fs/quota/dquot.c | 136 | ||||
-rw-r--r-- | fs/quota/quota.c | 22 |
2 files changed, 61 insertions, 97 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 8738a0d62c09..406fed92362a 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -119,8 +119,7 @@ * spinlock to internal buffers before writing. * * Lock ordering (including related VFS locks) is the following: - * dqonoff_mutex > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex - * dqonoff_mutex > i_mutex comes from dquot_quota_sync, dquot_enable, etc. + * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); @@ -572,7 +571,8 @@ int dquot_scan_active(struct super_block *sb, struct dquot *dquot, *old_dquot = NULL; int ret = 0; - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); + WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); + spin_lock(&dq_list_lock); list_for_each_entry(dquot, &inuse_list, dq_inuse) { if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) @@ -603,7 +603,6 @@ int dquot_scan_active(struct super_block *sb, spin_unlock(&dq_list_lock); out: dqput(old_dquot); - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); return ret; } EXPORT_SYMBOL(dquot_scan_active); @@ -617,7 +616,8 @@ int dquot_writeback_dquots(struct super_block *sb, int type) int cnt; int err, ret = 0; - mutex_lock(&dqopt->dqonoff_mutex); + WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; @@ -653,7 +653,6 @@ int dquot_writeback_dquots(struct super_block *sb, int type) && info_dirty(&dqopt->info[cnt])) sb->dq_op->write_info(sb, cnt); dqstats_inc(DQST_SYNCS); - mutex_unlock(&dqopt->dqonoff_mutex); return ret; } @@ -683,7 +682,6 @@ int dquot_quota_sync(struct super_block *sb, int type) * Now when everything is written we can discard the pagecache so * that userspace sees the changes. */ - mutex_lock(&dqopt->dqonoff_mutex); for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; @@ -693,7 +691,6 @@ int dquot_quota_sync(struct super_block *sb, int type) truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); inode_unlock(dqopt->files[cnt]); } - mutex_unlock(&dqopt->dqonoff_mutex); return 0; } @@ -935,7 +932,7 @@ static int dqinit_needed(struct inode *inode, int type) return 0; } -/* This routine is guarded by dqonoff_mutex mutex */ +/* This routine is guarded by s_umount semaphore */ static void add_dquot_ref(struct super_block *sb, int type) { struct inode *inode, *old_inode = NULL; @@ -2050,21 +2047,13 @@ int dquot_get_next_id(struct super_block *sb, struct kqid *qid) struct quota_info *dqopt = sb_dqopt(sb); int err; - mutex_lock(&dqopt->dqonoff_mutex); - if (!sb_has_quota_active(sb, qid->type)) { - err = -ESRCH; - goto out; - } - if (!dqopt->ops[qid->type]->get_next_id) { - err = -ENOSYS; - goto out; - } + if (!sb_has_quota_active(sb, qid->type)) + return -ESRCH; + if (!dqopt->ops[qid->type]->get_next_id) + return -ENOSYS; mutex_lock(&dqopt->dqio_mutex); err = dqopt->ops[qid->type]->get_next_id(sb, qid); mutex_unlock(&dqopt->dqio_mutex); -out: - mutex_unlock(&dqopt->dqonoff_mutex); - return err; } EXPORT_SYMBOL(dquot_get_next_id); @@ -2107,6 +2096,10 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) struct quota_info *dqopt = sb_dqopt(sb); struct inode *toputinode[MAXQUOTAS]; + /* s_umount should be held in exclusive mode */ + if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) + up_read(&sb->s_umount); + /* Cannot turn off usage accounting without turning off limits, or * suspend quotas and simultaneously turn quotas off. */ if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) @@ -2114,18 +2107,14 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) DQUOT_USAGE_ENABLED))) return -EINVAL; - /* We need to serialize quota_off() for device */ - mutex_lock(&dqopt->dqonoff_mutex); - /* * Skip everything if there's nothing to do. We have to do this because * sometimes we are called when fill_super() failed and calling * sync_fs() in such cases does no good. */ - if (!sb_any_quota_loaded(sb)) { - mutex_unlock(&dqopt->dqonoff_mutex); + if (!sb_any_quota_loaded(sb)) return 0; - } + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { toputinode[cnt] = NULL; if (type != -1 && cnt != type) @@ -2179,7 +2168,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) dqopt->info[cnt].dqi_bgrace = 0; dqopt->ops[cnt] = NULL; } - mutex_unlock(&dqopt->dqonoff_mutex); /* Skip syncing and setting flags if quota files are hidden */ if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) @@ -2196,20 +2184,14 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) * must also discard the blockdev buffers so that we see the * changes done by userspace on the next quotaon() */ for (cnt = 0; cnt < MAXQUOTAS; cnt++) - if (toputinode[cnt]) { - mutex_lock(&dqopt->dqonoff_mutex); - /* If quota was reenabled in the meantime, we have - * nothing to do */ - if (!sb_has_quota_loaded(sb, cnt)) { - inode_lock(toputinode[cnt]); - toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | + /* This can happen when suspending quotas on remount-ro... */ + if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { + inode_lock(toputinode[cnt]); + toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | S_NOATIME | S_NOQUOTA); - truncate_inode_pages(&toputinode[cnt]->i_data, - 0); - inode_unlock(toputinode[cnt]); - mark_inode_dirty_sync(toputinode[cnt]); - } - mutex_unlock(&dqopt->dqonoff_mutex); + truncate_inode_pages(&toputinode[cnt]->i_data, 0); + inode_unlock(toputinode[cnt]); + mark_inode_dirty_sync(toputinode[cnt]); } if (sb->s_bdev) invalidate_bdev(sb->s_bdev); @@ -2281,6 +2263,10 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, error = -EINVAL; goto out_fmt; } + if (sb_has_quota_loaded(sb, type)) { + error = -EBUSY; + goto out_fmt; + } if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { /* As we bypass the pagecache we must now flush all the @@ -2292,11 +2278,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, sync_filesystem(sb); invalidate_bdev(sb->s_bdev); } - mutex_lock(&dqopt->dqonoff_mutex); - if (sb_has_quota_loaded(sb, type)) { - error = -EBUSY; - goto out_lock; - } if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { /* We don't want quota and atime on quota files (deadlocks @@ -2317,7 +2298,7 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, error = -EIO; dqopt->files[type] = igrab(inode); if (!dqopt->files[type]) - goto out_lock; + goto out_file_flags; error = -EINVAL; if (!fmt->qf_ops->check_quota_file(sb, type)) goto out_file_init; @@ -2340,14 +2321,13 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, spin_unlock(&dq_state_lock); add_dquot_ref(sb, type); - mutex_unlock(&dqopt->dqonoff_mutex); return 0; out_file_init: dqopt->files[type] = NULL; iput(inode); -out_lock: +out_file_flags: if (oldflags != -1) { inode_lock(inode); /* Set the flags back (in the case of accidental quotaon() @@ -2356,7 +2336,6 @@ out_lock: inode->i_flags |= oldflags; inode_unlock(inode); } - mutex_unlock(&dqopt->dqonoff_mutex); out_fmt: put_quota_format(fmt); @@ -2371,15 +2350,16 @@ int dquot_resume(struct super_block *sb, int type) int ret = 0, cnt; unsigned int flags; + /* s_umount should be held in exclusive mode */ + if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) + up_read(&sb->s_umount); + for (cnt = 0; cnt < MAXQUOTAS; cnt++) { if (type != -1 && cnt != type) continue; - - mutex_lock(&dqopt->dqonoff_mutex); - if (!sb_has_quota_suspended(sb, cnt)) { - mutex_unlock(&dqopt->dqonoff_mutex); + if (!sb_has_quota_suspended(sb, cnt)) continue; - } + inode = dqopt->files[cnt]; dqopt->files[cnt] = NULL; spin_lock(&dq_state_lock); @@ -2388,7 +2368,6 @@ int dquot_resume(struct super_block *sb, int type) cnt); dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); spin_unlock(&dq_state_lock); - mutex_unlock(&dqopt->dqonoff_mutex); flags = dquot_generic_flag(flags, cnt); ret = vfs_load_quota_inode(inode, cnt, @@ -2424,42 +2403,30 @@ EXPORT_SYMBOL(dquot_quota_on); int dquot_enable(struct inode *inode, int type, int format_id, unsigned int flags) { - int ret = 0; struct super_block *sb = inode->i_sb; - struct quota_info *dqopt = sb_dqopt(sb); /* Just unsuspend quotas? */ BUG_ON(flags & DQUOT_SUSPENDED); + /* s_umount should be held in exclusive mode */ + if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) + up_read(&sb->s_umount); if (!flags) return 0; /* Just updating flags needed? */ if (sb_has_quota_loaded(sb, type)) { - mutex_lock(&dqopt->dqonoff_mutex); - /* Now do a reliable test... */ - if (!sb_has_quota_loaded(sb, type)) { - mutex_unlock(&dqopt->dqonoff_mutex); - goto load_quota; - } if (flags & DQUOT_USAGE_ENABLED && - sb_has_quota_usage_enabled(sb, type)) { - ret = -EBUSY; - goto out_lock; - } + sb_has_quota_usage_enabled(sb, type)) + return -EBUSY; if (flags & DQUOT_LIMITS_ENABLED && - sb_has_quota_limits_enabled(sb, type)) { - ret = -EBUSY; - goto out_lock; - } + sb_has_quota_limits_enabled(sb, type)) + return -EBUSY; spin_lock(&dq_state_lock); sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); spin_unlock(&dq_state_lock); -out_lock: - mutex_unlock(&dqopt->dqonoff_mutex); - return ret; + return 0; } -load_quota: return vfs_load_quota_inode(inode, type, format_id, flags); } EXPORT_SYMBOL(dquot_enable); @@ -2751,7 +2718,6 @@ int dquot_get_state(struct super_block *sb, struct qc_state *state) struct quota_info *dqopt = sb_dqopt(sb); int type; - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); memset(state, 0, sizeof(*state)); for (type = 0; type < MAXQUOTAS; type++) { if (!sb_has_quota_active(sb, type)) @@ -2773,7 +2739,6 @@ int dquot_get_state(struct super_block *sb, struct qc_state *state) tstate->nextents = 1; /* We don't know... */ spin_unlock(&dq_data_lock); } - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); return 0; } EXPORT_SYMBOL(dquot_get_state); @@ -2787,18 +2752,13 @@ int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) if ((ii->i_fieldmask & QC_WARNS_MASK) || (ii->i_fieldmask & QC_RT_SPC_TIMER)) return -EINVAL; - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!sb_has_quota_active(sb, type)) { - err = -ESRCH; - goto out; - } + if (!sb_has_quota_active(sb, type)) + return -ESRCH; mi = sb_dqopt(sb)->info + type; if (ii->i_fieldmask & QC_FLAGS) { if ((ii->i_flags & QCI_ROOT_SQUASH && - mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) { - err = -EINVAL; - goto out; - } + mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) + return -EINVAL; } spin_lock(&dq_data_lock); if (ii->i_fieldmask & QC_SPC_TIMER) @@ -2815,8 +2775,6 @@ int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) mark_info_dirty(sb, type); /* Force write to disk */ sb->dq_op->write_info(sb, type); -out: - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); return err; } EXPORT_SYMBOL(dquot_set_dqinfo); diff --git a/fs/quota/quota.c b/fs/quota/quota.c index 5acd0c4769af..07e08c7d05ca 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -104,13 +104,9 @@ static int quota_getfmt(struct super_block *sb, int type, void __user *addr) { __u32 fmt; - mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); - if (!sb_has_quota_active(sb, type)) { - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); + if (!sb_has_quota_active(sb, type)) return -ESRCH; - } fmt = sb_dqopt(sb)->info[type].dqi_format->qf_fmt_id; - mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); if (copy_to_user(addr, &fmt, sizeof(fmt))) return -EFAULT; return 0; @@ -789,9 +785,14 @@ static int quotactl_cmd_write(int cmd) } return 1; } - #endif /* CONFIG_BLOCK */ +/* Return true if quotactl command is manipulating quota on/off state */ +static bool quotactl_cmd_onoff(int cmd) +{ + return (cmd == Q_QUOTAON) || (cmd == Q_QUOTAOFF); +} + /* * look up a superblock on which quota ops will be performed * - use the name of a block device to find the superblock thereon @@ -809,7 +810,9 @@ static struct super_block *quotactl_block(const char __user *special, int cmd) putname(tmp); if (IS_ERR(bdev)) return ERR_CAST(bdev); - if (quotactl_cmd_write(cmd)) + if (quotactl_cmd_onoff(cmd)) + sb = get_super_exclusive_thawed(bdev); + else if (quotactl_cmd_write(cmd)) sb = get_super_thawed(bdev); else sb = get_super(bdev); @@ -872,7 +875,10 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, ret = do_quotactl(sb, type, cmds, id, addr, pathp); - drop_super(sb); + if (!quotactl_cmd_onoff(cmds)) + drop_super(sb); + else + drop_super_exclusive(sb); out: if (pathp && !IS_ERR(pathp)) path_put(pathp); |