Commit e50e5129 authored by Andreas Dilger's avatar Andreas Dilger Committed by Theodore Ts'o
Browse files

ext4: xattr-in-inode support 

Large xattr support is implemented for EXT4_FEATURE_INCOMPAT_EA_INODE.

If the size of an xattr value is larger than will fit in a single
external block, then the xattr value will be saved into the body
of an external xattr inode.

The also helps support a larger number of xattr, since only the headers
will be stored in the in-inode space or the single external block.

The inode is referenced from the xattr header via "e_value_inum",
which was formerly "e_value_block", but that field was never used.
The e_value_size still contains the xattr size so that listing
xattrs does not need to look up the inode if the data is not accessed.

struct ext4_xattr_entry {
        __u8    e_name_len;     /* length of name */
        __u8    e_name_index;   /* attribute name index */
        __le16  e_value_offs;   /* offset in disk block of value */
        __le32  e_value_inum;   /* inode in which value is stored */
        __le32  e_value_size;   /* size of attribute value */
        __le32  e_hash;         /* hash value of name and value */
        char    e_name[0];      /* attribute name */
};

The xattr inode is marked with the EXT4_EA_INODE_FL flag and also
holds a back-reference to the owning inode in its i_mtime field,
allowing the ext4/e2fsck to verify the correct inode is accessed.

[ Applied fix by Dan Carpenter to avoid freeing an ERR_PTR. ]

Lustre-Jira: https://jira.hpdd.intel.com/browse/LU-80
Lustre-bugzilla: https://bugzilla.lustre.org/show_bug.cgi?id=4424


Signed-off-by: default avatarKalpak Shah <kalpak.shah@sun.com>
Signed-off-by: default avatarJames Simmons <uja.ornl@gmail.com>
Signed-off-by: default avatarAndreas Dilger <andreas.dilger@intel.com>
Signed-off-by: default avatarTahsin Erdogan <tahsin@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
parent e08ac99f

fs/ext4/ext4.h

+12 −0
Original line number Diff line number Diff line
@@ -1797,6 +1797,7 @@ EXT4_FEATURE_INCOMPAT_FUNCS(encrypt, ENCRYPT) 
					 EXT4_FEATURE_INCOMPAT_EXTENTS| \

					 EXT4_FEATURE_INCOMPAT_64BIT| \

					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \

					 EXT4_FEATURE_INCOMPAT_EA_INODE| \

					 EXT4_FEATURE_INCOMPAT_MMP | \

					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \

					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
@@ -2230,6 +2231,12 @@ struct mmpd_data { 
 */

#define EXT4_MMP_MAX_CHECK_INTERVAL	300UL



/*

 * Maximum size of xattr attributes for FEATURE_INCOMPAT_EA_INODE 1Mb

 * This limit is arbitrary, but is reasonable for the xattr API.

 */

#define EXT4_XATTR_MAX_LARGE_EA_SIZE    (1024 * 1024)



/*

 * Function prototypes

 */
@@ -2242,6 +2249,10 @@ struct mmpd_data { 
# define ATTRIB_NORET	__attribute__((noreturn))

# define NORET_AND	noreturn,



struct ext4_xattr_ino_array {

	unsigned int xia_count;		/* # of used item in the array */

	unsigned int xia_inodes[0];

};

/* bitmap.c */

extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);

void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
@@ -2489,6 +2500,7 @@ extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks); 
extern void ext4_set_inode_flags(struct inode *);

extern int ext4_alloc_da_blocks(struct inode *inode);

extern void ext4_set_aops(struct inode *inode);

extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int chunk);

extern int ext4_writepage_trans_blocks(struct inode *);

extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);

extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,

fs/ext4/ialloc.c

+0 −1
Original line number Diff line number Diff line
@@ -294,7 +294,6 @@ void ext4_free_inode(handle_t *handle, struct inode *inode) 
	 * as writing the quota to disk may need the lock as well.

	 */

	dquot_initialize(inode);

	ext4_xattr_delete_inode(handle, inode);

	dquot_free_inode(inode);

	dquot_drop(inode);

fs/ext4/inline.c

+1 −1
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ static int get_max_inline_xattr_value_size(struct inode *inode, 


	/* Compute min_offs. */

	for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {

		if (!entry->e_value_block && entry->e_value_size) {

		if (!entry->e_value_inum && entry->e_value_size) {

			size_t offs = le16_to_cpu(entry->e_value_offs);

			if (offs < min_offs)

				min_offs = offs;

fs/ext4/inode.c

+40 −9
Original line number Diff line number Diff line
@@ -139,8 +139,6 @@ static void ext4_invalidatepage(struct page *page, unsigned int offset, 
				unsigned int length);

static int __ext4_journalled_writepage(struct page *page, unsigned int len);

static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);

static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,

				  int pextents);



/*

 * Test whether an inode is a fast symlink.
@@ -189,6 +187,8 @@ void ext4_evict_inode(struct inode *inode) 
{

	handle_t *handle;

	int err;

	int extra_credits = 3;

	struct ext4_xattr_ino_array *lea_ino_array = NULL;



	trace_ext4_evict_inode(inode);
@@ -238,8 +238,8 @@ void ext4_evict_inode(struct inode *inode) 
	 * protection against it

	 */

	sb_start_intwrite(inode->i_sb);

	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,

				    ext4_blocks_for_truncate(inode)+3);



	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, extra_credits);

	if (IS_ERR(handle)) {

		ext4_std_error(inode->i_sb, PTR_ERR(handle));

		/*
@@ -251,9 +251,36 @@ void ext4_evict_inode(struct inode *inode) 
		sb_end_intwrite(inode->i_sb);

		goto no_delete;

	}



	if (IS_SYNC(inode))

		ext4_handle_sync(handle);



	/*

	 * Delete xattr inode before deleting the main inode.

	 */

	err = ext4_xattr_delete_inode(handle, inode, &lea_ino_array);

	if (err) {

		ext4_warning(inode->i_sb,

			     "couldn't delete inode's xattr (err %d)", err);

		goto stop_handle;

	}



	if (!IS_NOQUOTA(inode))

		extra_credits += 2 * EXT4_QUOTA_DEL_BLOCKS(inode->i_sb);



	if (!ext4_handle_has_enough_credits(handle,

			ext4_blocks_for_truncate(inode) + extra_credits)) {

		err = ext4_journal_extend(handle,

			ext4_blocks_for_truncate(inode) + extra_credits);

		if (err > 0)

			err = ext4_journal_restart(handle,

			ext4_blocks_for_truncate(inode) + extra_credits);

		if (err != 0) {

			ext4_warning(inode->i_sb,

				     "couldn't extend journal (err %d)", err);

			goto stop_handle;

		}

	}



	inode->i_size = 0;

	err = ext4_mark_inode_dirty(handle, inode);

	if (err) {
@@ -277,10 +304,10 @@ void ext4_evict_inode(struct inode *inode) 
	 * enough credits left in the handle to remove the inode from

	 * the orphan list and set the dtime field.

	 */

	if (!ext4_handle_has_enough_credits(handle, 3)) {

		err = ext4_journal_extend(handle, 3);

	if (!ext4_handle_has_enough_credits(handle, extra_credits)) {

		err = ext4_journal_extend(handle, extra_credits);

		if (err > 0)

			err = ext4_journal_restart(handle, 3);

			err = ext4_journal_restart(handle, extra_credits);

		if (err != 0) {

			ext4_warning(inode->i_sb,

				     "couldn't extend journal (err %d)", err);
@@ -315,8 +342,12 @@ void ext4_evict_inode(struct inode *inode) 
		ext4_clear_inode(inode);

	else

		ext4_free_inode(handle, inode);



	ext4_journal_stop(handle);

	sb_end_intwrite(inode->i_sb);



	if (lea_ino_array != NULL)

		ext4_xattr_inode_array_free(inode, lea_ino_array);

	return;

no_delete:

	ext4_clear_inode(inode);	/* We must guarantee clearing of inode... */
@@ -5504,7 +5535,7 @@ static int ext4_index_trans_blocks(struct inode *inode, int lblocks, 
 *

 * Also account for superblock, inode, quota and xattr blocks

 */

static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,

int ext4_meta_trans_blocks(struct inode *inode, int lblocks,

				  int pextents)

{

	ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);

fs/ext4/xattr.c

+521 −42

File changed.

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