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-rw-r--r--fs/ext4/xattr.c3165
1 files changed, 3165 insertions, 0 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
new file mode 100644
index 000000000..eaed9fd2f
--- /dev/null
+++ b/fs/ext4/xattr.c
@@ -0,0 +1,3165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext4/xattr.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
+ *
+ * Fix by Harrison Xing <harrison@mountainviewdata.com>.
+ * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>.
+ * Extended attributes for symlinks and special files added per
+ * suggestion of Luka Renko <luka.renko@hermes.si>.
+ * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
+ * Red Hat Inc.
+ * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
+ * and Andreas Gruenbacher <agruen@suse.de>.
+ */
+
+/*
+ * Extended attributes are stored directly in inodes (on file systems with
+ * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
+ * field contains the block number if an inode uses an additional block. All
+ * attributes must fit in the inode and one additional block. Blocks that
+ * contain the identical set of attributes may be shared among several inodes.
+ * Identical blocks are detected by keeping a cache of blocks that have
+ * recently been accessed.
+ *
+ * The attributes in inodes and on blocks have a different header; the entries
+ * are stored in the same format:
+ *
+ * +------------------+
+ * | header |
+ * | entry 1 | |
+ * | entry 2 | | growing downwards
+ * | entry 3 | v
+ * | four null bytes |
+ * | . . . |
+ * | value 1 | ^
+ * | value 3 | | growing upwards
+ * | value 2 | |
+ * +------------------+
+ *
+ * The header is followed by multiple entry descriptors. In disk blocks, the
+ * entry descriptors are kept sorted. In inodes, they are unsorted. The
+ * attribute values are aligned to the end of the block in no specific order.
+ *
+ * Locking strategy
+ * ----------------
+ * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem.
+ * EA blocks are only changed if they are exclusive to an inode, so
+ * holding xattr_sem also means that nothing but the EA block's reference
+ * count can change. Multiple writers to the same block are synchronized
+ * by the buffer lock.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/mbcache.h>
+#include <linux/quotaops.h>
+#include <linux/iversion.h>
+#include "ext4_jbd2.h"
+#include "ext4.h"
+#include "xattr.h"
+#include "acl.h"
+
+#ifdef EXT4_XATTR_DEBUG
+# define ea_idebug(inode, fmt, ...) \
+ printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \
+ inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__)
+# define ea_bdebug(bh, fmt, ...) \
+ printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \
+ bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__)
+#else
+# define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
+# define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
+#endif
+
+static void ext4_xattr_block_cache_insert(struct mb_cache *,
+ struct buffer_head *);
+static struct buffer_head *
+ext4_xattr_block_cache_find(struct inode *, struct ext4_xattr_header *,
+ struct mb_cache_entry **);
+static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
+ size_t value_count);
+static void ext4_xattr_rehash(struct ext4_xattr_header *);
+
+static const struct xattr_handler * const ext4_xattr_handler_map[] = {
+ [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+ [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
+ [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
+#endif
+ [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
+#ifdef CONFIG_EXT4_FS_SECURITY
+ [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
+#endif
+ [EXT4_XATTR_INDEX_HURD] = &ext4_xattr_hurd_handler,
+};
+
+const struct xattr_handler *ext4_xattr_handlers[] = {
+ &ext4_xattr_user_handler,
+ &ext4_xattr_trusted_handler,
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+ &posix_acl_access_xattr_handler,
+ &posix_acl_default_xattr_handler,
+#endif
+#ifdef CONFIG_EXT4_FS_SECURITY
+ &ext4_xattr_security_handler,
+#endif
+ &ext4_xattr_hurd_handler,
+ NULL
+};
+
+#define EA_BLOCK_CACHE(inode) (((struct ext4_sb_info *) \
+ inode->i_sb->s_fs_info)->s_ea_block_cache)
+
+#define EA_INODE_CACHE(inode) (((struct ext4_sb_info *) \
+ inode->i_sb->s_fs_info)->s_ea_inode_cache)
+
+static int
+ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
+ struct inode *inode);
+
+#ifdef CONFIG_LOCKDEP
+void ext4_xattr_inode_set_class(struct inode *ea_inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(ea_inode);
+
+ lockdep_set_subclass(&ea_inode->i_rwsem, 1);
+ (void) ei; /* shut up clang warning if !CONFIG_LOCKDEP */
+ lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_EA);
+}
+#endif
+
+static __le32 ext4_xattr_block_csum(struct inode *inode,
+ sector_t block_nr,
+ struct ext4_xattr_header *hdr)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ __u32 csum;
+ __le64 dsk_block_nr = cpu_to_le64(block_nr);
+ __u32 dummy_csum = 0;
+ int offset = offsetof(struct ext4_xattr_header, h_checksum);
+
+ csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&dsk_block_nr,
+ sizeof(dsk_block_nr));
+ csum = ext4_chksum(sbi, csum, (__u8 *)hdr, offset);
+ csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, sizeof(dummy_csum));
+ offset += sizeof(dummy_csum);
+ csum = ext4_chksum(sbi, csum, (__u8 *)hdr + offset,
+ EXT4_BLOCK_SIZE(inode->i_sb) - offset);
+
+ return cpu_to_le32(csum);
+}
+
+static int ext4_xattr_block_csum_verify(struct inode *inode,
+ struct buffer_head *bh)
+{
+ struct ext4_xattr_header *hdr = BHDR(bh);
+ int ret = 1;
+
+ if (ext4_has_metadata_csum(inode->i_sb)) {
+ lock_buffer(bh);
+ ret = (hdr->h_checksum == ext4_xattr_block_csum(inode,
+ bh->b_blocknr, hdr));
+ unlock_buffer(bh);
+ }
+ return ret;
+}
+
+static void ext4_xattr_block_csum_set(struct inode *inode,
+ struct buffer_head *bh)
+{
+ if (ext4_has_metadata_csum(inode->i_sb))
+ BHDR(bh)->h_checksum = ext4_xattr_block_csum(inode,
+ bh->b_blocknr, BHDR(bh));
+}
+
+static inline const struct xattr_handler *
+ext4_xattr_handler(int name_index)
+{
+ const struct xattr_handler *handler = NULL;
+
+ if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
+ handler = ext4_xattr_handler_map[name_index];
+ return handler;
+}
+
+static int
+ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end,
+ void *value_start)
+{
+ struct ext4_xattr_entry *e = entry;
+
+ /* Find the end of the names list */
+ while (!IS_LAST_ENTRY(e)) {
+ struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
+ if ((void *)next >= end)
+ return -EFSCORRUPTED;
+ if (strnlen(e->e_name, e->e_name_len) != e->e_name_len)
+ return -EFSCORRUPTED;
+ e = next;
+ }
+
+ /* Check the values */
+ while (!IS_LAST_ENTRY(entry)) {
+ u32 size = le32_to_cpu(entry->e_value_size);
+
+ if (size > EXT4_XATTR_SIZE_MAX)
+ return -EFSCORRUPTED;
+
+ if (size != 0 && entry->e_value_inum == 0) {
+ u16 offs = le16_to_cpu(entry->e_value_offs);
+ void *value;
+
+ /*
+ * The value cannot overlap the names, and the value
+ * with padding cannot extend beyond 'end'. Check both
+ * the padded and unpadded sizes, since the size may
+ * overflow to 0 when adding padding.
+ */
+ if (offs > end - value_start)
+ return -EFSCORRUPTED;
+ value = value_start + offs;
+ if (value < (void *)e + sizeof(u32) ||
+ size > end - value ||
+ EXT4_XATTR_SIZE(size) > end - value)
+ return -EFSCORRUPTED;
+ }
+ entry = EXT4_XATTR_NEXT(entry);
+ }
+
+ return 0;
+}
+
+static inline int
+__ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh,
+ const char *function, unsigned int line)
+{
+ int error = -EFSCORRUPTED;
+
+ if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
+ BHDR(bh)->h_blocks != cpu_to_le32(1))
+ goto errout;
+ if (buffer_verified(bh))
+ return 0;
+
+ error = -EFSBADCRC;
+ if (!ext4_xattr_block_csum_verify(inode, bh))
+ goto errout;
+ error = ext4_xattr_check_entries(BFIRST(bh), bh->b_data + bh->b_size,
+ bh->b_data);
+errout:
+ if (error)
+ __ext4_error_inode(inode, function, line, 0, -error,
+ "corrupted xattr block %llu",
+ (unsigned long long) bh->b_blocknr);
+ else
+ set_buffer_verified(bh);
+ return error;
+}
+
+#define ext4_xattr_check_block(inode, bh) \
+ __ext4_xattr_check_block((inode), (bh), __func__, __LINE__)
+
+
+static int
+__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
+ void *end, const char *function, unsigned int line)
+{
+ int error = -EFSCORRUPTED;
+
+ if (end - (void *)header < sizeof(*header) + sizeof(u32) ||
+ (header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)))
+ goto errout;
+ error = ext4_xattr_check_entries(IFIRST(header), end, IFIRST(header));
+errout:
+ if (error)
+ __ext4_error_inode(inode, function, line, 0, -error,
+ "corrupted in-inode xattr");
+ return error;
+}
+
+#define xattr_check_inode(inode, header, end) \
+ __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
+
+static int
+xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry,
+ void *end, int name_index, const char *name, int sorted)
+{
+ struct ext4_xattr_entry *entry, *next;
+ size_t name_len;
+ int cmp = 1;
+
+ if (name == NULL)
+ return -EINVAL;
+ name_len = strlen(name);
+ for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) {
+ next = EXT4_XATTR_NEXT(entry);
+ if ((void *) next >= end) {
+ EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+ return -EFSCORRUPTED;
+ }
+ cmp = name_index - entry->e_name_index;
+ if (!cmp)
+ cmp = name_len - entry->e_name_len;
+ if (!cmp)
+ cmp = memcmp(name, entry->e_name, name_len);
+ if (cmp <= 0 && (sorted || cmp == 0))
+ break;
+ }
+ *pentry = entry;
+ return cmp ? -ENODATA : 0;
+}
+
+static u32
+ext4_xattr_inode_hash(struct ext4_sb_info *sbi, const void *buffer, size_t size)
+{
+ return ext4_chksum(sbi, sbi->s_csum_seed, buffer, size);
+}
+
+static u64 ext4_xattr_inode_get_ref(struct inode *ea_inode)
+{
+ return ((u64)ea_inode->i_ctime.tv_sec << 32) |
+ (u32) inode_peek_iversion_raw(ea_inode);
+}
+
+static void ext4_xattr_inode_set_ref(struct inode *ea_inode, u64 ref_count)
+{
+ ea_inode->i_ctime.tv_sec = (u32)(ref_count >> 32);
+ inode_set_iversion_raw(ea_inode, ref_count & 0xffffffff);
+}
+
+static u32 ext4_xattr_inode_get_hash(struct inode *ea_inode)
+{
+ return (u32)ea_inode->i_atime.tv_sec;
+}
+
+static void ext4_xattr_inode_set_hash(struct inode *ea_inode, u32 hash)
+{
+ ea_inode->i_atime.tv_sec = hash;
+}
+
+/*
+ * Read the EA value from an inode.
+ */
+static int ext4_xattr_inode_read(struct inode *ea_inode, void *buf, size_t size)
+{
+ int blocksize = 1 << ea_inode->i_blkbits;
+ int bh_count = (size + blocksize - 1) >> ea_inode->i_blkbits;
+ int tail_size = (size % blocksize) ?: blocksize;
+ struct buffer_head *bhs_inline[8];
+ struct buffer_head **bhs = bhs_inline;
+ int i, ret;
+
+ if (bh_count > ARRAY_SIZE(bhs_inline)) {
+ bhs = kmalloc_array(bh_count, sizeof(*bhs), GFP_NOFS);
+ if (!bhs)
+ return -ENOMEM;
+ }
+
+ ret = ext4_bread_batch(ea_inode, 0 /* block */, bh_count,
+ true /* wait */, bhs);
+ if (ret)
+ goto free_bhs;
+
+ for (i = 0; i < bh_count; i++) {
+ /* There shouldn't be any holes in ea_inode. */
+ if (!bhs[i]) {
+ ret = -EFSCORRUPTED;
+ goto put_bhs;
+ }
+ memcpy((char *)buf + blocksize * i, bhs[i]->b_data,
+ i < bh_count - 1 ? blocksize : tail_size);
+ }
+ ret = 0;
+put_bhs:
+ for (i = 0; i < bh_count; i++)
+ brelse(bhs[i]);
+free_bhs:
+ if (bhs != bhs_inline)
+ kfree(bhs);
+ return ret;
+}
+
+#define EXT4_XATTR_INODE_GET_PARENT(inode) ((__u32)(inode)->i_mtime.tv_sec)
+
+static int ext4_xattr_inode_iget(struct inode *parent, unsigned long ea_ino,
+ u32 ea_inode_hash, struct inode **ea_inode)
+{
+ struct inode *inode;
+ int err;
+
+ /*
+ * We have to check for this corruption early as otherwise
+ * iget_locked() could wait indefinitely for the state of our
+ * parent inode.
+ */
+ if (parent->i_ino == ea_ino) {
+ ext4_error(parent->i_sb,
+ "Parent and EA inode have the same ino %lu", ea_ino);
+ return -EFSCORRUPTED;
+ }
+
+ inode = ext4_iget(parent->i_sb, ea_ino, EXT4_IGET_EA_INODE);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ ext4_error(parent->i_sb,
+ "error while reading EA inode %lu err=%d", ea_ino,
+ err);
+ return err;
+ }
+ ext4_xattr_inode_set_class(inode);
+
+ /*
+ * Check whether this is an old Lustre-style xattr inode. Lustre
+ * implementation does not have hash validation, rather it has a
+ * backpointer from ea_inode to the parent inode.
+ */
+ if (ea_inode_hash != ext4_xattr_inode_get_hash(inode) &&
+ EXT4_XATTR_INODE_GET_PARENT(inode) == parent->i_ino &&
+ inode->i_generation == parent->i_generation) {
+ ext4_set_inode_state(inode, EXT4_STATE_LUSTRE_EA_INODE);
+ ext4_xattr_inode_set_ref(inode, 1);
+ } else {
+ inode_lock(inode);
+ inode->i_flags |= S_NOQUOTA;
+ inode_unlock(inode);
+ }
+
+ *ea_inode = inode;
+ return 0;
+}
+
+/* Remove entry from mbcache when EA inode is getting evicted */
+void ext4_evict_ea_inode(struct inode *inode)
+{
+ struct mb_cache_entry *oe;
+
+ if (!EA_INODE_CACHE(inode))
+ return;
+ /* Wait for entry to get unused so that we can remove it */
+ while ((oe = mb_cache_entry_delete_or_get(EA_INODE_CACHE(inode),
+ ext4_xattr_inode_get_hash(inode), inode->i_ino))) {
+ mb_cache_entry_wait_unused(oe);
+ mb_cache_entry_put(EA_INODE_CACHE(inode), oe);
+ }
+}
+
+static int
+ext4_xattr_inode_verify_hashes(struct inode *ea_inode,
+ struct ext4_xattr_entry *entry, void *buffer,
+ size_t size)
+{
+ u32 hash;
+
+ /* Verify stored hash matches calculated hash. */
+ hash = ext4_xattr_inode_hash(EXT4_SB(ea_inode->i_sb), buffer, size);
+ if (hash != ext4_xattr_inode_get_hash(ea_inode))
+ return -EFSCORRUPTED;
+
+ if (entry) {
+ __le32 e_hash, tmp_data;
+
+ /* Verify entry hash. */
+ tmp_data = cpu_to_le32(hash);
+ e_hash = ext4_xattr_hash_entry(entry->e_name, entry->e_name_len,
+ &tmp_data, 1);
+ if (e_hash != entry->e_hash)
+ return -EFSCORRUPTED;
+ }
+ return 0;
+}
+
+/*
+ * Read xattr value from the EA inode.
+ */
+static int
+ext4_xattr_inode_get(struct inode *inode, struct ext4_xattr_entry *entry,
+ void *buffer, size_t size)
+{
+ struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
+ struct inode *ea_inode;
+ int err;
+
+ err = ext4_xattr_inode_iget(inode, le32_to_cpu(entry->e_value_inum),
+ le32_to_cpu(entry->e_hash), &ea_inode);
+ if (err) {
+ ea_inode = NULL;
+ goto out;
+ }
+
+ if (i_size_read(ea_inode) != size) {
+ ext4_warning_inode(ea_inode,
+ "ea_inode file size=%llu entry size=%zu",
+ i_size_read(ea_inode), size);
+ err = -EFSCORRUPTED;
+ goto out;
+ }
+
+ err = ext4_xattr_inode_read(ea_inode, buffer, size);
+ if (err)
+ goto out;
+
+ if (!ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE)) {
+ err = ext4_xattr_inode_verify_hashes(ea_inode, entry, buffer,
+ size);
+ if (err) {
+ ext4_warning_inode(ea_inode,
+ "EA inode hash validation failed");
+ goto out;
+ }
+
+ if (ea_inode_cache)
+ mb_cache_entry_create(ea_inode_cache, GFP_NOFS,
+ ext4_xattr_inode_get_hash(ea_inode),
+ ea_inode->i_ino, true /* reusable */);
+ }
+out:
+ iput(ea_inode);
+ return err;
+}
+
+static int
+ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ struct buffer_head *bh = NULL;
+ struct ext4_xattr_entry *entry;
+ size_t size;
+ void *end;
+ int error;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
+ name_index, name, buffer, (long)buffer_size);
+
+ if (!EXT4_I(inode)->i_file_acl)
+ return -ENODATA;
+ ea_idebug(inode, "reading block %llu",
+ (unsigned long long)EXT4_I(inode)->i_file_acl);
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ ea_bdebug(bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+ error = ext4_xattr_check_block(inode, bh);
+ if (error)
+ goto cleanup;
+ ext4_xattr_block_cache_insert(ea_block_cache, bh);
+ entry = BFIRST(bh);
+ end = bh->b_data + bh->b_size;
+ error = xattr_find_entry(inode, &entry, end, name_index, name, 1);
+ if (error)
+ goto cleanup;
+ size = le32_to_cpu(entry->e_value_size);
+ error = -ERANGE;
+ if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+ goto cleanup;
+ if (buffer) {
+ if (size > buffer_size)
+ goto cleanup;
+ if (entry->e_value_inum) {
+ error = ext4_xattr_inode_get(inode, entry, buffer,
+ size);
+ if (error)
+ goto cleanup;
+ } else {
+ u16 offset = le16_to_cpu(entry->e_value_offs);
+ void *p = bh->b_data + offset;
+
+ if (unlikely(p + size > end))
+ goto cleanup;
+ memcpy(buffer, p, size);
+ }
+ }
+ error = size;
+
+cleanup:
+ brelse(bh);
+ return error;
+}
+
+int
+ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_xattr_entry *entry;
+ struct ext4_inode *raw_inode;
+ struct ext4_iloc iloc;
+ size_t size;
+ void *end;
+ int error;
+
+ if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
+ return -ENODATA;
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+ raw_inode = ext4_raw_inode(&iloc);
+ header = IHDR(inode, raw_inode);
+ end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+ error = xattr_check_inode(inode, header, end);
+ if (error)
+ goto cleanup;
+ entry = IFIRST(header);
+ error = xattr_find_entry(inode, &entry, end, name_index, name, 0);
+ if (error)
+ goto cleanup;
+ size = le32_to_cpu(entry->e_value_size);
+ error = -ERANGE;
+ if (unlikely(size > EXT4_XATTR_SIZE_MAX))
+ goto cleanup;
+ if (buffer) {
+ if (size > buffer_size)
+ goto cleanup;
+ if (entry->e_value_inum) {
+ error = ext4_xattr_inode_get(inode, entry, buffer,
+ size);
+ if (error)
+ goto cleanup;
+ } else {
+ u16 offset = le16_to_cpu(entry->e_value_offs);
+ void *p = (void *)IFIRST(header) + offset;
+
+ if (unlikely(p + size > end))
+ goto cleanup;
+ memcpy(buffer, p, size);
+ }
+ }
+ error = size;
+
+cleanup:
+ brelse(iloc.bh);
+ return error;
+}
+
+/*
+ * ext4_xattr_get()
+ *
+ * Copy an extended attribute into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+int
+ext4_xattr_get(struct inode *inode, int name_index, const char *name,
+ void *buffer, size_t buffer_size)
+{
+ int error;
+
+ if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+ return -EIO;
+
+ if (strlen(name) > 255)
+ return -ERANGE;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ 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);
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return error;
+}
+
+static int
+ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
+ char *buffer, size_t buffer_size)
+{
+ size_t rest = buffer_size;
+
+ for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
+ const struct xattr_handler *handler =
+ ext4_xattr_handler(entry->e_name_index);
+
+ if (handler && (!handler->list || handler->list(dentry))) {
+ const char *prefix = handler->prefix ?: handler->name;
+ size_t prefix_len = strlen(prefix);
+ size_t size = prefix_len + entry->e_name_len + 1;
+
+ if (buffer) {
+ if (size > rest)
+ return -ERANGE;
+ memcpy(buffer, prefix, prefix_len);
+ buffer += prefix_len;
+ memcpy(buffer, entry->e_name, entry->e_name_len);
+ buffer += entry->e_name_len;
+ *buffer++ = 0;
+ }
+ rest -= size;
+ }
+ }
+ return buffer_size - rest; /* total size */
+}
+
+static int
+ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ struct inode *inode = d_inode(dentry);
+ struct buffer_head *bh = NULL;
+ int error;
+
+ ea_idebug(inode, "buffer=%p, buffer_size=%ld",
+ buffer, (long)buffer_size);
+
+ if (!EXT4_I(inode)->i_file_acl)
+ return 0;
+ ea_idebug(inode, "reading block %llu",
+ (unsigned long long)EXT4_I(inode)->i_file_acl);
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ ea_bdebug(bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
+ error = ext4_xattr_check_block(inode, bh);
+ if (error)
+ goto cleanup;
+ ext4_xattr_block_cache_insert(EA_BLOCK_CACHE(inode), bh);
+ error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer,
+ buffer_size);
+cleanup:
+ brelse(bh);
+ return error;
+}
+
+static int
+ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ struct inode *inode = d_inode(dentry);
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_inode *raw_inode;
+ struct ext4_iloc iloc;
+ void *end;
+ int error;
+
+ if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
+ return 0;
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error)
+ return error;
+ raw_inode = ext4_raw_inode(&iloc);
+ header = IHDR(inode, raw_inode);
+ end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+ error = xattr_check_inode(inode, header, end);
+ if (error)
+ goto cleanup;
+ error = ext4_xattr_list_entries(dentry, IFIRST(header),
+ buffer, buffer_size);
+
+cleanup:
+ brelse(iloc.bh);
+ return error;
+}
+
+/*
+ * Inode operation listxattr()
+ *
+ * d_inode(dentry)->i_rwsem: don't care
+ *
+ * Copy a list of attribute names into the buffer
+ * provided, or compute the buffer size required.
+ * Buffer is NULL to compute the size of the buffer required.
+ *
+ * Returns a negative error number on failure, or the number of bytes
+ * used / required on success.
+ */
+ssize_t
+ext4_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
+{
+ int ret, ret2;
+
+ down_read(&EXT4_I(d_inode(dentry))->xattr_sem);
+ ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
+ if (ret < 0)
+ goto errout;
+ if (buffer) {
+ buffer += ret;
+ buffer_size -= ret;
+ }
+ ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
+ if (ret < 0)
+ goto errout;
+ ret += ret2;
+errout:
+ up_read(&EXT4_I(d_inode(dentry))->xattr_sem);
+ return ret;
+}
+
+/*
+ * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
+ * not set, set it.
+ */
+static void ext4_xattr_update_super_block(handle_t *handle,
+ struct super_block *sb)
+{
+ if (ext4_has_feature_xattr(sb))
+ return;
+
+ BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
+ if (ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh,
+ EXT4_JTR_NONE) == 0) {
+ lock_buffer(EXT4_SB(sb)->s_sbh);
+ ext4_set_feature_xattr(sb);
+ ext4_superblock_csum_set(sb);
+ unlock_buffer(EXT4_SB(sb)->s_sbh);
+ ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
+ }
+}
+
+int ext4_get_inode_usage(struct inode *inode, qsize_t *usage)
+{
+ struct ext4_iloc iloc = { .bh = NULL };
+ struct buffer_head *bh = NULL;
+ struct ext4_inode *raw_inode;
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_xattr_entry *entry;
+ qsize_t ea_inode_refs = 0;
+ void *end;
+ int ret;
+
+ lockdep_assert_held_read(&EXT4_I(inode)->xattr_sem);
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ goto out;
+ raw_inode = ext4_raw_inode(&iloc);
+ header = IHDR(inode, raw_inode);
+ end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+ ret = xattr_check_inode(inode, header, end);
+ if (ret)
+ goto out;
+
+ for (entry = IFIRST(header); !IS_LAST_ENTRY(entry);
+ entry = EXT4_XATTR_NEXT(entry))
+ if (entry->e_value_inum)
+ ea_inode_refs++;
+ }
+
+ if (EXT4_I(inode)->i_file_acl) {
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh)) {
+ ret = PTR_ERR(bh);
+ bh = NULL;
+ goto out;
+ }
+
+ ret = ext4_xattr_check_block(inode, bh);
+ if (ret)
+ goto out;
+
+ for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
+ entry = EXT4_XATTR_NEXT(entry))
+ if (entry->e_value_inum)
+ ea_inode_refs++;
+ }
+ *usage = ea_inode_refs + 1;
+ ret = 0;
+out:
+ brelse(iloc.bh);
+ brelse(bh);
+ return ret;
+}
+
+static inline size_t round_up_cluster(struct inode *inode, size_t length)
+{
+ struct super_block *sb = inode->i_sb;
+ size_t cluster_size = 1 << (EXT4_SB(sb)->s_cluster_bits +
+ inode->i_blkbits);
+ size_t mask = ~(cluster_size - 1);
+
+ return (length + cluster_size - 1) & mask;
+}
+
+static int ext4_xattr_inode_alloc_quota(struct inode *inode, size_t len)
+{
+ int err;
+
+ err = dquot_alloc_inode(inode);
+ if (err)
+ return err;
+ err = dquot_alloc_space_nodirty(inode, round_up_cluster(inode, len));
+ if (err)
+ dquot_free_inode(inode);
+ return err;
+}
+
+static void ext4_xattr_inode_free_quota(struct inode *parent,
+ struct inode *ea_inode,
+ size_t len)
+{
+ if (ea_inode &&
+ ext4_test_inode_state(ea_inode, EXT4_STATE_LUSTRE_EA_INODE))
+ return;
+ dquot_free_space_nodirty(parent, round_up_cluster(parent, len));
+ dquot_free_inode(parent);
+}
+
+int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
+ struct buffer_head *block_bh, size_t value_len,
+ bool is_create)
+{
+ int credits;
+ int blocks;
+
+ /*
+ * 1) Owner inode update
+ * 2) Ref count update on old xattr block
+ * 3) new xattr block
+ * 4) block bitmap update for new xattr block
+ * 5) group descriptor for new xattr block
+ * 6) block bitmap update for old xattr block
+ * 7) group descriptor for old block
+ *
+ * 6 & 7 can happen if we have two racing threads T_a and T_b
+ * which are each trying to set an xattr on inodes I_a and I_b
+ * which were both initially sharing an xattr block.
+ */
+ credits = 7;
+
+ /* Quota updates. */
+ credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(sb);
+
+ /*
+ * In case of inline data, we may push out the data to a block,
+ * so we need to reserve credits for this eventuality
+ */
+ if (inode && ext4_has_inline_data(inode))
+ credits += ext4_writepage_trans_blocks(inode) + 1;
+
+ /* We are done if ea_inode feature is not enabled. */
+ if (!ext4_has_feature_ea_inode(sb))
+ return credits;
+
+ /* New ea_inode, inode map, block bitmap, group descriptor. */
+ credits += 4;
+
+ /* Data blocks. */
+ blocks = (value_len + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+
+ /* Indirection block or one level of extent tree. */
+ blocks += 1;
+
+ /* Block bitmap and group descriptor updates for each block. */
+ credits += blocks * 2;
+
+ /* Blocks themselves. */
+ credits += blocks;
+
+ if (!is_create) {
+ /* Dereference ea_inode holding old xattr value.
+ * Old ea_inode, inode map, block bitmap, group descriptor.
+ */
+ credits += 4;
+
+ /* Data blocks for old ea_inode. */
+ blocks = XATTR_SIZE_MAX >> sb->s_blocksize_bits;
+
+ /* Indirection block or one level of extent tree for old
+ * ea_inode.
+ */
+ blocks += 1;
+
+ /* Block bitmap and group descriptor updates for each block. */
+ credits += blocks * 2;
+ }
+
+ /* We may need to clone the existing xattr block in which case we need
+ * to increment ref counts for existing ea_inodes referenced by it.
+ */
+ if (block_bh) {
+ struct ext4_xattr_entry *entry = BFIRST(block_bh);
+
+ for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry))
+ if (entry->e_value_inum)
+ /* Ref count update on ea_inode. */
+ credits += 1;
+ }
+ return credits;
+}
+
+static int ext4_xattr_inode_update_ref(handle_t *handle, struct inode *ea_inode,
+ int ref_change)
+{
+ struct ext4_iloc iloc;
+ s64 ref_count;
+ int ret;
+
+ inode_lock(ea_inode);
+
+ ret = ext4_reserve_inode_write(handle, ea_inode, &iloc);
+ if (ret)
+ goto out;
+
+ ref_count = ext4_xattr_inode_get_ref(ea_inode);
+ ref_count += ref_change;
+ ext4_xattr_inode_set_ref(ea_inode, ref_count);
+
+ if (ref_change > 0) {
+ WARN_ONCE(ref_count <= 0, "EA inode %lu ref_count=%lld",
+ ea_inode->i_ino, ref_count);
+
+ if (ref_count == 1) {
+ WARN_ONCE(ea_inode->i_nlink, "EA inode %lu i_nlink=%u",
+ ea_inode->i_ino, ea_inode->i_nlink);
+
+ set_nlink(ea_inode, 1);
+ ext4_orphan_del(handle, ea_inode);
+ }
+ } else {
+ WARN_ONCE(ref_count < 0, "EA inode %lu ref_count=%lld",
+ ea_inode->i_ino, ref_count);
+
+ if (ref_count == 0) {
+ WARN_ONCE(ea_inode->i_nlink != 1,
+ "EA inode %lu i_nlink=%u",
+ ea_inode->i_ino, ea_inode->i_nlink);
+
+ clear_nlink(ea_inode);
+ ext4_orphan_add(handle, ea_inode);
+ }
+ }
+
+ ret = ext4_mark_iloc_dirty(handle, ea_inode, &iloc);
+ if (ret)
+ ext4_warning_inode(ea_inode,
+ "ext4_mark_iloc_dirty() failed ret=%d", ret);
+out:
+ inode_unlock(ea_inode);
+ return ret;
+}
+
+static int ext4_xattr_inode_inc_ref(handle_t *handle, struct inode *ea_inode)
+{
+ return ext4_xattr_inode_update_ref(handle, ea_inode, 1);
+}
+
+static int ext4_xattr_inode_dec_ref(handle_t *handle, struct inode *ea_inode)
+{
+ return ext4_xattr_inode_update_ref(handle, ea_inode, -1);
+}
+
+static int ext4_xattr_inode_inc_ref_all(handle_t *handle, struct inode *parent,
+ struct ext4_xattr_entry *first)
+{
+ struct inode *ea_inode;
+ struct ext4_xattr_entry *entry;
+ struct ext4_xattr_entry *failed_entry;
+ unsigned int ea_ino;
+ int err, saved_err;
+
+ for (entry = first; !IS_LAST_ENTRY(entry);
+ entry = EXT4_XATTR_NEXT(entry)) {
+ if (!entry->e_value_inum)
+ continue;
+ ea_ino = le32_to_cpu(entry->e_value_inum);
+ err = ext4_xattr_inode_iget(parent, ea_ino,
+ le32_to_cpu(entry->e_hash),
+ &ea_inode);
+ if (err)
+ goto cleanup;
+ err = ext4_xattr_inode_inc_ref(handle, ea_inode);
+ if (err) {
+ ext4_warning_inode(ea_inode, "inc ref error %d", err);
+ iput(ea_inode);
+ goto cleanup;
+ }
+ iput(ea_inode);
+ }
+ return 0;
+
+cleanup:
+ saved_err = err;
+ failed_entry = entry;
+
+ for (entry = first; entry != failed_entry;
+ entry = EXT4_XATTR_NEXT(entry)) {
+ if (!entry->e_value_inum)
+ continue;
+ ea_ino = le32_to_cpu(entry->e_value_inum);
+ err = ext4_xattr_inode_iget(parent, ea_ino,
+ le32_to_cpu(entry->e_hash),
+ &ea_inode);
+ if (err) {
+ ext4_warning(parent->i_sb,
+ "cleanup ea_ino %u iget error %d", ea_ino,
+ err);
+ continue;
+ }
+ err = ext4_xattr_inode_dec_ref(handle, ea_inode);
+ if (err)
+ ext4_warning_inode(ea_inode, "cleanup dec ref error %d",
+ err);
+ iput(ea_inode);
+ }
+ return saved_err;
+}
+
+static int ext4_xattr_restart_fn(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh, bool block_csum, bool dirty)
+{
+ int error;
+
+ if (bh && dirty) {
+ if (block_csum)
+ ext4_xattr_block_csum_set(inode, bh);
+ error = ext4_handle_dirty_metadata(handle, NULL, bh);
+ if (error) {
+ ext4_warning(inode->i_sb, "Handle metadata (error %d)",
+ error);
+ return error;
+ }
+ }
+ return 0;
+}
+
+static void
+ext4_xattr_inode_dec_ref_all(handle_t *handle, struct inode *parent,
+ struct buffer_head *bh,
+ struct ext4_xattr_entry *first, bool block_csum,
+ struct ext4_xattr_inode_array **ea_inode_array,
+ int extra_credits, bool skip_quota)
+{
+ struct inode *ea_inode;
+ struct ext4_xattr_entry *entry;
+ bool dirty = false;
+ unsigned int ea_ino;
+ int err;
+ int credits;
+
+ /* One credit for dec ref on ea_inode, one for orphan list addition, */
+ credits = 2 + extra_credits;
+
+ for (entry = first; !IS_LAST_ENTRY(entry);
+ entry = EXT4_XATTR_NEXT(entry)) {
+ if (!entry->e_value_inum)
+ continue;
+ ea_ino = le32_to_cpu(entry->e_value_inum);
+ err = ext4_xattr_inode_iget(parent, ea_ino,
+ le32_to_cpu(entry->e_hash),
+ &ea_inode);
+ if (err)
+ continue;
+
+ err = ext4_expand_inode_array(ea_inode_array, ea_inode);
+ if (err) {
+ ext4_warning_inode(ea_inode,
+ "Expand inode array err=%d", err);
+ iput(ea_inode);
+ continue;
+ }
+
+ err = ext4_journal_ensure_credits_fn(handle, credits, credits,
+ ext4_free_metadata_revoke_credits(parent->i_sb, 1),
+ ext4_xattr_restart_fn(handle, parent, bh, block_csum,
+ dirty));
+ if (err < 0) {
+ ext4_warning_inode(ea_inode, "Ensure credits err=%d",
+ err);
+ continue;
+ }
+ if (err > 0) {
+ err = ext4_journal_get_write_access(handle,
+ parent->i_sb, bh, EXT4_JTR_NONE);
+ if (err) {
+ ext4_warning_inode(ea_inode,
+ "Re-get write access err=%d",
+ err);
+ continue;
+ }
+ }
+
+ err = ext4_xattr_inode_dec_ref(handle, ea_inode);
+ if (err) {
+ ext4_warning_inode(ea_inode, "ea_inode dec ref err=%d",
+ err);
+ continue;
+ }
+
+ if (!skip_quota)
+ ext4_xattr_inode_free_quota(parent, ea_inode,
+ le32_to_cpu(entry->e_value_size));
+
+ /*
+ * Forget about ea_inode within the same transaction that
+ * decrements the ref count. This avoids duplicate decrements in
+ * case the rest of the work spills over to subsequent
+ * transactions.
+ */
+ entry->e_value_inum = 0;
+ entry->e_value_size = 0;
+
+ dirty = true;
+ }
+
+ if (dirty) {
+ /*
+ * Note that we are deliberately skipping csum calculation for
+ * the final update because we do not expect any journal
+ * restarts until xattr block is freed.
+ */
+
+ err = ext4_handle_dirty_metadata(handle, NULL, bh);
+ if (err)
+ ext4_warning_inode(parent,
+ "handle dirty metadata err=%d", err);
+ }
+}
+
+/*
+ * Release the xattr block BH: If the reference count is > 1, decrement it;
+ * otherwise free the block.
+ */
+static void
+ext4_xattr_release_block(handle_t *handle, struct inode *inode,
+ struct buffer_head *bh,
+ struct ext4_xattr_inode_array **ea_inode_array,
+ int extra_credits)
+{
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+ u32 hash, ref;
+ int error = 0;
+
+ BUFFER_TRACE(bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto out;
+
+retry_ref:
+ lock_buffer(bh);
+ hash = le32_to_cpu(BHDR(bh)->h_hash);
+ ref = le32_to_cpu(BHDR(bh)->h_refcount);
+ if (ref == 1) {
+ ea_bdebug(bh, "refcount now=0; freeing");
+ /*
+ * This must happen under buffer lock for
+ * ext4_xattr_block_set() to reliably detect freed block
+ */
+ if (ea_block_cache) {
+ struct mb_cache_entry *oe;
+
+ oe = mb_cache_entry_delete_or_get(ea_block_cache, hash,
+ bh->b_blocknr);
+ if (oe) {
+ unlock_buffer(bh);
+ mb_cache_entry_wait_unused(oe);
+ mb_cache_entry_put(ea_block_cache, oe);
+ goto retry_ref;
+ }
+ }
+ get_bh(bh);
+ unlock_buffer(bh);
+
+ if (ext4_has_feature_ea_inode(inode->i_sb))
+ ext4_xattr_inode_dec_ref_all(handle, inode, bh,
+ BFIRST(bh),
+ true /* block_csum */,
+ ea_inode_array,
+ extra_credits,
+ true /* skip_quota */);
+ ext4_free_blocks(handle, inode, bh, 0, 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
+ } else {
+ ref--;
+ BHDR(bh)->h_refcount = cpu_to_le32(ref);
+ if (ref == EXT4_XATTR_REFCOUNT_MAX - 1) {
+ struct mb_cache_entry *ce;
+
+ if (ea_block_cache) {
+ ce = mb_cache_entry_get(ea_block_cache, hash,
+ bh->b_blocknr);
+ if (ce) {
+ set_bit(MBE_REUSABLE_B, &ce->e_flags);
+ mb_cache_entry_put(ea_block_cache, ce);
+ }
+ }
+ }
+
+ ext4_xattr_block_csum_set(inode, bh);
+ /*
+ * Beware of this ugliness: Releasing of xattr block references
+ * from different inodes can race and so we have to protect
+ * from a race where someone else frees the block (and releases
+ * its journal_head) before we are done dirtying the buffer. In
+ * nojournal mode this race is harmless and we actually cannot
+ * call ext4_handle_dirty_metadata() with locked buffer as
+ * that function can call sync_dirty_buffer() so for that case
+ * we handle the dirtying after unlocking the buffer.
+ */
+ if (ext4_handle_valid(handle))
+ error = ext4_handle_dirty_metadata(handle, inode, bh);
+ unlock_buffer(bh);
+ if (!ext4_handle_valid(handle))
+ error = ext4_handle_dirty_metadata(handle, inode, bh);
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+ dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1));
+ ea_bdebug(bh, "refcount now=%d; releasing",
+ le32_to_cpu(BHDR(bh)->h_refcount));
+ }
+out:
+ ext4_std_error(inode->i_sb, error);
+ 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)) {
+ if (!last->e_value_inum && last->e_value_size) {
+ size_t offs = le16_to_cpu(last->e_value_offs);
+ if (offs < *min_offs)
+ *min_offs = offs;
+ }
+ if (total)
+ *total += EXT4_XATTR_LEN(last->e_name_len);
+ }
+ return (*min_offs - ((void *)last - base) - sizeof(__u32));
+}
+
+/*
+ * Write the value of the EA in an inode.
+ */
+static int ext4_xattr_inode_write(handle_t *handle, struct inode *ea_inode,
+ const void *buf, int bufsize)
+{
+ struct buffer_head *bh = NULL;
+ unsigned long block = 0;
+ int blocksize = ea_inode->i_sb->s_blocksize;
+ int max_blocks = (bufsize + blocksize - 1) >> ea_inode->i_blkbits;
+ int csize, wsize = 0;
+ int ret = 0, ret2 = 0;
+ int retries = 0;
+
+retry:
+ while (ret >= 0 && ret < max_blocks) {
+ struct ext4_map_blocks map;
+ map.m_lblk = block += ret;
+ map.m_len = max_blocks -= ret;
+
+ ret = ext4_map_blocks(handle, ea_inode, &map,
+ EXT4_GET_BLOCKS_CREATE);
+ if (ret <= 0) {
+ ext4_mark_inode_dirty(handle, ea_inode);
+ if (ret == -ENOSPC &&
+ ext4_should_retry_alloc(ea_inode->i_sb, &retries)) {
+ ret = 0;
+ goto retry;
+ }
+ break;
+ }
+ }
+
+ if (ret < 0)
+ return ret;
+
+ block = 0;
+ while (wsize < bufsize) {
+ brelse(bh);
+ csize = (bufsize - wsize) > blocksize ? blocksize :
+ bufsize - wsize;
+ bh = ext4_getblk(handle, ea_inode, block, 0);
+ if (IS_ERR(bh))
+ return PTR_ERR(bh);
+ if (!bh) {
+ WARN_ON_ONCE(1);
+ EXT4_ERROR_INODE(ea_inode,
+ "ext4_getblk() return bh = NULL");
+ return -EFSCORRUPTED;
+ }
+ ret = ext4_journal_get_write_access(handle, ea_inode->i_sb, bh,
+ EXT4_JTR_NONE);
+ if (ret)
+ goto out;
+
+ memcpy(bh->b_data, buf, csize);
+ set_buffer_uptodate(bh);
+ ext4_handle_dirty_metadata(handle, ea_inode, bh);
+
+ buf += csize;
+ wsize += csize;
+ block += 1;
+ }
+
+ inode_lock(ea_inode);
+ i_size_write(ea_inode, wsize);
+ ext4_update_i_disksize(ea_inode, wsize);
+ inode_unlock(ea_inode);
+
+ ret2 = ext4_mark_inode_dirty(handle, ea_inode);
+ if (unlikely(ret2 && !ret))
+ ret = ret2;
+
+out:
+ brelse(bh);
+
+ return ret;
+}
+
+/*
+ * Create an inode to store the value of a large EA.
+ */
+static struct inode *ext4_xattr_inode_create(handle_t *handle,
+ struct inode *inode, u32 hash)
+{
+ struct inode *ea_inode = NULL;
+ uid_t owner[2] = { i_uid_read(inode), i_gid_read(inode) };
+ int err;
+
+ if (inode->i_sb->s_root == NULL) {
+ ext4_warning(inode->i_sb,
+ "refuse to create EA inode when umounting");
+ WARN_ON(1);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /*
+ * Let the next inode be the goal, so we try and allocate the EA inode
+ * in the same group, or nearby one.
+ */
+ ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
+ S_IFREG | 0600, NULL, inode->i_ino + 1, owner,
+ EXT4_EA_INODE_FL);
+ if (!IS_ERR(ea_inode)) {
+ ea_inode->i_op = &ext4_file_inode_operations;
+ ea_inode->i_fop = &ext4_file_operations;
+ ext4_set_aops(ea_inode);
+ ext4_xattr_inode_set_class(ea_inode);
+ unlock_new_inode(ea_inode);
+ ext4_xattr_inode_set_ref(ea_inode, 1);
+ ext4_xattr_inode_set_hash(ea_inode, hash);
+ err = ext4_mark_inode_dirty(handle, ea_inode);
+ if (!err)
+ err = ext4_inode_attach_jinode(ea_inode);
+ if (err) {
+ if (ext4_xattr_inode_dec_ref(handle, ea_inode))
+ ext4_warning_inode(ea_inode,
+ "cleanup dec ref error %d", err);
+ iput(ea_inode);
+ return ERR_PTR(err);
+ }
+
+ /*
+ * Xattr inodes are shared therefore quota charging is performed
+ * at a higher level.
+ */
+ dquot_free_inode(ea_inode);
+ dquot_drop(ea_inode);
+ inode_lock(ea_inode);
+ ea_inode->i_flags |= S_NOQUOTA;
+ inode_unlock(ea_inode);
+ }
+
+ return ea_inode;
+}
+
+static struct inode *
+ext4_xattr_inode_cache_find(struct inode *inode, const void *value,
+ size_t value_len, u32 hash)
+{
+ struct inode *ea_inode;
+ struct mb_cache_entry *ce;
+ struct mb_cache *ea_inode_cache = EA_INODE_CACHE(inode);
+ void *ea_data;
+
+ if (!ea_inode_cache)
+ return NULL;
+
+ ce = mb_cache_entry_find_first(ea_inode_cache, hash);
+ if (!ce)
+ return NULL;
+
+ WARN_ON_ONCE(ext4_handle_valid(journal_current_handle()) &&
+ !(current->flags & PF_MEMALLOC_NOFS));
+
+ ea_data = kvmalloc(value_len, GFP_KERNEL);
+ if (!ea_data) {
+ mb_cache_entry_put(ea_inode_cache, ce);
+ return NULL;
+ }
+
+ while (ce) {
+ ea_inode = ext4_iget(inode->i_sb, ce->e_value,
+ EXT4_IGET_EA_INODE);
+ if (IS_ERR(ea_inode))
+ goto next_entry;
+ ext4_xattr_inode_set_class(ea_inode);
+ if (i_size_read(ea_inode) == value_len &&
+ !ext4_xattr_inode_read(ea_inode, ea_data, value_len) &&
+ !ext4_xattr_inode_verify_hashes(ea_inode, NULL, ea_data,
+ value_len) &&
+ !memcmp(value, ea_data, value_len)) {
+ mb_cache_entry_touch(ea_inode_cache, ce);
+ mb_cache_entry_put(ea_inode_cache, ce);
+ kvfree(ea_data);
+ return ea_inode;
+ }
+ iput(ea_inode);
+ next_entry:
+ ce = mb_cache_entry_find_next(ea_inode_cache, ce);
+ }
+ kvfree(ea_data);
+ return NULL;
+}
+
+/*
+ * Add value of the EA in an inode.
+ */
+static int ext4_xattr_inode_lookup_create(handle_t *handle, struct inode *inode,
+ const void *value, size_t value_len,
+ struct inode **ret_inode)
+{
+ struct inode *ea_inode;
+ u32 hash;
+ int err;
+
+ hash = ext4_xattr_inode_hash(EXT4_SB(inode->i_sb), value, value_len);
+ ea_inode = ext4_xattr_inode_cache_find(inode, value, value_len, hash);
+ if (ea_inode) {
+ err = ext4_xattr_inode_inc_ref(handle, ea_inode);
+ if (err) {
+ iput(ea_inode);
+ return err;
+ }
+
+ *ret_inode = ea_inode;
+ return 0;
+ }
+
+ /* Create an inode for the EA value */
+ ea_inode = ext4_xattr_inode_create(handle, inode, hash);
+ if (IS_ERR(ea_inode))
+ return PTR_ERR(ea_inode);
+
+ err = ext4_xattr_inode_write(handle, ea_inode, value, value_len);
+ if (err) {
+ ext4_xattr_inode_dec_ref(handle, ea_inode);
+ iput(ea_inode);
+ return err;
+ }
+
+ if (EA_INODE_CACHE(inode))
+ mb_cache_entry_create(EA_INODE_CACHE(inode), GFP_NOFS, hash,
+ ea_inode->i_ino, true /* reusable */);
+
+ *ret_inode = ea_inode;
+ return 0;
+}
+
+/*
+ * Reserve min(block_size/8, 1024) bytes for xattr entries/names if ea_inode
+ * feature is enabled.
+ */
+#define EXT4_XATTR_BLOCK_RESERVE(inode) min(i_blocksize(inode)/8, 1024U)
+
+static int ext4_xattr_set_entry(struct ext4_xattr_info *i,
+ struct ext4_xattr_search *s,
+ handle_t *handle, struct inode *inode,
+ bool is_block)
+{
+ struct ext4_xattr_entry *last, *next;
+ struct ext4_xattr_entry *here = s->here;
+ size_t min_offs = s->end - s->base, name_len = strlen(i->name);
+ int in_inode = i->in_inode;
+ struct inode *old_ea_inode = NULL;
+ struct inode *new_ea_inode = NULL;
+ size_t old_size, new_size;
+ int ret;
+
+ /* Space used by old and new values. */
+ old_size = (!s->not_found && !here->e_value_inum) ?
+ EXT4_XATTR_SIZE(le32_to_cpu(here->e_value_size)) : 0;
+ new_size = (i->value && !in_inode) ? EXT4_XATTR_SIZE(i->value_len) : 0;
+
+ /*
+ * Optimization for the simple case when old and new values have the
+ * same padded sizes. Not applicable if external inodes are involved.
+ */
+ if (new_size && new_size == old_size) {
+ size_t offs = le16_to_cpu(here->e_value_offs);
+ void *val = s->base + offs;
+
+ here->e_value_size = cpu_to_le32(i->value_len);
+ if (i->value == EXT4_ZERO_XATTR_VALUE) {
+ memset(val, 0, new_size);
+ } else {
+ memcpy(val, i->value, i->value_len);
+ /* Clear padding bytes. */
+ memset(val + i->value_len, 0, new_size - i->value_len);
+ }
+ goto update_hash;
+ }
+
+ /* Compute min_offs and last. */
+ last = s->first;
+ for (; !IS_LAST_ENTRY(last); last = next) {
+ next = EXT4_XATTR_NEXT(last);
+ if ((void *)next >= s->end) {
+ EXT4_ERROR_INODE(inode, "corrupted xattr entries");
+ ret = -EFSCORRUPTED;
+ goto out;
+ }
+ if (!last->e_value_inum && last->e_value_size) {
+ size_t offs = le16_to_cpu(last->e_value_offs);
+ if (offs < min_offs)
+ min_offs = offs;
+ }
+ }
+
+ /* Check whether we have enough space. */
+ if (i->value) {
+ size_t free;
+
+ free = min_offs - ((void *)last - s->base) - sizeof(__u32);
+ if (!s->not_found)
+ free += EXT4_XATTR_LEN(name_len) + old_size;
+
+ if (free < EXT4_XATTR_LEN(name_len) + new_size) {
+ ret = -ENOSPC;
+ goto out;
+ }
+
+ /*
+ * If storing the value in an external inode is an option,
+ * reserve space for xattr entries/names in the external
+ * attribute block so that a long value does not occupy the
+ * whole space and prevent further entries being added.
+ */
+ if (ext4_has_feature_ea_inode(inode->i_sb) &&
+ new_size && is_block &&
+ (min_offs + old_size - new_size) <
+ EXT4_XATTR_BLOCK_RESERVE(inode)) {
+ ret = -ENOSPC;
+ goto out;
+ }
+ }
+
+ /*
+ * Getting access to old and new ea inodes is subject to failures.
+ * Finish that work before doing any modifications to the xattr data.
+ */
+ if (!s->not_found && here->e_value_inum) {
+ ret = ext4_xattr_inode_iget(inode,
+ le32_to_cpu(here->e_value_inum),
+ le32_to_cpu(here->e_hash),
+ &old_ea_inode);
+ if (ret) {
+ old_ea_inode = NULL;
+ goto out;
+ }
+ }
+ if (i->value && in_inode) {
+ WARN_ON_ONCE(!i->value_len);
+
+ ret = ext4_xattr_inode_alloc_quota(inode, i->value_len);
+ if (ret)
+ goto out;
+
+ ret = ext4_xattr_inode_lookup_create(handle, inode, i->value,
+ i->value_len,
+ &new_ea_inode);
+ if (ret) {
+ new_ea_inode = NULL;
+ ext4_xattr_inode_free_quota(inode, NULL, i->value_len);
+ goto out;
+ }
+ }
+
+ if (old_ea_inode) {
+ /* We are ready to release ref count on the old_ea_inode. */
+ ret = ext4_xattr_inode_dec_ref(handle, old_ea_inode);
+ if (ret) {
+ /* Release newly required ref count on new_ea_inode. */
+ if (new_ea_inode) {
+ int err;
+
+ err = ext4_xattr_inode_dec_ref(handle,
+ new_ea_inode);
+ if (err)
+ ext4_warning_inode(new_ea_inode,
+ "dec ref new_ea_inode err=%d",
+ err);
+ ext4_xattr_inode_free_quota(inode, new_ea_inode,
+ i->value_len);
+ }
+ goto out;
+ }
+
+ ext4_xattr_inode_free_quota(inode, old_ea_inode,
+ le32_to_cpu(here->e_value_size));
+ }
+
+ /* No failures allowed past this point. */
+
+ if (!s->not_found && here->e_value_size && !here->e_value_inum) {
+ /* Remove the old value. */
+ void *first_val = s->base + min_offs;
+ size_t offs = le16_to_cpu(here->e_value_offs);
+ void *val = s->base + offs;
+
+ memmove(first_val + old_size, first_val, val - first_val);
+ memset(first_val, 0, old_size);
+ min_offs += old_size;
+
+ /* Adjust all value offsets. */
+ last = s->first;
+ while (!IS_LAST_ENTRY(last)) {
+ size_t o = le16_to_cpu(last->e_value_offs);
+
+ if (!last->e_value_inum &&
+ last->e_value_size && o < offs)
+ last->e_value_offs = cpu_to_le16(o + old_size);
+ last = EXT4_XATTR_NEXT(last);
+ }
+ }
+
+ if (!i->value) {
+ /* Remove old name. */
+ size_t size = EXT4_XATTR_LEN(name_len);
+
+ last = ENTRY((void *)last - size);
+ memmove(here, (void *)here + size,
+ (void *)last - (void *)here + sizeof(__u32));
+ memset(last, 0, size);
+
+ /*
+ * Update i_inline_off - moved ibody region might contain
+ * system.data attribute. Handling a failure here won't
+ * cause other complications for setting an xattr.
+ */
+ if (!is_block && ext4_has_inline_data(inode)) {
+ ret = ext4_find_inline_data_nolock(inode);
+ if (ret) {
+ ext4_warning_inode(inode,
+ "unable to update i_inline_off");
+ goto out;
+ }
+ }
+ } else if (s->not_found) {
+ /* Insert new name. */
+ size_t size = EXT4_XATTR_LEN(name_len);
+ size_t rest = (void *)last - (void *)here + sizeof(__u32);
+
+ memmove((void *)here + size, here, rest);
+ memset(here, 0, size);
+ here->e_name_index = i->name_index;
+ here->e_name_len = name_len;
+ memcpy(here->e_name, i->name, name_len);
+ } else {
+ /* This is an update, reset value info. */
+ here->e_value_inum = 0;
+ here->e_value_offs = 0;
+ here->e_value_size = 0;
+ }
+
+ if (i->value) {
+ /* Insert new value. */
+ if (in_inode) {
+ here->e_value_inum = cpu_to_le32(new_ea_inode->i_ino);
+ } else if (i->value_len) {
+ void *val = s->base + min_offs - new_size;
+
+ here->e_value_offs = cpu_to_le16(min_offs - new_size);
+ if (i->value == EXT4_ZERO_XATTR_VALUE) {
+ memset(val, 0, new_size);
+ } else {
+ memcpy(val, i->value, i->value_len);
+ /* Clear padding bytes. */
+ memset(val + i->value_len, 0,
+ new_size - i->value_len);
+ }
+ }
+ here->e_value_size = cpu_to_le32(i->value_len);
+ }
+
+update_hash:
+ if (i->value) {
+ __le32 hash = 0;
+
+ /* Entry hash calculation. */
+ if (in_inode) {
+ __le32 crc32c_hash;
+
+ /*
+ * Feed crc32c hash instead of the raw value for entry
+ * hash calculation. This is to avoid walking
+ * potentially long value buffer again.
+ */
+ crc32c_hash = cpu_to_le32(
+ ext4_xattr_inode_get_hash(new_ea_inode));
+ hash = ext4_xattr_hash_entry(here->e_name,
+ here->e_name_len,
+ &crc32c_hash, 1);
+ } else if (is_block) {
+ __le32 *value = s->base + le16_to_cpu(
+ here->e_value_offs);
+
+ hash = ext4_xattr_hash_entry(here->e_name,
+ here->e_name_len, value,
+ new_size >> 2);
+ }
+ here->e_hash = hash;
+ }
+
+ if (is_block)
+ ext4_xattr_rehash((struct ext4_xattr_header *)s->base);
+
+ ret = 0;
+out:
+ iput(old_ea_inode);
+ iput(new_ea_inode);
+ return ret;
+}
+
+struct ext4_xattr_block_find {
+ struct ext4_xattr_search s;
+ struct buffer_head *bh;
+};
+
+static int
+ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
+ struct ext4_xattr_block_find *bs)
+{
+ struct super_block *sb = inode->i_sb;
+ int error;
+
+ ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
+ i->name_index, i->name, i->value, (long)i->value_len);
+
+ if (EXT4_I(inode)->i_file_acl) {
+ /* The inode already has an extended attribute block. */
+ bs->bh = ext4_sb_bread(sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bs->bh)) {
+ error = PTR_ERR(bs->bh);
+ bs->bh = NULL;
+ return error;
+ }
+ ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
+ atomic_read(&(bs->bh->b_count)),
+ le32_to_cpu(BHDR(bs->bh)->h_refcount));
+ error = ext4_xattr_check_block(inode, bs->bh);
+ if (error)
+ return error;
+ /* Find the named attribute. */
+ bs->s.base = BHDR(bs->bh);
+ bs->s.first = BFIRST(bs->bh);
+ bs->s.end = bs->bh->b_data + bs->bh->b_size;
+ bs->s.here = bs->s.first;
+ error = xattr_find_entry(inode, &bs->s.here, bs->s.end,
+ i->name_index, i->name, 1);
+ if (error && error != -ENODATA)
+ return error;
+ bs->s.not_found = error;
+ }
+ return 0;
+}
+
+static int
+ext4_xattr_block_set(handle_t *handle, struct inode *inode,
+ struct ext4_xattr_info *i,
+ struct ext4_xattr_block_find *bs)
+{
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *new_bh = NULL;
+ struct ext4_xattr_search s_copy = bs->s;
+ struct ext4_xattr_search *s = &s_copy;
+ struct mb_cache_entry *ce = NULL;
+ int error = 0;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+ struct inode *ea_inode = NULL, *tmp_inode;
+ size_t old_ea_inode_quota = 0;
+ unsigned int ea_ino;
+
+
+#define header(x) ((struct ext4_xattr_header *)(x))
+
+ if (s->base) {
+ int offset = (char *)s->here - bs->bh->b_data;
+
+ BUFFER_TRACE(bs->bh, "get_write_access");
+ error = ext4_journal_get_write_access(handle, sb, bs->bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto cleanup;
+ lock_buffer(bs->bh);
+
+ if (header(s->base)->h_refcount == cpu_to_le32(1)) {
+ __u32 hash = le32_to_cpu(BHDR(bs->bh)->h_hash);
+
+ /*
+ * This must happen under buffer lock for
+ * ext4_xattr_block_set() to reliably detect modified
+ * block
+ */
+ if (ea_block_cache) {
+ struct mb_cache_entry *oe;
+
+ oe = mb_cache_entry_delete_or_get(ea_block_cache,
+ hash, bs->bh->b_blocknr);
+ if (oe) {
+ /*
+ * Xattr block is getting reused. Leave
+ * it alone.
+ */
+ mb_cache_entry_put(ea_block_cache, oe);
+ goto clone_block;
+ }
+ }
+ ea_bdebug(bs->bh, "modifying in-place");
+ error = ext4_xattr_set_entry(i, s, handle, inode,
+ true /* is_block */);
+ ext4_xattr_block_csum_set(inode, bs->bh);
+ unlock_buffer(bs->bh);
+ if (error == -EFSCORRUPTED)
+ goto bad_block;
+ if (!error)
+ error = ext4_handle_dirty_metadata(handle,
+ inode,
+ bs->bh);
+ if (error)
+ goto cleanup;
+ goto inserted;
+ }
+clone_block:
+ unlock_buffer(bs->bh);
+ ea_bdebug(bs->bh, "cloning");
+ s->base = kmemdup(BHDR(bs->bh), bs->bh->b_size, GFP_NOFS);
+ error = -ENOMEM;
+ if (s->base == NULL)
+ goto cleanup;
+ s->first = ENTRY(header(s->base)+1);
+ header(s->base)->h_refcount = cpu_to_le32(1);
+ s->here = ENTRY(s->base + offset);
+ s->end = s->base + bs->bh->b_size;
+
+ /*
+ * If existing entry points to an xattr inode, we need
+ * to prevent ext4_xattr_set_entry() from decrementing
+ * ref count on it because the reference belongs to the
+ * original block. In this case, make the entry look
+ * like it has an empty value.
+ */
+ if (!s->not_found && s->here->e_value_inum) {
+ ea_ino = le32_to_cpu(s->here->e_value_inum);
+ error = ext4_xattr_inode_iget(inode, ea_ino,
+ le32_to_cpu(s->here->e_hash),
+ &tmp_inode);
+ if (error)
+ goto cleanup;
+
+ if (!ext4_test_inode_state(tmp_inode,
+ EXT4_STATE_LUSTRE_EA_INODE)) {
+ /*
+ * Defer quota free call for previous
+ * inode until success is guaranteed.
+ */
+ old_ea_inode_quota = le32_to_cpu(
+ s->here->e_value_size);
+ }
+ iput(tmp_inode);
+
+ s->here->e_value_inum = 0;
+ s->here->e_value_size = 0;
+ }
+ } else {
+ /* Allocate a buffer where we construct the new block. */
+ s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
+ error = -ENOMEM;
+ if (s->base == NULL)
+ goto cleanup;
+ header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
+ header(s->base)->h_blocks = cpu_to_le32(1);
+ header(s->base)->h_refcount = cpu_to_le32(1);
+ s->first = ENTRY(header(s->base)+1);
+ s->here = ENTRY(header(s->base)+1);
+ s->end = s->base + sb->s_blocksize;
+ }
+
+ error = ext4_xattr_set_entry(i, s, handle, inode, true /* is_block */);
+ if (error == -EFSCORRUPTED)
+ goto bad_block;
+ if (error)
+ goto cleanup;
+
+ if (i->value && s->here->e_value_inum) {
+ /*
+ * A ref count on ea_inode has been taken as part of the call to
+ * ext4_xattr_set_entry() above. We would like to drop this
+ * extra ref but we have to wait until the xattr block is
+ * initialized and has its own ref count on the ea_inode.
+ */
+ ea_ino = le32_to_cpu(s->here->e_value_inum);
+ error = ext4_xattr_inode_iget(inode, ea_ino,
+ le32_to_cpu(s->here->e_hash),
+ &ea_inode);
+ if (error) {
+ ea_inode = NULL;
+ goto cleanup;
+ }
+ }
+
+inserted:
+ if (!IS_LAST_ENTRY(s->first)) {
+ new_bh = ext4_xattr_block_cache_find(inode, header(s->base),
+ &ce);
+ if (new_bh) {
+ /* We found an identical block in the cache. */
+ if (new_bh == bs->bh)
+ ea_bdebug(new_bh, "keeping");
+ else {
+ u32 ref;
+
+#ifdef EXT4_XATTR_DEBUG
+ WARN_ON_ONCE(dquot_initialize_needed(inode));
+#endif
+ /* The old block is released after updating
+ the inode. */
+ error = dquot_alloc_block(inode,
+ EXT4_C2B(EXT4_SB(sb), 1));
+ if (error)
+ goto cleanup;
+ BUFFER_TRACE(new_bh, "get_write_access");
+ error = ext4_journal_get_write_access(
+ handle, sb, new_bh,
+ EXT4_JTR_NONE);
+ if (error)
+ goto cleanup_dquot;
+ lock_buffer(new_bh);
+ /*
+ * We have to be careful about races with
+ * adding references to xattr block. Once we
+ * hold buffer lock xattr block's state is
+ * stable so we can check the additional
+ * reference fits.
+ */
+ ref = le32_to_cpu(BHDR(new_bh)->h_refcount) + 1;
+ if (ref > EXT4_XATTR_REFCOUNT_MAX) {
+ /*
+ * Undo everything and check mbcache
+ * again.
+ */
+ unlock_buffer(new_bh);
+ dquot_free_block(inode,
+ EXT4_C2B(EXT4_SB(sb),
+ 1));
+ brelse(new_bh);
+ mb_cache_entry_put(ea_block_cache, ce);
+ ce = NULL;
+ new_bh = NULL;
+ goto inserted;
+ }
+ BHDR(new_bh)->h_refcount = cpu_to_le32(ref);
+ if (ref == EXT4_XATTR_REFCOUNT_MAX)
+ clear_bit(MBE_REUSABLE_B, &ce->e_flags);
+ ea_bdebug(new_bh, "reusing; refcount now=%d",
+ ref);
+ ext4_xattr_block_csum_set(inode, new_bh);
+ unlock_buffer(new_bh);
+ error = ext4_handle_dirty_metadata(handle,
+ inode,
+ new_bh);
+ if (error)
+ goto cleanup_dquot;
+ }
+ mb_cache_entry_touch(ea_block_cache, ce);
+ mb_cache_entry_put(ea_block_cache, ce);
+ ce = NULL;
+ } else if (bs->bh && s->base == bs->bh->b_data) {
+ /* We were modifying this block in-place. */
+ ea_bdebug(bs->bh, "keeping this block");
+ ext4_xattr_block_cache_insert(ea_block_cache, bs->bh);
+ new_bh = bs->bh;
+ get_bh(new_bh);
+ } else {
+ /* We need to allocate a new block */
+ ext4_fsblk_t goal, block;
+
+#ifdef EXT4_XATTR_DEBUG
+ WARN_ON_ONCE(dquot_initialize_needed(inode));
+#endif
+ goal = ext4_group_first_block_no(sb,
+ EXT4_I(inode)->i_block_group);
+ block = ext4_new_meta_blocks(handle, inode, goal, 0,
+ NULL, &error);
+ if (error)
+ goto cleanup;
+
+ ea_idebug(inode, "creating block %llu",
+ (unsigned long long)block);
+
+ new_bh = sb_getblk(sb, block);
+ if (unlikely(!new_bh)) {
+ error = -ENOMEM;
+getblk_failed:
+ ext4_free_blocks(handle, inode, NULL, block, 1,
+ EXT4_FREE_BLOCKS_METADATA);
+ goto cleanup;
+ }
+ error = ext4_xattr_inode_inc_ref_all(handle, inode,
+ ENTRY(header(s->base)+1));
+ if (error)
+ goto getblk_failed;
+ if (ea_inode) {
+ /* Drop the extra ref on ea_inode. */
+ error = ext4_xattr_inode_dec_ref(handle,
+ ea_inode);
+ if (error)
+ ext4_warning_inode(ea_inode,
+ "dec ref error=%d",
+ error);
+ iput(ea_inode);
+ ea_inode = NULL;
+ }
+
+ lock_buffer(new_bh);
+ error = ext4_journal_get_create_access(handle, sb,
+ new_bh, EXT4_JTR_NONE);
+ if (error) {
+ unlock_buffer(new_bh);
+ error = -EIO;
+ goto getblk_failed;
+ }
+ memcpy(new_bh->b_data, s->base, new_bh->b_size);
+ ext4_xattr_block_csum_set(inode, new_bh);
+ set_buffer_uptodate(new_bh);
+ unlock_buffer(new_bh);
+ ext4_xattr_block_cache_insert(ea_block_cache, new_bh);
+ error = ext4_handle_dirty_metadata(handle, inode,
+ new_bh);
+ if (error)
+ goto cleanup;
+ }
+ }
+
+ if (old_ea_inode_quota)
+ ext4_xattr_inode_free_quota(inode, NULL, old_ea_inode_quota);
+
+ /* Update the inode. */
+ EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
+
+ /* Drop the previous xattr block. */
+ if (bs->bh && bs->bh != new_bh) {
+ struct ext4_xattr_inode_array *ea_inode_array = NULL;
+
+ ext4_xattr_release_block(handle, inode, bs->bh,
+ &ea_inode_array,
+ 0 /* extra_credits */);
+ ext4_xattr_inode_array_free(ea_inode_array);
+ }
+ error = 0;
+
+cleanup:
+ if (ea_inode) {
+ int error2;
+
+ error2 = ext4_xattr_inode_dec_ref(handle, ea_inode);
+ if (error2)
+ ext4_warning_inode(ea_inode, "dec ref error=%d",
+ error2);
+
+ /* If there was an error, revert the quota charge. */
+ if (error)
+ ext4_xattr_inode_free_quota(inode, ea_inode,
+ i_size_read(ea_inode));
+ iput(ea_inode);
+ }
+ if (ce)
+ mb_cache_entry_put(ea_block_cache, ce);
+ brelse(new_bh);
+ if (!(bs->bh && s->base == bs->bh->b_data))
+ kfree(s->base);
+
+ return error;
+
+cleanup_dquot:
+ dquot_free_block(inode, EXT4_C2B(EXT4_SB(sb), 1));
+ goto cleanup;
+
+bad_block:
+ EXT4_ERROR_INODE(inode, "bad block %llu",
+ EXT4_I(inode)->i_file_acl);
+ goto cleanup;
+
+#undef header
+}
+
+int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
+ struct ext4_xattr_ibody_find *is)
+{
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_inode *raw_inode;
+ int error;
+
+ if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+ return 0;
+
+ raw_inode = ext4_raw_inode(&is->iloc);
+ header = IHDR(inode, raw_inode);
+ is->s.base = is->s.first = IFIRST(header);
+ is->s.here = is->s.first;
+ is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+ if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+ error = xattr_check_inode(inode, header, is->s.end);
+ if (error)
+ return error;
+ /* Find the named attribute. */
+ error = xattr_find_entry(inode, &is->s.here, is->s.end,
+ i->name_index, i->name, 0);
+ if (error && error != -ENODATA)
+ return error;
+ is->s.not_found = error;
+ }
+ return 0;
+}
+
+int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+ struct ext4_xattr_info *i,
+ struct ext4_xattr_ibody_find *is)
+{
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_xattr_search *s = &is->s;
+ int error;
+
+ if (!EXT4_INODE_HAS_XATTR_SPACE(inode))
+ return -ENOSPC;
+
+ error = ext4_xattr_set_entry(i, s, handle, inode, false /* is_block */);
+ if (error)
+ return error;
+ header = IHDR(inode, ext4_raw_inode(&is->iloc));
+ if (!IS_LAST_ENTRY(s->first)) {
+ header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
+ ext4_set_inode_state(inode, EXT4_STATE_XATTR);
+ } else {
+ header->h_magic = cpu_to_le32(0);
+ ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
+ }
+ return 0;
+}
+
+static int ext4_xattr_value_same(struct ext4_xattr_search *s,
+ struct ext4_xattr_info *i)
+{
+ void *value;
+
+ /* When e_value_inum is set the value is stored externally. */
+ if (s->here->e_value_inum)
+ return 0;
+ if (le32_to_cpu(s->here->e_value_size) != i->value_len)
+ return 0;
+ value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);
+ return !memcmp(value, i->value, i->value_len);
+}
+
+static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
+{
+ struct buffer_head *bh;
+ int error;
+
+ if (!EXT4_I(inode)->i_file_acl)
+ return NULL;
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh))
+ return bh;
+ error = ext4_xattr_check_block(inode, bh);
+ if (error) {
+ brelse(bh);
+ return ERR_PTR(error);
+ }
+ return bh;
+}
+
+/*
+ * ext4_xattr_set_handle()
+ *
+ * Create, replace or remove an extended attribute for this inode. Value
+ * is NULL to remove an existing extended attribute, and non-NULL to
+ * either replace an existing extended attribute, or create a new extended
+ * attribute. The flags XATTR_REPLACE and XATTR_CREATE
+ * specify that an extended attribute must exist and must not exist
+ * previous to the call, respectively.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
+ const char *name, const void *value, size_t value_len,
+ int flags)
+{
+ struct ext4_xattr_info i = {
+ .name_index = name_index,
+ .name = name,
+ .value = value,
+ .value_len = value_len,
+ .in_inode = 0,
+ };
+ struct ext4_xattr_ibody_find is = {
+ .s = { .not_found = -ENODATA, },
+ };
+ struct ext4_xattr_block_find bs = {
+ .s = { .not_found = -ENODATA, },
+ };
+ int no_expand;
+ int error;
+
+ if (!name)
+ return -EINVAL;
+ if (strlen(name) > 255)
+ return -ERANGE;
+
+ ext4_write_lock_xattr(inode, &no_expand);
+
+ /* Check journal credits under write lock. */
+ if (ext4_handle_valid(handle)) {
+ struct buffer_head *bh;
+ int credits;
+
+ bh = ext4_xattr_get_block(inode);
+ if (IS_ERR(bh)) {
+ error = PTR_ERR(bh);
+ goto cleanup;
+ }
+
+ credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
+ value_len,
+ flags & XATTR_CREATE);
+ brelse(bh);
+
+ if (jbd2_handle_buffer_credits(handle) < credits) {
+ error = -ENOSPC;
+ goto cleanup;
+ }
+ WARN_ON_ONCE(!(current->flags & PF_MEMALLOC_NOFS));
+ }
+
+ error = ext4_reserve_inode_write(handle, inode, &is.iloc);
+ if (error)
+ goto cleanup;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
+ struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
+ memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
+ ext4_clear_inode_state(inode, EXT4_STATE_NEW);
+ }
+
+ error = ext4_xattr_ibody_find(inode, &i, &is);
+ if (error)
+ goto cleanup;
+ if (is.s.not_found)
+ error = ext4_xattr_block_find(inode, &i, &bs);
+ if (error)
+ goto cleanup;
+ if (is.s.not_found && bs.s.not_found) {
+ error = -ENODATA;
+ if (flags & XATTR_REPLACE)
+ goto cleanup;
+ error = 0;
+ if (!value)
+ goto cleanup;
+ } else {
+ error = -EEXIST;
+ if (flags & XATTR_CREATE)
+ goto cleanup;
+ }
+
+ if (!value) {
+ if (!is.s.not_found)
+ error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ else if (!bs.s.not_found)
+ error = ext4_xattr_block_set(handle, inode, &i, &bs);
+ } else {
+ error = 0;
+ /* Xattr value did not change? Save us some work and bail out */
+ if (!is.s.not_found && ext4_xattr_value_same(&is.s, &i))
+ goto cleanup;
+ if (!bs.s.not_found && ext4_xattr_value_same(&bs.s, &i))
+ goto cleanup;
+
+ if (ext4_has_feature_ea_inode(inode->i_sb) &&
+ (EXT4_XATTR_SIZE(i.value_len) >
+ EXT4_XATTR_MIN_LARGE_EA_SIZE(inode->i_sb->s_blocksize)))
+ i.in_inode = 1;
+retry_inode:
+ error = ext4_xattr_ibody_set(handle, inode, &i, &is);
+ if (!error && !bs.s.not_found) {
+ i.value = NULL;
+ error = ext4_xattr_block_set(handle, inode, &i, &bs);
+ } else if (error == -ENOSPC) {
+ if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
+ brelse(bs.bh);
+ bs.bh = NULL;
+ error = ext4_xattr_block_find(inode, &i, &bs);
+ if (error)
+ goto cleanup;
+ }
+ error = ext4_xattr_block_set(handle, inode, &i, &bs);
+ if (!error && !is.s.not_found) {
+ i.value = NULL;
+ error = ext4_xattr_ibody_set(handle, inode, &i,
+ &is);
+ } else if (error == -ENOSPC) {
+ /*
+ * Xattr does not fit in the block, store at
+ * external inode if possible.
+ */
+ if (ext4_has_feature_ea_inode(inode->i_sb) &&
+ i.value_len && !i.in_inode) {
+ i.in_inode = 1;
+ goto retry_inode;
+ }
+ }
+ }
+ }
+ if (!error) {
+ ext4_xattr_update_super_block(handle, inode->i_sb);
+ inode->i_ctime = current_time(inode);
+ inode_inc_iversion(inode);
+ if (!value)
+ no_expand = 0;
+ error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
+ /*
+ * The bh is consumed by ext4_mark_iloc_dirty, even with
+ * error != 0.
+ */
+ is.iloc.bh = NULL;
+ if (IS_SYNC(inode))
+ ext4_handle_sync(handle);
+ }
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
+
+cleanup:
+ brelse(is.iloc.bh);
+ brelse(bs.bh);
+ ext4_write_unlock_xattr(inode, &no_expand);
+ return error;
+}
+
+int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
+ bool is_create, int *credits)
+{
+ struct buffer_head *bh;
+ int err;
+
+ *credits = 0;
+
+ if (!EXT4_SB(inode->i_sb)->s_journal)
+ return 0;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+
+ bh = ext4_xattr_get_block(inode);
+ if (IS_ERR(bh)) {
+ err = PTR_ERR(bh);
+ } else {
+ *credits = __ext4_xattr_set_credits(inode->i_sb, inode, bh,
+ value_len, is_create);
+ brelse(bh);
+ err = 0;
+ }
+
+ up_read(&EXT4_I(inode)->xattr_sem);
+ return err;
+}
+
+/*
+ * ext4_xattr_set()
+ *
+ * Like ext4_xattr_set_handle, but start from an inode. This extended
+ * attribute modification is a filesystem transaction by itself.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+int
+ext4_xattr_set(struct inode *inode, int name_index, const char *name,
+ const void *value, size_t value_len, int flags)
+{
+ handle_t *handle;
+ struct super_block *sb = inode->i_sb;
+ int error, retries = 0;
+ int credits;
+
+ error = dquot_initialize(inode);
+ if (error)
+ return error;
+
+retry:
+ error = ext4_xattr_set_credits(inode, value_len, flags & XATTR_CREATE,
+ &credits);
+ if (error)
+ return error;
+
+ handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
+ if (IS_ERR(handle)) {
+ error = PTR_ERR(handle);
+ } else {
+ int error2;
+
+ error = ext4_xattr_set_handle(handle, inode, name_index, name,
+ value, value_len, flags);
+ error2 = ext4_journal_stop(handle);
+ if (error == -ENOSPC &&
+ ext4_should_retry_alloc(sb, &retries))
+ goto retry;
+ if (error == 0)
+ error = error2;
+ }
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, NULL);
+
+ return error;
+}
+
+/*
+ * 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)
+{
+ struct ext4_xattr_entry *last = entry;
+ int new_offs;
+
+ /* We always shift xattr headers further thus offsets get lower */
+ BUG_ON(value_offs_shift > 0);
+
+ /* Adjust the value offsets of the entries */
+ for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ if (!last->e_value_inum && last->e_value_size) {
+ new_offs = le16_to_cpu(last->e_value_offs) +
+ value_offs_shift;
+ last->e_value_offs = cpu_to_le16(new_offs);
+ }
+ }
+ /* Shift the entries by n bytes */
+ memmove(to, from, n);
+}
+
+/*
+ * Move xattr pointed to by 'entry' from inode into external xattr block
+ */
+static int ext4_xattr_move_to_block(handle_t *handle, struct inode *inode,
+ struct ext4_inode *raw_inode,
+ struct ext4_xattr_entry *entry)
+{
+ struct ext4_xattr_ibody_find *is = NULL;
+ struct ext4_xattr_block_find *bs = NULL;
+ char *buffer = NULL, *b_entry_name = NULL;
+ size_t value_size = le32_to_cpu(entry->e_value_size);
+ struct ext4_xattr_info i = {
+ .value = NULL,
+ .value_len = 0,
+ .name_index = entry->e_name_index,
+ .in_inode = !!entry->e_value_inum,
+ };
+ struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
+ int needs_kvfree = 0;
+ int error;
+
+ is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
+ bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
+ b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
+ if (!is || !bs || !b_entry_name) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ is->s.not_found = -ENODATA;
+ bs->s.not_found = -ENODATA;
+ is->iloc.bh = NULL;
+ bs->bh = NULL;
+
+ /* Save the entry name and the entry value */
+ if (entry->e_value_inum) {
+ buffer = kvmalloc(value_size, GFP_NOFS);
+ if (!buffer) {
+ error = -ENOMEM;
+ goto out;
+ }
+ needs_kvfree = 1;
+ error = ext4_xattr_inode_get(inode, entry, buffer, value_size);
+ if (error)
+ goto out;
+ } else {
+ size_t value_offs = le16_to_cpu(entry->e_value_offs);
+ buffer = (void *)IFIRST(header) + value_offs;
+ }
+
+ 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 out;
+
+ error = ext4_xattr_ibody_find(inode, &i, is);
+ if (error)
+ goto out;
+
+ i.value = buffer;
+ i.value_len = value_size;
+ error = ext4_xattr_block_find(inode, &i, bs);
+ if (error)
+ goto out;
+
+ /* Move ea entry from the inode into the block */
+ error = ext4_xattr_block_set(handle, inode, &i, bs);
+ if (error)
+ goto out;
+
+ /* Remove the chosen entry from the inode */
+ i.value = NULL;
+ i.value_len = 0;
+ error = ext4_xattr_ibody_set(handle, inode, &i, is);
+
+out:
+ kfree(b_entry_name);
+ if (needs_kvfree && buffer)
+ kvfree(buffer);
+ if (is)
+ brelse(is->iloc.bh);
+ if (bs)
+ brelse(bs->bh);
+ kfree(is);
+ kfree(bs);
+
+ return error;
+}
+
+static int ext4_xattr_make_inode_space(handle_t *handle, struct inode *inode,
+ struct ext4_inode *raw_inode,
+ int isize_diff, size_t ifree,
+ size_t bfree, int *total_ino)
+{
+ struct ext4_xattr_ibody_header *header = IHDR(inode, raw_inode);
+ struct ext4_xattr_entry *small_entry;
+ struct ext4_xattr_entry *entry;
+ struct ext4_xattr_entry *last;
+ unsigned int entry_size; /* EA entry size */
+ unsigned int total_size; /* EA entry size + value size */
+ unsigned int min_total_size;
+ int error;
+
+ while (isize_diff > ifree) {
+ entry = NULL;
+ small_entry = NULL;
+ min_total_size = ~0U;
+ last = IFIRST(header);
+ /* Find the entry best suited to be pushed into EA block */
+ for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
+ /* never move system.data out of the inode */
+ if ((last->e_name_len == 4) &&
+ (last->e_name_index == EXT4_XATTR_INDEX_SYSTEM) &&
+ !memcmp(last->e_name, "data", 4))
+ continue;
+ total_size = EXT4_XATTR_LEN(last->e_name_len);
+ if (!last->e_value_inum)
+ total_size += EXT4_XATTR_SIZE(
+ le32_to_cpu(last->e_value_size));
+ if (total_size <= bfree &&
+ total_size < min_total_size) {
+ if (total_size + ifree < isize_diff) {
+ small_entry = last;
+ } else {
+ entry = last;
+ min_total_size = total_size;
+ }
+ }
+ }
+
+ if (entry == NULL) {
+ if (small_entry == NULL)
+ return -ENOSPC;
+ entry = small_entry;
+ }
+
+ entry_size = EXT4_XATTR_LEN(entry->e_name_len);
+ total_size = entry_size;
+ if (!entry->e_value_inum)
+ total_size += EXT4_XATTR_SIZE(
+ le32_to_cpu(entry->e_value_size));
+ error = ext4_xattr_move_to_block(handle, inode, raw_inode,
+ entry);
+ if (error)
+ return error;
+
+ *total_ino -= entry_size;
+ ifree += total_size;
+ bfree -= total_size;
+ }
+
+ return 0;
+}
+
+/*
+ * 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_sb_info *sbi = EXT4_SB(inode->i_sb);
+ static unsigned int mnt_count;
+ size_t min_offs;
+ size_t ifree, bfree;
+ int total_ino;
+ void *base, *end;
+ int error = 0, tried_min_extra_isize = 0;
+ int s_min_extra_isize = le16_to_cpu(sbi->s_es->s_min_extra_isize);
+ int isize_diff; /* How much do we need to grow i_extra_isize */
+
+retry:
+ isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
+ if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
+ return 0;
+
+ header = IHDR(inode, raw_inode);
+
+ /*
+ * Check if enough free space is available in the inode to shift the
+ * entries ahead by new_extra_isize.
+ */
+
+ base = IFIRST(header);
+ end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
+ min_offs = end - base;
+ total_ino = sizeof(struct ext4_xattr_ibody_header) + sizeof(u32);
+
+ error = xattr_check_inode(inode, header, end);
+ if (error)
+ goto cleanup;
+
+ ifree = ext4_xattr_free_space(base, &min_offs, base, &total_ino);
+ if (ifree >= isize_diff)
+ goto shift;
+
+ /*
+ * 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) {
+ struct buffer_head *bh;
+
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh)) {
+ error = PTR_ERR(bh);
+ goto cleanup;
+ }
+ error = ext4_xattr_check_block(inode, bh);
+ if (error) {
+ brelse(bh);
+ goto cleanup;
+ }
+ base = BHDR(bh);
+ end = bh->b_data + bh->b_size;
+ min_offs = end - base;
+ bfree = ext4_xattr_free_space(BFIRST(bh), &min_offs, base,
+ NULL);
+ brelse(bh);
+ if (bfree + ifree < isize_diff) {
+ if (!tried_min_extra_isize && s_min_extra_isize) {
+ tried_min_extra_isize++;
+ new_extra_isize = s_min_extra_isize;
+ goto retry;
+ }
+ error = -ENOSPC;
+ goto cleanup;
+ }
+ } else {
+ bfree = inode->i_sb->s_blocksize;
+ }
+
+ error = ext4_xattr_make_inode_space(handle, inode, raw_inode,
+ isize_diff, ifree, bfree,
+ &total_ino);
+ if (error) {
+ if (error == -ENOSPC && !tried_min_extra_isize &&
+ s_min_extra_isize) {
+ tried_min_extra_isize++;
+ new_extra_isize = s_min_extra_isize;
+ goto retry;
+ }
+ goto cleanup;
+ }
+shift:
+ /* Adjust the offsets and shift the remaining entries ahead */
+ ext4_xattr_shift_entries(IFIRST(header), EXT4_I(inode)->i_extra_isize
+ - new_extra_isize, (void *)raw_inode +
+ EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
+ (void *)header, total_ino);
+ EXT4_I(inode)->i_extra_isize = new_extra_isize;
+
+ if (ext4_has_inline_data(inode))
+ error = ext4_find_inline_data_nolock(inode);
+
+cleanup:
+ if (error && (mnt_count != le16_to_cpu(sbi->s_es->s_mnt_count))) {
+ ext4_warning(inode->i_sb, "Unable to expand inode %lu. Delete some EAs or run e2fsck.",
+ inode->i_ino);
+ mnt_count = le16_to_cpu(sbi->s_es->s_mnt_count);
+ }
+ return error;
+}
+
+#define EIA_INCR 16 /* must be 2^n */
+#define EIA_MASK (EIA_INCR - 1)
+
+/* Add the large xattr @inode into @ea_inode_array for deferred iput().
+ * If @ea_inode_array is new or full it will be grown and the old
+ * contents copied over.
+ */
+static int
+ext4_expand_inode_array(struct ext4_xattr_inode_array **ea_inode_array,
+ struct inode *inode)
+{
+ if (*ea_inode_array == NULL) {
+ /*
+ * Start with 15 inodes, so it fits into a power-of-two size.
+ * If *ea_inode_array is NULL, this is essentially offsetof()
+ */
+ (*ea_inode_array) =
+ kmalloc(offsetof(struct ext4_xattr_inode_array,
+ inodes[EIA_MASK]),
+ GFP_NOFS);
+ if (*ea_inode_array == NULL)
+ return -ENOMEM;
+ (*ea_inode_array)->count = 0;
+ } else if (((*ea_inode_array)->count & EIA_MASK) == EIA_MASK) {
+ /* expand the array once all 15 + n * 16 slots are full */
+ struct ext4_xattr_inode_array *new_array = NULL;
+ int count = (*ea_inode_array)->count;
+
+ /* if new_array is NULL, this is essentially offsetof() */
+ new_array = kmalloc(
+ offsetof(struct ext4_xattr_inode_array,
+ inodes[count + EIA_INCR]),
+ GFP_NOFS);
+ if (new_array == NULL)
+ return -ENOMEM;
+ memcpy(new_array, *ea_inode_array,
+ offsetof(struct ext4_xattr_inode_array, inodes[count]));
+ kfree(*ea_inode_array);
+ *ea_inode_array = new_array;
+ }
+ (*ea_inode_array)->inodes[(*ea_inode_array)->count++] = inode;
+ return 0;
+}
+
+/*
+ * ext4_xattr_delete_inode()
+ *
+ * Free extended attribute resources associated with this inode. Traverse
+ * all entries and decrement reference on any xattr inodes associated with this
+ * inode. This is called immediately before an inode is freed. We have exclusive
+ * access to the inode. If an orphan inode is deleted it will also release its
+ * references on xattr block and xattr inodes.
+ */
+int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
+ struct ext4_xattr_inode_array **ea_inode_array,
+ int extra_credits)
+{
+ struct buffer_head *bh = NULL;
+ struct ext4_xattr_ibody_header *header;
+ struct ext4_iloc iloc = { .bh = NULL };
+ struct ext4_xattr_entry *entry;
+ struct inode *ea_inode;
+ int error;
+
+ error = ext4_journal_ensure_credits(handle, extra_credits,
+ ext4_free_metadata_revoke_credits(inode->i_sb, 1));
+ if (error < 0) {
+ EXT4_ERROR_INODE(inode, "ensure credits (error %d)", error);
+ goto cleanup;
+ }
+
+ if (ext4_has_feature_ea_inode(inode->i_sb) &&
+ ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
+
+ error = ext4_get_inode_loc(inode, &iloc);
+ if (error) {
+ EXT4_ERROR_INODE(inode, "inode loc (error %d)", error);
+ goto cleanup;
+ }
+
+ error = ext4_journal_get_write_access(handle, inode->i_sb,
+ iloc.bh, EXT4_JTR_NONE);
+ if (error) {
+ EXT4_ERROR_INODE(inode, "write access (error %d)",
+ error);
+ goto cleanup;
+ }
+
+ header = IHDR(inode, ext4_raw_inode(&iloc));
+ if (header->h_magic == cpu_to_le32(EXT4_XATTR_MAGIC))
+ ext4_xattr_inode_dec_ref_all(handle, inode, iloc.bh,
+ IFIRST(header),
+ false /* block_csum */,
+ ea_inode_array,
+ extra_credits,
+ false /* skip_quota */);
+ }
+
+ if (EXT4_I(inode)->i_file_acl) {
+ bh = ext4_sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl, REQ_PRIO);
+ if (IS_ERR(bh)) {
+ error = PTR_ERR(bh);
+ if (error == -EIO) {
+ EXT4_ERROR_INODE_ERR(inode, EIO,
+ "block %llu read error",
+ EXT4_I(inode)->i_file_acl);
+ }
+ bh = NULL;
+ goto cleanup;
+ }
+ error = ext4_xattr_check_block(inode, bh);
+ if (error)
+ goto cleanup;
+
+ if (ext4_has_feature_ea_inode(inode->i_sb)) {
+ for (entry = BFIRST(bh); !IS_LAST_ENTRY(entry);
+ entry = EXT4_XATTR_NEXT(entry)) {
+ if (!entry->e_value_inum)
+ continue;
+ error = ext4_xattr_inode_iget(inode,
+ le32_to_cpu(entry->e_value_inum),
+ le32_to_cpu(entry->e_hash),
+ &ea_inode);
+ if (error)
+ continue;
+ ext4_xattr_inode_free_quota(inode, ea_inode,
+ le32_to_cpu(entry->e_value_size));
+ iput(ea_inode);
+ }
+
+ }
+
+ ext4_xattr_release_block(handle, inode, bh, ea_inode_array,
+ extra_credits);
+ /*
+ * Update i_file_acl value in the same transaction that releases
+ * block.
+ */
+ EXT4_I(inode)->i_file_acl = 0;
+ error = ext4_mark_inode_dirty(handle, inode);
+ if (error) {
+ EXT4_ERROR_INODE(inode, "mark inode dirty (error %d)",
+ error);
+ goto cleanup;
+ }
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_XATTR, handle);
+ }
+ error = 0;
+cleanup:
+ brelse(iloc.bh);
+ brelse(bh);
+ return error;
+}
+
+void ext4_xattr_inode_array_free(struct ext4_xattr_inode_array *ea_inode_array)
+{
+ int idx;
+
+ if (ea_inode_array == NULL)
+ return;
+
+ for (idx = 0; idx < ea_inode_array->count; ++idx)
+ iput(ea_inode_array->inodes[idx]);
+ kfree(ea_inode_array);
+}
+
+/*
+ * ext4_xattr_block_cache_insert()
+ *
+ * Create a new entry in the extended attribute block cache, and insert
+ * it unless such an entry is already in the cache.
+ *
+ * Returns 0, or a negative error number on failure.
+ */
+static void
+ext4_xattr_block_cache_insert(struct mb_cache *ea_block_cache,
+ struct buffer_head *bh)
+{
+ struct ext4_xattr_header *header = BHDR(bh);
+ __u32 hash = le32_to_cpu(header->h_hash);
+ int reusable = le32_to_cpu(header->h_refcount) <
+ EXT4_XATTR_REFCOUNT_MAX;
+ int error;
+
+ if (!ea_block_cache)
+ return;
+ error = mb_cache_entry_create(ea_block_cache, GFP_NOFS, hash,
+ bh->b_blocknr, reusable);
+ if (error) {
+ if (error == -EBUSY)
+ ea_bdebug(bh, "already in cache");
+ } else
+ ea_bdebug(bh, "inserting [%x]", (int)hash);
+}
+
+/*
+ * ext4_xattr_cmp()
+ *
+ * Compare two extended attribute blocks for equality.
+ *
+ * Returns 0 if the blocks are equal, 1 if they differ, and
+ * a negative error number on errors.
+ */
+static int
+ext4_xattr_cmp(struct ext4_xattr_header *header1,
+ struct ext4_xattr_header *header2)
+{
+ struct ext4_xattr_entry *entry1, *entry2;
+
+ entry1 = ENTRY(header1+1);
+ entry2 = ENTRY(header2+1);
+ while (!IS_LAST_ENTRY(entry1)) {
+ if (IS_LAST_ENTRY(entry2))
+ return 1;
+ if (entry1->e_hash != entry2->e_hash ||
+ entry1->e_name_index != entry2->e_name_index ||
+ entry1->e_name_len != entry2->e_name_len ||
+ entry1->e_value_size != entry2->e_value_size ||
+ entry1->e_value_inum != entry2->e_value_inum ||
+ memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
+ return 1;
+ if (!entry1->e_value_inum &&
+ memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
+ (char *)header2 + le16_to_cpu(entry2->e_value_offs),
+ le32_to_cpu(entry1->e_value_size)))
+ return 1;
+
+ entry1 = EXT4_XATTR_NEXT(entry1);
+ entry2 = EXT4_XATTR_NEXT(entry2);
+ }
+ if (!IS_LAST_ENTRY(entry2))
+ return 1;
+ return 0;
+}
+
+/*
+ * ext4_xattr_block_cache_find()
+ *
+ * Find an identical extended attribute block.
+ *
+ * Returns a pointer to the block found, or NULL if such a block was
+ * not found or an error occurred.
+ */
+static struct buffer_head *
+ext4_xattr_block_cache_find(struct inode *inode,
+ struct ext4_xattr_header *header,
+ struct mb_cache_entry **pce)
+{
+ __u32 hash = le32_to_cpu(header->h_hash);
+ struct mb_cache_entry *ce;
+ struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
+
+ if (!ea_block_cache)
+ return NULL;
+ if (!header->h_hash)
+ return NULL; /* never share */
+ ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
+ ce = mb_cache_entry_find_first(ea_block_cache, hash);
+ while (ce) {
+ struct buffer_head *bh;
+
+ bh = ext4_sb_bread(inode->i_sb, ce->e_value, REQ_PRIO);
+ if (IS_ERR(bh)) {
+ if (PTR_ERR(bh) == -ENOMEM)
+ return NULL;
+ bh = NULL;
+ EXT4_ERROR_INODE(inode, "block %lu read error",
+ (unsigned long)ce->e_value);
+ } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
+ *pce = ce;
+ return bh;
+ }
+ brelse(bh);
+ ce = mb_cache_entry_find_next(ea_block_cache, ce);
+ }
+ return NULL;
+}
+
+#define NAME_HASH_SHIFT 5
+#define VALUE_HASH_SHIFT 16
+
+/*
+ * ext4_xattr_hash_entry()
+ *
+ * Compute the hash of an extended attribute.
+ */
+static __le32 ext4_xattr_hash_entry(char *name, size_t name_len, __le32 *value,
+ size_t value_count)
+{
+ __u32 hash = 0;
+
+ while (name_len--) {
+ hash = (hash << NAME_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
+ *name++;
+ }
+ while (value_count--) {
+ hash = (hash << VALUE_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
+ le32_to_cpu(*value++);
+ }
+ return cpu_to_le32(hash);
+}
+
+#undef NAME_HASH_SHIFT
+#undef VALUE_HASH_SHIFT
+
+#define BLOCK_HASH_SHIFT 16
+
+/*
+ * ext4_xattr_rehash()
+ *
+ * Re-compute the extended attribute hash value after an entry has changed.
+ */
+static void ext4_xattr_rehash(struct ext4_xattr_header *header)
+{
+ struct ext4_xattr_entry *here;
+ __u32 hash = 0;
+
+ here = ENTRY(header+1);
+ while (!IS_LAST_ENTRY(here)) {
+ if (!here->e_hash) {
+ /* Block is not shared if an entry's hash value == 0 */
+ hash = 0;
+ break;
+ }
+ hash = (hash << BLOCK_HASH_SHIFT) ^
+ (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
+ le32_to_cpu(here->e_hash);
+ here = EXT4_XATTR_NEXT(here);
+ }
+ header->h_hash = cpu_to_le32(hash);
+}
+
+#undef BLOCK_HASH_SHIFT
+
+#define HASH_BUCKET_BITS 10
+
+struct mb_cache *
+ext4_xattr_create_cache(void)
+{
+ return mb_cache_create(HASH_BUCKET_BITS);
+}
+
+void ext4_xattr_destroy_cache(struct mb_cache *cache)
+{
+ if (cache)
+ mb_cache_destroy(cache);
+}
+