diff options
Diffstat (limited to 'fs/ext4/xattr.c')
| -rw-r--r-- | fs/ext4/xattr.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 1f5cf5880718..e7387337060c 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -369,6 +369,9 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name, { int error; + 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); @@ -513,6 +516,7 @@ static void ext4_xattr_update_super_block(handle_t *handle, if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR)) return; + BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) { EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR); ext4_handle_dirty_super(handle, sb); @@ -520,8 +524,8 @@ static void ext4_xattr_update_super_block(handle_t *handle, } /* - * Release the xattr block BH: If the reference count is > 1, decrement - * it; otherwise free the block. + * 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, @@ -532,6 +536,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, struct mb_cache *ext4_mb_cache = EXT4_GET_MB_CACHE(inode); ce = mb_cache_entry_get(ext4_mb_cache, bh->b_bdev, bh->b_blocknr); + BUFFER_TRACE(bh, "get_write_access"); error = ext4_journal_get_write_access(handle, bh); if (error) goto out; @@ -542,16 +547,31 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, if (ce) mb_cache_entry_free(ce); get_bh(bh); + unlock_buffer(bh); ext4_free_blocks(handle, inode, bh, 0, 1, EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); - unlock_buffer(bh); } else { le32_add_cpu(&BHDR(bh)->h_refcount, -1); if (ce) mb_cache_entry_release(ce); + /* + * 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_xattr_block() 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_xattr_block(handle, inode, + bh); unlock_buffer(bh); - error = ext4_handle_dirty_xattr_block(handle, inode, bh); + if (!ext4_handle_valid(handle)) + error = ext4_handle_dirty_xattr_block(handle, inode, + bh); if (IS_SYNC(inode)) ext4_handle_sync(handle); dquot_free_block(inode, EXT4_C2B(EXT4_SB(inode->i_sb), 1)); @@ -759,6 +779,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode, if (s->base) { ce = mb_cache_entry_get(ext4_mb_cache, bs->bh->b_bdev, bs->bh->b_blocknr); + BUFFER_TRACE(bs->bh, "get_write_access"); error = ext4_journal_get_write_access(handle, bs->bh); if (error) goto cleanup; @@ -844,6 +865,7 @@ inserted: EXT4_C2B(EXT4_SB(sb), 1)); if (error) goto cleanup; + BUFFER_TRACE(new_bh, "get_write_access"); error = ext4_journal_get_write_access(handle, new_bh); if (error) @@ -881,7 +903,7 @@ inserted: * take i_data_sem because we will test * i_delalloc_reserved_flag in ext4_mb_new_blocks */ - down_read((&EXT4_I(inode)->i_data_sem)); + down_read(&EXT4_I(inode)->i_data_sem); block = ext4_new_meta_blocks(handle, inode, goal, 0, NULL, &error); up_read((&EXT4_I(inode)->i_data_sem)); |