Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Some locking and page fault bug fixes from Jan Kara, some ext4
  encryption fixes from me, and Li Xi's Project Quota commits"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  fs: clean up the flags definition in uapi/linux/fs.h
  ext4: add FS_IOC_FSSETXATTR/FS_IOC_FSGETXATTR interface support
  ext4: add project quota support
  ext4: adds project ID support
  ext4 crypto: simplify interfaces to directory entry insert functions
  ext4 crypto: add missing locking for keyring_key access
  ext4: use pre-zeroed blocks for DAX page faults
  ext4: implement allocation of pre-zeroed blocks
  ext4: provide ext4_issue_zeroout()
  ext4: get rid of EXT4_GET_BLOCKS_NO_LOCK flag
  ext4: document lock ordering
  ext4: fix races of writeback with punch hole and zero range
  ext4: fix races between buffered IO and collapse / insert range
  ext4: move unlocked dio protection from ext4_alloc_file_blocks()
  ext4: fix races between page faults and hole punching

fs/ext4/crypto.c

@@ -384,14 +384,12 @@ int ext4_decrypt(struct page *page)
 				EXT4_DECRYPT, page->index, page, page);
 }
 
-int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
+int ext4_encrypted_zeroout(struct inode *inode, ext4_lblk_t lblk,
+			   ext4_fsblk_t pblk, ext4_lblk_t len)
 {
 	struct ext4_crypto_ctx	*ctx;
 	struct page		*ciphertext_page = NULL;
 	struct bio		*bio;
-	ext4_lblk_t		lblk = le32_to_cpu(ex->ee_block);
-	ext4_fsblk_t		pblk = ext4_ext_pblock(ex);
-	unsigned int		len = ext4_ext_get_actual_len(ex);
 	int			ret, err = 0;
 
 #if 0

fs/ext4/crypto_key.c

@@ -213,9 +213,11 @@ int _ext4_get_encryption_info(struct inode *inode)
 		res = -ENOKEY;
 		goto out;
 	}
+	down_read(&keyring_key->sem);
 	ukp = user_key_payload(keyring_key);
 	if (ukp->datalen != sizeof(struct ext4_encryption_key)) {
 		res = -EINVAL;
+		up_read(&keyring_key->sem);
 		goto out;
 	}
 	master_key = (struct ext4_encryption_key *)ukp->data;
@@ -226,10 +228,12 @@ int _ext4_get_encryption_info(struct inode *inode)
 			    "ext4: key size incorrect: %d\n",
 			    master_key->size);
 		res = -ENOKEY;
+		up_read(&keyring_key->sem);
 		goto out;
 	}
 	res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
 				  raw_key);
+	up_read(&keyring_key->sem);
 	if (res)
 		goto out;
 got_key:

fs/ext4/ext4.h

@@ -378,14 +378,22 @@ struct flex_groups {
 #define EXT4_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
 
-#define EXT4_FL_USER_VISIBLE		0x004BDFFF /* User visible flags */
-#define EXT4_FL_USER_MODIFIABLE		0x004380FF /* User modifiable flags */
+#define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
+#define EXT4_FL_USER_MODIFIABLE		0x204380FF /* User modifiable flags */
+
+#define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
+					 EXT4_IMMUTABLE_FL | \
+					 EXT4_APPEND_FL | \
+					 EXT4_NODUMP_FL | \
+					 EXT4_NOATIME_FL | \
+					 EXT4_PROJINHERIT_FL)
 
 /* Flags that should be inherited by new inodes from their parent. */
 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
 			   EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
 			   EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
-			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
+			   EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
+			   EXT4_PROJINHERIT_FL)
 
 /* Flags that are appropriate for regular files (all but dir-specific ones). */
 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
@@ -555,10 +563,12 @@ enum {
 #define EXT4_GET_BLOCKS_NO_NORMALIZE		0x0040
 	/* Request will not result in inode size update (user for fallocate) */
 #define EXT4_GET_BLOCKS_KEEP_SIZE		0x0080
-	/* Do not take i_data_sem locking in ext4_map_blocks */
-#define EXT4_GET_BLOCKS_NO_LOCK			0x0100
 	/* Convert written extents to unwritten */
-#define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0200
+#define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN	0x0100
+	/* Write zeros to newly created written extents */
+#define EXT4_GET_BLOCKS_ZERO			0x0200
+#define EXT4_GET_BLOCKS_CREATE_ZERO		(EXT4_GET_BLOCKS_CREATE |\
+					EXT4_GET_BLOCKS_ZERO)
 
 /*
  * The bit position of these flags must not overlap with any of the
@@ -616,6 +626,46 @@ enum {
 #define EXT4_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
 #define EXT4_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct ext4_encryption_policy)
 
+#ifndef FS_IOC_FSGETXATTR
+/* Until the uapi changes get merged for project quota... */
+
+#define FS_IOC_FSGETXATTR		_IOR('X', 31, struct fsxattr)
+#define FS_IOC_FSSETXATTR		_IOW('X', 32, struct fsxattr)
+
+/*
+ * Structure for FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR.
+ */
+struct fsxattr {
+	__u32		fsx_xflags;	/* xflags field value (get/set) */
+	__u32		fsx_extsize;	/* extsize field value (get/set)*/
+	__u32		fsx_nextents;	/* nextents field value (get)	*/
+	__u32		fsx_projid;	/* project identifier (get/set) */
+	unsigned char	fsx_pad[12];
+};
+
+/*
+ * Flags for the fsx_xflags field
+ */
+#define FS_XFLAG_REALTIME	0x00000001	/* data in realtime volume */
+#define FS_XFLAG_PREALLOC	0x00000002	/* preallocated file extents */
+#define FS_XFLAG_IMMUTABLE	0x00000008	/* file cannot be modified */
+#define FS_XFLAG_APPEND		0x00000010	/* all writes append */
+#define FS_XFLAG_SYNC		0x00000020	/* all writes synchronous */
+#define FS_XFLAG_NOATIME	0x00000040	/* do not update access time */
+#define FS_XFLAG_NODUMP		0x00000080	/* do not include in backups */
+#define FS_XFLAG_RTINHERIT	0x00000100	/* create with rt bit set */
+#define FS_XFLAG_PROJINHERIT	0x00000200	/* create with parents projid */
+#define FS_XFLAG_NOSYMLINKS	0x00000400	/* disallow symlink creation */
+#define FS_XFLAG_EXTSIZE	0x00000800	/* extent size allocator hint */
+#define FS_XFLAG_EXTSZINHERIT	0x00001000	/* inherit inode extent size */
+#define FS_XFLAG_NODEFRAG	0x00002000  	/* do not defragment */
+#define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
+#define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this */
+#endif /* !defined(FS_IOC_FSGETXATTR) */
+
+#define EXT4_IOC_FSGETXATTR		FS_IOC_FSGETXATTR
+#define EXT4_IOC_FSSETXATTR		FS_IOC_FSSETXATTR
+
 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
 /*
  * ioctl commands in 32 bit emulation
@@ -910,6 +960,15 @@ struct ext4_inode_info {
 	 * by other means, so we have i_data_sem.
 	 */
 	struct rw_semaphore i_data_sem;
+	/*
+	 * i_mmap_sem is for serializing page faults with truncate / punch hole
+	 * operations. We have to make sure that new page cannot be faulted in
+	 * a section of the inode that is being punched. We cannot easily use
+	 * i_data_sem for this since we need protection for the whole punch
+	 * operation and i_data_sem ranks below transaction start so we have
+	 * to occasionally drop it.
+	 */
+	struct rw_semaphore i_mmap_sem;
 	struct inode vfs_inode;
 	struct jbd2_inode *jinode;
 
@@ -993,6 +1052,7 @@ struct ext4_inode_info {
 	/* Encryption params */
 	struct ext4_crypt_info *i_crypt_info;
 #endif
+	kprojid_t i_projid;
 };
 
 /*
@@ -1248,7 +1308,7 @@ struct ext4_super_block {
 #endif
 
 /* Number of quota types we support */
-#define EXT4_MAXQUOTAS 2
+#define EXT4_MAXQUOTAS 3
 
 /*
  * fourth extended-fs super-block data in memory
@@ -1754,7 +1814,8 @@ EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,		ENCRYPT)
 					 EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
 					 EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
 					 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
-					 EXT4_FEATURE_RO_COMPAT_QUOTA)
+					 EXT4_FEATURE_RO_COMPAT_QUOTA |\
+					 EXT4_FEATURE_RO_COMPAT_PROJECT)
 
 #define EXTN_FEATURE_FUNCS(ver) \
 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
@@ -1796,6 +1857,11 @@ static inline bool ext4_has_incompat_features(struct super_block *sb)
 #define	EXT4_DEF_RESUID		0
 #define	EXT4_DEF_RESGID		0
 
+/*
+ * Default project ID
+ */
+#define	EXT4_DEF_PROJID		0
+
 #define EXT4_DEF_INODE_READAHEAD_BLKS	32
 
 /*
@@ -2234,7 +2300,8 @@ void ext4_restore_control_page(struct page *data_page);
 struct page *ext4_encrypt(struct inode *inode,
 			  struct page *plaintext_page);
 int ext4_decrypt(struct page *page);
-int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex);
+int ext4_encrypted_zeroout(struct inode *inode, ext4_lblk_t lblk,
+			   ext4_fsblk_t pblk, ext4_lblk_t len);
 
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 int ext4_init_crypto(void);
@@ -2440,8 +2507,8 @@ struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
 int ext4_get_block_write(struct inode *inode, sector_t iblock,
 			 struct buffer_head *bh_result, int create);
-int ext4_get_block_dax(struct inode *inode, sector_t iblock,
-			 struct buffer_head *bh_result, int create);
+int ext4_dax_mmap_get_block(struct inode *inode, sector_t iblock,
+			    struct buffer_head *bh_result, int create);
 int ext4_get_block(struct inode *inode, sector_t iblock,
 				struct buffer_head *bh_result, int create);
 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
@@ -2484,9 +2551,13 @@ extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
 			     loff_t lstart, loff_t lend);
 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
+extern int ext4_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
+extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
 extern void ext4_da_update_reserve_space(struct inode *inode,
 					int used, int quota_claim);
+extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
+			      ext4_fsblk_t pblk, ext4_lblk_t len);
 
 /* indirect.c */
 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
@@ -2848,6 +2919,9 @@ static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
 	return changed;
 }
 
+int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
+				      loff_t len);
+
 struct ext4_group_info {
 	unsigned long   bb_state;
 	struct rb_root  bb_free_root;
@@ -2986,8 +3060,7 @@ extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
 					 struct page *page);
 extern int ext4_try_add_inline_entry(handle_t *handle,
 				     struct ext4_filename *fname,
-				     struct dentry *dentry,
-				     struct inode *inode);
+				     struct inode *dir, struct inode *inode);
 extern int ext4_try_create_inline_dir(handle_t *handle,
 				      struct inode *parent,
 				      struct inode *inode);

fs/ext4/extents.c

@@ -3119,19 +3119,11 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
 {
 	ext4_fsblk_t ee_pblock;
 	unsigned int ee_len;
-	int ret;
 
 	ee_len    = ext4_ext_get_actual_len(ex);
 	ee_pblock = ext4_ext_pblock(ex);
-
-	if (ext4_encrypted_inode(inode))
-		return ext4_encrypted_zeroout(inode, ex);
-
-	ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
-	if (ret > 0)
-		ret = 0;
-
-	return ret;
+	return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
+				  ee_len);
 }
 
 /*
@@ -4052,6 +4044,14 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
 	}
 	/* IO end_io complete, convert the filled extent to written */
 	if (flags & EXT4_GET_BLOCKS_CONVERT) {
+		if (flags & EXT4_GET_BLOCKS_ZERO) {
+			if (allocated > map->m_len)
+				allocated = map->m_len;
+			err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
+						 allocated);
+			if (err < 0)
+				goto out2;
+		}
 		ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
 							   ppath);
 		if (ret >= 0) {
@@ -4685,10 +4685,6 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 	if (len <= EXT_UNWRITTEN_MAX_LEN)
 		flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
 
-	/* Wait all existing dio workers, newcomers will block on i_mutex */
-	ext4_inode_block_unlocked_dio(inode);
-	inode_dio_wait(inode);
-
 	/*
 	 * credits to insert 1 extent into extent tree
 	 */
@@ -4752,8 +4748,6 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 		goto retry;
 	}
 
-	ext4_inode_resume_unlocked_dio(inode);
-
 	return ret > 0 ? ret2 : ret;
 }
 
@@ -4770,7 +4764,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	int partial_begin, partial_end;
 	loff_t start, end;
 	ext4_lblk_t lblk;
-	struct address_space *mapping = inode->i_mapping;
 	unsigned int blkbits = inode->i_blkbits;
 
 	trace_ext4_zero_range(inode, offset, len, mode);
@@ -4785,17 +4778,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 			return ret;
 	}
 
-	/*
-	 * Write out all dirty pages to avoid race conditions
-	 * Then release them.
-	 */
-	if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
-		ret = filemap_write_and_wait_range(mapping, offset,
-						   offset + len - 1);
-		if (ret)
-			return ret;
-	}
-
 	/*
 	 * Round up offset. This is not fallocate, we neet to zero out
 	 * blocks, so convert interior block aligned part of the range to
@@ -4839,6 +4821,10 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	if (mode & FALLOC_FL_KEEP_SIZE)
 		flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
 
+	/* Wait all existing dio workers, newcomers will block on i_mutex */
+	ext4_inode_block_unlocked_dio(inode);
+	inode_dio_wait(inode);
+
 	/* Preallocate the range including the unaligned edges */
 	if (partial_begin || partial_end) {
 		ret = ext4_alloc_file_blocks(file,
@@ -4847,7 +4833,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 				 round_down(offset, 1 << blkbits)) >> blkbits,
 				new_size, flags, mode);
 		if (ret)
-			goto out_mutex;
+			goto out_dio;
 
 	}
 
@@ -4856,16 +4842,23 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 		flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
 			  EXT4_EX_NOCACHE);
 
-		/* Now release the pages and zero block aligned part of pages*/
+		/*
+		 * Prevent page faults from reinstantiating pages we have
+		 * released from page cache.
+		 */
+		down_write(&EXT4_I(inode)->i_mmap_sem);
+		ret = ext4_update_disksize_before_punch(inode, offset, len);
+		if (ret) {
+			up_write(&EXT4_I(inode)->i_mmap_sem);
+			goto out_dio;
+		}
+		/* Now release the pages and zero block aligned part of pages */
 		truncate_pagecache_range(inode, start, end - 1);
 		inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 
-		/* Wait all existing dio workers, newcomers will block on i_mutex */
-		ext4_inode_block_unlocked_dio(inode);
-		inode_dio_wait(inode);
-
 		ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
 					     flags, mode);
+		up_write(&EXT4_I(inode)->i_mmap_sem);
 		if (ret)
 			goto out_dio;
 	}
@@ -4998,8 +4991,13 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 			goto out;
 	}
 
+	/* Wait all existing dio workers, newcomers will block on i_mutex */
+	ext4_inode_block_unlocked_dio(inode);
+	inode_dio_wait(inode);
+
 	ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
 				     flags, mode);
+	ext4_inode_resume_unlocked_dio(inode);
 	if (ret)
 		goto out;
 
@@ -5494,21 +5492,7 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 			return ret;
 	}
 
-	/*
-	 * Need to round down offset to be aligned with page size boundary
-	 * for page size > block size.
-	 */
-	ioffset = round_down(offset, PAGE_SIZE);
-
-	/* Write out all dirty pages */
-	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
-					   LLONG_MAX);
-	if (ret)
-		return ret;
-
-	/* Take mutex lock */
 	mutex_lock(&inode->i_mutex);
-
 	/*
 	 * There is no need to overlap collapse range with EOF, in which case
 	 * it is effectively a truncate operation
@@ -5524,17 +5508,43 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 		goto out_mutex;
 	}
 
-	truncate_pagecache(inode, ioffset);
-
 	/* Wait for existing dio to complete */
 	ext4_inode_block_unlocked_dio(inode);
 	inode_dio_wait(inode);
 
+	/*
+	 * Prevent page faults from reinstantiating pages we have released from
+	 * page cache.
+	 */
+	down_write(&EXT4_I(inode)->i_mmap_sem);
+	/*
+	 * Need to round down offset to be aligned with page size boundary
+	 * for page size > block size.
+	 */
+	ioffset = round_down(offset, PAGE_SIZE);
+	/*
+	 * Write tail of the last page before removed range since it will get
+	 * removed from the page cache below.
+	 */
+	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
+	if (ret)
+		goto out_mmap;
+	/*
+	 * Write data that will be shifted to preserve them when discarding
+	 * page cache below. We are also protected from pages becoming dirty
+	 * by i_mmap_sem.
+	 */
+	ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
+					   LLONG_MAX);
+	if (ret)
+		goto out_mmap;
+	truncate_pagecache(inode, ioffset);
+
 	credits = ext4_writepage_trans_blocks(inode);
 	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
 	if (IS_ERR(handle)) {
 		ret = PTR_ERR(handle);
-		goto out_dio;
+		goto out_mmap;
 	}
 
 	down_write(&EXT4_I(inode)->i_data_sem);
@@ -5573,7 +5583,8 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 
 out_stop:
 	ext4_journal_stop(handle);
-out_dio:
+out_mmap:
+	up_write(&EXT4_I(inode)->i_mmap_sem);
 	ext4_inode_resume_unlocked_dio(inode);
 out_mutex:
 	mutex_unlock(&inode->i_mutex);
@@ -5627,21 +5638,7 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 			return ret;
 	}
 
-	/*
-	 * Need to round down to align start offset to page size boundary
-	 * for page size > block size.
-	 */
-	ioffset = round_down(offset, PAGE_SIZE);
-
-	/* Write out all dirty pages */
-	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
-			LLONG_MAX);
-	if (ret)
-		return ret;
-
-	/* Take mutex lock */
 	mutex_lock(&inode->i_mutex);
-
 	/* Currently just for extent based files */
 	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
 		ret = -EOPNOTSUPP;
@@ -5660,17 +5657,32 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 		goto out_mutex;
 	}
 
-	truncate_pagecache(inode, ioffset);
-
 	/* Wait for existing dio to complete */
 	ext4_inode_block_unlocked_dio(inode);
 	inode_dio_wait(inode);
 
+	/*
+	 * Prevent page faults from reinstantiating pages we have released from
+	 * page cache.
+	 */
+	down_write(&EXT4_I(inode)->i_mmap_sem);
+	/*
+	 * Need to round down to align start offset to page size boundary
+	 * for page size > block size.
+	 */
+	ioffset = round_down(offset, PAGE_SIZE);
+	/* Write out all dirty pages */
+	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
+			LLONG_MAX);
+	if (ret)
+		goto out_mmap;
+	truncate_pagecache(inode, ioffset);
+
 	credits = ext4_writepage_trans_blocks(inode);
 	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
 	if (IS_ERR(handle)) {
 		ret = PTR_ERR(handle);
-		goto out_dio;
+		goto out_mmap;
 	}
 
 	/* Expand file to avoid data loss if there is error while shifting */
@@ -5741,7 +5753,8 @@ int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
 
 out_stop:
 	ext4_journal_stop(handle);
-out_dio:
+out_mmap:
+	up_write(&EXT4_I(inode)->i_mmap_sem);
 	ext4_inode_resume_unlocked_dio(inode);
 out_mutex:
 	mutex_unlock(&inode->i_mutex);

fs/ext4/file.c

@@ -193,43 +193,35 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 }
 
 #ifdef CONFIG_FS_DAX
-static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate)
-{
-	struct inode *inode = bh->b_assoc_map->host;
-	/* XXX: breaks on 32-bit > 16TB. Is that even supported? */
-	loff_t offset = (loff_t)(uintptr_t)bh->b_private << inode->i_blkbits;
-	int err;
-	if (!uptodate)
-		return;
-	WARN_ON(!buffer_unwritten(bh));
-	err = ext4_convert_unwritten_extents(NULL, inode, offset, bh->b_size);
-}
-
 static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	int result;
 	handle_t *handle = NULL;
-	struct super_block *sb = file_inode(vma->vm_file)->i_sb;
+	struct inode *inode = file_inode(vma->vm_file);
+	struct super_block *sb = inode->i_sb;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
 
 	if (write) {
 		sb_start_pagefault(sb);
 		file_update_time(vma->vm_file);
+		down_read(&EXT4_I(inode)->i_mmap_sem);
 		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 						EXT4_DATA_TRANS_BLOCKS(sb));
-	}
+	} else
+		down_read(&EXT4_I(inode)->i_mmap_sem);
 
 	if (IS_ERR(handle))
 		result = VM_FAULT_SIGBUS;
 	else
-		result = __dax_fault(vma, vmf, ext4_get_block_dax,
-						ext4_end_io_unwritten);
+		result = __dax_fault(vma, vmf, ext4_dax_mmap_get_block, NULL);
 
 	if (write) {
 		if (!IS_ERR(handle))
 			ext4_journal_stop(handle);
+		up_read(&EXT4_I(inode)->i_mmap_sem);
 		sb_end_pagefault(sb);
-	}
+	} else
+		up_read(&EXT4_I(inode)->i_mmap_sem);
 
 	return result;
 }
@@ -246,44 +238,86 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
 	if (write) {
 		sb_start_pagefault(sb);
 		file_update_time(vma->vm_file);
+		down_read(&EXT4_I(inode)->i_mmap_sem);
 		handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
 				ext4_chunk_trans_blocks(inode,
 							PMD_SIZE / PAGE_SIZE));
-	}
+	} else
+		down_read(&EXT4_I(inode)->i_mmap_sem);
 
 	if (IS_ERR(handle))
 		result = VM_FAULT_SIGBUS;
 	else
 		result = __dax_pmd_fault(vma, addr, pmd, flags,
-				ext4_get_block_dax, ext4_end_io_unwritten);
+				ext4_dax_mmap_get_block, NULL);
 
 	if (write) {
 		if (!IS_ERR(handle))
 			ext4_journal_stop(handle);
+		up_read(&EXT4_I(inode)->i_mmap_sem);
 		sb_end_pagefault(sb);
-	}
+	} else
+		up_read(&EXT4_I(inode)->i_mmap_sem);
 
 	return result;
 }
 
 static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-	return dax_mkwrite(vma, vmf, ext4_get_block_dax,
-				ext4_end_io_unwritten);
+	int err;
+	struct inode *inode = file_inode(vma->vm_file);
+
+	sb_start_pagefault(inode->i_sb);
+	file_update_time(vma->vm_file);
+	down_read(&EXT4_I(inode)->i_mmap_sem);
+	err = __dax_mkwrite(vma, vmf, ext4_dax_mmap_get_block, NULL);
+	up_read(&EXT4_I(inode)->i_mmap_sem);
+	sb_end_pagefault(inode->i_sb);
+
+	return err;
+}
+
+/*
+ * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_mkwrite()
+ * handler we check for races agaist truncate. Note that since we cycle through
+ * i_mmap_sem, we are sure that also any hole punching that began before we
+ * were called is finished by now and so if it included part of the file we
+ * are working on, our pte will get unmapped and the check for pte_same() in
+ * wp_pfn_shared() fails. Thus fault gets retried and things work out as
+ * desired.
+ */
+static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
+				struct vm_fault *vmf)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+	struct super_block *sb = inode->i_sb;
+	int ret = VM_FAULT_NOPAGE;
+	loff_t size;
+
+	sb_start_pagefault(sb);
+	file_update_time(vma->vm_file);
+	down_read(&EXT4_I(inode)->i_mmap_sem);
+	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	if (vmf->pgoff >= size)
+		ret = VM_FAULT_SIGBUS;
+	up_read(&EXT4_I(inode)->i_mmap_sem);
+	sb_end_pagefault(sb);
+
+	return ret;
 }
 
 static const struct vm_operations_struct ext4_dax_vm_ops = {
 	.fault		= ext4_dax_fault,
 	.pmd_fault	= ext4_dax_pmd_fault,
 	.page_mkwrite	= ext4_dax_mkwrite,
-	.pfn_mkwrite	= dax_pfn_mkwrite,
+	.pfn_mkwrite	= ext4_dax_pfn_mkwrite,
 };
 #else
 #define ext4_dax_vm_ops	ext4_file_vm_ops
 #endif
 
 static const struct vm_operations_struct ext4_file_vm_ops = {
-	.fault		= filemap_fault,
+	.fault		= ext4_filemap_fault,
 	.map_pages	= filemap_map_pages,
 	.page_mkwrite   = ext4_page_mkwrite,
 };

fs/ext4/ialloc.c

@@ -799,6 +799,13 @@ struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
 		inode->i_gid = dir->i_gid;
 	} else
 		inode_init_owner(inode, dir, mode);
+
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_PROJECT) &&
+	    ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT))
+		ei->i_projid = EXT4_I(dir)->i_projid;
+	else
+		ei->i_projid = make_kprojid(&init_user_ns, EXT4_DEF_PROJID);
+
 	err = dquot_initialize(inode);
 	if (err)
 		goto out;

fs/ext4/inline.c

@@ -995,12 +995,11 @@ void ext4_show_inline_dir(struct inode *dir, struct buffer_head *bh,
  */
 static int ext4_add_dirent_to_inline(handle_t *handle,
 				     struct ext4_filename *fname,
-				     struct dentry *dentry,
+				     struct inode *dir,
 				     struct inode *inode,
 				     struct ext4_iloc *iloc,
 				     void *inline_start, int inline_size)
 {
-	struct inode	*dir = d_inode(dentry->d_parent);
 	int		err;
 	struct ext4_dir_entry_2 *de;
 
@@ -1245,12 +1244,11 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
  * the new created block.
  */
 int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
-			      struct dentry *dentry, struct inode *inode)
+			      struct inode *dir, struct inode *inode)
 {
 	int ret, inline_size;
 	void *inline_start;
 	struct ext4_iloc iloc;
-	struct inode *dir = d_inode(dentry->d_parent);
 
 	ret = ext4_get_inode_loc(dir, &iloc);
 	if (ret)
@@ -1264,7 +1262,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
 						 EXT4_INLINE_DOTDOT_SIZE;
 	inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
 
-	ret = ext4_add_dirent_to_inline(handle, fname, dentry, inode, &iloc,
+	ret = ext4_add_dirent_to_inline(handle, fname, dir, inode, &iloc,
 					inline_start, inline_size);
 	if (ret != -ENOSPC)
 		goto out;
@@ -1285,7 +1283,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
 	if (inline_size) {
 		inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
 
-		ret = ext4_add_dirent_to_inline(handle, fname, dentry,
+		ret = ext4_add_dirent_to_inline(handle, fname, dir,
 						inode, &iloc, inline_start,
 						inline_size);
 

fs/ext4/namei.c

@@ -273,7 +273,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 		struct ext4_filename *fname,
 		struct ext4_dir_entry_2 **res_dir);
 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
-			     struct dentry *dentry, struct inode *inode);
+			     struct inode *dir, struct inode *inode);
 
 /* checksumming functions */
 void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
@@ -1928,10 +1928,9 @@ static int add_dirent_to_buf(handle_t *handle, struct ext4_filename *fname,
  * directory, and adds the dentry to the indexed directory.
  */
 static int make_indexed_dir(handle_t *handle, struct ext4_filename *fname,
-			    struct dentry *dentry,
+			    struct inode *dir,
 			    struct inode *inode, struct buffer_head *bh)
 {
-	struct inode	*dir = d_inode(dentry->d_parent);
 	struct buffer_head *bh2;
 	struct dx_root	*root;
 	struct dx_frame	frames[2], *frame;
@@ -2086,8 +2085,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 		return retval;
 
 	if (ext4_has_inline_data(dir)) {
-		retval = ext4_try_add_inline_entry(handle, &fname,
-						   dentry, inode);
+		retval = ext4_try_add_inline_entry(handle, &fname, dir, inode);
 		if (retval < 0)
 			goto out;
 		if (retval == 1) {
@@ -2097,7 +2095,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 	}
 
 	if (is_dx(dir)) {
-		retval = ext4_dx_add_entry(handle, &fname, dentry, inode);
+		retval = ext4_dx_add_entry(handle, &fname, dir, inode);
 		if (!retval || (retval != ERR_BAD_DX_DIR))
 			goto out;
 		ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
@@ -2119,7 +2117,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
 
 		if (blocks == 1 && !dx_fallback &&
 		    ext4_has_feature_dir_index(sb)) {
-			retval = make_indexed_dir(handle, &fname, dentry,
+			retval = make_indexed_dir(handle, &fname, dir,
 						  inode, bh);
 			bh = NULL; /* make_indexed_dir releases bh */
 			goto out;
@@ -2154,12 +2152,11 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
  * Returns 0 for success, or a negative error value
  */
 static int ext4_dx_add_entry(handle_t *handle, struct ext4_filename *fname,
-			     struct dentry *dentry, struct inode *inode)
+			     struct inode *dir, struct inode *inode)
 {
 	struct dx_frame frames[2], *frame;
 	struct dx_entry *entries, *at;
 	struct buffer_head *bh;
-	struct inode *dir = d_inode(dentry->d_parent);
 	struct super_block *sb = dir->i_sb;
 	struct ext4_dir_entry_2 *de;
 	int err;
@@ -3212,6 +3209,12 @@ static int ext4_link(struct dentry *old_dentry,
 	if (ext4_encrypted_inode(dir) &&
 	    !ext4_is_child_context_consistent_with_parent(dir, inode))
 		return -EPERM;
+
+       if ((ext4_test_inode_flag(dir, EXT4_INODE_PROJINHERIT)) &&
+	   (!projid_eq(EXT4_I(dir)->i_projid,
+		       EXT4_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
 	err = dquot_initialize(dir);
 	if (err)
 		return err;
@@ -3492,6 +3495,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int credits;
 	u8 old_file_type;
 
+	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT)) &&
+	    (!projid_eq(EXT4_I(new_dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
 	retval = dquot_initialize(old.dir);
 	if (retval)
 		return retval;
@@ -3701,6 +3709,14 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 							   new.inode)))
 		return -EPERM;
 
+	if ((ext4_test_inode_flag(new_dir, EXT4_INODE_PROJINHERIT) &&
+	     !projid_eq(EXT4_I(new_dir)->i_projid,
+			EXT4_I(old_dentry->d_inode)->i_projid)) ||
+	    (ext4_test_inode_flag(old_dir, EXT4_INODE_PROJINHERIT) &&
+	     !projid_eq(EXT4_I(old_dir)->i_projid,
+			EXT4_I(new_dentry->d_inode)->i_projid)))
+		return -EXDEV;
+
 	retval = dquot_initialize(old.dir);
 	if (retval)
 		return retval;

fs/ext4/super.c

@@ -80,6 +80,36 @@ static void ext4_destroy_lazyinit_thread(void);
 static void ext4_unregister_li_request(struct super_block *sb);
 static void ext4_clear_request_list(void);
 
+/*
+ * Lock ordering
+ *
+ * Note the difference between i_mmap_sem (EXT4_I(inode)->i_mmap_sem) and
+ * i_mmap_rwsem (inode->i_mmap_rwsem)!
+ *
+ * page fault path:
+ * mmap_sem -> sb_start_pagefault -> i_mmap_sem (r) -> transaction start ->
+ *   page lock -> i_data_sem (rw)
+ *
+ * buffered write path:
+ * sb_start_write -> i_mutex -> mmap_sem
+ * sb_start_write -> i_mutex -> transaction start -> page lock ->
+ *   i_data_sem (rw)
+ *
+ * truncate:
+ * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
+ *   i_mmap_rwsem (w) -> page lock
+ * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (w) -> i_mmap_sem (w) ->
+ *   transaction start -> i_data_sem (rw)
+ *
+ * direct IO:
+ * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) -> mmap_sem
+ * sb_start_write -> i_mutex -> EXT4_STATE_DIOREAD_LOCK (r) ->
+ *   transaction start -> i_data_sem (rw)
+ *
+ * writepages:
+ * transaction start -> page lock(s) -> i_data_sem (rw)
+ */
+
 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT2)
 static struct file_system_type ext2_fs_type = {
 	.owner		= THIS_MODULE,
@@ -958,6 +988,7 @@ static void init_once(void *foo)
 	INIT_LIST_HEAD(&ei->i_orphan);
 	init_rwsem(&ei->xattr_sem);
 	init_rwsem(&ei->i_data_sem);
+	init_rwsem(&ei->i_mmap_sem);
 	inode_init_once(&ei->vfs_inode);
 }
 
@@ -1066,8 +1097,8 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 }
 
 #ifdef CONFIG_QUOTA
-#define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
-#define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
+static char *quotatypes[] = INITQFNAMES;
+#define QTYPE2NAME(t) (quotatypes[t])
 
 static int ext4_write_dquot(struct dquot *dquot);
 static int ext4_acquire_dquot(struct dquot *dquot);
@@ -1100,6 +1131,7 @@ static const struct dquot_operations ext4_quota_operations = {
 	.write_info	= ext4_write_info,
 	.alloc_dquot	= dquot_alloc,
 	.destroy_dquot	= dquot_destroy,
+	.get_projid	= ext4_get_projid,
 };
 
 static const struct quotactl_ops ext4_qctl_operations = {
@@ -2526,6 +2558,12 @@ static int ext4_feature_set_ok(struct super_block *sb, int readonly)
 			 "without CONFIG_QUOTA");
 		return 0;
 	}
+	if (ext4_has_feature_project(sb) && !readonly) {
+		ext4_msg(sb, KERN_ERR,
+			 "Filesystem with project quota feature cannot be mounted RDWR "
+			 "without CONFIG_QUOTA");
+		return 0;
+	}
 #endif  /* CONFIG_QUOTA */
 	return 1;
 }
@@ -3654,7 +3692,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		sb->s_qcop = &dquot_quotactl_sysfile_ops;
 	else
 		sb->s_qcop = &ext4_qctl_operations;
-	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
+	sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
 #endif
 	memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
 
@@ -4790,6 +4828,48 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	return err;
 }
 
+#ifdef CONFIG_QUOTA
+static int ext4_statfs_project(struct super_block *sb,
+			       kprojid_t projid, struct kstatfs *buf)
+{
+	struct kqid qid;
+	struct dquot *dquot;
+	u64 limit;
+	u64 curblock;
+
+	qid = make_kqid_projid(projid);
+	dquot = dqget(sb, qid);
+	if (IS_ERR(dquot))
+		return PTR_ERR(dquot);
+	spin_lock(&dq_data_lock);
+
+	limit = (dquot->dq_dqb.dqb_bsoftlimit ?
+		 dquot->dq_dqb.dqb_bsoftlimit :
+		 dquot->dq_dqb.dqb_bhardlimit) >> sb->s_blocksize_bits;
+	if (limit && buf->f_blocks > limit) {
+		curblock = dquot->dq_dqb.dqb_curspace >> sb->s_blocksize_bits;
+		buf->f_blocks = limit;
+		buf->f_bfree = buf->f_bavail =
+			(buf->f_blocks > curblock) ?
+			 (buf->f_blocks - curblock) : 0;
+	}
+
+	limit = dquot->dq_dqb.dqb_isoftlimit ?
+		dquot->dq_dqb.dqb_isoftlimit :
+		dquot->dq_dqb.dqb_ihardlimit;
+	if (limit && buf->f_files > limit) {
+		buf->f_files = limit;
+		buf->f_ffree =
+			(buf->f_files > dquot->dq_dqb.dqb_curinodes) ?
+			 (buf->f_files - dquot->dq_dqb.dqb_curinodes) : 0;
+	}
+
+	spin_unlock(&dq_data_lock);
+	dqput(dquot);
+	return 0;
+}
+#endif
+
 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 {
 	struct super_block *sb = dentry->d_sb;
@@ -4822,6 +4902,11 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
 	buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
 	buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
 
+#ifdef CONFIG_QUOTA
+	if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) &&
+	    sb_has_quota_limits_enabled(sb, PRJQUOTA))
+		ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf);
+#endif
 	return 0;
 }
 
@@ -4986,7 +5071,8 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
 	struct inode *qf_inode;
 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
-		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
 	};
 
 	BUG_ON(!ext4_has_feature_quota(sb));
@@ -5014,7 +5100,8 @@ static int ext4_enable_quotas(struct super_block *sb)
 	int type, err = 0;
 	unsigned long qf_inums[EXT4_MAXQUOTAS] = {
 		le32_to_cpu(EXT4_SB(sb)->s_es->s_usr_quota_inum),
-		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum)
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_grp_quota_inum),
+		le32_to_cpu(EXT4_SB(sb)->s_es->s_prj_quota_inum)
 	};
 
 	sb_dqopt(sb)->flags |= DQUOT_QUOTA_SYS_FILE;

fs/ext4/truncate.h

@@ -10,8 +10,10 @@
  */
 static inline void ext4_truncate_failed_write(struct inode *inode)
 {
+	down_write(&EXT4_I(inode)->i_mmap_sem);
 	truncate_inode_pages(inode->i_mapping, inode->i_size);
 	ext4_truncate(inode);
+	up_write(&EXT4_I(inode)->i_mmap_sem);
 }
 
 /*

include/trace/events/ext4.h

@@ -43,7 +43,7 @@ struct extent_status;
 	{ EXT4_GET_BLOCKS_METADATA_NOFAIL,	"METADATA_NOFAIL" },	\
 	{ EXT4_GET_BLOCKS_NO_NORMALIZE,		"NO_NORMALIZE" },	\
 	{ EXT4_GET_BLOCKS_KEEP_SIZE,		"KEEP_SIZE" },		\
-	{ EXT4_GET_BLOCKS_NO_LOCK,		"NO_LOCK" })
+	{ EXT4_GET_BLOCKS_ZERO,			"ZERO" })
 
 #define show_mflags(flags) __print_flags(flags, "",	\
 	{ EXT4_MAP_NEW,		"N" },			\

include/uapi/linux/fs.h

@@ -2,8 +2,11 @@
 #define _UAPI_LINUX_FS_H
 
 /*
- * This file has definitions for some important file table
- * structures etc.
+ * This file has definitions for some important file table structures
+ * and constants and structures used by various generic file system
+ * ioctl's.  Please do not make any changes in this file before
+ * sending patches for review to linux-fsdevel@vger.kernel.org and
+ * linux-api@vger.kernel.org.
  */
 
 #include <linux/limits.h>
@@ -246,6 +249,23 @@ struct fsxattr {
 
 /*
  * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
+ *
+ * Note: for historical reasons, these flags were originally used and
+ * defined for use by ext2/ext3, and then other file systems started
+ * using these flags so they wouldn't need to write their own version
+ * of chattr/lsattr (which was shipped as part of e2fsprogs).  You
+ * should think twice before trying to use these flags in new
+ * contexts, or trying to assign these flags, since they are used both
+ * as the UAPI and the on-disk encoding for ext2/3/4.  Also, we are
+ * almost out of 32-bit flags.  :-)
+ *
+ * We have recently hoisted FS_IOC_FSGETXATTR / FS_IOC_FSSETXATTR from
+ * XFS to the generic FS level interface.  This uses a structure that
+ * has padding and hence has more room to grow, so it may be more
+ * appropriate for many new use cases.
+ *
+ * Please do not change these flags or interfaces before checking with
+ * linux-fsdevel@vger.kernel.org and linux-api@vger.kernel.org.
  */
 #define	FS_SECRM_FL			0x00000001 /* Secure deletion */
 #define	FS_UNRM_FL			0x00000002 /* Undelete */
@@ -259,8 +279,8 @@ struct fsxattr {
 #define FS_DIRTY_FL			0x00000100
 #define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
 #define FS_NOCOMP_FL			0x00000400 /* Don't compress */
-#define FS_ECOMPR_FL			0x00000800 /* Compression error */
 /* End compression flags --- maybe not all used */
+#define FS_ENCRYPT_FL			0x00000800 /* Encrypted file */
 #define FS_BTREE_FL			0x00001000 /* btree format dir */
 #define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
 #define FS_IMAGIC_FL			0x00002000 /* AFS directory */
@@ -268,9 +288,12 @@ struct fsxattr {
 #define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
 #define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
 #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
+#define FS_HUGE_FILE_FL			0x00040000 /* Reserved for ext4 */
 #define FS_EXTENT_FL			0x00080000 /* Extents */
-#define FS_DIRECTIO_FL			0x00100000 /* Use direct i/o */
+#define FS_EA_INODE_FL			0x00200000 /* Inode used for large EA */
+#define FS_EOFBLOCKS_FL			0x00400000 /* Reserved for ext4 */
 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
+#define FS_INLINE_DATA_FL		0x10000000 /* Reserved for ext4 */
 #define FS_PROJINHERIT_FL		0x20000000 /* Create with parents projid */
 #define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */