From c7d3d28360fdb3ed3a5aa0bab19315e0fdc994a1 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 1 Nov 2019 17:45:31 +0100 Subject: quota: Factor out setup of quota inode Factor out setting up of quota inode and eventual error cleanup from vfs_load_quota_inode(). This will simplify situation for filesystems that don't have any quota inodes. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 108 ++++++++++++++++++++++++++++++++++--------------------- 1 file changed, 67 insertions(+), 41 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 6e826b454082..9e8eb6e71675 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2299,28 +2299,60 @@ EXPORT_SYMBOL(dquot_quota_off); * Turn quotas on on a device */ -/* - * Helper function to turn quotas on when we already have the inode of - * quota file and no quota information is loaded. - */ -static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, +static int vfs_setup_quota_inode(struct inode *inode, int type) +{ + struct super_block *sb = inode->i_sb; + struct quota_info *dqopt = sb_dqopt(sb); + + if (!S_ISREG(inode->i_mode)) + return -EACCES; + if (IS_RDONLY(inode)) + return -EROFS; + if (sb_has_quota_loaded(sb, type)) + return -EBUSY; + + dqopt->files[type] = igrab(inode); + if (!dqopt->files[type]) + return -EIO; + if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { + /* We don't want quota and atime on quota files (deadlocks + * possible) Also nobody should write to the file - we use + * special IO operations which ignore the immutable bit. */ + inode_lock(inode); + inode->i_flags |= S_NOQUOTA; + inode_unlock(inode); + /* + * When S_NOQUOTA is set, remove dquot references as no more + * references can be added + */ + __dquot_drop(inode); + } + return 0; +} + +static void vfs_cleanup_quota_inode(struct super_block *sb, int type) +{ + struct quota_info *dqopt = sb_dqopt(sb); + struct inode *inode = dqopt->files[type]; + + if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { + inode_lock(inode); + inode->i_flags &= ~S_NOQUOTA; + inode_unlock(inode); + } + dqopt->files[type] = NULL; + iput(inode); +} + +int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, unsigned int flags) { struct quota_format_type *fmt = find_quota_format(format_id); - struct super_block *sb = inode->i_sb; struct quota_info *dqopt = sb_dqopt(sb); int error; if (!fmt) return -ESRCH; - if (!S_ISREG(inode->i_mode)) { - error = -EACCES; - goto out_fmt; - } - if (IS_RDONLY(inode)) { - error = -EROFS; - goto out_fmt; - } if (!sb->s_op->quota_write || !sb->s_op->quota_read || (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { error = -EINVAL; @@ -2352,27 +2384,9 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, invalidate_bdev(sb->s_bdev); } - if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { - /* We don't want quota and atime on quota files (deadlocks - * possible) Also nobody should write to the file - we use - * special IO operations which ignore the immutable bit. */ - inode_lock(inode); - inode->i_flags |= S_NOQUOTA; - inode_unlock(inode); - /* - * When S_NOQUOTA is set, remove dquot references as no more - * references can be added - */ - __dquot_drop(inode); - } - - error = -EIO; - dqopt->files[type] = igrab(inode); - if (!dqopt->files[type]) - goto out_file_flags; error = -EINVAL; if (!fmt->qf_ops->check_quota_file(sb, type)) - goto out_file_init; + goto out_fmt; dqopt->ops[type] = fmt->qf_ops; dqopt->info[type].dqi_format = fmt; @@ -2380,7 +2394,7 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); error = dqopt->ops[type]->read_file_info(sb, type); if (error < 0) - goto out_file_init; + goto out_fmt; if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { spin_lock(&dq_data_lock); dqopt->info[type].dqi_flags |= DQF_SYS_FILE; @@ -2395,18 +2409,30 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, dquot_disable(sb, type, flags); return error; -out_file_init: - dqopt->files[type] = NULL; - iput(inode); -out_file_flags: - inode_lock(inode); - inode->i_flags &= ~S_NOQUOTA; - inode_unlock(inode); out_fmt: put_quota_format(fmt); return error; } +EXPORT_SYMBOL(dquot_load_quota_sb); + +/* + * Helper function to turn quotas on when we already have the inode of + * quota file and no quota information is loaded. + */ +static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, + unsigned int flags) +{ + int err; + + err = vfs_setup_quota_inode(inode, type); + if (err < 0) + return err; + err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); + if (err < 0) + vfs_cleanup_quota_inode(inode->i_sb, type); + return err; +} /* Reenable quotas on remount RW */ int dquot_resume(struct super_block *sb, int type) -- cgit v1.2.3 From ae45f07d47cc30e9170488a4e5fe91ba4fe5ed4e Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 1 Nov 2019 17:51:05 +0100 Subject: quota: Simplify dquot_resume() We already have quota inode loaded when resuming quotas. Use vfs_load_quota() to avoid some pointless churn with the quota inode. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 9e8eb6e71675..ecdae91029ed 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2438,7 +2438,6 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, int dquot_resume(struct super_block *sb, int type) { struct quota_info *dqopt = sb_dqopt(sb); - struct inode *inode; int ret = 0, cnt; unsigned int flags; @@ -2452,8 +2451,6 @@ int dquot_resume(struct super_block *sb, int type) if (!sb_has_quota_suspended(sb, cnt)) continue; - inode = dqopt->files[cnt]; - dqopt->files[cnt] = NULL; spin_lock(&dq_state_lock); flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED, @@ -2462,9 +2459,10 @@ int dquot_resume(struct super_block *sb, int type) spin_unlock(&dq_state_lock); flags = dquot_generic_flag(flags, cnt); - ret = vfs_load_quota_inode(inode, cnt, - dqopt->info[cnt].dqi_fmt_id, flags); - iput(inode); + ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, + flags); + if (ret < 0) + vfs_cleanup_quota_inode(sb, type); } return ret; -- cgit v1.2.3 From dc19432ae1c22d696f91edea11ae06c348b4e88a Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 1 Nov 2019 18:37:44 +0100 Subject: quota: Rename vfs_load_quota_inode() to dquot_load_quota_inode() Rename vfs_load_quota_inode() to dquot_load_quota_inode() to be consistent with naming of other functions used for enabling quota accounting from filesystems. Also export the function and add some sanity checks to assure filesystems are calling the function properly. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index ecdae91029ed..0ddcbce596f8 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2351,6 +2351,12 @@ int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, struct quota_info *dqopt = sb_dqopt(sb); int error; + /* 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 (!fmt) return -ESRCH; if (!sb->s_op->quota_write || !sb->s_op->quota_read || @@ -2417,10 +2423,10 @@ out_fmt: EXPORT_SYMBOL(dquot_load_quota_sb); /* - * Helper function to turn quotas on when we already have the inode of - * quota file and no quota information is loaded. + * More powerful function for turning on quotas on given quota inode allowing + * setting of individual quota flags */ -static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, +int dquot_load_quota_inode(struct inode *inode, int type, int format_id, unsigned int flags) { int err; @@ -2433,6 +2439,7 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, vfs_cleanup_quota_inode(inode->i_sb, type); return err; } +EXPORT_SYMBOL(dquot_load_quota_inode); /* Reenable quotas on remount RW */ int dquot_resume(struct super_block *sb, int type) @@ -2479,7 +2486,7 @@ int dquot_quota_on(struct super_block *sb, int type, int format_id, if (path->dentry->d_sb != sb) error = -EXDEV; else - error = vfs_load_quota_inode(d_inode(path->dentry), type, + error = dquot_load_quota_inode(d_inode(path->dentry), type, format_id, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); return error; @@ -2517,7 +2524,7 @@ int dquot_enable(struct inode *inode, int type, int format_id, return 0; } - return vfs_load_quota_inode(inode, type, format_id, flags); + return dquot_load_quota_inode(inode, type, format_id, flags); } EXPORT_SYMBOL(dquot_enable); @@ -2542,7 +2549,7 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name, error = security_quota_on(dentry); if (!error) - error = vfs_load_quota_inode(d_inode(dentry), type, format_id, + error = dquot_load_quota_inode(d_inode(dentry), type, format_id, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); out: -- cgit v1.2.3 From 069a9166369773627e51c5249cd7f9169aecd7fa Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 1 Nov 2019 18:57:56 +0100 Subject: quota: Drop dquot_enable() Now dquot_enable() has only two internal callers and both of them just need to update quota flags and don't need most of checks. Just drop dquot_enable() and fold necessary functionality into the two calling places. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 61 +++++++++++++++----------------------------------------- 1 file changed, 16 insertions(+), 45 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 0ddcbce596f8..3e4cf0d10955 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2493,41 +2493,6 @@ int dquot_quota_on(struct super_block *sb, int type, int format_id, } EXPORT_SYMBOL(dquot_quota_on); -/* - * More powerful function for turning on quotas allowing setting - * of individual quota flags - */ -int dquot_enable(struct inode *inode, int type, int format_id, - unsigned int flags) -{ - struct super_block *sb = inode->i_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)) { - if (flags & DQUOT_USAGE_ENABLED && - sb_has_quota_usage_enabled(sb, type)) - return -EBUSY; - if (flags & DQUOT_LIMITS_ENABLED && - 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); - return 0; - } - - return dquot_load_quota_inode(inode, type, format_id, flags); -} -EXPORT_SYMBOL(dquot_enable); - /* * This function is used when filesystem needs to initialize quotas * during mount time. @@ -2574,13 +2539,17 @@ static int dquot_quota_enable(struct super_block *sb, unsigned int flags) if (!(flags & qtype_enforce_flag(type))) continue; /* Can't enforce without accounting */ - if (!sb_has_quota_usage_enabled(sb, type)) - return -EINVAL; - ret = dquot_enable(dqopt->files[type], type, - dqopt->info[type].dqi_fmt_id, - DQUOT_LIMITS_ENABLED); - if (ret < 0) + if (!sb_has_quota_usage_enabled(sb, type)) { + ret = -EINVAL; + goto out_err; + } + if (sb_has_quota_limits_enabled(sb, type)) { + ret = -EBUSY; goto out_err; + } + spin_lock(&dq_state_lock); + dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); + spin_unlock(&dq_state_lock); } return 0; out_err: @@ -2630,10 +2599,12 @@ static int dquot_quota_disable(struct super_block *sb, unsigned int flags) out_err: /* Backout enforcement disabling we already did */ for (type--; type >= 0; type--) { - if (flags & qtype_enforce_flag(type)) - dquot_enable(dqopt->files[type], type, - dqopt->info[type].dqi_fmt_id, - DQUOT_LIMITS_ENABLED); + if (flags & qtype_enforce_flag(type)) { + spin_lock(&dq_state_lock); + dqopt->flags |= + dquot_state_flag(DQUOT_LIMITS_ENABLED, type); + spin_unlock(&dq_state_lock); + } } return ret; } -- cgit v1.2.3 From 2ec1f3011f3fdcbafcaad23aafa5acb6861a2646 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 4 Nov 2019 11:12:44 +0100 Subject: quota: Make dquot_disable() work without quota inodes Quota on and quota off are protected by s_umount semaphore held in exclusive mode since commit 7d6cd73d33b6 "quota: Hold s_umount in exclusive mode when enabling / disabling quotas". This makes it impossible for dquot_disable() to race with other enabling or disabling of quotas. Simplify the cleanup done by dquot_disable() based on this fact and also remove some stale comments. As a bonus this cleanup makes dquot_disable() properly handle a case when there are no quota inodes. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 73 ++++++++++++++++++++++---------------------------------- 1 file changed, 29 insertions(+), 44 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 3e4cf0d10955..4c3da4ea31bc 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2162,14 +2162,29 @@ int dquot_file_open(struct inode *inode, struct file *file) } EXPORT_SYMBOL(dquot_file_open); +static void vfs_cleanup_quota_inode(struct super_block *sb, int type) +{ + struct quota_info *dqopt = sb_dqopt(sb); + struct inode *inode = dqopt->files[type]; + + if (!inode) + return; + if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { + inode_lock(inode); + inode->i_flags &= ~S_NOQUOTA; + inode_unlock(inode); + } + dqopt->files[type] = NULL; + iput(inode); +} + /* * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) */ int dquot_disable(struct super_block *sb, int type, unsigned int flags) { - int cnt, ret = 0; + int cnt; 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))) @@ -2191,7 +2206,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) return 0; for (cnt = 0; cnt < MAXQUOTAS; cnt++) { - toputinode[cnt] = NULL; if (type != -1 && cnt != type) continue; if (!sb_has_quota_loaded(sb, cnt)) @@ -2211,8 +2225,7 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) dqopt->flags &= ~dquot_state_flag( DQUOT_SUSPENDED, cnt); spin_unlock(&dq_state_lock); - iput(dqopt->files[cnt]); - dqopt->files[cnt] = NULL; + vfs_cleanup_quota_inode(sb, cnt); continue; } spin_unlock(&dq_state_lock); @@ -2234,10 +2247,6 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags) if (dqopt->ops[cnt]->free_file_info) dqopt->ops[cnt]->free_file_info(sb, cnt); put_quota_format(dqopt->info[cnt].dqi_format); - - toputinode[cnt] = dqopt->files[cnt]; - if (!sb_has_quota_loaded(sb, cnt)) - dqopt->files[cnt] = NULL; dqopt->info[cnt].dqi_flags = 0; dqopt->info[cnt].dqi_igrace = 0; dqopt->info[cnt].dqi_bgrace = 0; @@ -2259,32 +2268,22 @@ 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++) - /* 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_NOQUOTA; - truncate_inode_pages(&toputinode[cnt]->i_data, 0); - inode_unlock(toputinode[cnt]); - mark_inode_dirty_sync(toputinode[cnt]); + if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { + inode_lock(dqopt->files[cnt]); + truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); + inode_unlock(dqopt->files[cnt]); } if (sb->s_bdev) invalidate_bdev(sb->s_bdev); put_inodes: + /* We are done when suspending quotas */ + if (flags & DQUOT_SUSPENDED) + return 0; + for (cnt = 0; cnt < MAXQUOTAS; cnt++) - if (toputinode[cnt]) { - /* On remount RO, we keep the inode pointer so that we - * can reenable quota on the subsequent remount RW. We - * have to check 'flags' variable and not use sb_has_ - * function because another quotaon / quotaoff could - * change global state before we got here. We refuse - * to suspend quotas when there is pending delete on - * the quota file... */ - if (!(flags & DQUOT_SUSPENDED)) - iput(toputinode[cnt]); - else if (!toputinode[cnt]->i_nlink) - ret = -EBUSY; - } - return ret; + if (!sb_has_quota_loaded(sb, cnt)) + vfs_cleanup_quota_inode(sb, cnt); + return 0; } EXPORT_SYMBOL(dquot_disable); @@ -2330,20 +2329,6 @@ static int vfs_setup_quota_inode(struct inode *inode, int type) return 0; } -static void vfs_cleanup_quota_inode(struct super_block *sb, int type) -{ - struct quota_info *dqopt = sb_dqopt(sb); - struct inode *inode = dqopt->files[type]; - - if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { - inode_lock(inode); - inode->i_flags &= ~S_NOQUOTA; - inode_unlock(inode); - } - dqopt->files[type] = NULL; - iput(inode); -} - int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, unsigned int flags) { -- cgit v1.2.3 From a0828b6ccbdfd46afbbaa9f28df359081c29109b Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 4 Nov 2019 11:18:17 +0100 Subject: quota: Handle quotas without quota inodes in dquot_get_state() Make dquot_get_state() gracefully handle a situation when there are no quota files present even though quotas are enabled. Signed-off-by: Jan Kara --- fs/quota/dquot.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 4c3da4ea31bc..a69a657209a6 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2787,8 +2787,10 @@ int dquot_get_state(struct super_block *sb, struct qc_state *state) tstate->flags |= QCI_LIMITS_ENFORCED; tstate->spc_timelimit = mi->dqi_bgrace; tstate->ino_timelimit = mi->dqi_igrace; - tstate->ino = dqopt->files[type]->i_ino; - tstate->blocks = dqopt->files[type]->i_blocks; + if (dqopt->files[type]) { + tstate->ino = dqopt->files[type]->i_ino; + tstate->blocks = dqopt->files[type]->i_blocks; + } tstate->nextents = 1; /* We don't know... */ spin_unlock(&dq_data_lock); } -- cgit v1.2.3