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2020-03-11ext4: fix potential race between online resizing and write operationsTheodore Ts'o1-3/+11
commit 1d0c3924a92e69bfa91163bda83c12a994b4d106 upstream. During an online resize an array of pointers to buffer heads gets replaced so it can get enlarged. If there is a racing block allocation or deallocation which uses the old array, and the old array has gotten reused this can lead to a GPF or some other random kernel memory getting modified. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-2-tytso@mit.edu Reported-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org # 4.4.x Cc: stable@kernel.org # 4.9.x Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-08-06ext4: check for allocation block validity with block group lockedTheodore Ts'o1-0/+3
commit 8d5a803c6a6ce4ec258e31f76059ea5153ba46ef upstream. With commit 044e6e3d74a3: "ext4: don't update checksum of new initialized bitmaps" the buffer valid bit will get set without actually setting up the checksum for the allocation bitmap, since the checksum will get calculated once we actually allocate an inode or block. If we are doing this, then we need to (re-)check the verified bit after we take the block group lock. Otherwise, we could race with another process reading and verifying the bitmap, which would then complain about the checksum being invalid. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1780137 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11ext4: only look at the bg_flags field if it is validTheodore Ts'o1-1/+10
commit 8844618d8aa7a9973e7b527d038a2a589665002c upstream. The bg_flags field in the block group descripts is only valid if the uninit_bg or metadata_csum feature is enabled. We were not consistently looking at this field; fix this. Also block group #0 must never have uninitialized allocation bitmaps, or need to be zeroed, since that's where the root inode, and other special inodes are set up. Check for these conditions and mark the file system as corrupted if they are detected. This addresses CVE-2018-10876. https://bugzilla.kernel.org/show_bug.cgi?id=199403 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-11ext4: always check block group bounds in ext4_init_block_bitmap()Theodore Ts'o1-7/+3
commit 819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream. Regardless of whether the flex_bg feature is set, we should always check to make sure the bits we are setting in the block bitmap are within the block group bounds. https://bugzilla.kernel.org/show_bug.cgi?id=199865 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02ext4: fix bitmap position validationLukas Czerner1-4/+5
commit 22be37acce25d66ecf6403fc8f44df9c5ded2372 upstream. Currently in ext4_valid_block_bitmap() we expect the bitmap to be positioned anywhere between 0 and s_blocksize clusters, but that's wrong because the bitmap can be placed anywhere in the block group. This causes false positives when validating bitmaps on perfectly valid file system layouts. Fix it by checking whether the bitmap is within the group boundary. The problem can be reproduced using the following mkfs -t ext3 -E stride=256 /dev/vdb1 mount /dev/vdb1 /mnt/test cd /mnt/test wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.16.3.tar.xz tar xf linux-4.16.3.tar.xz This will result in the warnings in the logs EXT4-fs error (device vdb1): ext4_validate_block_bitmap:399: comm tar: bg 84: block 2774529: invalid block bitmap [ Changed slightly for clarity and to not drop a overflow test -- TYT ] Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Ilya Dryomov <idryomov@gmail.com> Fixes: 7dac4a1726a9 ("ext4: add validity checks for bitmap block numbers") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-02ext4: add validity checks for bitmap block numbersTheodore Ts'o1-2/+14
commit 7dac4a1726a9c64a517d595c40e95e2d0d135f6f upstream. An privileged attacker can cause a crash by mounting a crafted ext4 image which triggers a out-of-bounds read in the function ext4_valid_block_bitmap() in fs/ext4/balloc.c. This issue has been assigned CVE-2018-1093. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199181 BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1560782 Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-04-24ext4: don't update checksum of new initialized bitmapsTheodore Ts'o1-2/+1
commit 044e6e3d74a3d7103a0c8a9305dfd94d64000660 upstream. When reading the inode or block allocation bitmap, if the bitmap needs to be initialized, do not update the checksum in the block group descriptor. That's because we're not set up to journal those changes. Instead, just set the verified bit on the bitmap block, so that it's not necessary to validate the checksum. When a block or inode allocation actually happens, at that point the checksum will be calculated, and update of the bg descriptor block will be properly journalled. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-16ext4: validate s_reserved_gdt_blocks on mountTheodore Ts'o1-0/+3
commit 5b9554dc5bf008ae7f68a52e3d7e76c0920938a2 upstream. If s_reserved_gdt_blocks is extremely large, it's possible for ext4_init_block_bitmap(), which is called when ext4 sets up an uninitialized block bitmap, to corrupt random kernel memory. Add the same checks which e2fsck has --- it must never be larger than blocksize / sizeof(__u32) --- and then add a backup check in ext4_init_block_bitmap() in case the superblock gets modified after the file system is mounted. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-25ext4: fix scheduling in atomic on group checksum failureJan Kara1-3/+4
commit 05145bd799e498ce4e3b5145894174ee881f02b0 upstream. When block group checksum is wrong, we call ext4_error() while holding group spinlock from ext4_init_block_bitmap() or ext4_init_inode_bitmap() which results in scheduling while in atomic. Fix the issue by calling ext4_error() later after dropping the spinlock. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-18ext4: make the bitmap read routines return real error codesDarrick J. Wong1-33/+41
Make the bitmap reaading routines return real error codes (EIO, EFSCORRUPTED, EFSBADCRC) which can then be reflected back to userspace for more precise diagnosis work. In particular, this means that mballoc no longer claims that we're out of memory if the block bitmaps become corrupt. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-10-17ext4: clean up feature test macros with predicate functionsDarrick J. Wong1-9/+7
Create separate predicate functions to test/set/clear feature flags, thereby replacing the wordy old macros. Furthermore, clean out the places where we open-coded feature tests. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2015-10-17ext4: call out CRC and corruption errors with specific error codesDarrick J. Wong1-1/+1
Instead of overloading EIO for CRC errors and corrupt structures, return the same error codes that XFS returns for the same issues. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-06-08ext4: verify block bitmap even after fresh initializationLukas Czerner1-2/+2
If we want to rely on the buffer_verified() flag of the block bitmap buffer, we have to set it consistently. However currently if we're initializing uninitialized block bitmap in ext4_read_block_bitmap_nowait() we're not going to set buffer verified at all. We can do this by simply setting the flag on the buffer, but I think it's actually better to run ext4_validate_block_bitmap() to make sure that what we did in the ext4_init_block_bitmap() is right. So run ext4_validate_block_bitmap() even after the block bitmap initialization. Also bail out early from ext4_validate_block_bitmap() if we see corrupt bitmap, since we already know it's corrupt and we do not need to verify that. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-04-03ext4: remove unnecessary lock/unlock of i_block_reservation_lockMaurizio Lombardi1-2/+0
This is a leftover of commit 71d4f7d032149b935a26eb3ff85c6c837f3714e1 Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2015-04-03ext4: remove unused header filesSheng Yong1-1/+0
Remove unused header files and header files which are included in ext4.h. Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-13ext4: move error report out of atomic context in ext4_init_block_bitmap()Dmitry Monakhov1-4/+8
Error report likely result in IO so it is bad idea to do it from atomic context. This patch should fix following issue: BUG: sleeping function called from invalid context at include/linux/buffer_head.h:349 in_atomic(): 1, irqs_disabled(): 0, pid: 137, name: kworker/u128:1 5 locks held by kworker/u128:1/137: #0: ("writeback"){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0 #1: ((&(&wb->dwork)->work)){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0 #2: (jbd2_handle){......}, at: [<ffffffff81242622>] start_this_handle+0x712/0x7b0 #3: (&ei->i_data_sem){......}, at: [<ffffffff811fa387>] ext4_map_blocks+0x297/0x430 #4: (&(&bgl->locks[i].lock)->rlock){......}, at: [<ffffffff811f3180>] ext4_read_block_bitmap_nowait+0x5d0/0x630 CPU: 3 PID: 137 Comm: kworker/u128:1 Not tainted 3.17.0-rc2-00184-g82752e4 #165 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 Workqueue: writeback bdi_writeback_workfn (flush-1:0) 0000000000000411 ffff880813777288 ffffffff815c7fdc ffff880813777288 ffff880813a8bba0 ffff8808137772a8 ffffffff8108fb30 ffff880803e01e38 ffff880803e01e38 ffff8808137772c8 ffffffff811a8d53 ffff88080ecc6000 Call Trace: [<ffffffff815c7fdc>] dump_stack+0x51/0x6d [<ffffffff8108fb30>] __might_sleep+0xf0/0x100 [<ffffffff811a8d53>] __sync_dirty_buffer+0x43/0xe0 [<ffffffff811a8e03>] sync_dirty_buffer+0x13/0x20 [<ffffffff8120f581>] ext4_commit_super+0x1d1/0x230 [<ffffffff8120fa03>] save_error_info+0x23/0x30 [<ffffffff8120fd06>] __ext4_error+0xb6/0xd0 [<ffffffff8120f260>] ? ext4_group_desc_csum+0x140/0x190 [<ffffffff811f2d8c>] ext4_read_block_bitmap_nowait+0x1dc/0x630 [<ffffffff8122e23a>] ext4_mb_init_cache+0x21a/0x8f0 [<ffffffff8113ae95>] ? lru_cache_add+0x55/0x60 [<ffffffff8112e16c>] ? add_to_page_cache_lru+0x6c/0x80 [<ffffffff8122eaa0>] ext4_mb_init_group+0x190/0x280 [<ffffffff8122ec51>] ext4_mb_good_group+0xc1/0x190 [<ffffffff8123309a>] ext4_mb_regular_allocator+0x17a/0x410 [<ffffffff8122c821>] ? ext4_mb_use_preallocated+0x31/0x380 [<ffffffff81233535>] ? ext4_mb_new_blocks+0x205/0x8e0 [<ffffffff8116ed5c>] ? kmem_cache_alloc+0xfc/0x180 [<ffffffff812335b0>] ext4_mb_new_blocks+0x280/0x8e0 [<ffffffff8116f2c4>] ? __kmalloc+0x144/0x1c0 [<ffffffff81221797>] ? ext4_find_extent+0x97/0x320 [<ffffffff812257f4>] ext4_ext_map_blocks+0xbc4/0x1050 [<ffffffff811fa387>] ? ext4_map_blocks+0x297/0x430 [<ffffffff811fa3ab>] ext4_map_blocks+0x2bb/0x430 [<ffffffff81200e43>] ? ext4_init_io_end+0x23/0x50 [<ffffffff811feb44>] ext4_writepages+0x564/0xaf0 [<ffffffff815cde3b>] ? _raw_spin_unlock+0x2b/0x40 [<ffffffff810ac7bd>] ? lock_release_non_nested+0x2fd/0x3c0 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490 [<ffffffff811377e3>] do_writepages+0x23/0x40 [<ffffffff8119c8ce>] __writeback_single_inode+0x9e/0x280 [<ffffffff811a026b>] writeback_sb_inodes+0x2db/0x490 [<ffffffff811a0664>] wb_writeback+0x174/0x2d0 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190 [<ffffffff811a0863>] wb_do_writeback+0xa3/0x200 [<ffffffff811a0a40>] bdi_writeback_workfn+0x80/0x230 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0 [<ffffffff810856cd>] process_one_work+0x2dd/0x4d0 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0 [<ffffffff81085c1d>] worker_thread+0x35d/0x460 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0 [<ffffffff8108a885>] kthread+0xf5/0x100 [<ffffffff810990e5>] ? local_clock+0x25/0x30 [<ffffffff8108a790>] ? __init_kthread_worker+0x70/0x70 [<ffffffff815ce2ac>] ret_from_fork+0x7c/0xb0 [<ffffffff8108a790>] ? __init_kthread_work Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-09-05ext4: prepare to drop EXT4_STATE_DELALLOC_RESERVEDTheodore Ts'o1-2/+1
The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented because it was too hard to make sure the mballoc and get_block flags could be reliably passed down through all of the codepaths that end up calling ext4_mb_new_blocks(). Since then, we have mb_flags passed down through most of the code paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky as it used to. This commit plumbs in the last of what is required, and then adds a WARN_ON check to make sure we haven't missed anything. If this passes a full regression test run, we can then drop EXT4_STATE_DELALLOC_RESERVED. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2014-07-15ext4: remove metadata reservation checksTheodore Ts'o1-1/+0
Commit 27dd43854227b ("ext4: introduce reserved space") reserves 2% of the file system space to make sure metadata allocations will always succeed. Given that, tracking the reservation of metadata blocks is no longer necessary. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-06-26ext4: decrement free clusters/inodes counters when block group declared badNamjae Jeon1-0/+16
We should decrement free clusters counter when block bitmap is marked as corrupt and free inodes counter when the allocation bitmap is marked as corrupt to avoid misunderstanding due to incorrect available size in statfs result. User can get immediately ENOSPC error from write begin without reaching for the writepages. Cc: Darrick J. Wong<darrick.wong@oracle.com> Reported-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
2014-05-12ext4: make local functions staticStephen Hemminger1-10/+11
I have been running make namespacecheck to look for unneeded globals, and found these in ext4. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12ext4: fix block bitmap validation when bigalloc, ^flex_bgDarrick J. Wong1-5/+7
On a bigalloc,^flex_bg filesystem, the ext4_valid_block_bitmap function fails to convert from blocks to clusters when spot-checking the validity of the bitmap block that we've just read from disk. This causes ext4 to think that the bitmap is garbage, which results in the block group being taken offline when it's not necessary. Add in the necessary EXT4_B2C() calls to perform the conversions. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12ext4: fix block bitmap initialization under sparse_super2Darrick J. Wong1-14/+19
The ext4_bg_has_super() function doesn't know about the new rules for where backup superblocks go on a sparse_super2 filesystem. Therefore, block bitmap initialization doesn't know that it shouldn't reserve space for backups in groups that are never going to contain backups. The result of this is e2fsck complaining about the block bitmap being incorrect (fortunately not in a way that results in cross-linked files), so fix the whole thing. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-15ext4: fix ext4_count_free_clusters() with EXT4FS_DEBUG and bigalloc enabledAzat Khuzhin1-1/+1
With bigalloc enabled we must use EXT4_CLUSTERS_PER_GROUP() instead of EXT4_BLOCKS_PER_GROUP() otherwise we will go beyond the allocated buffer. $ mount -t ext4 /dev/vde /vde [ 70.573993] EXT4-fs DEBUG (fs/ext4/mballoc.c, 2346): ext4_mb_alloc_groupinfo: [ 70.575174] allocated s_groupinfo array for 1 meta_bg's [ 70.576172] EXT4-fs DEBUG (fs/ext4/super.c, 2092): ext4_check_descriptors: [ 70.576972] Checking group descriptorsBUG: unable to handle kernel paging request at ffff88006ab56000 [ 72.463686] IP: [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.464168] PGD 295e067 PUD 2961067 PMD 7fa8e067 PTE 800000006ab56060 [ 72.464738] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [ 72.465139] Modules linked in: [ 72.465402] CPU: 1 PID: 3560 Comm: mount Tainted: G W 3.14.0-rc2-00069-ge57bce1 #60 [ 72.466079] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 72.466505] task: ffff88007ce6c8a0 ti: ffff88006b7f0000 task.ti: ffff88006b7f0000 [ 72.466505] RIP: 0010:[<ffffffff81394eb9>] [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.466505] RSP: 0018:ffff88006b7f1c00 EFLAGS: 00010206 [ 72.466505] RAX: 0000000000000000 RBX: 000000000000050a RCX: 0000000000000040 [ 72.466505] RDX: 0000000000000000 RSI: 0000000000080000 RDI: 0000000000000000 [ 72.466505] RBP: ffff88006b7f1c28 R08: 0000000000000002 R09: 0000000000000000 [ 72.466505] R10: 000000000000babe R11: 0000000000000400 R12: 0000000000080000 [ 72.466505] R13: 0000000000000200 R14: 0000000000002000 R15: ffff88006ab55000 [ 72.466505] FS: 00007f43ba1fa840(0000) GS:ffff88007f800000(0000) knlGS:0000000000000000 [ 72.466505] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 72.466505] CR2: ffff88006ab56000 CR3: 000000006b7e6000 CR4: 00000000000006e0 [ 72.466505] Stack: [ 72.466505] ffff88006ab65000 0000000000000000 0000000000000000 0000000000010000 [ 72.466505] ffff88006ab6f400 ffff88006b7f1c58 ffffffff81396bb8 0000000000010000 [ 72.466505] 0000000000000000 ffff88007b869a90 ffff88006a48a000 ffff88006b7f1c70 [ 72.466505] Call Trace: [ 72.466505] [<ffffffff81396bb8>] memweight+0x5f/0x8a [ 72.466505] [<ffffffff811c3b19>] ext4_count_free+0x13/0x21 [ 72.466505] [<ffffffff811c396c>] ext4_count_free_clusters+0xdb/0x171 [ 72.466505] [<ffffffff811e3bdd>] ext4_fill_super+0x117c/0x28ef [ 72.466505] [<ffffffff81391569>] ? vsnprintf+0x1c7/0x3f7 [ 72.466505] [<ffffffff8114d8dc>] mount_bdev+0x145/0x19c [ 72.466505] [<ffffffff811e2a61>] ? ext4_calculate_overhead+0x2a1/0x2a1 [ 72.466505] [<ffffffff811dab1d>] ext4_mount+0x15/0x17 [ 72.466505] [<ffffffff8114e3aa>] mount_fs+0x67/0x150 [ 72.466505] [<ffffffff811637ea>] vfs_kern_mount+0x64/0xde [ 72.466505] [<ffffffff81165d19>] do_mount+0x6fe/0x7f5 [ 72.466505] [<ffffffff81126cc8>] ? strndup_user+0x3a/0xd9 [ 72.466505] [<ffffffff8116604b>] SyS_mount+0x85/0xbe [ 72.466505] [<ffffffff81619e90>] tracesys+0xdd/0xe2 [ 72.466505] Code: c3 89 f0 b9 40 00 00 00 55 99 48 89 e5 41 57 f7 f9 41 56 49 89 ff 41 55 45 31 ed 41 54 41 89 f4 53 31 db 41 89 c6 45 39 ee 7e 10 <4b> 8b 3c ef 49 ff c5 e8 bf ff ff ff 01 c3 eb eb 31 c0 45 85 f6 [ 72.466505] RIP [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.466505] RSP <ffff88006b7f1c00> [ 72.466505] CR2: ffff88006ab56000 [ 72.466505] ---[ end trace 7d051a08ae138573 ]--- Killed Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-10-31ext4: don't count free clusters from a corrupt block groupDarrick J. Wong1-2/+11
A bg that's been flagged "corrupt" by definition has no free blocks, so that the allocator won't be tempted to use the damaged bg. Therefore, we shouldn't count the clusters in the damaged group when calculating free counts. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-08-29ext4: mark group corrupt on group descriptor checksumDarrick J. Wong1-5/+4
If the group descriptor fails validation, mark the whole blockgroup corrupt so that the inode/block allocators skip this group. The previous approach takes the risk of writing to a damaged group descriptor; hopefully it was never the case that the [ib]bitmap fields pointed to another valid block and got dirtied, since the memset would fill the page with 1s. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-29ext4: mark block group as corrupt on block bitmap errorDarrick J. Wong1-0/+3
When we notice a block-bitmap corruption (because of device failure or something else), we should mark this group as corrupt and prevent further block allocations/deallocations from it. Currently, we end up generating one error message for every block in the bitmap. This potentially could make the system unstable as noticed in some bugs. With this patch, the error will be printed only the first time and mark the entire block group as corrupted. This prevents future access allocations/deallocations from it. Also tested by corrupting the block bitmap and forcefully introducing the mb_free_blocks error: (1) create a largefile (2Gb) $ dd if=/dev/zero of=largefile oflag=direct bs=10485760 count=200 (2) umount filesystem. use dumpe2fs to see which block-bitmaps are in use by largefile and note their block numbers (3) use dd to zero-out the used block bitmaps $ dd if=/dev/zero of=/dev/hdc4 bs=4096 seek=14 count=8 oflag=direct (4) mount the FS and delete the largefile. (5) recreate the largefile. verify that the new largefile does not get any blocks from the groups marked as bad. Without the patch, we will see mb_free_blocks error for each bit in each zero'ed out bitmap at (4). With the patch, we only see the error once per blockgroup: [ 309.706803] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 15: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.720824] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 14: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.732858] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.748321] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 13: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.760331] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.769695] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 12: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.781721] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.798166] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 11: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.810184] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.819532] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 10: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. Google-Bug-Id: 7258357 [darrick.wong@oracle.com] Further modifications (by Darrick) to make more obvious that this corruption bit applies to blocks only. Set the corruption flag if the block group bitmap verification fails. Original-author: Aditya Kali <adityakali@google.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28ext4: fix type declaration of ext4_validate_block_bitmapDarrick J. Wong1-2/+2
The block_group parameter to ext4_validate_block_bitmap is both used as a ext4_group_t inside the function and the same type is passed in by all callers. We might as well use the typedef consistently instead of open-coding the 'unsigned int'. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28ext4: error out if verifying the block bitmap failsDarrick J. Wong1-2/+6
The block bitmap verification code assumes that calling ext4_error() either panics the system or makes the fs readonly. However, this is not always true: when 'errors=continue' is specified, an error is printed but we don't return any indication of error to the caller, which is (probably) the block allocator, which pretends that the crud we read in off the disk is a usable bitmap. Yuck. A block bitmap that fails the check should at least return no bitmap to the caller. The block allocator should be told to go look in a different group, but that's a separate issue. The easiest way to reproduce this is to modify bg_block_bitmap (on a ^flex_bg fs) to point to a block outside the block group; or you can create a metadata_csum filesystem and zero out the block bitmaps. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-06ext4: fix ext4_get_group_number()Theodore Ts'o1-2/+2
The function ext4_get_group_number() was introduced as an optimization in commit bd86298e60b8. Unfortunately, this commit incorrectly calculate the group number for file systems with a 1k block size (when s_first_data_block is 1 instead of zero). This could cause the following kernel BUG: [ 568.877799] ------------[ cut here ]------------ [ 568.877833] kernel BUG at fs/ext4/mballoc.c:3728! [ 568.877840] Oops: Exception in kernel mode, sig: 5 [#1] [ 568.877845] SMP NR_CPUS=32 NUMA pSeries [ 568.877852] Modules linked in: binfmt_misc [ 568.877861] CPU: 1 PID: 3516 Comm: fs_mark Not tainted 3.10.0-03216-g7c6809f-dirty #1 [ 568.877867] task: c0000001fb0b8000 ti: c0000001fa954000 task.ti: c0000001fa954000 [ 568.877873] NIP: c0000000002f42a4 LR: c0000000002f4274 CTR: c000000000317ef8 [ 568.877879] REGS: c0000001fa956ed0 TRAP: 0700 Not tainted (3.10.0-03216-g7c6809f-dirty) [ 568.877884] MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 24000428 XER: 00000000 [ 568.877902] SOFTE: 1 [ 568.877905] CFAR: c0000000002b5464 [ 568.877908] GPR00: 0000000000000001 c0000001fa957150 c000000000c6a408 c0000001fb588000 GPR04: 0000000000003fff c0000001fa9571c0 c0000001fa9571c4 000138098c50625f GPR08: 1301200000000000 0000000000000002 0000000000000001 0000000000000000 GPR12: 0000000024000422 c00000000f33a300 0000000000008000 c0000001fa9577f0 GPR16: c0000001fb7d0100 c000000000c29190 c0000000007f46e8 c000000000a14672 GPR20: 0000000000000001 0000000000000008 ffffffffffffffff 0000000000000000 GPR24: 0000000000000100 c0000001fa957278 c0000001fdb2bc78 c0000001fa957288 GPR28: 0000000000100100 c0000001fa957288 c0000001fb588000 c0000001fdb2bd10 [ 568.877993] NIP [c0000000002f42a4] .ext4_mb_release_group_pa+0xec/0x1c0 [ 568.877999] LR [c0000000002f4274] .ext4_mb_release_group_pa+0xbc/0x1c0 [ 568.878004] Call Trace: [ 568.878008] [c0000001fa957150] [c0000000002f4274] .ext4_mb_release_group_pa+0xbc/0x1c0 (unreliable) [ 568.878017] [c0000001fa957200] [c0000000002fb070] .ext4_mb_discard_lg_preallocations+0x394/0x444 [ 568.878025] [c0000001fa957340] [c0000000002fb45c] .ext4_mb_release_context+0x33c/0x734 [ 568.878032] [c0000001fa957440] [c0000000002fbcf8] .ext4_mb_new_blocks+0x4a4/0x5f4 [ 568.878039] [c0000001fa957510] [c0000000002ef56c] .ext4_ext_map_blocks+0xc28/0x1178 [ 568.878047] [c0000001fa957640] [c0000000002c1a94] .ext4_map_blocks+0x2c8/0x490 [ 568.878054] [c0000001fa957730] [c0000000002c536c] .ext4_writepages+0x738/0xc60 [ 568.878062] [c0000001fa957950] [c000000000168a78] .do_writepages+0x5c/0x80 [ 568.878069] [c0000001fa9579d0] [c00000000015d1c4] .__filemap_fdatawrite_range+0x88/0xb0 [ 568.878078] [c0000001fa957aa0] [c00000000015d23c] .filemap_write_and_wait_range+0x50/0xfc [ 568.878085] [c0000001fa957b30] [c0000000002b8edc] .ext4_sync_file+0x220/0x3c4 [ 568.878092] [c0000001fa957be0] [c0000000001f849c] .vfs_fsync_range+0x64/0x80 [ 568.878098] [c0000001fa957c70] [c0000000001f84f0] .vfs_fsync+0x38/0x4c [ 568.878105] [c0000001fa957d00] [c0000000001f87f4] .do_fsync+0x54/0x90 [ 568.878111] [c0000001fa957db0] [c0000000001f8894] .SyS_fsync+0x28/0x3c [ 568.878120] [c0000001fa957e30] [c000000000009c88] syscall_exit+0x0/0x7c [ 568.878125] Instruction dump: [ 568.878130] 60000000 813d0034 81610070 38000000 7f8b4800 419e001c 813f007c 7d2bfe70 [ 568.878144] 7d604a78 7c005850 54000ffe 7c0007b4 <0b000000> e8a10076 e87f0090 7fa4eb78 [ 568.878160] ---[ end trace 594d911d9654770b ]--- In addition fix the STD_GROUP optimization so that it works for bigalloc file systems as well. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Li Zhong <lizhongfs@gmail.com> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org # 3.10
2013-06-06ext4: optimize test_root()Theodore Ts'o1-5/+9
The test_root() function could potentially loop forever due to overflow issues. So rewrite test_root() to avoid this issue; as a bonus, it is 38% faster when benchmarked via a test loop: int main(int argc, char **argv) { int i; for (i = 0; i < 1 << 24; i++) { if (test_root(i, 7)) printf("%d\n", i); } } Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-20ext4: mark all metadata I/O with REQ_METATheodore Ts'o1-1/+1
As Dave Chinner pointed out at the 2013 LSF/MM workshop, it's important that metadata I/O requests are marked as such to avoid priority inversions caused by I/O bandwidth throttling. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-10ext4: introduce reserved spaceLukas Czerner1-5/+13
Currently in ENOSPC condition when writing into unwritten space, or punching a hole, we might need to split the extent and grow extent tree. However since we can not allocate any new metadata blocks we'll have to zero out unwritten part of extent or punched out part of extent, or in the worst case return ENOSPC even though use actually does not allocate any space. Also in delalloc path we do reserve metadata and data blocks for the time we're going to write out, however metadata block reservation is very tricky especially since we expect that logical connectivity implies physical connectivity, however that might not be the case and hence we might end up allocating more metadata blocks than previously reserved. So in future, metadata reservation checks should be removed since we can not assure that we do not under reserve. And this is where reserved space comes into the picture. When mounting the file system we slice off a little bit of the file system space (2% or 4096 clusters, whichever is smaller) which can be then used for the cases mentioned above to prevent costly zeroout, or unexpected ENOSPC. The number of reserved clusters can be set via sysfs, however it can never be bigger than number of free clusters in the file system. Note that this patch fixes the failure of xfstest 274 as expected. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-04-04ext4: introduce ext4_get_group_number()Lukas Czerner1-7/+18
Currently on many places in ext4 we're using ext4_get_group_no_and_offset() even though we're only interested in knowing the block group of the particular block, not the offset within the block group so we can use more efficient way to compute block group. This patch introduces ext4_get_group_number() which computes block group for a given block much more efficiently. Use this function instead of ext4_get_group_no_and_offset() everywhere where we're only interested in knowing the block group. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-04ext4: make ext4_block_in_group() much more efficientLukas Czerner1-6/+16
Currently in when getting the block group number for a particular block in ext4_block_in_group() we're using ext4_get_group_no_and_offset() which uses do_div() to get the block group and the remainer which is offset within the group. We don't need all of that in ext4_block_in_group() as we only need to figure out the group number. This commit changes ext4_block_in_group() to calculate group number directly. This shows as a big improvement with regards to cpu utilization. Measuring fallocate -l 15T on fresh file system with perf showed that 23% of cpu time was spend in the ext4_get_group_no_and_offset(). With this change it completely disappears from the list only bumping the occurrence of ext4_init_block_bitmap() which is the biggest user of ext4_block_in_group() by 4%. As the result of this change on my system the fallocate call was approx. 10% faster. However since there is '-g' option in mkfs which allow us setting different groups size (mostly for developers) I've introduced new per file system flag whether we have a standard block group size or not. The flag is used to determine whether we can use the bit shift optimization or not. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-03-03ext4: convert number of blocks to clusters properlyLukas Czerner1-1/+1
We're using macro EXT4_B2C() to convert number of blocks to number of clusters for bigalloc file systems. However, we should be using EXT4_NUM_B2C(). Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2013-02-23ext4: fix free clusters calculation in bigalloc filesystemLukas Czerner1-2/+7
ext4_has_free_clusters() should tell us whether there is enough free clusters to allocate, however number of free clusters in the file system is converted to blocks using EXT4_C2B() which is not only wrong use of the macro (we should have used EXT4_NUM_B2C) but it's also completely wrong concept since everything else is in cluster units. Moreover when calculating number of root clusters we should be using macro EXT4_NUM_B2C() instead of EXT4_B2C() otherwise the result might be off by one. However r_blocks_count should always be a multiple of the cluster ratio so doing a plain bit shift should be enough here. We avoid using EXT4_B2C() because it's confusing. As a result of the first problem number of free clusters is much bigger than it should have been and ext4_has_free_clusters() would return 1 even if there is really not enough free clusters available. Fix this by removing the EXT4_C2B() conversion of free clusters and using bit shift when calculating number of root clusters. This bug affects number of xfstests tests covering file system ENOSPC situation handling. With this patch most of the ENOSPC problems with bigalloc file system disappear, especially the errors caused by delayed allocation not having enough space when the actual allocation is finally requested. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2013-01-13ext4: check bh in ext4_read_block_bitmap()Eryu Guan1-1/+3
Validate the bh pointer before using it, since ext4_read_block_bitmap_nowait() might return NULL. I've seen this in fsfuzz testing. EXT4-fs error (device loop0): ext4_read_block_bitmap_nowait:385: comm touch: Cannot get buffer for block bitmap - block_group = 0, block_bitmap = 3925999616 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8121de25>] ext4_wait_block_bitmap+0x25/0xe0 ... Call Trace: [<ffffffff8121e1e5>] ext4_read_block_bitmap+0x35/0x60 [<ffffffff8125e9c6>] ext4_free_blocks+0x236/0xb80 [<ffffffff811d0d36>] ? __getblk+0x36/0x70 [<ffffffff811d0a5f>] ? __find_get_block+0x8f/0x210 [<ffffffff81191ef3>] ? kmem_cache_free+0x33/0x140 [<ffffffff812678e5>] ext4_xattr_release_block+0x1b5/0x1d0 [<ffffffff812679be>] ext4_xattr_delete_inode+0xbe/0x100 [<ffffffff81222a7c>] ext4_free_inode+0x7c/0x4d0 [<ffffffff812277b8>] ? ext4_mark_inode_dirty+0x88/0x230 [<ffffffff8122993c>] ext4_evict_inode+0x32c/0x490 [<ffffffff811b8cd7>] evict+0xa7/0x1c0 [<ffffffff811b8ed3>] iput_final+0xe3/0x170 [<ffffffff811b8f9e>] iput+0x3e/0x50 [<ffffffff812316fd>] ext4_add_nondir+0x4d/0x90 [<ffffffff81231d0b>] ext4_create+0xeb/0x170 [<ffffffff811aae9c>] vfs_create+0xac/0xd0 [<ffffffff811ac845>] lookup_open+0x185/0x1c0 [<ffffffff8129e3b9>] ? selinux_inode_permission+0xa9/0x170 [<ffffffff811acb54>] do_last+0x2d4/0x7a0 [<ffffffff811af743>] path_openat+0xb3/0x480 [<ffffffff8116a8a1>] ? handle_mm_fault+0x251/0x3b0 [<ffffffff811afc49>] do_filp_open+0x49/0xa0 [<ffffffff811bbaad>] ? __alloc_fd+0xdd/0x150 [<ffffffff8119da28>] do_sys_open+0x108/0x1f0 [<ffffffff8119db51>] sys_open+0x21/0x30 [<ffffffff81618959>] system_call_fastpath+0x16/0x1b Also fix comment for ext4_read_block_bitmap_nowait() Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-10-22ext4: Checksum the block bitmap properly with bigalloc enabledTao Ma1-5/+3
In mke2fs, we only checksum the whole bitmap block and it is right. While in the kernel, we use EXT4_BLOCKS_PER_GROUP to indicate the size of the checksumed bitmap which is wrong when we enable bigalloc. The right size should be EXT4_CLUSTERS_PER_GROUP and this patch fixes it. Also as every caller of ext4_block_bitmap_csum_set and ext4_block_bitmap_csum_verify pass in EXT4_BLOCKS_PER_GROUP(sb)/8, we'd better removes this parameter and sets it in the function itself. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org
2012-08-17ext4: don't call ext4_error while block group is lockedTheodore Ts'o1-25/+37
While in ext4_validate_block_bitmap(), if an block allocation bitmap is found to be invalid, we call ext4_error() while the block group is still locked. This causes ext4_commit_super() to call a function which might sleep while in an atomic context. There's no need to keep the block group locked at this point, so hoist the ext4_error() call up to ext4_validate_block_bitmap() and release the block group spinlock before calling ext4_error(). The reported stack trace can be found at: http://article.gmane.org/gmane.comp.file-systems.ext4/33731 Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
2012-07-01ext4: pass a char * to ext4_count_free() instead of a buffer_head ptrTheodore Ts'o1-1/+2
Make it possible for ext4_count_free to operate on buffers and not just data in buffer_heads. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@kernel.org
2012-06-08ext4: fix the free blocks calculation for ext3 file systems w/ uninit_bgTheodore Ts'o1-4/+4
Ext3 filesystems that are converted to use as many ext4 file system features as possible will enable uninit_bg to speed up e2fsck times. These file systems will have a native ext3 layout of inode tables and block allocation bitmaps (as opposed to ext4's flex_bg layout). Unfortunately, in these cases, when first allocating a block in an uninitialized block group, ext4 would incorrectly calculate the number of free blocks in that block group, and then errorneously report that the file system was corrupt: EXT4-fs error (device vdd): ext4_mb_generate_buddy:741: group 30, 32254 clusters in bitmap, 32258 in gd This problem can be reproduced via: mke2fs -q -t ext4 -O ^flex_bg /dev/vdd 5g mount -t ext4 /dev/vdd /mnt fallocate -l 4600m /mnt/test The problem was caused by a bone headed mistake in the check to see if a particular metadata block was part of the block group. Many thanks to Kees Cook for finding and bisecting the buggy commit which introduced this bug (commit fd034a84e1, present since v3.2). Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Reported-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Tested-by: Kees Cook <keescook@chromium.org> Cc: stable@kernel.org
2012-06-01Merge tag 'ext4_for_linus' of ↵Linus Torvalds1-8/+33
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull Ext4 updates from Theodore Ts'o: "The major new feature added in this update is Darrick J Wong's metadata checksum feature, which adds crc32 checksums to ext4's metadata fields. There is also the usual set of cleanups and bug fixes." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (44 commits) ext4: hole-punch use truncate_pagecache_range jbd2: use kmem_cache_zalloc wrapper instead of flag ext4: remove mb_groups before tearing down the buddy_cache ext4: add ext4_mb_unload_buddy in the error path ext4: don't trash state flags in EXT4_IOC_SETFLAGS ext4: let getattr report the right blocks in delalloc+bigalloc ext4: add missing save_error_info() to ext4_error() ext4: add debugging trigger for ext4_error() ext4: protect group inode free counting with group lock ext4: use consistent ssize_t type in ext4_file_write() ext4: fix format flag in ext4_ext_binsearch_idx() ext4: cleanup in ext4_discard_allocated_blocks() ext4: return ENOMEM when mounts fail due to lack of memory ext4: remove redundundant "(char *) bh->b_data" casts ext4: disallow hard-linked directory in ext4_lookup ext4: fix potential integer overflow in alloc_flex_gd() ext4: remove needs_recovery in ext4_mb_init() ext4: force ro mount if ext4_setup_super() fails ext4: fix potential NULL dereference in ext4_free_inodes_counts() ext4/jbd2: add metadata checksumming to the list of supported features ...
2012-05-16userns: Convert ext4 to user kuid/kgid where appropriateEric W. Biederman1-2/+2
Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-30ext4: make block group checksums use metadata_csum algorithmDarrick J. Wong1-2/+2
metadata_csum supersedes uninit_bg. Convert the ROCOMPAT uninit_bg flag check to a helper function that covers both, and make the checksum calculation algorithm use either crc16 or the metadata_csum chosen algorithm depending on which flag is set. Print a warning if we try to mount a filesystem with both feature flags set. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-04-30ext4: calculate and verify block bitmap checksumDarrick J. Wong1-7/+32
Compute and verify the checksum of the block bitmap; this checksum is stored in the block group descriptor. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-02-21ext4: fix balloc.c printk-format-warningHeiko Carstens1-1/+1
Get rid of this one: fs/ext4/balloc.c: In function 'ext4_wait_block_bitmap': fs/ext4/balloc.c:405:3: warning: format '%llu' expects argument of type 'long long unsigned int', but argument 6 has type 'sector_t' [-Wformat] Happens because sector_t is u64 (unsigned long long) or unsigned long dependent on CONFIG_64BIT. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-02-21ext4: fix race when setting bitmap_uptodate flagTheodore Ts'o1-19/+44
In ext4_read_{inode,block}_bitmap() we were setting bitmap_uptodate() before submitting the buffer for read. The is bad, since we check bitmap_uptodate() without locking the buffer, and so if another process is racing with us, it's possible that they will think the bitmap is uptodate even though the read has not completed yet, resulting in inodes and blocks potentially getting allocated more than once if we get really unlucky. Addresses-Google-Bug: 2828254 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-01-05ext4: make more symbols staticEric Sandeen1-1/+3
A couple more functions can reasonably be made static if desired. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-11-21ext4: fix up a undefined error in ext4_free_blocks in debugging codeYongqiang Yang1-1/+1
sbi is not defined, so let ext4_free_blocks use EXT4_SB(sb) instead when EXT4FS_DEBUG is defined. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
2011-09-10ext4: rename ext4_has_free_blocks() to ext4_has_free_clusters()Theodore Ts'o1-21/+22
Rename the function so it is more clear what is going on. Also rename the various variables so it's clearer what's happening. Also fix a missing blocks to cluster conversion when reading the number of reserved blocks for root. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>