From de4c0e7ca8b526a82ff7e5ee5533787bb6d01724 Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Tue, 25 Jul 2023 16:45:09 +0200 Subject: [PATCH] shmem: Add default quota limit mount options Allow system administrator to set default global quota limits at tmpfs mount time. Signed-off-by: Lukas Czerner Signed-off-by: Carlos Maiolino Reviewed-by: Jan Kara Message-Id: <20230725144510.253763-7-cem@kernel.org> Signed-off-by: Christian Brauner --- 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 06d6195eaa2c..67422ee10e03 100644 --- a/Documentation/filesystems/tmpfs.rst +++ b/Documentation/filesystems/tmpfs.rst @@ -125,15 +125,31 @@ force huge pages on all tmpfs mounts for testing. 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 1a568a0f542f..c0058f3bba70 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -42,6 +42,13 @@ 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 */ @@ -60,6 +67,7 @@ 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 ec76ce9aea5f..5f2c9e2961c2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -118,6 +118,7 @@ struct shmem_options { int seen; bool noswap; unsigned short quota_types; + struct shmem_quota_limits qlimits; #define SHMEM_SEEN_BLOCKS 1 #define SHMEM_SEEN_INODES 2 #define SHMEM_SEEN_HUGE 4 @@ -3738,6 +3739,10 @@ 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[] = { @@ -3764,6 +3769,10 @@ 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 {} }; @@ -3874,6 +3883,42 @@ 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; @@ -3987,6 +4032,18 @@ 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) @@ -4166,6 +4223,10 @@ 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 e92b8ece9880..062d1c1097ae 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 @@ out_unlock: 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.grpquota_bhardlimit; + ihardlimit = sbinfo->qlimits.grpquota_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); -- 2.11.0