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-rw-r--r--Documentation/filesystems/tmpfs.rst15
-rw-r--r--include/linux/shmem_fs.h8
-rw-r--r--mm/shmem.c186
3 files changed, 201 insertions, 8 deletions
diff --git a/Documentation/filesystems/tmpfs.rst b/Documentation/filesystems/tmpfs.rst
index 2cd8fa332feb..06d6195eaa2c 100644
--- a/Documentation/filesystems/tmpfs.rst
+++ b/Documentation/filesystems/tmpfs.rst
@@ -123,6 +123,21 @@ sysfs file /sys/kernel/mm/transparent_hugepage/shmem_enabled: which can
be used to deny huge pages on all tmpfs mounts in an emergency, or to
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.
+======== =============================================================
+
+Note that tmpfs quotas do not support user namespaces so no uid/gid
+translation is done if quotas are enabled inside user namespaces.
+
tmpfs has a mount option to set the NUMA memory allocation policy for
all files in that instance (if CONFIG_NUMA is enabled) - which can be
adjusted on the fly via 'mount -o remount ...'
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 7abfaf70b58a..1a568a0f542f 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -31,6 +31,9 @@ struct shmem_inode_info {
atomic_t stop_eviction; /* hold when working on inode */
struct timespec64 i_crtime; /* file creation time */
unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */
+#ifdef CONFIG_TMPFS_QUOTA
+ struct dquot *i_dquot[MAXQUOTAS];
+#endif
struct inode vfs_inode;
};
@@ -184,4 +187,9 @@ extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
#define SHMEM_QUOTA_MAX_SPC_LIMIT 0x7fffffffffffffffLL /* 2^63-1 */
#define SHMEM_QUOTA_MAX_INO_LIMIT 0x7fffffffffffffffLL
+#ifdef CONFIG_TMPFS_QUOTA
+extern const struct dquot_operations shmem_quota_operations;
+extern struct quota_format_type shmem_quota_format;
+#endif /* CONFIG_TMPFS_QUOTA */
+
#endif
diff --git a/mm/shmem.c b/mm/shmem.c
index e89c35c65586..ec76ce9aea5f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -78,6 +78,7 @@ static struct vfsmount *shm_mnt;
#include <uapi/linux/memfd.h>
#include <linux/rmap.h>
#include <linux/uuid.h>
+#include <linux/quotaops.h>
#include <linux/uaccess.h>
@@ -116,11 +117,13 @@ struct shmem_options {
int huge;
int seen;
bool noswap;
+ unsigned short quota_types;
#define SHMEM_SEEN_BLOCKS 1
#define SHMEM_SEEN_INODES 2
#define SHMEM_SEEN_HUGE 4
#define SHMEM_SEEN_INUMS 8
#define SHMEM_SEEN_NOSWAP 16
+#define SHMEM_SEEN_QUOTA 32
};
#ifdef CONFIG_TMPFS
@@ -212,7 +215,16 @@ static inline int shmem_inode_acct_block(struct inode *inode, long pages)
if (percpu_counter_compare(&sbinfo->used_blocks,
sbinfo->max_blocks - pages) > 0)
goto unacct;
+
+ err = dquot_alloc_block_nodirty(inode, pages);
+ if (err)
+ goto unacct;
+
percpu_counter_add(&sbinfo->used_blocks, pages);
+ } else {
+ err = dquot_alloc_block_nodirty(inode, pages);
+ if (err)
+ goto unacct;
}
return 0;
@@ -227,6 +239,8 @@ static inline void shmem_inode_unacct_blocks(struct inode *inode, long pages)
struct shmem_inode_info *info = SHMEM_I(inode);
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+ dquot_free_block_nodirty(inode, pages);
+
if (sbinfo->max_blocks)
percpu_counter_sub(&sbinfo->used_blocks, pages);
shmem_unacct_blocks(info->flags, pages);
@@ -255,6 +269,47 @@ bool vma_is_shmem(struct vm_area_struct *vma)
static LIST_HEAD(shmem_swaplist);
static DEFINE_MUTEX(shmem_swaplist_mutex);
+#ifdef CONFIG_TMPFS_QUOTA
+
+static int shmem_enable_quotas(struct super_block *sb,
+ unsigned short quota_types)
+{
+ int type, err = 0;
+
+ sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE | DQUOT_NOLIST_DIRTY;
+ for (type = 0; type < SHMEM_MAXQUOTAS; type++) {
+ if (!(quota_types & (1 << type)))
+ continue;
+ err = dquot_load_quota_sb(sb, type, QFMT_SHMEM,
+ DQUOT_USAGE_ENABLED |
+ DQUOT_LIMITS_ENABLED);
+ if (err)
+ goto out_err;
+ }
+ return 0;
+
+out_err:
+ pr_warn("tmpfs: failed to enable quota tracking (type=%d, err=%d)\n",
+ type, err);
+ for (type--; type >= 0; type--)
+ dquot_quota_off(sb, type);
+ return err;
+}
+
+static void shmem_disable_quotas(struct super_block *sb)
+{
+ int type;
+
+ for (type = 0; type < SHMEM_MAXQUOTAS; type++)
+ dquot_quota_off(sb, type);
+}
+
+static struct dquot **shmem_get_dquots(struct inode *inode)
+{
+ return SHMEM_I(inode)->i_dquot;
+}
+#endif /* CONFIG_TMPFS_QUOTA */
+
/*
* shmem_reserve_inode() performs bookkeeping to reserve a shmem inode, and
* produces a novel ino for the newly allocated inode.
@@ -361,7 +416,6 @@ static void shmem_recalc_inode(struct inode *inode)
freed = info->alloced - info->swapped - inode->i_mapping->nrpages;
if (freed > 0) {
info->alloced -= freed;
- inode->i_blocks -= freed * BLOCKS_PER_PAGE;
shmem_inode_unacct_blocks(inode, freed);
}
}
@@ -379,7 +433,6 @@ bool shmem_charge(struct inode *inode, long pages)
spin_lock_irqsave(&info->lock, flags);
info->alloced += pages;
- inode->i_blocks += pages * BLOCKS_PER_PAGE;
shmem_recalc_inode(inode);
spin_unlock_irqrestore(&info->lock, flags);
@@ -395,7 +448,6 @@ void shmem_uncharge(struct inode *inode, long pages)
spin_lock_irqsave(&info->lock, flags);
info->alloced -= pages;
- inode->i_blocks -= pages * BLOCKS_PER_PAGE;
shmem_recalc_inode(inode);
spin_unlock_irqrestore(&info->lock, flags);
@@ -1141,6 +1193,21 @@ static int shmem_setattr(struct mnt_idmap *idmap,
}
}
+ if (is_quota_modification(idmap, inode, attr)) {
+ error = dquot_initialize(inode);
+ if (error)
+ return error;
+ }
+
+ /* Transfer quota accounting */
+ if (i_uid_needs_update(idmap, attr, inode) ||
+ i_gid_needs_update(idmap, attr, inode)) {
+ error = dquot_transfer(idmap, inode, attr);
+
+ if (error)
+ return error;
+ }
+
setattr_copy(idmap, inode, attr);
if (attr->ia_valid & ATTR_MODE)
error = posix_acl_chmod(idmap, dentry, inode->i_mode);
@@ -1187,6 +1254,10 @@ static void shmem_evict_inode(struct inode *inode)
WARN_ON(inode->i_blocks);
shmem_free_inode(inode->i_sb);
clear_inode(inode);
+#ifdef CONFIG_TMPFS_QUOTA
+ dquot_free_inode(inode);
+ dquot_drop(inode);
+#endif
}
static int shmem_find_swap_entries(struct address_space *mapping,
@@ -1986,7 +2057,6 @@ alloc_nohuge:
spin_lock_irq(&info->lock);
info->alloced += folio_nr_pages(folio);
- inode->i_blocks += (blkcnt_t)BLOCKS_PER_PAGE << folio_order(folio);
shmem_recalc_inode(inode);
spin_unlock_irq(&info->lock);
alloced = true;
@@ -2357,9 +2427,10 @@ static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags)
#define shmem_initxattrs NULL
#endif
-static struct inode *shmem_get_inode(struct mnt_idmap *idmap, struct super_block *sb,
- struct inode *dir, umode_t mode, dev_t dev,
- unsigned long flags)
+static struct inode *__shmem_get_inode(struct mnt_idmap *idmap,
+ struct super_block *sb,
+ struct inode *dir, umode_t mode,
+ dev_t dev, unsigned long flags)
{
struct inode *inode;
struct shmem_inode_info *info;
@@ -2436,6 +2507,43 @@ static struct inode *shmem_get_inode(struct mnt_idmap *idmap, struct super_block
return inode;
}
+#ifdef CONFIG_TMPFS_QUOTA
+static struct inode *shmem_get_inode(struct mnt_idmap *idmap,
+ struct super_block *sb, struct inode *dir,
+ umode_t mode, dev_t dev, unsigned long flags)
+{
+ int err;
+ struct inode *inode;
+
+ inode = __shmem_get_inode(idmap, sb, dir, mode, dev, flags);
+ if (IS_ERR(inode))
+ return inode;
+
+ err = dquot_initialize(inode);
+ if (err)
+ goto errout;
+
+ err = dquot_alloc_inode(inode);
+ if (err) {
+ dquot_drop(inode);
+ goto errout;
+ }
+ return inode;
+
+errout:
+ inode->i_flags |= S_NOQUOTA;
+ iput(inode);
+ return ERR_PTR(err);
+}
+#else
+static inline struct inode *shmem_get_inode(struct mnt_idmap *idmap,
+ struct super_block *sb, struct inode *dir,
+ umode_t mode, dev_t dev, unsigned long flags)
+{
+ return __shmem_get_inode(idmap, sb, dir, mode, dev, flags);
+}
+#endif /* CONFIG_TMPFS_QUOTA */
+
#ifdef CONFIG_USERFAULTFD
int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
@@ -2538,7 +2646,6 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
spin_lock_irq(&info->lock);
info->alloced++;
- inode->i_blocks += BLOCKS_PER_PAGE;
shmem_recalc_inode(inode);
spin_unlock_irq(&info->lock);
@@ -3519,6 +3626,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
static const struct inode_operations shmem_short_symlink_operations = {
.getattr = shmem_getattr,
+ .setattr = shmem_setattr,
.get_link = simple_get_link,
#ifdef CONFIG_TMPFS_XATTR
.listxattr = shmem_listxattr,
@@ -3527,6 +3635,7 @@ static const struct inode_operations shmem_short_symlink_operations = {
static const struct inode_operations shmem_symlink_inode_operations = {
.getattr = shmem_getattr,
+ .setattr = shmem_setattr,
.get_link = shmem_get_link,
#ifdef CONFIG_TMPFS_XATTR
.listxattr = shmem_listxattr,
@@ -3626,6 +3735,9 @@ enum shmem_param {
Opt_inode32,
Opt_inode64,
Opt_noswap,
+ Opt_quota,
+ Opt_usrquota,
+ Opt_grpquota,
};
static const struct constant_table shmem_param_enums_huge[] = {
@@ -3648,6 +3760,11 @@ const struct fs_parameter_spec shmem_fs_parameters[] = {
fsparam_flag ("inode32", Opt_inode32),
fsparam_flag ("inode64", Opt_inode64),
fsparam_flag ("noswap", Opt_noswap),
+#ifdef CONFIG_TMPFS_QUOTA
+ fsparam_flag ("quota", Opt_quota),
+ fsparam_flag ("usrquota", Opt_usrquota),
+ fsparam_flag ("grpquota", Opt_grpquota),
+#endif
{}
};
@@ -3739,6 +3856,24 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
ctx->noswap = true;
ctx->seen |= SHMEM_SEEN_NOSWAP;
break;
+ case Opt_quota:
+ if (fc->user_ns != &init_user_ns)
+ return invalfc(fc, "Quotas in unprivileged tmpfs mounts are unsupported");
+ ctx->seen |= SHMEM_SEEN_QUOTA;
+ ctx->quota_types |= (QTYPE_MASK_USR | QTYPE_MASK_GRP);
+ break;
+ case Opt_usrquota:
+ if (fc->user_ns != &init_user_ns)
+ return invalfc(fc, "Quotas in unprivileged tmpfs mounts are unsupported");
+ ctx->seen |= SHMEM_SEEN_QUOTA;
+ ctx->quota_types |= QTYPE_MASK_USR;
+ break;
+ case Opt_grpquota:
+ if (fc->user_ns != &init_user_ns)
+ return invalfc(fc, "Quotas in unprivileged tmpfs mounts are unsupported");
+ ctx->seen |= SHMEM_SEEN_QUOTA;
+ ctx->quota_types |= QTYPE_MASK_GRP;
+ break;
}
return 0;
@@ -3846,6 +3981,12 @@ static int shmem_reconfigure(struct fs_context *fc)
goto out;
}
+ if (ctx->seen & SHMEM_SEEN_QUOTA &&
+ !sb_any_quota_loaded(fc->root->d_sb)) {
+ err = "Cannot enable quota on remount";
+ goto out;
+ }
+
if (ctx->seen & SHMEM_SEEN_HUGE)
sbinfo->huge = ctx->huge;
if (ctx->seen & SHMEM_SEEN_INUMS)
@@ -3937,6 +4078,9 @@ static void shmem_put_super(struct super_block *sb)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
+#ifdef CONFIG_TMPFS_QUOTA
+ shmem_disable_quotas(sb);
+#endif
free_percpu(sbinfo->ino_batch);
percpu_counter_destroy(&sbinfo->used_blocks);
mpol_put(sbinfo->mpol);
@@ -4016,6 +4160,17 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
#endif
uuid_gen(&sb->s_uuid);
+#ifdef CONFIG_TMPFS_QUOTA
+ if (ctx->seen & SHMEM_SEEN_QUOTA) {
+ sb->dq_op = &shmem_quota_operations;
+ sb->s_qcop = &dquot_quotactl_sysfile_ops;
+ sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+
+ if (shmem_enable_quotas(sb, ctx->quota_types))
+ goto failed;
+ }
+#endif /* CONFIG_TMPFS_QUOTA */
+
inode = shmem_get_inode(&nop_mnt_idmap, sb, NULL, S_IFDIR | sbinfo->mode, 0,
VM_NORESERVE);
if (IS_ERR(inode)) {
@@ -4192,6 +4347,9 @@ static const struct super_operations shmem_ops = {
.statfs = shmem_statfs,
.show_options = shmem_show_options,
#endif
+#ifdef CONFIG_TMPFS_QUOTA
+ .get_dquots = shmem_get_dquots,
+#endif
.evict_inode = shmem_evict_inode,
.drop_inode = generic_delete_inode,
.put_super = shmem_put_super,
@@ -4257,6 +4415,14 @@ void __init shmem_init(void)
shmem_init_inodecache();
+#ifdef CONFIG_TMPFS_QUOTA
+ error = register_quota_format(&shmem_quota_format);
+ if (error < 0) {
+ pr_err("Could not register quota format\n");
+ goto out3;
+ }
+#endif
+
error = register_filesystem(&shmem_fs_type);
if (error) {
pr_err("Could not register tmpfs\n");
@@ -4281,6 +4447,10 @@ void __init shmem_init(void)
out1:
unregister_filesystem(&shmem_fs_type);
out2:
+#ifdef CONFIG_TMPFS_QUOTA
+ unregister_quota_format(&shmem_quota_format);
+out3:
+#endif
shmem_destroy_inodecache();
shm_mnt = ERR_PTR(error);
}