3 files changed, 346 insertions, 8 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b83f91edebd1..f6d8528c4f55 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3106,6 +3106,39 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 }
 
 /*
+ * Expand an inode by new_extra_isize bytes.
+ * Returns 0 on success or negative error number on failure.
+ */
+int ext4_expand_extra_isize(struct inode *inode, unsigned int new_extra_isize,
+                        struct ext4_iloc iloc, handle_t *handle)
+{
+        struct ext4_inode *raw_inode;
+        struct ext4_xattr_ibody_header *header;
+        struct ext4_xattr_entry *entry;
+
+        if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
+                return 0;
+
+        raw_inode = ext4_raw_inode(&iloc);
+
+        header = IHDR(inode, raw_inode);
+        entry = IFIRST(header);
+
+        /* No extended attributes present */
+        if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) ||
+                header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
+                memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
+                        new_extra_isize);
+                EXT4_I(inode)->i_extra_isize = new_extra_isize;
+                return 0;
+        }
+
+        /* try to expand with EAs present */
+        return ext4_expand_extra_isize_ea(inode, new_extra_isize,
+                                          raw_inode, handle);
+}
+
+/*
  * What we do here is to mark the in-core inode as clean with respect to inode
  * dirtiness (it may still be data-dirty).
  * This means that the in-core inode may be reaped by prune_icache
@@ -3129,10 +3162,38 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 {
         struct ext4_iloc iloc;
-        int err;
+        struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+        static unsigned int mnt_count;
+        int err, ret;
 
         might_sleep();
         err = ext4_reserve_inode_write(handle, inode, &iloc);
+        if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
+            !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
+                /*
+                 * We need extra buffer credits since we may write into EA block
+                 * with this same handle. If journal_extend fails, then it will
+                 * only result in a minor loss of functionality for that inode.
+                 * If this is felt to be critical, then e2fsck should be run to
+                 * force a large enough s_min_extra_isize.
+                 */
+                if ((jbd2_journal_extend(handle,
+                             EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
+                        ret = ext4_expand_extra_isize(inode,
+                                                      sbi->s_want_extra_isize,
+                                                      iloc, handle);
+                        if (ret) {
+                                EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+                                if (mnt_count != sbi->s_es->s_mnt_count) {
+                                        ext4_warning(inode->i_sb, __FUNCTION__,
+                                        "Unable to expand inode %lu. Delete"
+                                        " some EAs or run e2fsck.",
+                                        inode->i_ino);
+                                        mnt_count = sbi->s_es->s_mnt_count;
+                                }
+                        }
+                }
+        }
         if (!err)
                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
         return err;
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index fe16a569d06b..b10d68fffb55 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -66,13 +66,6 @@
 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
 
-#define IHDR(inode, raw_inode) \
-        ((struct ext4_xattr_ibody_header *) \
-                ((void *)raw_inode + \
-                 EXT4_GOOD_OLD_INODE_SIZE + \
-                 EXT4_I(inode)->i_extra_isize))
-#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
-
 #ifdef EXT4_XATTR_DEBUG
 # define ea_idebug(inode, f...) do { \
                 printk(KERN_DEBUG "inode %s:%lu: ", \
@@ -508,6 +501,24 @@ out:
         return;
 }
 
+/*
+ * Find the available free space for EAs. This also returns the total number of
+ * bytes used by EA entries.
+ */
+static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
+                                    size_t *min_offs, void *base, int *total)
+{
+        for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+                *total += EXT4_XATTR_LEN(last->e_name_len);
+                if (!last->e_value_block && last->e_value_size) {
+                        size_t offs = le16_to_cpu(last->e_value_offs);
+                        if (offs < *min_offs)
+                                *min_offs = offs;
+                }
+        }
+        return (*min_offs - ((void *)last - base) - sizeof(__u32));
+}
+
 struct ext4_xattr_info {
         int name_index;
         const char *name;
@@ -1014,6 +1025,8 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
         if (!error) {
                 ext4_xattr_update_super_block(handle, inode->i_sb);
                 inode->i_ctime = ext4_current_time(inode);
+                if (!value)
+                        EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
                 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
                 /*
                  * The bh is consumed by ext4_mark_iloc_dirty, even with
@@ -1067,6 +1080,253 @@ retry:
 }
 
 /*
+ * Shift the EA entries in the inode to create space for the increased
+ * i_extra_isize.
+ */
+static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
+                                     int value_offs_shift, void *to,
+                                     void *from, size_t n, int blocksize)
+{
+        struct ext4_xattr_entry *last = entry;
+        int new_offs;
+
+        /* Adjust the value offsets of the entries */
+        for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+                if (!last->e_value_block && last->e_value_size) {
+                        new_offs = le16_to_cpu(last->e_value_offs) +
+                                                        value_offs_shift;
+                        BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
+                                 > blocksize);
+                        last->e_value_offs = cpu_to_le16(new_offs);
+                }
+        }
+        /* Shift the entries by n bytes */
+        memmove(to, from, n);
+}
+
+/*
+ * Expand an inode by new_extra_isize bytes when EAs are present.
+ * Returns 0 on success or negative error number on failure.
+ */
+int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+                               struct ext4_inode *raw_inode, handle_t *handle)
+{
+        struct ext4_xattr_ibody_header *header;
+        struct ext4_xattr_entry *entry, *last, *first;
+        struct buffer_head *bh = NULL;
+        struct ext4_xattr_ibody_find *is = NULL;
+        struct ext4_xattr_block_find *bs = NULL;
+        char *buffer = NULL, *b_entry_name = NULL;
+        size_t min_offs, free;
+        int total_ino, total_blk;
+        void *base, *start, *end;
+        int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
+        int s_min_extra_isize = EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize;
+
+        down_write(&EXT4_I(inode)->xattr_sem);
+retry:
+        if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
+                up_write(&EXT4_I(inode)->xattr_sem);
+                return 0;
+        }
+
+        header = IHDR(inode, raw_inode);
+        entry = IFIRST(header);
+
+        /*
+         * Check if enough free space is available in the inode to shift the
+         * entries ahead by new_extra_isize.
+         */
+
+        base = start = entry;
+        end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+        min_offs = end - base;
+        last = entry;
+        total_ino = sizeof(struct ext4_xattr_ibody_header);
+
+        free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
+        if (free >= new_extra_isize) {
+                entry = IFIRST(header);
+                ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
+                                - new_extra_isize, (void *)raw_inode +
+                                EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
+                                (void *)header, total_ino,
+                                inode->i_sb->s_blocksize);
+                EXT4_I(inode)->i_extra_isize = new_extra_isize;
+                error = 0;
+                goto cleanup;
+        }
+
+        /*
+         * Enough free space isn't available in the inode, check if
+         * EA block can hold new_extra_isize bytes.
+         */
+        if (EXT4_I(inode)->i_file_acl) {
+                bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
+                error = -EIO;
+                if (!bh)
+                        goto cleanup;
+                if (ext4_xattr_check_block(bh)) {
+                        ext4_error(inode->i_sb, __FUNCTION__,
+                                "inode %lu: bad block %llu", inode->i_ino,
+                                EXT4_I(inode)->i_file_acl);
+                        error = -EIO;
+                        goto cleanup;
+                }
+                base = BHDR(bh);
+                first = BFIRST(bh);
+                end = bh->b_data + bh->b_size;
+                min_offs = end - base;
+                free = ext4_xattr_free_space(first, &min_offs, base,
+                                             &total_blk);
+                if (free < new_extra_isize) {
+                        if (!tried_min_extra_isize && s_min_extra_isize) {
+                                tried_min_extra_isize++;
+                                new_extra_isize = s_min_extra_isize;
+                                brelse(bh);
+                                goto retry;
+                        }
+                        error = -1;
+                        goto cleanup;
+                }
+        } else {
+                free = inode->i_sb->s_blocksize;
+        }
+
+        while (new_extra_isize > 0) {
+                size_t offs, size, entry_size;
+                struct ext4_xattr_entry *small_entry = NULL;
+                struct ext4_xattr_info i = {
+                        .value = NULL,
+                        .value_len = 0,
+                };
+                unsigned int total_size;  /* EA entry size + value size */
+                unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
+                unsigned int min_total_size = ~0U;
+
+                is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
+                bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
+                if (!is || !bs) {
+                        error = -ENOMEM;
+                        goto cleanup;
+                }
+
+                is->s.not_found = -ENODATA;
+                bs->s.not_found = -ENODATA;
+                is->iloc.bh = NULL;
+                bs->bh = NULL;
+
+                last = IFIRST(header);
+                /* Find the entry best suited to be pushed into EA block */
+                entry = NULL;
+                for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+                        total_size =
+                        EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
+                                        EXT4_XATTR_LEN(last->e_name_len);
+                        if (total_size <= free && total_size < min_total_size) {
+                                if (total_size < new_extra_isize) {
+                                        small_entry = last;
+                                } else {
+                                        entry = last;
+                                        min_total_size = total_size;
+                                }
+                        }
+                }
+
+                if (entry == NULL) {
+                        if (small_entry) {
+                                entry = small_entry;
+                        } else {
+                                if (!tried_min_extra_isize &&
+                                    s_min_extra_isize) {
+                                        tried_min_extra_isize++;
+                                        new_extra_isize = s_min_extra_isize;
+                                        goto retry;
+                                }
+                                error = -1;
+                                goto cleanup;
+                        }
+                }
+                offs = le16_to_cpu(entry->e_value_offs);
+                size = le32_to_cpu(entry->e_value_size);
+                entry_size = EXT4_XATTR_LEN(entry->e_name_len);
+                i.name_index = entry->e_name_index,
+                buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
+                b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
+                if (!buffer || !b_entry_name) {
+                        error = -ENOMEM;
+                        goto cleanup;
+                }
+                /* Save the entry name and the entry value */
+                memcpy(buffer, (void *)IFIRST(header) + offs,
+                       EXT4_XATTR_SIZE(size));
+                memcpy(b_entry_name, entry->e_name, entry->e_name_len);
+                b_entry_name[entry->e_name_len] = '\0';
+                i.name = b_entry_name;
+
+                error = ext4_get_inode_loc(inode, &is->iloc);
+                if (error)
+                        goto cleanup;
+
+                error = ext4_xattr_ibody_find(inode, &i, is);
+                if (error)
+                        goto cleanup;
+
+                /* Remove the chosen entry from the inode */
+                error = ext4_xattr_ibody_set(handle, inode, &i, is);
+
+                entry = IFIRST(header);
+                if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
+                        shift_bytes = new_extra_isize;
+                else
+                        shift_bytes = entry_size + size;
+                /* Adjust the offsets and shift the remaining entries ahead */
+                ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
+                        shift_bytes, (void *)raw_inode +
+                        EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
+                        (void *)header, total_ino - entry_size,
+                        inode->i_sb->s_blocksize);
+
+                extra_isize += shift_bytes;
+                new_extra_isize -= shift_bytes;
+                EXT4_I(inode)->i_extra_isize = extra_isize;
+
+                i.name = b_entry_name;
+                i.value = buffer;
+                i.value_len = cpu_to_le32(size);
+                error = ext4_xattr_block_find(inode, &i, bs);
+                if (error)
+                        goto cleanup;
+
+                /* Add entry which was removed from the inode into the block */
+                error = ext4_xattr_block_set(handle, inode, &i, bs);
+                if (error)
+                        goto cleanup;
+                kfree(b_entry_name);
+                kfree(buffer);
+                brelse(is->iloc.bh);
+                kfree(is);
+                kfree(bs);
+        }
+        brelse(bh);
+        up_write(&EXT4_I(inode)->xattr_sem);
+        return 0;
+
+cleanup:
+        kfree(b_entry_name);
+        kfree(buffer);
+        if (is)
+                brelse(is->iloc.bh);
+        kfree(is);
+        kfree(bs);
+        brelse(bh);
+        up_write(&EXT4_I(inode)->xattr_sem);
+        return error;
+}
+
+
+
+/*
  * ext4_xattr_delete_inode()
  *
  * Free extended attribute resources associated with this inode. This
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 79432b35398f..d7f5d6a12651 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -56,6 +56,13 @@ struct ext4_xattr_entry {
 #define EXT4_XATTR_SIZE(size) \
         (((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
 
+#define IHDR(inode, raw_inode) \
+        ((struct ext4_xattr_ibody_header *) \
+                ((void *)raw_inode + \
+                EXT4_GOOD_OLD_INODE_SIZE + \
+                EXT4_I(inode)->i_extra_isize))
+#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+
 # ifdef CONFIG_EXT4DEV_FS_XATTR
 
 extern struct xattr_handler ext4_xattr_user_handler;
@@ -74,6 +81,9 @@ extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *,
 extern void ext4_xattr_delete_inode(handle_t *, struct inode *);
 extern void ext4_xattr_put_super(struct super_block *);
 
+extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+                            struct ext4_inode *raw_inode, handle_t *handle);
+
 extern int init_ext4_xattr(void);
 extern void exit_ext4_xattr(void);
 
@@ -129,6 +139,13 @@ exit_ext4_xattr(void)
 {
 }
 
+static inline int
+ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+                            struct ext4_inode *raw_inode, handle_t *handle)
+{
+        return -EOPNOTSUPP;
+}
+
 #define ext4_xattr_handlers     NULL
 
 # endif  /* CONFIG_EXT4DEV_FS_XATTR */