kernel.git/fs/ext4/ext4.h, branch linux-4.20.y

ext4: avoid declaring fs inconsistent due to invalid file handles

2019-01-09T16:45:57Z

commit 8a363970d1dc38c4ec4ad575c862f776f468d057 upstream. If we receive a file handle, either from NFS or open_by_handle_at(2), and it points at an inode which has not been initialized, and the file system has metadata checksums enabled, we shouldn't try to get the inode, discover the checksum is invalid, and then declare the file system as being inconsistent. This can be reproduced by creating a test file system via "mke2fs -t ext4 -O metadata_csum /tmp/foo.img 8M", mounting it, cd'ing into that directory, and then running the following program. #define _GNU_SOURCE #include struct handle { struct file_handle fh; unsigned char fid[MAX_HANDLE_SZ]; }; int main(int argc, char **argv) { struct handle h = {{8, 1 }, { 12, }}; open_by_handle_at(AT_FDCWD, &h.fh, O_RDONLY); return 0; } Google-Bug-Id: 120690101 Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: add ext4_sb_bread() to disambiguate ENOMEM cases

2019-01-09T16:45:57Z

commit fb265c9cb49e2074ddcdd4de99728aefdd3b3592 upstream. Today, when sb_bread() returns NULL, this can either be because of an I/O error or because the system failed to allocate the buffer. Since it's an old interface, changing would require changing many call sites. So instead we create our own ext4_sb_bread(), which also allows us to set the REQ_META flag. Also fixed a problem in the xattr code where a NULL return in a function could also mean that the xattr was not found, which could lead to the wrong error getting returned to userspace. Fixes: ac27a0ec112a ("ext4: initial copy of files from ext3") Cc: stable@kernel.org # 2.6.19 Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

Merge tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux

2018-11-02T01:34:46Z

Pull compiler attribute updates from Miguel Ojeda: "This is an effort to disentangle the include/linux/compiler*.h headers and bring them up to date. The main idea behind the series is to use feature checking macros (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION), which are compiler-agnostic (so they can be shared, reducing the size of compiler-specific headers) and version-agnostic. Other related improvements have been performed in the headers as well, which on top of the use of __has_attribute it has amounted to a significant simplification of these headers (e.g. GCC_VERSION is now only guarding a few non-attribute macros). This series should also help the efforts to support compiling the kernel with clang and icc. A fair amount of documentation and comments have also been added, clarified or removed; and the headers are now more readable, which should help kernel developers in general. The series was triggered due to the move to gcc >= 4.6. In turn, this series has also triggered Sparse to gain the ability to recognize __has_attribute on its own. Finally, the __nonstring variable attribute series has been also applied on top; plus two related patches from Nick Desaulniers for unreachable() that came a bit afterwards" * tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux: compiler-gcc: remove comment about gcc 4.5 from unreachable() compiler.h: update definition of unreachable() Compiler Attributes: ext4: remove local __nonstring definition Compiler Attributes: auxdisplay: panel: use __nonstring Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8) Compiler Attributes: add support for __nonstring (gcc >= 8) Compiler Attributes: add MAINTAINERS entry Compiler Attributes: add Doc/process/programming-language.rst Compiler Attributes: remove uses of __attribute__ from compiler.h Compiler Attributes: KENTRY used twice the "used" attribute Compiler Attributes: use feature checks instead of version checks Compiler Attributes: add missing SPDX ID in compiler_types.h Compiler Attributes: remove unneeded sparse (__CHECKER__) tests Compiler Attributes: homogenize __must_be_array Compiler Attributes: remove unneeded tests Compiler Attributes: always use the extra-underscores syntax Compiler Attributes: remove unused attributes

ext4: fix use-after-free race in ext4_remount()'s error path

2018-10-12T13:28:09Z

It's possible for ext4_show_quota_options() to try reading s_qf_names[i] while it is being modified by ext4_remount() --- most notably, in ext4_remount's error path when the original values of the quota file name gets restored. Reported-by: syzbot+a2872d6feea6918008a9@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org # 3.2+

ext4: convert fault handler to use vm_fault_t type

2018-10-03T02:20:50Z

Return type of ext4_page_mkwrite and ext4_filemap_fault are changed to use vm_fault_t type. With this patch all the callers of block_page_mkwrite_return() are changed to handle vm_fault_t. So converting the return type of block_page_mkwrite_return() to vm_fault_t. Signed-off-by: Souptick Joarder Signed-off-by: Theodore Ts'o Reviewed-by: Matthew Wilcox

ext4: fix reserved cluster accounting at page invalidation time

2018-10-01T18:33:24Z

Add new code to count canceled pending cluster reservations on bigalloc file systems and to reduce the cluster reservation count on all file systems using delayed allocation. This replaces old code in ext4_da_page_release_reservations that was incorrect. Signed-off-by: Eric Whitney Signed-off-by: Theodore Ts'o

ext4: adjust reserved cluster count when removing extents

2018-10-01T18:25:08Z

Modify ext4_ext_remove_space() and the code it calls to correct the reserved cluster count for pending reservations (delayed allocated clusters shared with allocated blocks) when a block range is removed from the extent tree. Pending reservations may be found for the clusters at the ends of written or unwritten extents when a block range is removed. If a physical cluster at the end of an extent is freed, it's necessary to increment the reserved cluster count to maintain correct accounting if the corresponding logical cluster is shared with at least one delayed and unwritten extent as found in the extents status tree. Add a new function, ext4_rereserve_cluster(), to reapply a reservation on a delayed allocated cluster sharing blocks with a freed allocated cluster. To avoid ENOSPC on reservation, a flag is applied to ext4_free_blocks() to briefly defer updating the freeclusters counter when an allocated cluster is freed. This prevents another thread from allocating the freed block before the reservation can be reapplied. Redefine the partial cluster object as a struct to carry more state information and to clarify the code using it. Adjust the conditional code structure in ext4_ext_remove_space to reduce the indentation level in the main body of the code to improve readability. Signed-off-by: Eric Whitney Signed-off-by: Theodore Ts'o

ext4: fix reserved cluster accounting at delayed write time

2018-10-01T18:19:37Z

The code in ext4_da_map_blocks sometimes reserves space for more delayed allocated clusters than it should, resulting in premature ENOSPC, exceeded quota, and inaccurate free space reporting. Fix this by checking for written and unwritten blocks shared in the same cluster with the newly delayed allocated block. A cluster reservation should not be made for a cluster for which physical space has already been allocated. Signed-off-by: Eric Whitney Signed-off-by: Theodore Ts'o

ext4: add new pending reservation mechanism

2018-10-01T18:17:41Z

Add new pending reservation mechanism to help manage reserved cluster accounting. Its primary function is to avoid the need to read extents from the disk when invalidating pages as a result of a truncate, punch hole, or collapse range operation. Signed-off-by: Eric Whitney Signed-off-by: Theodore Ts'o

ext4: generalize extents status tree search functions

2018-10-01T18:10:39Z

Ext4 contains a few functions that are used to search for delayed extents or blocks in the extents status tree. Rather than duplicate code to add new functions to search for extents with different status values, such as written or a combination of delayed and unwritten, generalize the existing code to search for caller-specified extents status values. Also, move this code into extents_status.c where it is better associated with the data structures it operates upon, and where it can be more readily used to implement new extents status tree functions that might want a broader scope for i_es_lock. Three missing static specifiers in RFC version of patch reported and fixed by Fengguang Wu . Signed-off-by: Eric Whitney Signed-off-by: Theodore Ts'o