f2fs: support plain user/group quota

This patch adds to support plain user/group quota.

Change Note by Jaegeuk Kim.

- Use f2fs page cache for quota files in order to consider garbage collection.
  so, quota files are not tolerable for sudden power-cuts, so user needs to do
  quotacheck.

- setattr() calls dquot_transfer which will transfer inode->i_blocks.
  We can't reclaim that during f2fs_evict_inode(). So, we need to count
  node blocks as well in order to match i_blocks with dquot's space.

  Note that, Chao wrote a patch to count inode->i_blocks without inode block.
  (f2fs: don't count inode block in in-memory inode.i_blocks)

- in f2fs_remount, we need to make RW in prior to dquot_resume.

- handle fault_injection case during f2fs_quota_off_umount

- TODO: Project quota

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

8 files changed, 454 insertions, 40 deletions

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 8b04a6359530..273ccb26885e 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -162,6 +162,8 @@ mode=%s                Control block allocation mode which supports "adaptive"
                        writes towards main area.
 io_bits=%u             Set the bit size of write IO requests. It should be set
                        with "mode=lfs".
+usrquota               Enable plain user disk quota accounting.
+grpquota               Enable plain group disk quota accounting.
 
 ================================================================================
 DEBUGFS ENTRIES
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 7dd5fb647d43..251356859476 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -491,14 +491,15 @@ void f2fs_update_data_blkaddr(struct dnode_of_data *dn, block_t blkaddr)
 int reserve_new_blocks(struct dnode_of_data *dn, blkcnt_t count)
 {
         struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
+        int err;
 
         if (!count)
                 return 0;
 
         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
                 return -EPERM;
-        if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
-                return -ENOSPC;
+        if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
+                return err;
 
         trace_f2fs_reserve_new_blocks(dn->inode, dn->nid,
                                                 dn->ofs_in_node, count);
@@ -749,6 +750,7 @@ static int __allocate_data_block(struct dnode_of_data *dn)
         struct node_info ni;
         pgoff_t fofs;
         blkcnt_t count = 1;
+        int err;
 
         if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
                 return -EPERM;
@@ -757,8 +759,8 @@ static int __allocate_data_block(struct dnode_of_data *dn)
         if (dn->data_blkaddr == NEW_ADDR)
                 goto alloc;
 
-        if (unlikely(!inc_valid_block_count(sbi, dn->inode, &count)))
-                return -ENOSPC;
+        if (unlikely((err = inc_valid_block_count(sbi, dn->inode, &count))))
+                return err;
 
 alloc:
         get_node_info(sbi, dn->nid, &ni);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ced78035a416..42c39f0bfd88 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -22,6 +22,7 @@
 #include <linux/vmalloc.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/quotaops.h>
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
 #include <linux/fscrypt_supp.h>
 #else
@@ -88,6 +89,8 @@ extern char *fault_name[FAULT_MAX];
 #define F2FS_MOUNT_FAULT_INJECTION      0x00010000
 #define F2FS_MOUNT_ADAPTIVE             0x00020000
 #define F2FS_MOUNT_LFS                  0x00040000
+#define F2FS_MOUNT_USRQUOTA             0x00080000
+#define F2FS_MOUNT_GRPQUOTA             0x00100000
 
 #define clear_opt(sbi, option)  ((sbi)->mount_opt.opt &= ~F2FS_MOUNT_##option)
 #define set_opt(sbi, option)    ((sbi)->mount_opt.opt |= F2FS_MOUNT_##option)
@@ -521,6 +524,12 @@ struct f2fs_inode_info {
         nid_t i_xattr_nid;              /* node id that contains xattrs */
         loff_t  last_disk_size;         /* lastly written file size */
 
+#ifdef CONFIG_QUOTA
+        struct dquot *i_dquot[MAXQUOTAS];
+
+        /* quota space reservation, managed internally by quota code */
+        qsize_t i_reserved_quota;
+#endif
         struct list_head dirty_list;    /* dirty list for dirs and files */
         struct list_head gdirty_list;   /* linked in global dirty list */
         struct list_head inmem_pages;   /* inmemory pages managed by f2fs */
@@ -1376,17 +1385,23 @@ static inline bool f2fs_has_xattr_block(unsigned int ofs)
         return ofs == XATTR_NODE_OFFSET;
 }
 
-static inline void f2fs_i_blocks_write(struct inode *, block_t, bool);
-static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
+static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool);
+static inline int inc_valid_block_count(struct f2fs_sb_info *sbi,
                                  struct inode *inode, blkcnt_t *count)
 {
-        blkcnt_t diff;
+        blkcnt_t diff = 0, release = 0;
         block_t avail_user_block_count;
+        int ret;
+
+        ret = dquot_reserve_block(inode, *count);
+        if (ret)
+                return ret;
 
 #ifdef CONFIG_F2FS_FAULT_INJECTION
         if (time_to_inject(sbi, FAULT_BLOCK)) {
                 f2fs_show_injection_info(FAULT_BLOCK);
-                return false;
+                release = *count;
+                goto enospc;
         }
 #endif
         /*
@@ -1401,17 +1416,24 @@ static inline bool inc_valid_block_count(struct f2fs_sb_info *sbi,
         if (unlikely(sbi->total_valid_block_count > avail_user_block_count)) {
                 diff = sbi->total_valid_block_count - avail_user_block_count;
                 *count -= diff;
+                release = diff;
                 sbi->total_valid_block_count = avail_user_block_count;
                 if (!*count) {
                         spin_unlock(&sbi->stat_lock);
                         percpu_counter_sub(&sbi->alloc_valid_block_count, diff);
-                        return false;
+                        goto enospc;
                 }
         }
         spin_unlock(&sbi->stat_lock);
 
-        f2fs_i_blocks_write(inode, *count, true);
-        return true;
+        if (release)
+                dquot_release_reservation_block(inode, release);
+        f2fs_i_blocks_write(inode, *count, true, true);
+        return 0;
+
+enospc:
+        dquot_release_reservation_block(inode, release);
+        return -ENOSPC;
 }
 
 static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
@@ -1425,7 +1447,7 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,
         f2fs_bug_on(sbi, inode->i_blocks < sectors);
         sbi->total_valid_block_count -= (block_t)count;
         spin_unlock(&sbi->stat_lock);
-        f2fs_i_blocks_write(inode, count, false);
+        f2fs_i_blocks_write(inode, count, false, true);
 }
 
 static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
@@ -1554,11 +1576,18 @@ static inline block_t __start_sum_addr(struct f2fs_sb_info *sbi)
         return le32_to_cpu(F2FS_CKPT(sbi)->cp_pack_start_sum);
 }
 
-static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
+static inline int inc_valid_node_count(struct f2fs_sb_info *sbi,
                                         struct inode *inode, bool is_inode)
 {
         block_t valid_block_count;
         unsigned int valid_node_count;
+        bool quota = inode && !is_inode;
+
+        if (quota) {
+                int ret = dquot_reserve_block(inode, 1);
+                if (ret)
+                        return ret;
+        }
 
         spin_lock(&sbi->stat_lock);
 
@@ -1566,28 +1595,33 @@ static inline bool inc_valid_node_count(struct f2fs_sb_info *sbi,
         if (unlikely(valid_block_count + sbi->reserved_blocks >
                                                 sbi->user_block_count)) {
                 spin_unlock(&sbi->stat_lock);
-                return false;
+                goto enospc;
         }
 
         valid_node_count = sbi->total_valid_node_count + 1;
         if (unlikely(valid_node_count > sbi->total_node_count)) {
                 spin_unlock(&sbi->stat_lock);
-                return false;
+                goto enospc;
         }
 
+        sbi->total_valid_node_count++;
+        sbi->total_valid_block_count++;
+        spin_unlock(&sbi->stat_lock);
+
         if (inode) {
                 if (is_inode)
                         f2fs_mark_inode_dirty_sync(inode, true);
                 else
-                        f2fs_i_blocks_write(inode, 1, true);
+                        f2fs_i_blocks_write(inode, 1, true, true);
         }
 
-        sbi->total_valid_node_count++;
-        sbi->total_valid_block_count++;
-        spin_unlock(&sbi->stat_lock);
-
         percpu_counter_inc(&sbi->alloc_valid_block_count);
-        return true;
+        return 0;
+
+enospc:
+        if (quota)
+                dquot_release_reservation_block(inode, 1);
+        return -ENOSPC;
 }
 
 static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
@@ -1599,12 +1633,13 @@ static inline void dec_valid_node_count(struct f2fs_sb_info *sbi,
         f2fs_bug_on(sbi, !sbi->total_valid_node_count);
         f2fs_bug_on(sbi, !is_inode && !inode->i_blocks);
 
-        if (!is_inode)
-                f2fs_i_blocks_write(inode, 1, false);
         sbi->total_valid_node_count--;
         sbi->total_valid_block_count--;
 
         spin_unlock(&sbi->stat_lock);
+
+        if (!is_inode)
+                f2fs_i_blocks_write(inode, 1, false, true);
 }
 
 static inline unsigned int valid_node_count(struct f2fs_sb_info *sbi)
@@ -1879,14 +1914,21 @@ static inline void f2fs_i_links_write(struct inode *inode, bool inc)
 }
 
 static inline void f2fs_i_blocks_write(struct inode *inode,
-                                        block_t diff, bool add)
+                                        block_t diff, bool add, bool claim)
 {
         bool clean = !is_inode_flag_set(inode, FI_DIRTY_INODE);
         bool recover = is_inode_flag_set(inode, FI_AUTO_RECOVER);
-        blkcnt_t sectors = diff << F2FS_LOG_SECTORS_PER_BLOCK;
 
-        inode->i_blocks = add ? inode->i_blocks + sectors :
-                                inode->i_blocks - sectors;
+        /* add = 1, claim = 1 should be dquot_reserve_block in pair */
+        if (add) {
+                if (claim)
+                        dquot_claim_block(inode, diff);
+                else
+                        dquot_alloc_block_nofail(inode, diff);
+        } else {
+                dquot_free_block(inode, diff);
+        }
+
         f2fs_mark_inode_dirty_sync(inode, true);
         if (clean || recover)
                 set_inode_flag(inode, FI_AUTO_RECOVER);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 3f56b27e761b..527c9f36d971 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -442,11 +442,10 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
 
 static int f2fs_file_open(struct inode *inode, struct file *filp)
 {
-        int ret = generic_file_open(inode, filp);
         struct dentry *dir;
 
-        if (!ret && f2fs_encrypted_inode(inode)) {
-                ret = fscrypt_get_encryption_info(inode);
+        if (f2fs_encrypted_inode(inode)) {
+                int ret = fscrypt_get_encryption_info(inode);
                 if (ret)
                         return -EACCES;
                 if (!fscrypt_has_encryption_key(inode))
@@ -459,7 +458,7 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
                 return -EPERM;
         }
         dput(dir);
-        return ret;
+        return dquot_file_open(inode, filp);
 }
 
 int truncate_data_blocks_range(struct dnode_of_data *dn, int count)
@@ -710,6 +709,20 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
         if (err)
                 return err;
 
+        if (is_quota_modification(inode, attr)) {
+                err = dquot_initialize(inode);
+                if (err)
+                        return err;
+        }
+        if ((attr->ia_valid & ATTR_UID &&
+                !uid_eq(attr->ia_uid, inode->i_uid)) ||
+                (attr->ia_valid & ATTR_GID &&
+                !gid_eq(attr->ia_gid, inode->i_gid))) {
+                err = dquot_transfer(inode, attr);
+                if (err)
+                        return err;
+        }
+
         if (attr->ia_valid & ATTR_SIZE) {
                 if (f2fs_encrypted_inode(inode)) {
                         err = fscrypt_get_encryption_info(inode);
@@ -996,9 +1009,9 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode,
 
                                 if (do_replace[i]) {
                                         f2fs_i_blocks_write(src_inode,
-                                                                1, false);
+                                                        1, false, false);
                                         f2fs_i_blocks_write(dst_inode,
-                                                                1, true);
+                                                        1, true, false);
                                         f2fs_replace_block(sbi, &dn, dn.data_blkaddr,
                                         blkaddr[i], ni.version, true, false);
 
@@ -1523,6 +1536,13 @@ static int f2fs_ioc_setflags(struct file *filp, unsigned long arg)
 
         inode_lock(inode);
 
+        /* Is it quota file? Do not allow user to mess with it */
+        if (IS_NOQUOTA(inode)) {
+                inode_unlock(inode);
+                ret = -EPERM;
+                goto unlock_out;
+        }
+
         flags = f2fs_mask_flags(inode->i_mode, flags);
 
         oldflags = fi->i_flags;
@@ -1542,7 +1562,7 @@ static int f2fs_ioc_setflags(struct file *filp, unsigned long arg)
         inode->i_ctime = current_time(inode);
         f2fs_set_inode_flags(inode);
         f2fs_mark_inode_dirty_sync(inode, false);
-
+unlock_out:
         inode_unlock(inode);
 out:
         mnt_drop_write_file(filp);
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index e42a7a8805dc..6cd312a17c69 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -373,6 +373,8 @@ void f2fs_evict_inode(struct inode *inode)
         if (inode->i_nlink || is_bad_inode(inode))
                 goto no_delete;
 
+        dquot_initialize(inode);
+
         remove_ino_entry(sbi, inode->i_ino, APPEND_INO);
         remove_ino_entry(sbi, inode->i_ino, UPDATE_INO);
 
@@ -405,8 +407,11 @@ retry:
 
         if (err)
                 update_inode_page(inode);
+        dquot_free_inode(inode);
         sb_end_intwrite(inode->i_sb);
 no_delete:
+        dquot_drop(inode);
+
         stat_dec_inline_xattr(inode);
         stat_dec_inline_dir(inode);
         stat_dec_inline_inode(inode);
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index b75dc2f4ad57..760d85223c81 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -15,6 +15,7 @@
 #include <linux/ctype.h>
 #include <linux/dcache.h>
 #include <linux/namei.h>
+#include <linux/quotaops.h>
 
 #include "f2fs.h"
 #include "node.h"
@@ -42,6 +43,8 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
         }
         f2fs_unlock_op(sbi);
 
+        nid_free = true;
+
         inode_init_owner(inode, dir, mode);
 
         inode->i_ino = ino;
@@ -52,10 +55,17 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode)
         err = insert_inode_locked(inode);
         if (err) {
                 err = -EINVAL;
-                nid_free = true;
                 goto fail;
         }
 
+        err = dquot_initialize(inode);
+        if (err)
+                goto fail_drop;
+
+        err = dquot_alloc_inode(inode);
+        if (err)
+                goto fail_drop;
+
         /* If the directory encrypted, then we should encrypt the inode. */
         if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode))
                 f2fs_set_encrypted_inode(inode);
@@ -85,6 +95,16 @@ fail:
                 set_inode_flag(inode, FI_FREE_NID);
         iput(inode);
         return ERR_PTR(err);
+fail_drop:
+        trace_f2fs_new_inode(inode, err);
+        dquot_drop(inode);
+        inode->i_flags |= S_NOQUOTA;
+        if (nid_free)
+                set_inode_flag(inode, FI_FREE_NID);
+        clear_nlink(inode);
+        unlock_new_inode(inode);
+        iput(inode);
+        return ERR_PTR(err);
 }
 
 static int is_multimedia_file(const unsigned char *s, const char *sub)
@@ -136,6 +156,10 @@ static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
         nid_t ino = 0;
         int err;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         inode = f2fs_new_inode(dir, mode);
         if (IS_ERR(inode))
                 return PTR_ERR(inode);
@@ -180,6 +204,10 @@ static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
                         !fscrypt_has_permitted_context(dir, inode))
                 return -EPERM;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         f2fs_balance_fs(sbi, true);
 
         inode->i_ctime = current_time(inode);
@@ -347,6 +375,10 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
 
         trace_f2fs_unlink_enter(dir, dentry);
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         de = f2fs_find_entry(dir, &dentry->d_name, &page);
         if (!de) {
                 if (IS_ERR(page))
@@ -413,6 +445,10 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
         if (disk_link.len > dir->i_sb->s_blocksize)
                 return -ENAMETOOLONG;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         inode = f2fs_new_inode(dir, S_IFLNK | S_IRWXUGO);
         if (IS_ERR(inode))
                 return PTR_ERR(inode);
@@ -500,6 +536,10 @@ static int f2fs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
         struct inode *inode;
         int err;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         inode = f2fs_new_inode(dir, S_IFDIR | mode);
         if (IS_ERR(inode))
                 return PTR_ERR(inode);
@@ -548,6 +588,10 @@ static int f2fs_mknod(struct inode *dir, struct dentry *dentry,
         struct inode *inode;
         int err = 0;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         inode = f2fs_new_inode(dir, mode);
         if (IS_ERR(inode))
                 return PTR_ERR(inode);
@@ -583,6 +627,10 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,
         struct inode *inode;
         int err;
 
+        err = dquot_initialize(dir);
+        if (err)
+                return err;
+
         inode = f2fs_new_inode(dir, mode);
         if (IS_ERR(inode))
                 return PTR_ERR(inode);
@@ -676,6 +724,14 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
                 goto out;
         }
 
+        err = dquot_initialize(old_dir);
+        if (err)
+                goto out;
+
+        err = dquot_initialize(new_dir);
+        if (err)
+                goto out;
+
         old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
         if (!old_entry) {
                 if (IS_ERR(old_page))
@@ -856,6 +912,14 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
                          !fscrypt_has_permitted_context(old_dir, new_inode)))
                 return -EPERM;
 
+        err = dquot_initialize(old_dir);
+        if (err)
+                goto out;
+
+        err = dquot_initialize(new_dir);
+        if (err)
+                goto out;
+
         old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
         if (!old_entry) {
                 if (IS_ERR(old_page))
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index b9f14ba6441f..3ed2f947f5da 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1040,10 +1040,9 @@ struct page *new_node_page(struct dnode_of_data *dn,
         if (!page)
                 return ERR_PTR(-ENOMEM);
 
-        if (unlikely(!inc_valid_node_count(sbi, dn->inode, !ofs))) {
-                err = -ENOSPC;
+        if (unlikely((err = inc_valid_node_count(sbi, dn->inode, !ofs))))
                 goto fail;
-        }
+
 #ifdef CONFIG_F2FS_CHECK_FS
         get_node_info(sbi, dn->nid, &new_ni);
         f2fs_bug_on(sbi, new_ni.blk_addr != NULL_ADDR);
@@ -2210,7 +2209,7 @@ recover_xnid:
         /* 2: update xattr nid in inode */
         remove_free_nid(sbi, new_xnid);
         f2fs_i_xnid_write(inode, new_xnid);
-        if (unlikely(!inc_valid_node_count(sbi, inode, false)))
+        if (unlikely(inc_valid_node_count(sbi, inode, false)))
                 f2fs_bug_on(sbi, 1);
         update_inode_page(inode);
 
@@ -2268,7 +2267,7 @@ retry:
         new_ni = old_ni;
         new_ni.ino = ino;
 
-        if (unlikely(!inc_valid_node_count(sbi, NULL, true)))
+        if (unlikely(inc_valid_node_count(sbi, NULL, true)))
                 WARN_ON(1);
         set_node_addr(sbi, &new_ni, NEW_ADDR, false);
         inc_valid_inode_count(sbi);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index af472f7968d0..dd92170e0d6d 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -22,6 +22,7 @@
 #include <linux/random.h>
 #include <linux/exportfs.h>
 #include <linux/blkdev.h>
+#include <linux/quotaops.h>
 #include <linux/f2fs_fs.h>
 #include <linux/sysfs.h>
 
@@ -106,6 +107,8 @@ enum {
         Opt_fault_injection,
         Opt_lazytime,
         Opt_nolazytime,
+        Opt_usrquota,
+        Opt_grpquota,
         Opt_err,
 };
 
@@ -141,6 +144,8 @@ static match_table_t f2fs_tokens = {
         {Opt_fault_injection, "fault_injection=%u"},
         {Opt_lazytime, "lazytime"},
         {Opt_nolazytime, "nolazytime"},
+        {Opt_usrquota, "usrquota"},
+        {Opt_grpquota, "grpquota"},
         {Opt_err, NULL},
 };
 
@@ -380,6 +385,20 @@ static int parse_options(struct super_block *sb, char *options)
                 case Opt_nolazytime:
                         sb->s_flags &= ~MS_LAZYTIME;
                         break;
+#ifdef CONFIG_QUOTA
+                case Opt_usrquota:
+                        set_opt(sbi, USRQUOTA);
+                        break;
+                case Opt_grpquota:
+                        set_opt(sbi, GRPQUOTA);
+                        break;
+#else
+                case Opt_usrquota:
+                case Opt_grpquota:
+                        f2fs_msg(sb, KERN_INFO,
+                                        "quota operations not supported");
+                        break;
+#endif
                 default:
                         f2fs_msg(sb, KERN_ERR,
                                 "Unrecognized mount option \"%s\" or missing value",
@@ -421,6 +440,10 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
         init_rwsem(&fi->dio_rwsem[WRITE]);
         init_rwsem(&fi->i_mmap_sem);
 
+#ifdef CONFIG_QUOTA
+        memset(&fi->i_dquot, 0, sizeof(fi->i_dquot));
+        fi->i_reserved_quota = 0;
+#endif
         /* Will be used by directory only */
         fi->i_dir_level = F2FS_SB(sb)->dir_level;
         return &fi->vfs_inode;
@@ -561,11 +584,14 @@ static void destroy_device_list(struct f2fs_sb_info *sbi)
         kfree(sbi->devs);
 }
 
+static void f2fs_quota_off_umount(struct super_block *sb);
 static void f2fs_put_super(struct super_block *sb)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(sb);
         int i;
 
+        f2fs_quota_off_umount(sb);
+
         /* prevent remaining shrinker jobs */
         mutex_lock(&sbi->umount_mutex);
 
@@ -782,6 +808,12 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
                 seq_printf(seq, ",fault_injection=%u",
                                 sbi->fault_info.inject_rate);
 #endif
+#ifdef CONFIG_QUOTA
+        if (test_opt(sbi, USRQUOTA))
+                seq_puts(seq, ",usrquota");
+        if (test_opt(sbi, GRPQUOTA))
+                seq_puts(seq, ",grpquota");
+#endif
 
         return 0;
 }
@@ -822,6 +854,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 {
         struct f2fs_sb_info *sbi = F2FS_SB(sb);
         struct f2fs_mount_info org_mount_opt;
+        unsigned long old_sb_flags;
         int err, active_logs;
         bool need_restart_gc = false;
         bool need_stop_gc = false;
@@ -835,6 +868,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
          * need to restore them.
          */
         org_mount_opt = sbi->mount_opt;
+        old_sb_flags = sb->s_flags;
         active_logs = sbi->active_logs;
 
         /* recover superblocks we couldn't write due to previous RO mount */
@@ -860,6 +894,16 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
         if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
                 goto skip;
 
+        if (!f2fs_readonly(sb) && (*flags & MS_RDONLY)) {
+                err = dquot_suspend(sb, -1);
+                if (err < 0)
+                        goto restore_opts;
+        } else {
+                /* dquot_resume needs RW */
+                sb->s_flags &= ~MS_RDONLY;
+                dquot_resume(sb, -1);
+        }
+
         /* disallow enable/disable extent_cache dynamically */
         if (no_extent_cache == !!test_opt(sbi, EXTENT_CACHE)) {
                 err = -EINVAL;
@@ -924,12 +968,237 @@ restore_gc:
 restore_opts:
         sbi->mount_opt = org_mount_opt;
         sbi->active_logs = active_logs;
+        sb->s_flags = old_sb_flags;
 #ifdef CONFIG_F2FS_FAULT_INJECTION
         sbi->fault_info = ffi;
 #endif
         return err;
 }
 
+#ifdef CONFIG_QUOTA
+/* Read data from quotafile */
+static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data,
+                               size_t len, loff_t off)
+{
+        struct inode *inode = sb_dqopt(sb)->files[type];
+        struct address_space *mapping = inode->i_mapping;
+        block_t blkidx = F2FS_BYTES_TO_BLK(off);
+        int offset = off & (sb->s_blocksize - 1);
+        int tocopy;
+        size_t toread;
+        loff_t i_size = i_size_read(inode);
+        struct page *page;
+        char *kaddr;
+
+        if (off > i_size)
+                return 0;
+
+        if (off + len > i_size)
+                len = i_size - off;
+        toread = len;
+        while (toread > 0) {
+                tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread);
+repeat:
+                page = read_mapping_page(mapping, blkidx, NULL);
+                if (IS_ERR(page))
+                        return PTR_ERR(page);
+
+                lock_page(page);
+
+                if (unlikely(page->mapping != mapping)) {
+                        f2fs_put_page(page, 1);
+                        goto repeat;
+                }
+                if (unlikely(!PageUptodate(page))) {
+                        f2fs_put_page(page, 1);
+                        return -EIO;
+                }
+
+                kaddr = kmap_atomic(page);
+                memcpy(data, kaddr + offset, tocopy);
+                kunmap_atomic(kaddr);
+                f2fs_put_page(page, 1);
+
+                offset = 0;
+                toread -= tocopy;
+                data += tocopy;
+                blkidx++;
+        }
+        return len;
+}
+
+/* Write to quotafile */
+static ssize_t f2fs_quota_write(struct super_block *sb, int type,
+                                const char *data, size_t len, loff_t off)
+{
+        struct inode *inode = sb_dqopt(sb)->files[type];
+        struct address_space *mapping = inode->i_mapping;
+        const struct address_space_operations *a_ops = mapping->a_ops;
+        int offset = off & (sb->s_blocksize - 1);
+        size_t towrite = len;
+        struct page *page;
+        char *kaddr;
+        int err = 0;
+        int tocopy;
+
+        while (towrite > 0) {
+                tocopy = min_t(unsigned long, sb->s_blocksize - offset,
+                                                                towrite);
+
+                err = a_ops->write_begin(NULL, mapping, off, tocopy, 0,
+                                                        &page, NULL);
+                if (unlikely(err))
+                        break;
+
+                kaddr = kmap_atomic(page);
+                memcpy(kaddr + offset, data, tocopy);
+                kunmap_atomic(kaddr);
+                flush_dcache_page(page);
+
+                a_ops->write_end(NULL, mapping, off, tocopy, tocopy,
+                                                page, NULL);
+                offset = 0;
+                towrite -= tocopy;
+                off += tocopy;
+                data += tocopy;
+                cond_resched();
+        }
+
+        if (len == towrite)
+                return err;
+        inode->i_version++;
+        inode->i_mtime = inode->i_ctime = current_time(inode);
+        f2fs_mark_inode_dirty_sync(inode, false);
+        return len - towrite;
+}
+
+static struct dquot **f2fs_get_dquots(struct inode *inode)
+{
+        return F2FS_I(inode)->i_dquot;
+}
+
+static qsize_t *f2fs_get_reserved_space(struct inode *inode)
+{
+        return &F2FS_I(inode)->i_reserved_quota;
+}
+
+static int f2fs_quota_sync(struct super_block *sb, int type)
+{
+        struct quota_info *dqopt = sb_dqopt(sb);
+        int cnt;
+        int ret;
+
+        ret = dquot_writeback_dquots(sb, type);
+        if (ret)
+                return ret;
+
+        /*
+         * Now when everything is written we can discard the pagecache so
+         * that userspace sees the changes.
+         */
+        for (cnt = 0; cnt < MAXQUOTAS; cnt++) {
+                if (type != -1 && cnt != type)
+                        continue;
+                if (!sb_has_quota_active(sb, cnt))
+                        continue;
+
+                ret = filemap_write_and_wait(dqopt->files[cnt]->i_mapping);
+                if (ret)
+                        return ret;
+
+                inode_lock(dqopt->files[cnt]);
+                truncate_inode_pages(&dqopt->files[cnt]->i_data, 0);
+                inode_unlock(dqopt->files[cnt]);
+        }
+        return 0;
+}
+
+static int f2fs_quota_on(struct super_block *sb, int type, int format_id,
+                                                        const struct path *path)
+{
+        struct inode *inode;
+        int err;
+
+        err = f2fs_quota_sync(sb, -1);
+        if (err)
+                return err;
+
+        err = dquot_quota_on(sb, type, format_id, path);
+        if (err)
+                return err;
+
+        inode = d_inode(path->dentry);
+
+        inode_lock(inode);
+        F2FS_I(inode)->i_flags |= FS_NOATIME_FL | FS_IMMUTABLE_FL;
+        inode_set_flags(inode, S_NOATIME | S_IMMUTABLE,
+                                        S_NOATIME | S_IMMUTABLE);
+        inode_unlock(inode);
+        f2fs_mark_inode_dirty_sync(inode, false);
+
+        return 0;
+}
+
+static int f2fs_quota_off(struct super_block *sb, int type)
+{
+        struct inode *inode = sb_dqopt(sb)->files[type];
+        int err;
+
+        if (!inode || !igrab(inode))
+                return dquot_quota_off(sb, type);
+
+        f2fs_quota_sync(sb, -1);
+
+        err = dquot_quota_off(sb, type);
+        if (err)
+                goto out_put;
+
+        inode_lock(inode);
+        F2FS_I(inode)->i_flags &= ~(FS_NOATIME_FL | FS_IMMUTABLE_FL);
+        inode_set_flags(inode, 0, S_NOATIME | S_IMMUTABLE);
+        inode_unlock(inode);
+        f2fs_mark_inode_dirty_sync(inode, false);
+out_put:
+        iput(inode);
+        return err;
+}
+
+static void f2fs_quota_off_umount(struct super_block *sb)
+{
+        int type;
+
+        for (type = 0; type < MAXQUOTAS; type++)
+                f2fs_quota_off(sb, type);
+}
+
+static const struct dquot_operations f2fs_quota_operations = {
+        .get_reserved_space = f2fs_get_reserved_space,
+        .write_dquot    = dquot_commit,
+        .acquire_dquot  = dquot_acquire,
+        .release_dquot  = dquot_release,
+        .mark_dirty     = dquot_mark_dquot_dirty,
+        .write_info     = dquot_commit_info,
+        .alloc_dquot    = dquot_alloc,
+        .destroy_dquot  = dquot_destroy,
+        .get_next_id    = dquot_get_next_id,
+};
+
+static const struct quotactl_ops f2fs_quotactl_ops = {
+        .quota_on       = f2fs_quota_on,
+        .quota_off      = f2fs_quota_off,
+        .quota_sync     = f2fs_quota_sync,
+        .get_state      = dquot_get_state,
+        .set_info       = dquot_set_dqinfo,
+        .get_dqblk      = dquot_get_dqblk,
+        .set_dqblk      = dquot_set_dqblk,
+        .get_nextdqblk  = dquot_get_next_dqblk,
+};
+#else
+static inline void f2fs_quota_off_umount(struct super_block *sb)
+{
+}
+#endif
+
 static struct super_operations f2fs_sops = {
         .alloc_inode    = f2fs_alloc_inode,
         .drop_inode     = f2fs_drop_inode,
@@ -937,6 +1206,11 @@ static struct super_operations f2fs_sops = {
         .write_inode    = f2fs_write_inode,
         .dirty_inode    = f2fs_dirty_inode,
         .show_options   = f2fs_show_options,
+#ifdef CONFIG_QUOTA
+        .quota_read     = f2fs_quota_read,
+        .quota_write    = f2fs_quota_write,
+        .get_dquots     = f2fs_get_dquots,
+#endif
         .evict_inode    = f2fs_evict_inode,
         .put_super      = f2fs_put_super,
         .sync_fs        = f2fs_sync_fs,
@@ -1679,6 +1953,12 @@ try_onemore:
         sb->s_max_links = F2FS_LINK_MAX;
         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 
+#ifdef CONFIG_QUOTA
+        sb->dq_op = &f2fs_quota_operations;
+        sb->s_qcop = &f2fs_quotactl_ops;
+        sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+#endif
+
         sb->s_op = &f2fs_sops;
         sb->s_cop = &f2fs_cryptops;
         sb->s_xattr = f2fs_xattr_handlers;