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![Greg Kroah-Hartman](/assets/img/avatar_default.png)
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1034 lines
29 KiB
C
1034 lines
29 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext2/xattr.c
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*
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* Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
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*
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* Fix by Harrison Xing <harrison@mountainviewdata.com>.
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* Extended attributes for symlinks and special files added per
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* suggestion of Luka Renko <luka.renko@hermes.si>.
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* xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
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* Red Hat Inc.
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*
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*/
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/*
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* Extended attributes are stored on disk blocks allocated outside of
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* any inode. The i_file_acl field is then made to point to this allocated
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* block. If all extended attributes of an inode are identical, these
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* inodes may share the same extended attribute block. Such situations
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* are automatically detected by keeping a cache of recent attribute block
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* numbers and hashes over the block's contents in memory.
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*
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*
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* Extended attribute block layout:
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*
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* +------------------+
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* | header |
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* | entry 1 | |
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* | entry 2 | | growing downwards
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* | entry 3 | v
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* | four null bytes |
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* | . . . |
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* | value 1 | ^
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* | value 3 | | growing upwards
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* | value 2 | |
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* +------------------+
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*
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* The block header is followed by multiple entry descriptors. These entry
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* descriptors are variable in size, and aligned to EXT2_XATTR_PAD
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* byte boundaries. The entry descriptors are sorted by attribute name,
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* so that two extended attribute blocks can be compared efficiently.
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*
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* Attribute values are aligned to the end of the block, stored in
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* no specific order. They are also padded to EXT2_XATTR_PAD byte
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* boundaries. No additional gaps are left between them.
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*
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* Locking strategy
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* ----------------
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* EXT2_I(inode)->i_file_acl is protected by EXT2_I(inode)->xattr_sem.
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* EA blocks are only changed if they are exclusive to an inode, so
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* holding xattr_sem also means that nothing but the EA block's reference
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* count will change. Multiple writers to an EA block are synchronized
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* by the bh lock. No more than a single bh lock is held at any time
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* to avoid deadlocks.
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*/
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#include <linux/buffer_head.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/mbcache.h>
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#include <linux/quotaops.h>
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#include <linux/rwsem.h>
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#include <linux/security.h>
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#include "ext2.h"
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#include "xattr.h"
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#include "acl.h"
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#define HDR(bh) ((struct ext2_xattr_header *)((bh)->b_data))
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#define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
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#define FIRST_ENTRY(bh) ENTRY(HDR(bh)+1)
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#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
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#ifdef EXT2_XATTR_DEBUG
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# define ea_idebug(inode, f...) do { \
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printk(KERN_DEBUG "inode %s:%ld: ", \
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inode->i_sb->s_id, inode->i_ino); \
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printk(f); \
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printk("\n"); \
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} while (0)
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# define ea_bdebug(bh, f...) do { \
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printk(KERN_DEBUG "block %pg:%lu: ", \
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bh->b_bdev, (unsigned long) bh->b_blocknr); \
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printk(f); \
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printk("\n"); \
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} while (0)
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#else
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# define ea_idebug(f...)
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# define ea_bdebug(f...)
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#endif
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static int ext2_xattr_set2(struct inode *, struct buffer_head *,
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struct ext2_xattr_header *);
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static int ext2_xattr_cache_insert(struct mb_cache *, struct buffer_head *);
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static struct buffer_head *ext2_xattr_cache_find(struct inode *,
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struct ext2_xattr_header *);
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static void ext2_xattr_rehash(struct ext2_xattr_header *,
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struct ext2_xattr_entry *);
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static const struct xattr_handler *ext2_xattr_handler_map[] = {
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[EXT2_XATTR_INDEX_USER] = &ext2_xattr_user_handler,
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#ifdef CONFIG_EXT2_FS_POSIX_ACL
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[EXT2_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
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[EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
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#endif
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[EXT2_XATTR_INDEX_TRUSTED] = &ext2_xattr_trusted_handler,
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#ifdef CONFIG_EXT2_FS_SECURITY
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[EXT2_XATTR_INDEX_SECURITY] = &ext2_xattr_security_handler,
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#endif
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};
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const struct xattr_handler *ext2_xattr_handlers[] = {
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&ext2_xattr_user_handler,
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&ext2_xattr_trusted_handler,
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#ifdef CONFIG_EXT2_FS_POSIX_ACL
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&posix_acl_access_xattr_handler,
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&posix_acl_default_xattr_handler,
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#endif
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#ifdef CONFIG_EXT2_FS_SECURITY
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&ext2_xattr_security_handler,
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#endif
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NULL
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};
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#define EA_BLOCK_CACHE(inode) (EXT2_SB(inode->i_sb)->s_ea_block_cache)
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static inline const struct xattr_handler *
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ext2_xattr_handler(int name_index)
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{
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const struct xattr_handler *handler = NULL;
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if (name_index > 0 && name_index < ARRAY_SIZE(ext2_xattr_handler_map))
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handler = ext2_xattr_handler_map[name_index];
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return handler;
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}
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/*
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* ext2_xattr_get()
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*
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* Copy an extended attribute into the buffer
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* provided, or compute the buffer size required.
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* Buffer is NULL to compute the size of the buffer required.
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*
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* Returns a negative error number on failure, or the number of bytes
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* used / required on success.
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*/
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int
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ext2_xattr_get(struct inode *inode, int name_index, const char *name,
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void *buffer, size_t buffer_size)
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{
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struct buffer_head *bh = NULL;
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struct ext2_xattr_entry *entry;
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size_t name_len, size;
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char *end;
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int error;
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struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
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ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
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name_index, name, buffer, (long)buffer_size);
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if (name == NULL)
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return -EINVAL;
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name_len = strlen(name);
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if (name_len > 255)
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return -ERANGE;
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down_read(&EXT2_I(inode)->xattr_sem);
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error = -ENODATA;
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if (!EXT2_I(inode)->i_file_acl)
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goto cleanup;
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ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
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bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
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error = -EIO;
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if (!bh)
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goto cleanup;
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ea_bdebug(bh, "b_count=%d, refcount=%d",
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atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
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end = bh->b_data + bh->b_size;
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if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
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HDR(bh)->h_blocks != cpu_to_le32(1)) {
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bad_block: ext2_error(inode->i_sb, "ext2_xattr_get",
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"inode %ld: bad block %d", inode->i_ino,
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EXT2_I(inode)->i_file_acl);
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error = -EIO;
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goto cleanup;
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}
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/* find named attribute */
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entry = FIRST_ENTRY(bh);
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while (!IS_LAST_ENTRY(entry)) {
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struct ext2_xattr_entry *next =
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EXT2_XATTR_NEXT(entry);
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if ((char *)next >= end)
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goto bad_block;
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if (name_index == entry->e_name_index &&
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name_len == entry->e_name_len &&
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memcmp(name, entry->e_name, name_len) == 0)
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goto found;
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entry = next;
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}
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if (ext2_xattr_cache_insert(ea_block_cache, bh))
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ea_idebug(inode, "cache insert failed");
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error = -ENODATA;
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goto cleanup;
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found:
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/* check the buffer size */
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if (entry->e_value_block != 0)
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goto bad_block;
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size = le32_to_cpu(entry->e_value_size);
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if (size > inode->i_sb->s_blocksize ||
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le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
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goto bad_block;
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if (ext2_xattr_cache_insert(ea_block_cache, bh))
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ea_idebug(inode, "cache insert failed");
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if (buffer) {
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error = -ERANGE;
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if (size > buffer_size)
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goto cleanup;
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/* return value of attribute */
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memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
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size);
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}
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error = size;
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cleanup:
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brelse(bh);
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up_read(&EXT2_I(inode)->xattr_sem);
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return error;
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}
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/*
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* ext2_xattr_list()
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*
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* Copy a list of attribute names into the buffer
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* provided, or compute the buffer size required.
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* Buffer is NULL to compute the size of the buffer required.
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*
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* Returns a negative error number on failure, or the number of bytes
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* used / required on success.
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*/
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static int
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ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
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{
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struct inode *inode = d_inode(dentry);
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struct buffer_head *bh = NULL;
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struct ext2_xattr_entry *entry;
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char *end;
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size_t rest = buffer_size;
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int error;
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struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
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ea_idebug(inode, "buffer=%p, buffer_size=%ld",
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buffer, (long)buffer_size);
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down_read(&EXT2_I(inode)->xattr_sem);
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error = 0;
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if (!EXT2_I(inode)->i_file_acl)
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goto cleanup;
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ea_idebug(inode, "reading block %d", EXT2_I(inode)->i_file_acl);
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bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
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error = -EIO;
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if (!bh)
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goto cleanup;
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ea_bdebug(bh, "b_count=%d, refcount=%d",
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atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
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end = bh->b_data + bh->b_size;
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if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
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HDR(bh)->h_blocks != cpu_to_le32(1)) {
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bad_block: ext2_error(inode->i_sb, "ext2_xattr_list",
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"inode %ld: bad block %d", inode->i_ino,
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EXT2_I(inode)->i_file_acl);
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error = -EIO;
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goto cleanup;
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}
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/* check the on-disk data structure */
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entry = FIRST_ENTRY(bh);
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while (!IS_LAST_ENTRY(entry)) {
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struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry);
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if ((char *)next >= end)
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goto bad_block;
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entry = next;
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}
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if (ext2_xattr_cache_insert(ea_block_cache, bh))
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ea_idebug(inode, "cache insert failed");
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/* list the attribute names */
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for (entry = FIRST_ENTRY(bh); !IS_LAST_ENTRY(entry);
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entry = EXT2_XATTR_NEXT(entry)) {
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const struct xattr_handler *handler =
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ext2_xattr_handler(entry->e_name_index);
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if (handler && (!handler->list || handler->list(dentry))) {
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const char *prefix = handler->prefix ?: handler->name;
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size_t prefix_len = strlen(prefix);
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size_t size = prefix_len + entry->e_name_len + 1;
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if (buffer) {
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if (size > rest) {
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error = -ERANGE;
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goto cleanup;
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}
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memcpy(buffer, prefix, prefix_len);
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buffer += prefix_len;
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memcpy(buffer, entry->e_name, entry->e_name_len);
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buffer += entry->e_name_len;
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*buffer++ = 0;
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}
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rest -= size;
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}
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}
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error = buffer_size - rest; /* total size */
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cleanup:
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brelse(bh);
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up_read(&EXT2_I(inode)->xattr_sem);
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return error;
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}
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/*
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* Inode operation listxattr()
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*
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* d_inode(dentry)->i_mutex: don't care
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*/
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ssize_t
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ext2_listxattr(struct dentry *dentry, char *buffer, size_t size)
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{
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return ext2_xattr_list(dentry, buffer, size);
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}
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/*
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* If the EXT2_FEATURE_COMPAT_EXT_ATTR feature of this file system is
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* not set, set it.
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*/
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static void ext2_xattr_update_super_block(struct super_block *sb)
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{
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if (EXT2_HAS_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR))
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return;
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spin_lock(&EXT2_SB(sb)->s_lock);
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EXT2_SET_COMPAT_FEATURE(sb, EXT2_FEATURE_COMPAT_EXT_ATTR);
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spin_unlock(&EXT2_SB(sb)->s_lock);
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mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
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}
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/*
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* ext2_xattr_set()
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*
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* Create, replace or remove an extended attribute for this inode. Value
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* is NULL to remove an existing extended attribute, and non-NULL to
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* either replace an existing extended attribute, or create a new extended
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* attribute. The flags XATTR_REPLACE and XATTR_CREATE
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* specify that an extended attribute must exist and must not exist
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* previous to the call, respectively.
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*
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* Returns 0, or a negative error number on failure.
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*/
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int
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ext2_xattr_set(struct inode *inode, int name_index, const char *name,
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const void *value, size_t value_len, int flags)
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{
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struct super_block *sb = inode->i_sb;
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struct buffer_head *bh = NULL;
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struct ext2_xattr_header *header = NULL;
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struct ext2_xattr_entry *here, *last;
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size_t name_len, free, min_offs = sb->s_blocksize;
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int not_found = 1, error;
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char *end;
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|
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/*
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* header -- Points either into bh, or to a temporarily
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* allocated buffer.
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* here -- The named entry found, or the place for inserting, within
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* the block pointed to by header.
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* last -- Points right after the last named entry within the block
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* pointed to by header.
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* min_offs -- The offset of the first value (values are aligned
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* towards the end of the block).
|
|
* end -- Points right after the block pointed to by header.
|
|
*/
|
|
|
|
ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
|
|
name_index, name, value, (long)value_len);
|
|
|
|
if (value == NULL)
|
|
value_len = 0;
|
|
if (name == NULL)
|
|
return -EINVAL;
|
|
name_len = strlen(name);
|
|
if (name_len > 255 || value_len > sb->s_blocksize)
|
|
return -ERANGE;
|
|
down_write(&EXT2_I(inode)->xattr_sem);
|
|
if (EXT2_I(inode)->i_file_acl) {
|
|
/* The inode already has an extended attribute block. */
|
|
bh = sb_bread(sb, EXT2_I(inode)->i_file_acl);
|
|
error = -EIO;
|
|
if (!bh)
|
|
goto cleanup;
|
|
ea_bdebug(bh, "b_count=%d, refcount=%d",
|
|
atomic_read(&(bh->b_count)),
|
|
le32_to_cpu(HDR(bh)->h_refcount));
|
|
header = HDR(bh);
|
|
end = bh->b_data + bh->b_size;
|
|
if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
|
|
header->h_blocks != cpu_to_le32(1)) {
|
|
bad_block: ext2_error(sb, "ext2_xattr_set",
|
|
"inode %ld: bad block %d", inode->i_ino,
|
|
EXT2_I(inode)->i_file_acl);
|
|
error = -EIO;
|
|
goto cleanup;
|
|
}
|
|
/* Find the named attribute. */
|
|
here = FIRST_ENTRY(bh);
|
|
while (!IS_LAST_ENTRY(here)) {
|
|
struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(here);
|
|
if ((char *)next >= end)
|
|
goto bad_block;
|
|
if (!here->e_value_block && here->e_value_size) {
|
|
size_t offs = le16_to_cpu(here->e_value_offs);
|
|
if (offs < min_offs)
|
|
min_offs = offs;
|
|
}
|
|
not_found = name_index - here->e_name_index;
|
|
if (!not_found)
|
|
not_found = name_len - here->e_name_len;
|
|
if (!not_found)
|
|
not_found = memcmp(name, here->e_name,name_len);
|
|
if (not_found <= 0)
|
|
break;
|
|
here = next;
|
|
}
|
|
last = here;
|
|
/* We still need to compute min_offs and last. */
|
|
while (!IS_LAST_ENTRY(last)) {
|
|
struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(last);
|
|
if ((char *)next >= end)
|
|
goto bad_block;
|
|
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;
|
|
}
|
|
last = next;
|
|
}
|
|
|
|
/* Check whether we have enough space left. */
|
|
free = min_offs - ((char*)last - (char*)header) - sizeof(__u32);
|
|
} else {
|
|
/* We will use a new extended attribute block. */
|
|
free = sb->s_blocksize -
|
|
sizeof(struct ext2_xattr_header) - sizeof(__u32);
|
|
here = last = NULL; /* avoid gcc uninitialized warning. */
|
|
}
|
|
|
|
if (not_found) {
|
|
/* Request to remove a nonexistent attribute? */
|
|
error = -ENODATA;
|
|
if (flags & XATTR_REPLACE)
|
|
goto cleanup;
|
|
error = 0;
|
|
if (value == NULL)
|
|
goto cleanup;
|
|
} else {
|
|
/* Request to create an existing attribute? */
|
|
error = -EEXIST;
|
|
if (flags & XATTR_CREATE)
|
|
goto cleanup;
|
|
if (!here->e_value_block && here->e_value_size) {
|
|
size_t size = le32_to_cpu(here->e_value_size);
|
|
|
|
if (le16_to_cpu(here->e_value_offs) + size >
|
|
sb->s_blocksize || size > sb->s_blocksize)
|
|
goto bad_block;
|
|
free += EXT2_XATTR_SIZE(size);
|
|
}
|
|
free += EXT2_XATTR_LEN(name_len);
|
|
}
|
|
error = -ENOSPC;
|
|
if (free < EXT2_XATTR_LEN(name_len) + EXT2_XATTR_SIZE(value_len))
|
|
goto cleanup;
|
|
|
|
/* Here we know that we can set the new attribute. */
|
|
|
|
if (header) {
|
|
/* assert(header == HDR(bh)); */
|
|
lock_buffer(bh);
|
|
if (header->h_refcount == cpu_to_le32(1)) {
|
|
__u32 hash = le32_to_cpu(header->h_hash);
|
|
|
|
ea_bdebug(bh, "modifying in-place");
|
|
/*
|
|
* This must happen under buffer lock for
|
|
* ext2_xattr_set2() to reliably detect modified block
|
|
*/
|
|
mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
|
|
bh->b_blocknr);
|
|
|
|
/* keep the buffer locked while modifying it. */
|
|
} else {
|
|
int offset;
|
|
|
|
unlock_buffer(bh);
|
|
ea_bdebug(bh, "cloning");
|
|
header = kmalloc(bh->b_size, GFP_KERNEL);
|
|
error = -ENOMEM;
|
|
if (header == NULL)
|
|
goto cleanup;
|
|
memcpy(header, HDR(bh), bh->b_size);
|
|
header->h_refcount = cpu_to_le32(1);
|
|
|
|
offset = (char *)here - bh->b_data;
|
|
here = ENTRY((char *)header + offset);
|
|
offset = (char *)last - bh->b_data;
|
|
last = ENTRY((char *)header + offset);
|
|
}
|
|
} else {
|
|
/* Allocate a buffer where we construct the new block. */
|
|
header = kzalloc(sb->s_blocksize, GFP_KERNEL);
|
|
error = -ENOMEM;
|
|
if (header == NULL)
|
|
goto cleanup;
|
|
end = (char *)header + sb->s_blocksize;
|
|
header->h_magic = cpu_to_le32(EXT2_XATTR_MAGIC);
|
|
header->h_blocks = header->h_refcount = cpu_to_le32(1);
|
|
last = here = ENTRY(header+1);
|
|
}
|
|
|
|
/* Iff we are modifying the block in-place, bh is locked here. */
|
|
|
|
if (not_found) {
|
|
/* Insert the new name. */
|
|
size_t size = EXT2_XATTR_LEN(name_len);
|
|
size_t rest = (char *)last - (char *)here;
|
|
memmove((char *)here + size, here, rest);
|
|
memset(here, 0, size);
|
|
here->e_name_index = name_index;
|
|
here->e_name_len = name_len;
|
|
memcpy(here->e_name, name, name_len);
|
|
} else {
|
|
if (!here->e_value_block && here->e_value_size) {
|
|
char *first_val = (char *)header + min_offs;
|
|
size_t offs = le16_to_cpu(here->e_value_offs);
|
|
char *val = (char *)header + offs;
|
|
size_t size = EXT2_XATTR_SIZE(
|
|
le32_to_cpu(here->e_value_size));
|
|
|
|
if (size == EXT2_XATTR_SIZE(value_len)) {
|
|
/* The old and the new value have the same
|
|
size. Just replace. */
|
|
here->e_value_size = cpu_to_le32(value_len);
|
|
memset(val + size - EXT2_XATTR_PAD, 0,
|
|
EXT2_XATTR_PAD); /* Clear pad bytes. */
|
|
memcpy(val, value, value_len);
|
|
goto skip_replace;
|
|
}
|
|
|
|
/* Remove the old value. */
|
|
memmove(first_val + size, first_val, val - first_val);
|
|
memset(first_val, 0, size);
|
|
here->e_value_offs = 0;
|
|
min_offs += size;
|
|
|
|
/* Adjust all value offsets. */
|
|
last = ENTRY(header+1);
|
|
while (!IS_LAST_ENTRY(last)) {
|
|
size_t o = le16_to_cpu(last->e_value_offs);
|
|
if (!last->e_value_block && o < offs)
|
|
last->e_value_offs =
|
|
cpu_to_le16(o + size);
|
|
last = EXT2_XATTR_NEXT(last);
|
|
}
|
|
}
|
|
if (value == NULL) {
|
|
/* Remove the old name. */
|
|
size_t size = EXT2_XATTR_LEN(name_len);
|
|
last = ENTRY((char *)last - size);
|
|
memmove(here, (char*)here + size,
|
|
(char*)last - (char*)here);
|
|
memset(last, 0, size);
|
|
}
|
|
}
|
|
|
|
if (value != NULL) {
|
|
/* Insert the new value. */
|
|
here->e_value_size = cpu_to_le32(value_len);
|
|
if (value_len) {
|
|
size_t size = EXT2_XATTR_SIZE(value_len);
|
|
char *val = (char *)header + min_offs - size;
|
|
here->e_value_offs =
|
|
cpu_to_le16((char *)val - (char *)header);
|
|
memset(val + size - EXT2_XATTR_PAD, 0,
|
|
EXT2_XATTR_PAD); /* Clear the pad bytes. */
|
|
memcpy(val, value, value_len);
|
|
}
|
|
}
|
|
|
|
skip_replace:
|
|
if (IS_LAST_ENTRY(ENTRY(header+1))) {
|
|
/* This block is now empty. */
|
|
if (bh && header == HDR(bh))
|
|
unlock_buffer(bh); /* we were modifying in-place. */
|
|
error = ext2_xattr_set2(inode, bh, NULL);
|
|
} else {
|
|
ext2_xattr_rehash(header, here);
|
|
if (bh && header == HDR(bh))
|
|
unlock_buffer(bh); /* we were modifying in-place. */
|
|
error = ext2_xattr_set2(inode, bh, header);
|
|
}
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
if (!(bh && header == HDR(bh)))
|
|
kfree(header);
|
|
up_write(&EXT2_I(inode)->xattr_sem);
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Second half of ext2_xattr_set(): Update the file system.
|
|
*/
|
|
static int
|
|
ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh,
|
|
struct ext2_xattr_header *header)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
struct buffer_head *new_bh = NULL;
|
|
int error;
|
|
struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
|
|
|
if (header) {
|
|
new_bh = ext2_xattr_cache_find(inode, header);
|
|
if (new_bh) {
|
|
/* We found an identical block in the cache. */
|
|
if (new_bh == old_bh) {
|
|
ea_bdebug(new_bh, "keeping this block");
|
|
} else {
|
|
/* The old block is released after updating
|
|
the inode. */
|
|
ea_bdebug(new_bh, "reusing block");
|
|
|
|
error = dquot_alloc_block(inode, 1);
|
|
if (error) {
|
|
unlock_buffer(new_bh);
|
|
goto cleanup;
|
|
}
|
|
le32_add_cpu(&HDR(new_bh)->h_refcount, 1);
|
|
ea_bdebug(new_bh, "refcount now=%d",
|
|
le32_to_cpu(HDR(new_bh)->h_refcount));
|
|
}
|
|
unlock_buffer(new_bh);
|
|
} else if (old_bh && header == HDR(old_bh)) {
|
|
/* Keep this block. No need to lock the block as we
|
|
don't need to change the reference count. */
|
|
new_bh = old_bh;
|
|
get_bh(new_bh);
|
|
ext2_xattr_cache_insert(ea_block_cache, new_bh);
|
|
} else {
|
|
/* We need to allocate a new block */
|
|
ext2_fsblk_t goal = ext2_group_first_block_no(sb,
|
|
EXT2_I(inode)->i_block_group);
|
|
int block = ext2_new_block(inode, goal, &error);
|
|
if (error)
|
|
goto cleanup;
|
|
ea_idebug(inode, "creating block %d", block);
|
|
|
|
new_bh = sb_getblk(sb, block);
|
|
if (unlikely(!new_bh)) {
|
|
ext2_free_blocks(inode, block, 1);
|
|
mark_inode_dirty(inode);
|
|
error = -ENOMEM;
|
|
goto cleanup;
|
|
}
|
|
lock_buffer(new_bh);
|
|
memcpy(new_bh->b_data, header, new_bh->b_size);
|
|
set_buffer_uptodate(new_bh);
|
|
unlock_buffer(new_bh);
|
|
ext2_xattr_cache_insert(ea_block_cache, new_bh);
|
|
|
|
ext2_xattr_update_super_block(sb);
|
|
}
|
|
mark_buffer_dirty(new_bh);
|
|
if (IS_SYNC(inode)) {
|
|
sync_dirty_buffer(new_bh);
|
|
error = -EIO;
|
|
if (buffer_req(new_bh) && !buffer_uptodate(new_bh))
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
/* Update the inode. */
|
|
EXT2_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
|
|
inode->i_ctime = current_time(inode);
|
|
if (IS_SYNC(inode)) {
|
|
error = sync_inode_metadata(inode, 1);
|
|
/* In case sync failed due to ENOSPC the inode was actually
|
|
* written (only some dirty data were not) so we just proceed
|
|
* as if nothing happened and cleanup the unused block */
|
|
if (error && error != -ENOSPC) {
|
|
if (new_bh && new_bh != old_bh) {
|
|
dquot_free_block_nodirty(inode, 1);
|
|
mark_inode_dirty(inode);
|
|
}
|
|
goto cleanup;
|
|
}
|
|
} else
|
|
mark_inode_dirty(inode);
|
|
|
|
error = 0;
|
|
if (old_bh && old_bh != new_bh) {
|
|
/*
|
|
* If there was an old block and we are no longer using it,
|
|
* release the old block.
|
|
*/
|
|
lock_buffer(old_bh);
|
|
if (HDR(old_bh)->h_refcount == cpu_to_le32(1)) {
|
|
__u32 hash = le32_to_cpu(HDR(old_bh)->h_hash);
|
|
|
|
/*
|
|
* This must happen under buffer lock for
|
|
* ext2_xattr_set2() to reliably detect freed block
|
|
*/
|
|
mb_cache_entry_delete(ea_block_cache, hash,
|
|
old_bh->b_blocknr);
|
|
/* Free the old block. */
|
|
ea_bdebug(old_bh, "freeing");
|
|
ext2_free_blocks(inode, old_bh->b_blocknr, 1);
|
|
mark_inode_dirty(inode);
|
|
/* We let our caller release old_bh, so we
|
|
* need to duplicate the buffer before. */
|
|
get_bh(old_bh);
|
|
bforget(old_bh);
|
|
} else {
|
|
/* Decrement the refcount only. */
|
|
le32_add_cpu(&HDR(old_bh)->h_refcount, -1);
|
|
dquot_free_block_nodirty(inode, 1);
|
|
mark_inode_dirty(inode);
|
|
mark_buffer_dirty(old_bh);
|
|
ea_bdebug(old_bh, "refcount now=%d",
|
|
le32_to_cpu(HDR(old_bh)->h_refcount));
|
|
}
|
|
unlock_buffer(old_bh);
|
|
}
|
|
|
|
cleanup:
|
|
brelse(new_bh);
|
|
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext2_xattr_delete_inode()
|
|
*
|
|
* Free extended attribute resources associated with this inode. This
|
|
* is called immediately before an inode is freed.
|
|
*/
|
|
void
|
|
ext2_xattr_delete_inode(struct inode *inode)
|
|
{
|
|
struct buffer_head *bh = NULL;
|
|
struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
|
|
|
|
down_write(&EXT2_I(inode)->xattr_sem);
|
|
if (!EXT2_I(inode)->i_file_acl)
|
|
goto cleanup;
|
|
|
|
if (!ext2_data_block_valid(sbi, EXT2_I(inode)->i_file_acl, 0)) {
|
|
ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
|
"inode %ld: xattr block %d is out of data blocks range",
|
|
inode->i_ino, EXT2_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
|
|
bh = sb_bread(inode->i_sb, EXT2_I(inode)->i_file_acl);
|
|
if (!bh) {
|
|
ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
|
"inode %ld: block %d read error", inode->i_ino,
|
|
EXT2_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
|
|
if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
|
|
HDR(bh)->h_blocks != cpu_to_le32(1)) {
|
|
ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
|
|
"inode %ld: bad block %d", inode->i_ino,
|
|
EXT2_I(inode)->i_file_acl);
|
|
goto cleanup;
|
|
}
|
|
lock_buffer(bh);
|
|
if (HDR(bh)->h_refcount == cpu_to_le32(1)) {
|
|
__u32 hash = le32_to_cpu(HDR(bh)->h_hash);
|
|
|
|
/*
|
|
* This must happen under buffer lock for ext2_xattr_set2() to
|
|
* reliably detect freed block
|
|
*/
|
|
mb_cache_entry_delete(EA_BLOCK_CACHE(inode), hash,
|
|
bh->b_blocknr);
|
|
ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1);
|
|
get_bh(bh);
|
|
bforget(bh);
|
|
unlock_buffer(bh);
|
|
} else {
|
|
le32_add_cpu(&HDR(bh)->h_refcount, -1);
|
|
ea_bdebug(bh, "refcount now=%d",
|
|
le32_to_cpu(HDR(bh)->h_refcount));
|
|
unlock_buffer(bh);
|
|
mark_buffer_dirty(bh);
|
|
if (IS_SYNC(inode))
|
|
sync_dirty_buffer(bh);
|
|
dquot_free_block_nodirty(inode, 1);
|
|
}
|
|
EXT2_I(inode)->i_file_acl = 0;
|
|
|
|
cleanup:
|
|
brelse(bh);
|
|
up_write(&EXT2_I(inode)->xattr_sem);
|
|
}
|
|
|
|
/*
|
|
* ext2_xattr_cache_insert()
|
|
*
|
|
* Create a new entry in the extended attribute cache, and insert
|
|
* it unless such an entry is already in the cache.
|
|
*
|
|
* Returns 0, or a negative error number on failure.
|
|
*/
|
|
static int
|
|
ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
|
|
{
|
|
__u32 hash = le32_to_cpu(HDR(bh)->h_hash);
|
|
int error;
|
|
|
|
error = mb_cache_entry_create(cache, GFP_NOFS, hash, bh->b_blocknr, 1);
|
|
if (error) {
|
|
if (error == -EBUSY) {
|
|
ea_bdebug(bh, "already in cache (%d cache entries)",
|
|
atomic_read(&ext2_xattr_cache->c_entry_count));
|
|
error = 0;
|
|
}
|
|
} else
|
|
ea_bdebug(bh, "inserting [%x]", (int)hash);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* ext2_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
|
|
ext2_xattr_cmp(struct ext2_xattr_header *header1,
|
|
struct ext2_xattr_header *header2)
|
|
{
|
|
struct ext2_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 ||
|
|
memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
|
|
return 1;
|
|
if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
|
|
return -EIO;
|
|
if (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 = EXT2_XATTR_NEXT(entry1);
|
|
entry2 = EXT2_XATTR_NEXT(entry2);
|
|
}
|
|
if (!IS_LAST_ENTRY(entry2))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ext2_xattr_cache_find()
|
|
*
|
|
* Find an identical extended attribute block.
|
|
*
|
|
* Returns a locked buffer head to the block found, or NULL if such
|
|
* a block was not found or an error occurred.
|
|
*/
|
|
static struct buffer_head *
|
|
ext2_xattr_cache_find(struct inode *inode, struct ext2_xattr_header *header)
|
|
{
|
|
__u32 hash = le32_to_cpu(header->h_hash);
|
|
struct mb_cache_entry *ce;
|
|
struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode);
|
|
|
|
if (!header->h_hash)
|
|
return NULL; /* never share */
|
|
ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
|
|
again:
|
|
ce = mb_cache_entry_find_first(ea_block_cache, hash);
|
|
while (ce) {
|
|
struct buffer_head *bh;
|
|
|
|
bh = sb_bread(inode->i_sb, ce->e_value);
|
|
if (!bh) {
|
|
ext2_error(inode->i_sb, "ext2_xattr_cache_find",
|
|
"inode %ld: block %ld read error",
|
|
inode->i_ino, (unsigned long) ce->e_value);
|
|
} else {
|
|
lock_buffer(bh);
|
|
/*
|
|
* We have to be careful about races with freeing or
|
|
* rehashing of xattr block. Once we hold buffer lock
|
|
* xattr block's state is stable so we can check
|
|
* whether the block got freed / rehashed or not.
|
|
* Since we unhash mbcache entry under buffer lock when
|
|
* freeing / rehashing xattr block, checking whether
|
|
* entry is still hashed is reliable.
|
|
*/
|
|
if (hlist_bl_unhashed(&ce->e_hash_list)) {
|
|
mb_cache_entry_put(ea_block_cache, ce);
|
|
unlock_buffer(bh);
|
|
brelse(bh);
|
|
goto again;
|
|
} else if (le32_to_cpu(HDR(bh)->h_refcount) >
|
|
EXT2_XATTR_REFCOUNT_MAX) {
|
|
ea_idebug(inode, "block %ld refcount %d>%d",
|
|
(unsigned long) ce->e_value,
|
|
le32_to_cpu(HDR(bh)->h_refcount),
|
|
EXT2_XATTR_REFCOUNT_MAX);
|
|
} else if (!ext2_xattr_cmp(header, HDR(bh))) {
|
|
ea_bdebug(bh, "b_count=%d",
|
|
atomic_read(&(bh->b_count)));
|
|
mb_cache_entry_touch(ea_block_cache, ce);
|
|
mb_cache_entry_put(ea_block_cache, ce);
|
|
return bh;
|
|
}
|
|
unlock_buffer(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
|
|
|
|
/*
|
|
* ext2_xattr_hash_entry()
|
|
*
|
|
* Compute the hash of an extended attribute.
|
|
*/
|
|
static inline void ext2_xattr_hash_entry(struct ext2_xattr_header *header,
|
|
struct ext2_xattr_entry *entry)
|
|
{
|
|
__u32 hash = 0;
|
|
char *name = entry->e_name;
|
|
int n;
|
|
|
|
for (n=0; n < entry->e_name_len; n++) {
|
|
hash = (hash << NAME_HASH_SHIFT) ^
|
|
(hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
|
|
*name++;
|
|
}
|
|
|
|
if (entry->e_value_block == 0 && entry->e_value_size != 0) {
|
|
__le32 *value = (__le32 *)((char *)header +
|
|
le16_to_cpu(entry->e_value_offs));
|
|
for (n = (le32_to_cpu(entry->e_value_size) +
|
|
EXT2_XATTR_ROUND) >> EXT2_XATTR_PAD_BITS; n; n--) {
|
|
hash = (hash << VALUE_HASH_SHIFT) ^
|
|
(hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
|
|
le32_to_cpu(*value++);
|
|
}
|
|
}
|
|
entry->e_hash = cpu_to_le32(hash);
|
|
}
|
|
|
|
#undef NAME_HASH_SHIFT
|
|
#undef VALUE_HASH_SHIFT
|
|
|
|
#define BLOCK_HASH_SHIFT 16
|
|
|
|
/*
|
|
* ext2_xattr_rehash()
|
|
*
|
|
* Re-compute the extended attribute hash value after an entry has changed.
|
|
*/
|
|
static void ext2_xattr_rehash(struct ext2_xattr_header *header,
|
|
struct ext2_xattr_entry *entry)
|
|
{
|
|
struct ext2_xattr_entry *here;
|
|
__u32 hash = 0;
|
|
|
|
ext2_xattr_hash_entry(header, entry);
|
|
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 = EXT2_XATTR_NEXT(here);
|
|
}
|
|
header->h_hash = cpu_to_le32(hash);
|
|
}
|
|
|
|
#undef BLOCK_HASH_SHIFT
|
|
|
|
#define HASH_BUCKET_BITS 10
|
|
|
|
struct mb_cache *ext2_xattr_create_cache(void)
|
|
{
|
|
return mb_cache_create(HASH_BUCKET_BITS);
|
|
}
|
|
|
|
void ext2_xattr_destroy_cache(struct mb_cache *cache)
|
|
{
|
|
if (cache)
|
|
mb_cache_destroy(cache);
|
|
}
|