From: Lukas Czerner <lczerner@xxxxxxxxxx>
Allow system administrator to set default global quota limits at tmpfs
mount time.
Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx>
Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
---
V3:
- Do not enable quotas if usrquota or grpquota options are not
explicitly set.
- shmem_release_dquot() now also free up quota_info if there is
no usage and there are no custom limits set.
V2:
- Fix documentation phrasing
Documentation/filesystems/tmpfs.rst | 34 +++++++++++-----
include/linux/shmem_fs.h | 8 ++++
mm/shmem.c | 61 +++++++++++++++++++++++++++++
mm/shmem_quota.c | 34 +++++++++++++++-
4 files changed, 127 insertions(+), 10 deletions(-)
diff --git a/Documentation/filesystems/tmpfs.rst b/Documentation/filesystems/tmpfs.rst
index 595e607274afb..0c7bfba34baa6 100644
--- a/Documentation/filesystems/tmpfs.rst
+++ b/Documentation/filesystems/tmpfs.rst
@@ -88,15 +88,31 @@ that instance in a system with many CPUs making intensive use of it.
tmpfs also supports quota with the following mount options
-======== =============================================================
-quota User and group quota accounting and enforcement is enabled on
- the mount. Tmpfs is using hidden system quota files that are
- initialized on mount.
-usrquota User quota accounting and enforcement is enabled on the
- mount.
-grpquota Group quota accounting and enforcement is enabled on the
- mount.
-======== =============================================================
+======================== =================================================
+quota User and group quota accounting and enforcement
+ is enabled on the mount. Tmpfs is using hidden
+ system quota files that are initialized on mount.
+usrquota User quota accounting and enforcement is enabled
+ on the mount.
+grpquota Group quota accounting and enforcement is enabled
+ on the mount.
+usrquota_block_hardlimit Set global user quota block hard limit.
+usrquota_inode_hardlimit Set global user quota inode hard limit.
+grpquota_block_hardlimit Set global group quota block hard limit.
+grpquota_inode_hardlimit Set global group quota inode hard limit.
+======================== =================================================
+
+None of the quota related mount options can be set or changed on remount.
+
+Quota limit parameters accept a suffix k, m or g for kilo, mega and giga
+and can't be changed on remount. Default global quota limits are taking
+effect for any and all user/group/project except root the first time the
+quota entry for user/group/project id is being accessed - typically the
+first time an inode with a particular id ownership is being created after
+the mount. In other words, instead of the limits being initialized to zero,
+they are initialized with the particular value provided with these mount
+options. The limits can be changed for any user/group id at any time as they
+normally can be.
Note that tmpfs quotas do not support user namespaces so no uid/gid
translation is done if quotas are enabled inside user namespaces.
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index b8e421e349868..8ca5e969f00fc 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -41,6 +41,13 @@ struct shmem_inode_info {
(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL)
+struct shmem_quota_limits {
+ qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */
+ qsize_t usrquota_ihardlimit; /* Default user quota inode hard limit */
+ qsize_t grpquota_bhardlimit; /* Default group quota block hard limit */
+ qsize_t grpquota_ihardlimit; /* Default group quota inode hard limit */
+};
+
struct shmem_sb_info {
unsigned long max_blocks; /* How many blocks are allowed */
struct percpu_counter used_blocks; /* How many are allocated */
@@ -58,6 +65,7 @@ struct shmem_sb_info {
spinlock_t shrinklist_lock; /* Protects shrinklist */
struct list_head shrinklist; /* List of shinkable inodes */
unsigned long shrinklist_len; /* Length of shrinklist */
+ struct shmem_quota_limits qlimits; /* Default quota limits */
};
static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
diff --git a/mm/shmem.c b/mm/shmem.c
index 623d258af39f8..24bcb374ad27b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -118,6 +118,7 @@ struct shmem_options {
int huge;
int seen;
unsigned short quota_types;
+ struct shmem_quota_limits qlimits;
#define SHMEM_SEEN_BLOCKS 1
#define SHMEM_SEEN_INODES 2
#define SHMEM_SEEN_HUGE 4
@@ -3593,6 +3594,10 @@ enum shmem_param {
Opt_quota,
Opt_usrquota,
Opt_grpquota,
+ Opt_usrquota_block_hardlimit,
+ Opt_usrquota_inode_hardlimit,
+ Opt_grpquota_block_hardlimit,
+ Opt_grpquota_inode_hardlimit,
};
static const struct constant_table shmem_param_enums_huge[] = {
@@ -3618,6 +3623,10 @@ const struct fs_parameter_spec shmem_fs_parameters[] = {
fsparam_flag ("quota", Opt_quota),
fsparam_flag ("usrquota", Opt_usrquota),
fsparam_flag ("grpquota", Opt_grpquota),
+ fsparam_string("usrquota_block_hardlimit", Opt_usrquota_block_hardlimit),
+ fsparam_string("usrquota_inode_hardlimit", Opt_usrquota_inode_hardlimit),
+ fsparam_string("grpquota_block_hardlimit", Opt_grpquota_block_hardlimit),
+ fsparam_string("grpquota_inode_hardlimit", Opt_grpquota_inode_hardlimit),
#endif
{}
};
@@ -3714,6 +3723,42 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
ctx->seen |= SHMEM_SEEN_QUOTA;
ctx->quota_types |= QTYPE_MASK_GRP;
break;
+ case Opt_usrquota_block_hardlimit:
+ size = memparse(param->string, &rest);
+ if (*rest || !size)
+ goto bad_value;
+ if (size > SHMEM_QUOTA_MAX_SPC_LIMIT)
+ return invalfc(fc,
+ "User quota block hardlimit too large.");
+ ctx->qlimits.usrquota_bhardlimit = size;
+ break;
+ case Opt_grpquota_block_hardlimit:
+ size = memparse(param->string, &rest);
+ if (*rest || !size)
+ goto bad_value;
+ if (size > SHMEM_QUOTA_MAX_SPC_LIMIT)
+ return invalfc(fc,
+ "Group quota block hardlimit too large.");
+ ctx->qlimits.grpquota_bhardlimit = size;
+ break;
+ case Opt_usrquota_inode_hardlimit:
+ size = memparse(param->string, &rest);
+ if (*rest || !size)
+ goto bad_value;
+ if (size > SHMEM_QUOTA_MAX_INO_LIMIT)
+ return invalfc(fc,
+ "User quota inode hardlimit too large.");
+ ctx->qlimits.usrquota_ihardlimit = size;
+ break;
+ case Opt_grpquota_inode_hardlimit:
+ size = memparse(param->string, &rest);
+ if (*rest || !size)
+ goto bad_value;
+ if (size > SHMEM_QUOTA_MAX_INO_LIMIT)
+ return invalfc(fc,
+ "Group quota inode hardlimit too large.");
+ ctx->qlimits.grpquota_ihardlimit = size;
+ break;
}
return 0;
@@ -3819,6 +3864,18 @@ static int shmem_reconfigure(struct fs_context *fc)
goto out;
}
+#ifdef CONFIG_TMPFS_QUOTA
+#define CHANGED_LIMIT(name) \
+ (ctx->qlimits.name## hardlimit && \
+ (ctx->qlimits.name## hardlimit != sbinfo->qlimits.name## hardlimit))
+
+ if (CHANGED_LIMIT(usrquota_b) || CHANGED_LIMIT(usrquota_i) ||
+ CHANGED_LIMIT(grpquota_b) || CHANGED_LIMIT(grpquota_i)) {
+ err = "Cannot change global quota limit on remount";
+ goto out;
+ }
+#endif /* CONFIG_TMPFS_QUOTA */
+
if (ctx->seen & SHMEM_SEEN_HUGE)
sbinfo->huge = ctx->huge;
if (ctx->seen & SHMEM_SEEN_INUMS)
@@ -3988,6 +4045,10 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
sb->s_qcop = &dquot_quotactl_sysfile_ops;
sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+ /* Copy the default limits from ctx into sbinfo */
+ memcpy(&sbinfo->qlimits, &ctx->qlimits,
+ sizeof(struct shmem_quota_limits));
+
if (shmem_enable_quotas(sb, ctx->quota_types))
goto failed;
}
diff --git a/mm/shmem_quota.c b/mm/shmem_quota.c
index c0b531e2ef688..9d4c6545949e1 100644
--- a/mm/shmem_quota.c
+++ b/mm/shmem_quota.c
@@ -166,6 +166,7 @@ static int shmem_acquire_dquot(struct dquot *dquot)
{
struct mem_dqinfo *info = sb_dqinfo(dquot->dq_sb, dquot->dq_id.type);
struct rb_node **n = &((struct rb_root *)info->dqi_priv)->rb_node;
+ struct shmem_sb_info *sbinfo = dquot->dq_sb->s_fs_info;
struct rb_node *parent = NULL, *new_node = NULL;
struct quota_id *new_entry, *entry;
qid_t id = from_kqid(&init_user_ns, dquot->dq_id);
@@ -195,6 +196,14 @@ static int shmem_acquire_dquot(struct dquot *dquot)
}
new_entry->id = id;
+ if (dquot->dq_id.type == USRQUOTA) {
+ new_entry->bhardlimit = sbinfo->qlimits.usrquota_bhardlimit;
+ new_entry->ihardlimit = sbinfo->qlimits.usrquota_ihardlimit;
+ } else if (dquot->dq_id.type == GRPQUOTA) {
+ new_entry->bhardlimit = sbinfo->qlimits.grpquota_bhardlimit;
+ new_entry->ihardlimit = sbinfo->qlimits.grpquota_ihardlimit;
+ }
+
new_node = &new_entry->node;
rb_link_node(new_node, parent, n);
rb_insert_color(new_node, (struct rb_root *)info->dqi_priv);
@@ -224,6 +233,29 @@ static int shmem_acquire_dquot(struct dquot *dquot)
return ret;
}
+static bool shmem_is_empty_dquot(struct dquot *dquot)
+{
+ struct shmem_sb_info *sbinfo = dquot->dq_sb->s_fs_info;
+ qsize_t bhardlimit;
+ qsize_t ihardlimit;
+
+ if (dquot->dq_id.type == USRQUOTA) {
+ bhardlimit = sbinfo->qlimits.usrquota_bhardlimit;
+ ihardlimit = sbinfo->qlimits.usrquota_ihardlimit;
+ } else if (dquot->dq_id.type == GRPQUOTA) {
+ bhardlimit = sbinfo->qlimits.usrquota_bhardlimit;
+ ihardlimit = sbinfo->qlimits.usrquota_ihardlimit;
+ }
+
+ if (test_bit(DQ_FAKE_B, &dquot->dq_flags) ||
+ (dquot->dq_dqb.dqb_curspace == 0 &&
+ dquot->dq_dqb.dqb_curinodes == 0 &&
+ dquot->dq_dqb.dqb_bhardlimit == bhardlimit &&
+ dquot->dq_dqb.dqb_ihardlimit == ihardlimit))
+ return true;
+
+ return false;
+}
/*
* Store limits from dquot in the tree unless it's fake. If it is fake
* remove the id from the tree since there is no useful information in
@@ -261,7 +293,7 @@ static int shmem_release_dquot(struct dquot *dquot)
return -ENOENT;
found:
- if (test_bit(DQ_FAKE_B, &dquot->dq_flags)) {
+ if (shmem_is_empty_dquot(dquot)) {
/* Remove entry from the tree */
rb_erase(&entry->node, info->dqi_priv);
kfree(entry);
--
2.30.2
