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2013-01-02Merge tag 'ext4_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bug fixes from Ted Ts'o: "Various bug fixes for ext4. Perhaps the most serious bug fixed is one which could cause file system corruptions when performing file punch operations." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: avoid hang when mounting non-journal filesystems with orphan list ext4: lock i_mutex when truncating orphan inodes ext4: do not try to write superblock on ro remount w/o journal ext4: include journal blocks in df overhead calcs ext4: remove unaligned AIO warning printk ext4: fix an incorrect comment about i_mutex ext4: fix deadlock in journal_unmap_buffer() ext4: split off ext4_journalled_invalidatepage() jbd2: fix assertion failure in jbd2_journal_flush() ext4: check dioread_nolock on remount ext4: fix extent tree corruption caused by hole punch
2012-12-27ext4: avoid hang when mounting non-journal filesystems with orphan listTheodore Ts'o
When trying to mount a file system which does not contain a journal, but which does have a orphan list containing an inode which needs to be truncated, the mount call with hang forever in ext4_orphan_cleanup() because ext4_orphan_del() will return immediately without removing the inode from the orphan list, leading to an uninterruptible loop in kernel code which will busy out one of the CPU's on the system. This can be trivially reproduced by trying to mount the file system found in tests/f_orphan_extents_inode/image.gz from the e2fsprogs source tree. If a malicious user were to put this on a USB stick, and mount it on a Linux desktop which has automatic mounts enabled, this could be considered a potential denial of service attack. (Not a big deal in practice, but professional paranoids worry about such things, and have even been known to allocate CVE numbers for such problems.) Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Cc: stable@vger.kernel.org
2012-12-27ext4: lock i_mutex when truncating orphan inodesTheodore Ts'o
Commit c278531d39 added a warning when ext4_flush_unwritten_io() is called without i_mutex being taken. It had previously not been taken during orphan cleanup since races weren't possible at that point in the mount process, but as a result of this c278531d39, we will now see a kernel WARN_ON in this case. Take the i_mutex in ext4_orphan_cleanup() to suppress this warning. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Cc: stable@vger.kernel.org
2012-12-25ext4: do not try to write superblock on ro remount w/o journalMichael Tokarev
When a journal-less ext4 filesystem is mounted on a read-only block device (blockdev --setro will do), each remount (for other, unrelated, flags, like suid=>nosuid etc) results in a series of scary messages from kernel telling about I/O errors on the device. This is becauese of the following code ext4_remount(): if (sbi->s_journal == NULL) ext4_commit_super(sb, 1); at the end of remount procedure, which forces writing (flushing) of a superblock regardless whenever it is dirty or not, if the filesystem is readonly or not, and whenever the device itself is readonly or not. We only need call ext4_commit_super when the file system had been previously mounted read/write. Thanks to Eric Sandeen for help in diagnosing this issue. Signed-off-By: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-12-25ext4: include journal blocks in df overhead calcsEric Sandeen
To more accurately calculate overhead for "bsd" style df reporting, we should count the journal blocks as overhead as well. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Tested-by: Eric Whitney <enwlinux@gmail.com>
2012-12-25ext4: remove unaligned AIO warning printkEric Sandeen
Although I put this in, I now think it was a bad decision. For most users, there is very little to be done in this case. They get the message, once per day, with no real context or proposed action. TBH, it generates support calls when it probably does not need to; the message sounds more dire than the situation really is. Just nuke it. Normal investigation via blktrace or whatnot can reveal poor IO patterns if bad performance is encountered. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-25ext4: fix an incorrect comment about i_mutexAndy Lutomirski
i_mutex is not held when ->sync_file is called. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-25ext4: fix deadlock in journal_unmap_buffer()Jan Kara
We cannot wait for transaction commit in journal_unmap_buffer() because we hold page lock which ranks below transaction start. We solve the issue by bailing out of journal_unmap_buffer() and jbd2_journal_invalidatepage() with -EBUSY. Caller is then responsible for waiting for transaction commit to finish and try invalidation again. Since the issue can happen only for page stradding i_size, it is simple enough to manually call jbd2_journal_invalidatepage() for such page from ext4_setattr(), check the return value and wait if necessary. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-25ext4: split off ext4_journalled_invalidatepage()Jan Kara
In data=journal mode we don't need delalloc or DIO handling in invalidatepage and similarly in other modes we don't need the journal handling. So split invalidatepage implementations. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-20ext4: check dioread_nolock on remountJan Kara
Currently we allow enabling dioread_nolock mount option on remount for filesystems where blocksize < PAGE_CACHE_SIZE. This isn't really supported so fix the bug by moving the check for blocksize != PAGE_CACHE_SIZE into parse_options(). Change the original PAGE_SIZE to PAGE_CACHE_SIZE along the way because that's what we are really interested in. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Cc: stable@vger.kernel.org
2012-12-17lseek: the "whence" argument is called "whence"Andrew Morton
But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17ext4: fix extent tree corruption caused by hole punchForrest Liu
When depth of extent tree is greater than 1, logical start value of interior node is not correctly updated in ext4_ext_rm_idx. Signed-off-by: Forrest Liu <forrestl@synology.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Ashish Sangwan <ashishsangwan2@gmail.com> Cc: stable@vger.kernel.org
2012-12-16Merge tag 'ext4_for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 update from Ted Ts'o: "There are two major features for this merge window. The first is inline data, which allows small files or directories to be stored in the in-inode extended attribute area. (This requires that the file system use inodes which are at least 256 bytes or larger; 128 byte inodes do not have any room for in-inode xattrs.) The second new feature is SEEK_HOLE/SEEK_DATA support. This is enabled by the extent status tree patches, and this infrastructure will be used to further optimize ext4 in the future. Beyond that, we have the usual collection of code cleanups and bug fixes." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (63 commits) ext4: zero out inline data using memset() instead of empty_zero_page ext4: ensure Inode flags consistency are checked at build time ext4: Remove CONFIG_EXT4_FS_XATTR ext4: remove unused variable from ext4_ext_in_cache() ext4: remove redundant initialization in ext4_fill_super() ext4: remove redundant code in ext4_alloc_inode() ext4: use sync_inode_metadata() when syncing inode metadata ext4: enable ext4 inline support ext4: let fallocate handle inline data correctly ext4: let ext4_truncate handle inline data correctly ext4: evict inline data out if we need to strore xattr in inode ext4: let fiemap work with inline data ext4: let ext4_rename handle inline dir ext4: let empty_dir handle inline dir ext4: let ext4_delete_entry() handle inline data ext4: make ext4_delete_entry generic ext4: let ext4_find_entry handle inline data ext4: create a new function search_dir ext4: let ext4_readdir handle inline data ext4: let add_dir_entry handle inline data properly ...
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...
2012-12-11ext4: zero out inline data using memset() instead of empty_zero_pageTheodore Ts'o
Not all architectures (in particular, sparc64) have empty_zero_page. So instead of copying from empty_zero_page, use memset to clear the inline data by signalling to ext4_xattr_set_entry() via a magic pointer value, EXT4_ZERO_ATTR_VALUE, which is defined by casting -1 to a pointer. This fixes a build failure on sparc64, and the memset() should be more efficient than using memcpy() anyway. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: ensure Inode flags consistency are checked at build timeCarlos Maiolino
Flags being used by atomic operations in inode flags (e.g. ext4_test_inode_flag(), should be consistent with that actually stored in inodes, i.e.: EXT4_XXX_FL. It ensures that this consistency is checked at build-time, not at run-time. Currently, the flags consistency are being checked at run-time, but, there is no real reason to not do a build-time check instead of a run-time check. The code is comparing macro defined values with enum type variables, where both are constants, so, there is no problem in comparing constants at build-time. enum variables are treated as constants by the C compiler, according to the C99 specs (see www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf sec. 6.2.5, item 16), so, there is no real problem in comparing an enumeration type at build time Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: Remove CONFIG_EXT4_FS_XATTRTao Ma
Ted has sent out a RFC about removing this feature. Eric and Jan confirmed that both RedHat and SUSE enable this feature in all their product. David also said that "As far as I know, it's enabled in all Android kernels that use ext4." So it seems OK for us. And what's more, as inline data depends its implementation on xattr, and to be frank, I don't run any test again inline data enabled while xattr disabled. So I think we should add inline data and remove this config option in the same release. [ The savings if you disable CONFIG_EXT4_FS_XATTR is only 27k, which isn't much in the grand scheme of things. Since no one seems to be testing this configuration except for some automated compile farms, on balance we are better removing this config option, and so that it is effectively always enabled. -- tytso ] Cc: David Brown <davidb@codeaurora.org> Cc: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: remove unused variable from ext4_ext_in_cache()Zhi Yong Wu
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Reviewed-by: Zheng Liu <gnehzuil.liu@gmail.com>
2012-12-10ext4: remove redundant initialization in ext4_fill_super()Guo Chao
We use kzalloc() to allocate sbi, no need to zero its field. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: remove redundant code in ext4_alloc_inode()Guo Chao
inode_init_always() will initialize inode->i_data.writeback_index anyway, no need to do this in ext4_alloc_inode(). Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2012-12-10ext4: use sync_inode_metadata() when syncing inode metadataGuo Chao
We have a dedicated interface to sync inode metadata. Use it to simplify ext4's code some. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2012-12-10ext4: enable ext4 inline supportTao Ma
Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let fallocate handle inline data correctlyTao Ma
If we are punching hole in a file, we will return ENOTSUPP. As for the fallocation of some extents, we will convert the inline data to a normal extent based file first. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let ext4_truncate handle inline data correctlyTao Ma
Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: evict inline data out if we need to strore xattr in inodeTao Ma
Now we that store data in the inode, in case we need to store some xattrs and inode doesn't have enough space, Andreas suggested that we should keep the xattr(metadata) in and data should be pushed out. So this patch does the work. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let fiemap work with inline dataTao Ma
fiemap is used to find the disk layout of a file, as for inline data, let us just pretend like a file with just one extent. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let ext4_rename handle inline dirTao Ma
In case we rename a directory, ext4_rename has to read the dir block and change its dotdot's information. The old ext4_rename encapsulated the dir_block read into itself. So this patch adds a new function ext4_get_first_dir_block() which gets the dir buffer information so the ext4_rename can handle it properly. As it will also change the parent inode number, we return the parent_de so that ext4_rename() can handle it more easily. ext4_find_entry is also changed so that the caller(rename) can tell whether the found entry is an inlined one or not and journaling the corresponding buffer head. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let empty_dir handle inline dirTao Ma
empty_dir is used when deleting a dir. So it should handle inline dir properly. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let ext4_delete_entry() handle inline dataTao Ma
Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: make ext4_delete_entry genericTao Ma
Currently ext4_delete_entry() is used only for dir entry removing from a dir block. So let us create a new function ext4_generic_delete_entry and this function takes a entry_buf and a buf_size so that it can be used for inline data. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let ext4_find_entry handle inline dataTao Ma
Create a new function ext4_find_inline_entry() to handle the case of inline data. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: create a new function search_dirTao Ma
search_dirblock is used to search a dir block, but the code is almost the same for searching an inline dir. So create a new fuction search_dir and let search_dirblock call it. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let ext4_readdir handle inline dataTao Ma
For "." and "..", we just call filldir by ourselves instead of iterating the real dir entry. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: let add_dir_entry handle inline data properlyTao Ma
This patch let add_dir_entry handle the inline data case. So the dir is initialized as inline dir first and then we can try to add some files to it, when the inline space can't hold all the entries, a dir block will be created and the dir entry will be moved to it. Also for an inlined dir, "." and ".." are removed and we only use 4 bytes to store the parent inode number. These 2 entries will be added when we convert an inline dir to a block-based one. [ Folded in patch from Dan Carpenter to remove an unused variable. ] Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: create __ext4_insert_dentry for dir entry insertionTao Ma
The old add_dirent_to_buf handles all the work related to the work of adding dir entry to a dir block. Now we have inline data, so create 2 new function __ext4_find_dest_de and __ext4_insert_dentry that do the real work and let add_dirent_to_buf call them. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: refactor __ext4_check_dir_entry() to accept start and sizeTao Ma
The __ext4_check_dir_entry() function() is used to check whether the de is over the block boundary. Now with inline data, it could be within the block boundary while exceeds the inode size. So check this function to check the overflow more precisely. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: make ext4_init_dot_dotdot for inline dir usageTao Ma
Currently, the initialization of dot and dotdot are encapsulated in ext4_mkdir and also bond with dir_block. So create a new function named ext4_init_new_dir and the initialization is moved to ext4_init_dot_dotdot. Now it will called either in the normal non-inline case(rec_len of ".." will cover the whole block) or when we converting an inline dir to a block(rec len of ".." will be the real length). The start of the next entry is also returned for inline dir usage. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: add delalloc support for inline dataTao Ma
For delayed allocation mode, we write to inline data if the file is small enough. And in case of we write to some offset larger than the inline size, the 1st page is dirtied, so that ext4_da_writepages can handle the conversion. When the 1st page is initialized with blocks, the inline part is removed. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: add journalled write support for inline dataTao Ma
Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: add normal write support for inline dataTao Ma
For a normal write case (not journalled write, not delayed allocation), we write to the inline if the file is small and convert it to an extent based file when the write is larger than the max inline size. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: add read support for inline dataTao Ma
Let readpage and readpages handle the case when we want to read an inlined file. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-10ext4: add the basic function for inline data supportTao Ma
Implement inline data with xattr. Now we use "system.data" to store xattr, and the xattr will be extended if the i_size is increased while we don't release the space during truncate. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-05ext4: export inline xattr functionsTao Ma
The inline data feature will need some inline xattr functions, so export them from fs/ext4/xattr.c so that inline.c can use them. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-12-02ext4: move extra inode read to a new functionTao Ma
Currently, in ext4_iget we do a simple check to see whether there does exist some information starting from the end of i_extra_size. With inline data added, this procedure is more complicated. So move it to a new function named ext4_iget_extra_inode. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-29ext4: fix possible use after free with metadata csumTheodore Ts'o
Commit fa77dcfafeaa introduces block bitmap checksum calculation into ext4_new_inode() in the case that block group was uninitialized. However we brelse() the bitmap buffer before we attempt to checksum it so we have no guarantee that the buffer is still there. Fix this by releasing the buffer after the possible checksum computation. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Acked-by: Darrick J. Wong <darrick.wong@oracle.com> Cc: stable@vger.kernel.org
2012-11-29ext4: restructure ext4_ext_direct_IO()Theodore Ts'o
Remove a level of indentation by moving the DIO read and extending write case to the beginning of the file. This results in no actual programmatic changes to the file, but makes it easier to read/understand. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28ext4: rationalize ext4_extents.h inclusionTheodore Ts'o
Previously, ext4_extents.h was being included at the end of ext4.h, which was bad for a number of reasons: (a) it was not being included in the expected place, and (b) it caused the header to be included multiple times. There were #ifdef's to prevent this from causing any problems, but it still was unnecessary. By moving the function declarations that were in ext4_extents.h to ext4.h, which is standard practice for where the function declarations for the rest of ext4.h can be found, we can remove ext4_extents.h from being included in ext4.h at all, and then we can only include ext4_extents.h where it is needed in ext4's source files. It should be possible to move a few more things into ext4.h, and further reduce the number of source files that need to #include ext4_extents.h, but that's a cleanup for another day. Reported-by: Sachin Kamat <sachin.kamat@linaro.org> Reported-by: Wei Yongjun <weiyj.lk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28ext4: fixed potential NULL dereference in ext4_calculate_overhead()Vahram Martirosyan
The memset operation before check can cause a BUG if the memory allocation failed. Since we are using get_zeroed_age, there is no need to use memset anyway. Found by the Spruce system in cooperation with the KEDR Framework. Signed-off-by: Vahram Martirosyan <vmartirosyan@linuxtesting.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28ext4: simple cleanup in fiemap codepathLukas Czerner
This commit is simple cleanup of fiemap codepath which has not been included in previous commit to make the changes clearer. In this commit we rename cbex variable to newex in ext4_fill_fiemap_extents() because callback is no longer present Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-11-28ext4: prevent race while walking extent tree for fiemapLukas Czerner
Currently ext4_ext_walk_space() only takes i_data_sem for read when searching for the extent at given block with ext4_ext_find_extent(). Then it drops the lock and the extent tree can be changed at will. However later on we're searching for the 'next' extent, but the extent tree might already have changed, so the information might not be accurate. In fact we can hit BUG_ON(end <= start) if the extent got inserted into the tree after the one we found and before the block we were searching for. This has been reproduced by running xfstests 225 in loop on s390x architecture, but theoretically we could hit this on any other architecture as well, but probably not as often. Moreover the extent currently in delayed allocation might be allocated after we search the extent tree and before we search extent status tree delayed buffers resulting in those delayed buffers being completely missed, even though completely written and allocated. We fix all those problems in several steps: 1. remove unnecessary callback indirection 2. rename functions ext4_ext_walk_space -> ext4_fill_fiemap_extents ext4_ext_fiemap_cb -> ext4_find_delayed_extent 3. move fiemap_fill_next_extent() into ext4_fill_fiemap_extents() 4. hold the i_data_sem for: ext4_ext_find_extent() ext4_ext_next_allocated_block() ext4_find_delayed_extent() 5. call fiemap_fill_next_extent after releasing the i_data_sem 6. move path reinitialization into the critical section. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>