+Index: bionic/fs/ext4/ext4.h
+===================================================================
+--- bionic.orig/fs/ext4/ext4.h
++++ bionic/fs/ext4/ext4.h
+@@ -2669,6 +2669,7 @@ extern int ext4_ind_remove_space(handle_
+ /* ioctl.c */
+ extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
+ extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
++extern int ext4_ioctl_setproject(struct inode *, __u32);
+
+ /* migrate.c */
+ extern int ext4_ext_migrate(struct inode *);
+Index: bionic/fs/ext4/ioctl.c
+===================================================================
+--- bionic.orig/fs/ext4/ioctl.c
++++ bionic/fs/ext4/ioctl.c
+@@ -315,9 +315,8 @@ flags_out:
+ }
+
+ #ifdef CONFIG_QUOTA
+-static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
++int ext4_ioctl_setproject(struct inode *inode, __u32 projid)
+ {
+- struct inode *inode = file_inode(filp);
+ struct super_block *sb = inode->i_sb;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int err, rc;
+@@ -344,19 +343,14 @@ static int ext4_ioctl_setproject(struct
+ if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
+ return 0;
+
+- err = mnt_want_write_file(filp);
+- if (err)
+- return err;
+-
+ err = -EPERM;
+- inode_lock(inode);
+ /* Is it quota file? Do not allow user to mess with it */
+ if (ext4_is_quota_file(inode))
+- goto out_unlock;
++ goto out;
+
+ err = ext4_get_inode_loc(inode, &iloc);
+ if (err)
+- goto out_unlock;
++ goto out;
+
+ raw_inode = ext4_raw_inode(&iloc);
+ if (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) {
+@@ -364,7 +358,7 @@ static int ext4_ioctl_setproject(struct
+ EXT4_SB(sb)->s_want_extra_isize,
+ &iloc);
+ if (err)
+- goto out_unlock;
++ goto out;
+ } else {
+ brelse(iloc.bh);
+ }
+@@ -376,7 +370,7 @@ static int ext4_ioctl_setproject(struct
+ EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
+ if (IS_ERR(handle)) {
+ err = PTR_ERR(handle);
+- goto out_unlock;
++ goto out;
+ }
+
+ err = ext4_reserve_inode_write(handle, inode, &iloc);
+@@ -405,13 +399,11 @@ out_dirty:
+ err = rc;
+ out_stop:
+ ext4_journal_stop(handle);
+-out_unlock:
+- inode_unlock(inode);
+- mnt_drop_write_file(filp);
++out:
+ return err;
+ }
+ #else
+-static int ext4_ioctl_setproject(struct file *filp, __u32 projid)
++static int ext4_ioctl_setproject(struct inode *inode, __u32 projid)
+ {
+ if (projid != EXT4_DEF_PROJID)
+ return -EOPNOTSUPP;
+@@ -1037,7 +1029,14 @@ resizefs_out:
+ if (err)
+ return err;
+
++ err = mnt_want_write_file(filp);
++ if (err)
++ return err;
++
++ inode_lock(inode);
+ err = ext4_ioctl_setproject(filp, fa.fsx_projid);
++ inode_unlock(inode);
++ mnt_drop_write_file(filp);
+ if (err)
+ return err;
+
+Index: bionic/fs/ext4/xattr.c
+===================================================================
+--- bionic.orig/fs/ext4/xattr.c
++++ bionic/fs/ext4/xattr.c
+@@ -61,6 +61,8 @@
+ #include "xattr.h"
+ #include "acl.h"
+
++#define EXT4_XATTR_PROJID "projid"
++
+ #ifdef EXT4_XATTR_DEBUG
+ # define ea_idebug(inode, fmt, ...) \
+ printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \
+@@ -644,11 +646,30 @@ ext4_xattr_get(struct inode *inode, int
+ return -ERANGE;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
++ if (name_index == EXT4_XATTR_INDEX_TRUSTED &&
++ strncmp(name, EXT4_XATTR_PROJID, strlen(name)) == 0 &&
++ ext4_has_feature_project(inode->i_sb)) {
++ /* 10 chars to hold u32 in decimal, plus ending \0 */
++ char value[11];
++ __u32 projid = (__u32)from_kprojid(&init_user_ns,
++ EXT4_I(inode)->i_projid);
++ error = snprintf(value, sizeof(value), "%u", projid);
++ if (buffer) {
++ if (error > buffer_size) {
++ error = -ERANGE;
++ goto out;
++ }
++ memcpy(buffer, value, error);
++ }
++ goto out;
++ }
++
+ error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
+ buffer_size);
+ if (error == -ENODATA)
+ error = ext4_xattr_block_get(inode, name_index, name, buffer,
+ buffer_size);
++out:
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return error;
+ }
+@@ -773,7 +794,33 @@ ext4_listxattr(struct dentry *dentry, ch
+ ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
+ if (ret < 0)
+ goto errout;
++ if (buffer) {
++ buffer += ret;
++ buffer_size -= ret;
++ }
+ ret += ret2;
++ if (ext4_has_feature_project(dentry->d_sb)) {
++ size_t prefix_len = strlen(XATTR_TRUSTED_PREFIX);
++ size_t name_len = strlen(EXT4_XATTR_PROJID);
++ size_t size = prefix_len + name_len + 1;
++
++ if (__kprojid_val(EXT4_I(dentry->d_inode)->i_projid) ==
++ EXT4_DEF_PROJID)
++ goto errout;
++ if (buffer) {
++ if (size > buffer_size) {
++ ret = -ERANGE;
++ goto errout;
++ }
++ strncpy(buffer, XATTR_TRUSTED_PREFIX, prefix_len);
++ buffer += prefix_len;
++ strncpy(buffer, EXT4_XATTR_PROJID, name_len);
++ buffer += name_len;
++ *buffer++ = 0;
++ buffer_size -= size;
++ }
++ ret += size;
++ }
+ errout:
+ up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
+ return ret;
+@@ -2487,6 +2534,43 @@ ext4_xattr_set(struct inode *inode, int
+ int error, retries = 0;
+ int credits;
+
++ if (name_index == EXT4_XATTR_INDEX_TRUSTED &&
++ strncmp(name, EXT4_XATTR_PROJID, strlen(name)) == 0 &&
++ ext4_has_feature_project(inode->i_sb)) {
++ /* 10 chars to hold u32 in decimal, plus ending \0 */
++ char buffer[11];
++ __u32 projid;
++
++ /*
++ * Project Quota ID state is only allowed to change from within
++ * the init namespace.
++ */
++ if (current_user_ns() != &init_user_ns)
++ return -EINVAL;
++
++ if (value && value_len) {
++ if (value_len >= sizeof(buffer))
++ return -EINVAL;
++ memcpy(buffer, value, value_len);
++ buffer[value_len] = '\0';
++ error = kstrtouint(buffer, 0, &projid);
++ if (error)
++ return error;
++ } else {
++ projid = EXT4_DEF_PROJID;
++ }
++
++ /*
++ * Caller is allowed to change the project ID. If it is being
++ * changed, make sure that the new value is valid.
++ */
++ if (!projid_valid(make_kprojid(&init_user_ns, projid)))
++ return -EINVAL;
++
++ error = ext4_ioctl_setproject(inode, projid);
++ return error;
++ }
++
+ error = dquot_initialize(inode);
+ if (error)
+ return error;