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* ext4: fix fdatasync() for files with only i_size changesJan Kara2012-10-131-2/+6
| | | | | | | | | | | | | | | | | commit b71fc079b5d8f42b2a52743c8d2f1d35d655b1c5 upstream. Code tracking when transaction needs to be committed on fdatasync(2) forgets to handle a situation when only inode's i_size is changed. Thus in such situations fdatasync(2) doesn't force transaction with new i_size to disk and that can result in wrong i_size after a crash. Fix the issue by updating inode's i_datasync_tid whenever its size is updated. Reported-by: Kristian Nielsen <knielsen@knielsen-hq.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: always set i_op in ext4_mknod()Bernd Schubert2012-10-131-2/+0
| | | | | | | | | | | | | commit 6a08f447facb4f9e29fcc30fb68060bb5a0d21c2 upstream. ext4_special_inode_operations have their own ifdef CONFIG_EXT4_FS_XATTR to mask those methods. And ext4_iget also always sets it, so there is an inconsistency. Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: online defrag is not supported for journaled filesDmitry Monakhov2012-10-131-1/+6
| | | | | | | | | | | | | commit f066055a3449f0e5b0ae4f3ceab4445bead47638 upstream. Proper block swap for inodes with full journaling enabled is truly non obvious task. In order to be on a safe side let's explicitly disable it for now. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: avoid kmemcheck complaint from reading uninitialized memoryTheodore Ts'o2012-08-261-0/+1
| | | | | | | | | | | | | | | | | | | commit 7e731bc9a12339f344cddf82166b82633d99dd86 upstream. Commit 03179fe923 introduced a kmemcheck complaint in ext4_da_get_block_prep() because we save and restore ei->i_da_metadata_calc_last_lblock even though it is left uninitialized in the case where i_da_metadata_calc_len is zero. This doesn't hurt anything, but silencing the kmemcheck complaint makes it easier for people to find real bugs. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=45631 (which is marked as a regression). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: don't let i_reserved_meta_blocks go negativeBrian Foster2012-08-091-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 97795d2a5b8d3c8dc4365d4bd3404191840453ba upstream. If we hit a condition where we have allocated metadata blocks that were not appropriately reserved, we risk underflow of ei->i_reserved_meta_blocks. In turn, this can throw sbi->s_dirtyclusters_counter significantly out of whack and undermine the nondelalloc fallback logic in ext4_nonda_switch(). Warn if this occurs and set i_allocated_meta_blocks to avoid this problem. This condition is reproduced by xfstests 270 against ext2 with delalloc enabled: Mar 28 08:58:02 localhost kernel: [ 171.526344] EXT4-fs (loop1): delayed block allocation failed for inode 14 at logical offset 64486 with max blocks 64 with error -28 Mar 28 08:58:02 localhost kernel: [ 171.526346] EXT4-fs (loop1): This should not happen!! Data will be lost 270 ultimately fails with an inconsistent filesystem and requires an fsck to repair. The cause of the error is an underflow in ext4_da_update_reserve_space() due to an unreserved meta block allocation. Signed-off-by: Brian Foster <bfoster@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: pass a char * to ext4_count_free() instead of a buffer_head ptrTheodore Ts'o2012-08-094-8/+8
| | | | | | | | | | | commit f6fb99cadcd44660c68e13f6eab28333653621e6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: don't set i_flags in EXT4_IOC_SETFLAGSTao Ma2012-06-101-1/+0
| | | | | | | | | | | | | | commit b22b1f178f6799278d3178d894f37facb2085765 upstream. Commit 7990696 uses the ext4_{set,clear}_inode_flags() functions to change the i_flags automatically but fails to remove the error setting of i_flags. So we still have the problem of trashing state flags. Fix this by removing the assignment. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: remove mb_groups before tearing down the buddy_cacheSalman Qazi2012-06-101-2/+3
| | | | | | | | | | | | | | | | | | | | | commit 95599968d19db175829fb580baa6b68939b320fb upstream. We can't have references held on pages in the s_buddy_cache while we are trying to truncate its pages and put the inode. All the pages must be gone before we reach clear_inode. This can only be gauranteed if we can prevent new users from grabbing references to s_buddy_cache's pages. The original bug can be reproduced and the bug fix can be verified by: while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \ umount /export/hda3/ram0; done & while true; do cat /proc/fs/ext4/ram0/mb_groups; done Signed-off-by: Salman Qazi <sqazi@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: add ext4_mb_unload_buddy in the error pathSalman Qazi2012-06-101-0/+1
| | | | | | | | | | | | commit 02b7831019ea4e7994968c84b5826fa8b248ffc8 upstream. ext4_free_blocks fails to pair an ext4_mb_load_buddy with a matching ext4_mb_unload_buddy when it fails a memory allocation. Signed-off-by: Salman Qazi <sqazi@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: don't trash state flags in EXT4_IOC_SETFLAGSTheodore Ts'o2012-06-101-3/+9
| | | | | | | | | | | | | | | | commit 79906964a187c405db72a3abc60eb9b50d804fbc upstream. In commit 353eb83c we removed i_state_flags with 64-bit longs, But when handling the EXT4_IOC_SETFLAGS ioctl, we replace i_flags directly, which trashes the state flags which are stored in the high 32-bits of i_flags on 64-bit platforms. So use the the ext4_{set,clear}_inode_flags() functions which use atomic bit manipulation functions instead. Reported-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: add missing save_error_info() to ext4_error()Theodore Ts'o2012-06-101-0/+1
| | | | | | | | | | | | | | | | commit f3fc0210c0fc91900766c995f089c39170e68305 upstream. The ext4_error() function is missing a call to save_error_info(). Since this is the function which marks the file system as containing an error, this oversight (which was introduced in 2.6.36) is quite significant, and should be backported to older stable kernels with high urgency. Reported-by: Ken Sumrall <ksumrall@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: ksumrall@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: force ro mount if ext4_setup_super() failsEric Sandeen2012-06-101-1/+2
| | | | | | | | | | | | | | | | | | | | | | | commit 7e84b6216467b84cd332c8e567bf5aa113fd2f38 upstream. If ext4_setup_super() fails i.e. due to a too-high revision, the error is logged in dmesg but the fs is not mounted RO as indicated. Tested by: # mkfs.ext4 -r 4 /dev/sdb6 # mount /dev/sdb6 /mnt/test # dmesg | grep "too high" [164919.759248] EXT4-fs (sdb6): revision level too high, forcing read-only mode # grep sdb6 /proc/mounts /dev/sdb6 /mnt/test2 ext4 rw,seclabel,relatime,data=ordered 0 0 Reviewed-by: Andreas Dilger <adilger@whamcloud.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: fix error handling on inode bitmap corruptionJan Kara2012-05-211-2/+6
| | | | | | | | | | | | | | | commit acd6ad83517639e8f09a8c5525b1dccd81cd2a10 upstream. When insert_inode_locked() fails in ext4_new_inode() it most likely means inode bitmap got corrupted and we allocated again inode which is already in use. Also doing unlock_new_inode() during error recovery is wrong since the inode does not have I_NEW set. Fix the problem by jumping to fail: (instead of fail_drop:) which declares filesystem error and does not call unlock_new_inode(). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: avoid deadlock on sync-mounted FS w/o journalEric Sandeen2012-05-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c1bb05a657fb3d8c6179a4ef7980261fae4521d7 upstream. Processes hang forever on a sync-mounted ext2 file system that is mounted with the ext4 module (default in Fedora 16). I can reproduce this reliably by mounting an ext2 partition with "-o sync" and opening a new file an that partition with vim. vim will hang in "D" state forever. The same happens on ext4 without a journal. I am attaching a small patch here that solves this issue for me. In the sync mounted case without a journal, ext4_handle_dirty_metadata() may call sync_dirty_buffer(), which can't be called with buffer lock held. Also move mb_cache_entry_release inside lock to avoid race fixed previously by 8a2bfdcb ext[34]: EA block reference count racing fix Note too that ext2 fixed this same problem in 2006 with b2f49033 [PATCH] fix deadlock in ext2 Signed-off-by: Martin.Wilck@ts.fujitsu.com [sandeen@redhat.com: move mb_cache_entry_release before unlock, edit commit msg] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: fix endianness breakage in ext4_split_extent_at()Al Viro2012-04-271-1/+1
| | | | | | | | | | | | commit af1584f570b19b0285e4402a0b54731495d31784 upstream. ->ee_len is __le16, so assigning cpu_to_le32() to it is going to do Bad Things(tm) on big-endian hosts... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Ted Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: check for zero length extentTheodore Ts'o2012-04-021-0/+2
| | | | | | | | | | | | | | | | | | | | commit 31d4f3a2f3c73f279ff96a7135d7202ef6833f12 upstream. Explicitly test for an extent whose length is zero, and flag that as a corrupted extent. This avoids a kernel BUG_ON assertion failure. Tested: Without this patch, the file system image found in tests/f_ext_zero_len/image.gz in the latest e2fsprogs sources causes a kernel panic. With this patch, an ext4 file system error is noted instead, and the file system is marked as being corrupted. https://bugzilla.kernel.org/show_bug.cgi?id=42859 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: ignore EXT4_INODE_JOURNAL_DATA flag with delallocLukas Czerner2012-04-022-41/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3d2b158262826e8b75bbbfb7b97010838dd92ac7 upstream. Ext4 does not support data journalling with delayed allocation enabled. We even do not allow to mount the file system with delayed allocation and data journalling enabled, however it can be set via FS_IOC_SETFLAGS so we can hit the inode with EXT4_INODE_JOURNAL_DATA set even on file system mounted with delayed allocation (default) and that's where problem arises. The easies way to reproduce this problem is with the following set of commands: mkfs.ext4 /dev/sdd mount /dev/sdd /mnt/test1 dd if=/dev/zero of=/mnt/test1/file bs=1M count=4 chattr +j /mnt/test1/file dd if=/dev/zero of=/mnt/test1/file bs=1M count=4 conv=notrunc chattr -j /mnt/test1/file Additionally it can be reproduced quite reliably with xfstests 272 and 269. In fact the above reproducer is a part of test 272. To fix this we should ignore the EXT4_INODE_JOURNAL_DATA inode flag if the file system is mounted with delayed allocation. This can be easily done by fixing ext4_should_*_data() functions do ignore data journal flag when delalloc is set (suggested by Ted). We also have to set the appropriate address space operations for the inode (again, ignoring data journal flag if delalloc enabled). Additionally this commit introduces ext4_inode_journal_mode() function because ext4_should_*_data() has already had a lot of common code and this change is putting it all into one function so it is easier to read. Successfully tested with xfstests in following configurations: delalloc + data=ordered delalloc + data=writeback data=journal nodelalloc + data=ordered nodelalloc + data=writeback nodelalloc + data=journal Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: flush any pending end_io requests before DIO reads w/dioread_nolockJiaying Zhang2012-04-021-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit dccaf33fa37a1bc5d651baeb3bfeb6becb86597b upstream. (backported to 3.0 by mjt) There is a race between ext4 buffer write and direct_IO read with dioread_nolock mount option enabled. The problem is that we clear PageWriteback flag during end_io time but will do uninitialized-to-initialized extent conversion later with dioread_nolock. If an O_direct read request comes in during this period, ext4 will return zero instead of the recently written data. This patch checks whether there are any pending uninitialized-to-initialized extent conversion requests before doing O_direct read to close the race. Note that this is just a bandaid fix. The fundamental issue is that we clear PageWriteback flag before we really complete an IO, which is problem-prone. To fix the fundamental issue, we may need to implement an extent tree cache that we can use to look up pending to-be-converted extents. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ext4: fix undefined behavior in ext4_fill_flex_info()Xi Wang2012-01-251-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d50f2ab6f050311dbf7b8f5501b25f0bf64a439b upstream. Commit 503358ae01b70ce6909d19dd01287093f6b6271c ("ext4: avoid divide by zero when trying to mount a corrupted file system") fixes CVE-2009-4307 by performing a sanity check on s_log_groups_per_flex, since it can be set to a bogus value by an attacker. sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex; groups_per_flex = 1 << sbi->s_log_groups_per_flex; if (groups_per_flex < 2) { ... } This patch fixes two potential issues in the previous commit. 1) The sanity check might only work on architectures like PowerPC. On x86, 5 bits are used for the shifting amount. That means, given a large s_log_groups_per_flex value like 36, groups_per_flex = 1 << 36 is essentially 1 << 4 = 16, rather than 0. This will bypass the check, leaving s_log_groups_per_flex and groups_per_flex inconsistent. 2) The sanity check relies on undefined behavior, i.e., oversized shift. A standard-confirming C compiler could rewrite the check in unexpected ways. Consider the following equivalent form, assuming groups_per_flex is unsigned for simplicity. groups_per_flex = 1 << sbi->s_log_groups_per_flex; if (groups_per_flex == 0 || groups_per_flex == 1) { We compile the code snippet using Clang 3.0 and GCC 4.6. Clang will completely optimize away the check groups_per_flex == 0, leaving the patched code as vulnerable as the original. GCC keeps the check, but there is no guarantee that future versions will do the same. Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: handle EOF correctly in ext4_bio_write_page()Yongqiang Yang2011-12-211-0/+12
| | | | | | | | | | | | commit 5a0dc7365c240795bf190766eba7a27600be3b3e upstream. We need to zero out part of a page which beyond EOF before setting uptodate, otherwise, mapread or write will see non-zero data beyond EOF. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: avoid potential hang in mpage_submit_io() when blocksize < pagesizeYongqiang Yang2011-12-211-2/+5
| | | | | | | | | | | | | | | commit 13a79a4741d37fda2fbafb953f0f301dc007928f upstream. If there is an unwritten but clean buffer in a page and there is a dirty buffer after the buffer, then mpage_submit_io does not write the dirty buffer out. As a result, da_writepages loops forever. This patch fixes the problem by checking dirty flag. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: avoid hangs in ext4_da_should_update_i_disksize()Andrea Arcangeli2011-12-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ea51d132dbf9b00063169c1159bee253d9649224 upstream. If the pte mapping in generic_perform_write() is unmapped between iov_iter_fault_in_readable() and iov_iter_copy_from_user_atomic(), the "copied" parameter to ->end_write can be zero. ext4 couldn't cope with it with delayed allocations enabled. This skips the i_disksize enlargement logic if copied is zero and no new data was appeneded to the inode. gdb> bt #0 0xffffffff811afe80 in ext4_da_should_update_i_disksize (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x1\ 08000, len=0x1000, copied=0x0, page=0xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2467 #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 #2 0xffffffff810d97f1 in generic_perform_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value o\ ptimized out>, pos=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2440 #3 generic_file_buffered_write (iocb=<value optimized out>, iov=<value optimized out>, nr_segs=<value optimized out>, p\ os=0x108000, ppos=0xffff88001e26be40, count=<value optimized out>, written=0x0) at mm/filemap.c:2482 #4 0xffffffff810db5d1 in __generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, ppos=0\ xffff88001e26be40) at mm/filemap.c:2600 #5 0xffffffff810db853 in generic_file_aio_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=<value optimi\ zed out>, pos=<value optimized out>) at mm/filemap.c:2632 #6 0xffffffff811a71aa in ext4_file_write (iocb=0xffff88001e26bde8, iov=0xffff88001e26bec8, nr_segs=0x1, pos=0x108000) a\ t fs/ext4/file.c:136 #7 0xffffffff811375aa in do_sync_write (filp=0xffff88003f606a80, buf=<value optimized out>, len=<value optimized out>, \ ppos=0xffff88001e26bf48) at fs/read_write.c:406 #8 0xffffffff81137e56 in vfs_write (file=0xffff88003f606a80, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x4\ 000, pos=0xffff88001e26bf48) at fs/read_write.c:435 #9 0xffffffff8113816c in sys_write (fd=<value optimized out>, buf=0x1ec2960 <Address 0x1ec2960 out of bounds>, count=0x\ 4000) at fs/read_write.c:487 #10 <signal handler called> #11 0x00007f120077a390 in __brk_reservation_fn_dmi_alloc__ () #12 0x0000000000000000 in ?? () gdb> print offset $22 = 0xffffffffffffffff gdb> print idx $23 = 0xffffffff gdb> print inode->i_blkbits $24 = 0xc gdb> up #1 ext4_da_write_end (file=0xffff88003f606a80, mapping=0xffff88001d3824e0, pos=0x108000, len=0x1000, copied=0x0, page=0\ xffffea0000d792e8, fsdata=0x0) at fs/ext4/inode.c:2512 2512 if (ext4_da_should_update_i_disksize(page, end)) { gdb> print start $25 = 0x0 gdb> print end $26 = 0xffffffffffffffff gdb> print pos $27 = 0x108000 gdb> print new_i_size $28 = 0x108000 gdb> print ((struct ext4_inode_info *)((char *)inode-((int)(&((struct ext4_inode_info *)0)->vfs_inode))))->i_disksize $29 = 0xd9000 gdb> down 2467 for (i = 0; i < idx; i++) gdb> print i $30 = 0xd44acbee This is 100% reproducible with some autonuma development code tuned in a very aggressive manner (not normal way even for knumad) which does "exotic" changes to the ptes. It wouldn't normally trigger but I don't see why it can't happen normally if the page is added to swap cache in between the two faults leading to "copied" being zero (which then hangs in ext4). So it should be fixed. Especially possible with lumpy reclaim (albeit disabled if compaction is enabled) as that would ignore the young bits in the ptes. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: display the correct mount option in /proc/mounts for [no]init_itableTheodore Ts'o2011-12-211-9/+8
| | | | | | | | | | | | commit fc6cb1cda5db7b2d24bf32890826214b857c728e upstream. /proc/mounts was showing the mount option [no]init_inode_table when the correct mount option that will be accepted by parse_options() is [no]init_itable. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: remove i_mutex lock in ext4_evict_inode to fix lockdep complainingJiaying Zhang2011-11-113-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 8c0bec2151a47906bf779c6715a10ce04453ab77 upstream. The i_mutex lock and flush_completed_IO() added by commit 2581fdc810 in ext4_evict_inode() causes lockdep complaining about potential deadlock in several places. In most/all of these LOCKDEP complaints it looks like it's a false positive, since many of the potential circular locking cases can't take place by the time the ext4_evict_inode() is called; but since at the very least it may mask real problems, we need to address this. This change removes the flush_completed_IO() and i_mutex lock in ext4_evict_inode(). Instead, we take a different approach to resolve the software lockup that commit 2581fdc810 intends to fix. Rather than having ext4-dio-unwritten thread wait for grabing the i_mutex lock of an inode, we use mutex_trylock() instead, and simply requeue the work item if we fail to grab the inode's i_mutex lock. This should speed up work queue processing in general and also prevents the following deadlock scenario: During page fault, shrink_icache_memory is called that in turn evicts another inode B. Inode B has some pending io_end work so it calls ext4_ioend_wait() that waits for inode B's i_ioend_count to become zero. However, inode B's ioend work was queued behind some of inode A's ioend work on the same cpu's ext4-dio-unwritten workqueue. As the ext4-dio-unwritten thread on that cpu is processing inode A's ioend work, it tries to grab inode A's i_mutex lock. Since the i_mutex lock of inode A is still hold before the page fault happened, we enter a deadlock. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: fix race in xattr block allocation pathEric Sandeen2011-11-111-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6d6a435190bdf2e04c9465cde5bdc3ac68cf11a4 upstream. Ceph users reported that when using Ceph on ext4, the filesystem would often become corrupted, containing inodes with incorrect i_blocks counters. I managed to reproduce this with a very hacked-up "streamtest" binary from the Ceph tree. Ceph is doing a lot of xattr writes, to out-of-inode blocks. There is also another thread which does sync_file_range and close, of the same files. The problem appears to happen due to this race: sync/flush thread xattr-set thread ----------------- ---------------- do_writepages ext4_xattr_set ext4_da_writepages ext4_xattr_set_handle mpage_da_map_blocks ext4_xattr_block_set set DELALLOC_RESERVE ext4_new_meta_blocks ext4_mb_new_blocks if (!i_delalloc_reserved_flag) vfs_dq_alloc_block ext4_get_blocks down_write(i_data_sem) set i_delalloc_reserved_flag ... up_write(i_data_sem) if (i_delalloc_reserved_flag) vfs_dq_alloc_block_nofail In other words, the sync/flush thread pops in and sets i_delalloc_reserved_flag on the inode, which makes the xattr thread think that it's in a delalloc path in ext4_new_meta_blocks(), and add the block for a second time, after already having added it once in the !i_delalloc_reserved_flag case in ext4_mb_new_blocks The real problem is that we shouldn't be using the DELALLOC_RESERVED state flag, and instead we should be passing EXT4_GET_BLOCKS_DELALLOC_RESERVE down to ext4_map_blocks() instead of using an inode state flag. We'll fix this for now with using i_data_sem to prevent this race, but this is really not the right way to fix things. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: call ext4_handle_dirty_metadata with correct inode in ext4_dx_add_entryTheodore Ts'o2011-11-111-2/+2
| | | | | | | | | | | | | | | | commit 5930ea643805feb50a2f8383ae12eb6f10935e49 upstream. ext4_dx_add_entry manipulates bh2 and frames[0].bh, which are two buffer_heads that point to directory blocks assigned to the directory inode. However, the function calls ext4_handle_dirty_metadata with the inode of the file that's being added to the directory, not the directory inode itself. Therefore, correct the code to dirty the directory buffers with the directory inode, not the file inode. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: ext4_mkdir should dirty dir_block with newly created directory inodeDarrick J. Wong2011-11-111-1/+1
| | | | | | | | | | | | | | commit f9287c1f2d329f4d78a3bbc9cf0db0ebae6f146a upstream. ext4_mkdir calls ext4_handle_dirty_metadata with dir_block and the inode "dir". Unfortunately, dir_block belongs to the newly created directory (which is "inode"), not the parent directory (which is "dir"). Fix the incorrect association. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: ext4_rename should dirty dir_bh with the correct directoryDarrick J. Wong2011-11-111-1/+1
| | | | | | | | | | | | | | | | commit bcaa992975041e40449be8c010c26192b8c8b409 upstream. When ext4_rename performs a directory rename (move), dir_bh is a buffer that is modified to update the '..' link in the directory being moved (old_inode). However, ext4_handle_dirty_metadata is called with the old parent directory inode (old_dir) and dir_bh, which is incorrect because dir_bh does not belong to the parent inode. Fix this error. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext2,ext3,ext4: don't inherit APPEND_FL or IMMUTABLE_FL for new inodesTheodore Ts'o2011-11-111-2/+1
| | | | | | | | | | | | | | commit 1cd9f0976aa4606db8d6e3dc3edd0aca8019372a upstream. This doesn't make much sense, and it exposes a bug in the kernel where attempts to create a new file in an append-only directory using O_CREAT will fail (but still leave a zero-length file). This was discovered when xfstests #79 was generalized so it could run on all file systems. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stageWu Fengguang2011-10-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 6e6938b6d3130305a5960c86b1a9b21e58cf6144 upstream. sync(2) is performed in two stages: the WB_SYNC_NONE sync and the WB_SYNC_ALL sync. Identify the first stage with .tagged_writepages and do livelock prevention for it, too. Jan's commit f446daaea9 ("mm: implement writeback livelock avoidance using page tagging") is a partial fix in that it only fixed the WB_SYNC_ALL phase livelock. Although ext4 is tested to no longer livelock with commit f446daaea9, it may due to some "redirty_tail() after pages_skipped" effect which is by no means a guarantee for _all_ the file systems. Note that writeback_inodes_sb() is called by not only sync(), they are treated the same because the other callers also need livelock prevention. Impact: It changes the order in which pages/inodes are synced to disk. Now in the WB_SYNC_NONE stage, it won't proceed to write the next inode until finished with the current inode. Acked-by: Jan Kara <jack@suse.cz> CC: Dave Chinner <david@fromorbit.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: fix nomblk_io_submit option so it correctly converts uninit blocksTheodore Ts'o2011-08-291-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 9dd75f1f1a02d656a11a7b9b9e6c2759b9c1e946 upstream. Bug discovered by Jan Kara: Finally, commit 1449032be17abb69116dbc393f67ceb8bd034f92 returned back the old IO submission code but apparently it forgot to return the old handling of uninitialized buffers so we unconditionnaly call block_write_full_page() without specifying end_io function. So AFAICS we never convert unwritten extents to written in some cases. For example when I mount the fs as: mount -t ext4 -o nomblk_io_submit,dioread_nolock /dev/ubdb /mnt and do int fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC, 0600); char buf[1024]; memset(buf, 'a', sizeof(buf)); fallocate(fd, 0, 0, 16384); write(fd, buf, sizeof(buf)); I get a file full of zeros (after remounting the filesystem so that pagecache is dropped) instead of seeing the first KB contain 'a's. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: Resolve the hang of direct i/o read in handling EXT4_IO_END_UNWRITTEN.Tao Ma2011-08-292-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | commit 32c80b32c053dc52712dedac5e4d0aa7c93fc353 upstream. EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten should be done simultaneously since ext4_end_io_nolock always clear the flag and decrease the counter in the same time. We don't increase i_aiodio_unwritten when setting EXT4_IO_END_UNWRITTEN so it will go nagative and causes some process to wait forever. Part of the patch came from Eric in his e-mail, but it doesn't fix the problem met by Michael actually. http://marc.info/?l=linux-ext4&m=131316851417460&w=2 Reported-and-Tested-by: Michael Tokarev<mjt@tls.msk.ru> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: call ext4_ioend_wait and ext4_flush_completed_IO in ext4_evict_inodeJiaying Zhang2011-08-292-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2581fdc810889fdea97689cb62481201d579c796 upstream. Flush inode's i_completed_io_list before calling ext4_io_wait to prevent the following deadlock scenario: A page fault happens while some process is writing inode A. During page fault, shrink_icache_memory is called that in turn evicts another inode B. Inode B has some pending io_end work so it calls ext4_ioend_wait() that waits for inode B's i_ioend_count to become zero. However, inode B's ioend work was queued behind some of inode A's ioend work on the same cpu's ext4-dio-unwritten workqueue. As the ext4-dio-unwritten thread on that cpu is processing inode A's ioend work, it tries to grab inode A's i_mutex lock. Since the i_mutex lock of inode A is still hold before the page fault happened, we enter a deadlock. Also moves ext4_flush_completed_IO and ext4_ioend_wait from ext4_destroy_inode() to ext4_evict_inode(). During inode deleteion, ext4_evict_inode() is called before ext4_destroy_inode() and in ext4_evict_inode(), we may call ext4_truncate() without holding i_mutex lock. As a result, there is a race between flush_completed_IO that is called from ext4_ext_truncate() and ext4_end_io_work, which may cause corruption on an io_end structure. This change moves ext4_flush_completed_IO and ext4_ioend_wait from ext4_destroy_inode() to ext4_evict_inode() to resolve the race between ext4_truncate() and ext4_end_io_work during inode deletion. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: Fix ext4_should_writeback_data() for no-journal modeCurt Wohlgemuth2011-08-292-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 441c850857148935babe000fc2ba1455fe54a6a9 upstream. ext4_should_writeback_data() had an incorrect sequence of tests to determine if it should return 0 or 1: in particular, even in no-journal mode, 0 was being returned for a non-regular-file inode. This meant that, in non-journal mode, we would use ext4_journalled_aops for directories, symlinks, and other non-regular files. However, calling journalled aop callbacks when there is no valid handle, can cause problems. This would cause a kernel crash with Jan Kara's commit 2d859db3e4 ("ext4: fix data corruption in inodes with journalled data"), because we now dereference 'handle' in ext4_journalled_write_end(). I also added BUG_ONs to check for a valid handle in the obviously journal-only aops callbacks. I tested this running xfstests with a scratch device in these modes: - no-journal - data=ordered - data=writeback - data=journal All work fine; the data=journal run has many failures and a crash in xfstests 074, but this is no different from a vanilla kernel. Signed-off-by: Curt Wohlgemuth <curtw@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: Properly count journal credits for long symlinksEric Sandeen2011-08-151-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | commit 8c20871998c082f6fbc963f1449a5ba5140ee39a upstream. Commit df5e6223407e ("ext4: fix deadlock in ext4_symlink() in ENOSPC conditions") recalculated the number of credits needed for a long symlink, in the process of splitting it into two transactions. However, the first credit calculation under-counted because if selinux is enabled, credits are needed to create the selinux xattr as well. Overrunning the reservation will result in an OOPS in jbd2_journal_dirty_metadata() due to this assert: J_ASSERT_JH(jh, handle->h_buffer_credits > 0); Fix this by increasing the reservation size. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: free allocated and pre-allocated blocks when check_eofblocks_fl failsJiaying Zhang2011-08-041-4/+3
| | | | | | | | | | | | | | | | | commit 575a1d4bdfa2ea9fc10733013136145b497e1be0 upstream. Upon corrupted inode or disk failures, we may fail after we already allocate some blocks from the inode or take some blocks from the inode's preallocation list, but before we successfully insert the corresponding extent to the extent tree. In this case, we should free any allocated blocks and discard the inode's preallocated blocks because the entries in the inode's preallocation list may be in an inconsistent state. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: fix i_blocks/quota accounting when extent insertion failsMaxim Patlasov2011-08-043-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 7132de744ba76930d13033061018ddd7e3e8cd91 upstream. The current implementation of ext4_free_blocks() always calls dquot_free_block This looks quite sensible in the most cases: blocks to be freed are associated with inode and were accounted in quota and i_blocks some time ago. However, there is a case when blocks to free were not accounted by the time calling ext4_free_blocks() yet: 1. delalloc is on, write_begin pre-allocated some space in quota 2. write-back happens, ext4 allocates some blocks in ext4_ext_map_blocks() 3. then ext4_ext_map_blocks() gets an error (e.g. ENOSPC) from ext4_ext_insert_extent() and calls ext4_free_blocks(). In this scenario, ext4_free_blocks() calls dquot_free_block() who, in turn, decrements i_blocks for blocks which were not accounted yet (due to delalloc) After clean umount, e2fsck reports something like: > Inode 21, i_blocks is 5080, should be 5128. Fix<y>? because i_blocks was erroneously decremented as explained above. The patch fixes the problem by passing the new flag EXT4_FREE_BLOCKS_NO_QUOT_UPDATE to ext4_free_blocks(), to request that the dquot_free_block() call be skipped. Signed-off-by: Maxim Patlasov <maxim.patlasov@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ext4: fixed tracepoints cleanupLukas Czerner2011-06-062-4/+4
| | | | | | | | | | | | | While creating fixed tracepoints for ext3, basically by porting them from ext4, I found a lot of useless retyping, wrong type usage, useless variable passing and other inconsistencies in the ext4 fixed tracepoint code. This patch cleans the fixed tracepoint code for ext4 and also simplify some of them. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: use FIEMAP_EXTENT_LAST flag for last extent in fiemap Lukas Czerner2011-06-062-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | Currently we are not marking the extent as the last one (FIEMAP_EXTENT_LAST) if there is a hole at the end of the file. This is because we just do not check for it right now and continue searching for next extent. But at the point we hit the hole at the end of the file, it is too late. This commit adds check for the allocated block in subsequent extent and if there is no more extents (block = EXT_MAX_BLOCKS) just flag the current one as the last one. This behaviour has been spotted unintentionally by 252 xfstest, when the test hangs out, because of wrong loop condition. However on other filesystems (like xfs) it will exit anyway, because we notice the last extent flag and exit. With this patch xfstest 252 does not hang anymore, ext4 fiemap implementation still reports bad extent type in some cases, however this seems to be different issue. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Fix max file size and logical block counting of extent format fileLukas Czerner2011-06-064-27/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kazuya Mio reported that he was able to hit BUG_ON(next == lblock) in ext4_ext_put_gap_in_cache() while creating a sparse file in extent format and fill the tail of file up to its end. We will hit the BUG_ON when we write the last block (2^32-1) into the sparse file. The root cause of the problem lies in the fact that we specifically set s_maxbytes so that block at s_maxbytes fit into on-disk extent format, which is 32 bit long. However, we are not storing start and end block number, but rather start block number and length in blocks. It means that in order to cover extent from 0 to EXT_MAX_BLOCK we need EXT_MAX_BLOCK+1 to fit into len (because we counting block 0 as well) - and it does not. The only way to fix it without changing the meaning of the struct ext4_extent members is, as Kazuya Mio suggested, to lower s_maxbytes by one fs block so we can cover the whole extent we can get by the on-disk extent format. Also in many places EXT_MAX_BLOCK is used as length instead of maximum logical block number as the name suggests, it is all a bit messy. So this commit renames it to EXT_MAX_BLOCKS and change its usage in some places to actually be maximum number of blocks in the extent. The bug which this commit fixes can be reproduced as follows: dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-2)) sync dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-1)) Reported-by: Kazuya Mio <k-mio@sx.jp.nec.com> Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: correct comments for ext4_free_blocks()Yongqiang Yang2011-06-051-1/+1
| | | | | | | metadata is not parameter of ext4_free_blocks() any more. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* fs: pass exact type of data dirties to ->dirty_inodeChristoph Hellwig2011-05-272-2/+2
| | | | | | | | | | | | | | | | | Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or anything else, so that the filesystem can track internally if it needs to push out a transaction for fdatasync or not. This is just the prototype change with no user for it yet. I plan to push large XFS changes for the next merge window, and getting this trivial infrastructure in this window would help a lot to avoid tree interdependencies. Also remove incorrect comments that ->dirty_inode can't block. That has been changed a long time ago, and many implementations rely on it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-05-261-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem: xen: cleancache shim to Xen Transcendent Memory ocfs2: add cleancache support ext4: add cleancache support btrfs: add cleancache support ext3: add cleancache support mm/fs: add hooks to support cleancache mm: cleancache core ops functions and config fs: add field to superblock to support cleancache mm/fs: cleancache documentation Fix up trivial conflict in fs/btrfs/extent_io.c due to includes
| * ext4: add cleancache supportDan Magenheimer2011-05-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This seventh patch of eight in this cleancache series "opts-in" cleancache for ext4. Filesystems must explicitly enable cleancache by calling cleancache_init_fs anytime an instance of the filesystem is mounted. For ext4, all other cleancache hooks are in the VFS layer including the matching cleancache_flush_fs hook which must be called on unmount. Details and a FAQ can be found in Documentation/vm/cleancache.txt [v6-v8: no changes] [v5: jeremy@goop.org: simplify init hook and any future fs init changes] Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Andreas Dilger <adilger@sun.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik Van Riel <riel@redhat.com> Cc: Jan Beulich <JBeulich@novell.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Nitin Gupta <ngupta@vflare.org>
* | ext4: teach ext4_ext_split to calculate extents efficientlyYongqiang Yang2011-05-251-38/+46
| | | | | | | | | | | | | | | | Make ext4_ext_split() get extents to be moved by calculating in a statement instead of counting in a loop. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | ext4: Convert ext4 to new truncate calling conventionJan Kara2011-05-252-4/+1
| | | | | | | | | | | | | | | | | | | | | | Trivial conversion. Fixup one error handling case calling vmtruncate() and remove ->truncate callback. We also fix a bug that IS_IMMUTABLE and IS_APPEND files could not be truncated during failed writes. In fact, the test can be completely removed as upper layers do necessary permission checks for truncate in do_sys_[f]truncate() and may_open() anyway. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | ext4: do not normalize block requests from fallocate()Vivek Haldar2011-05-252-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, an fallocate request of size slightly larger than a power of 2 is turned into two block requests, each a power of 2, with the extra blocks pre-allocated for future use. When an application calls fallocate, it already has an idea about how large the file may grow so there is usually little benefit to reserve extra blocks on the preallocation list. This reduces disk fragmentation. Tested: fsstress. Also verified manually that fallocat'ed files are contiguously laid out with this change (whereas without it they begin at power-of-2 boundaries, leaving blocks in between). CPU usage of fallocate is not appreciably higher. In a tight fallocate loop, CPU usage hovers between 5%-8% with this change, and 5%-7% without it. Using a simulated file system aging program which the file system to 70%, the percentage of free extents larger than 8MB (as measured by e2freefrag) increased from 38.8% without this change, to 69.4% with this change. Signed-off-by: Vivek Haldar <haldar@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | ext4: enable "punch hole" functionalityAllison Henderson2011-05-253-11/+253
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds new routines: "ext4_punch_hole" "ext4_ext_punch_hole" and "ext4_ext_check_cache" fallocate has been modified to call ext4_punch_hole when the punch hole flag is passed. At the moment, we only support punching holes in extents, so this routine is pretty much a wrapper for the ext4_ext_punch_hole routine. The ext4_ext_punch_hole routine first completes all outstanding writes with the associated pages, and then releases them. The unblock aligned data is zeroed, and all blocks in between are punched out. The ext4_ext_check_cache routine is very similar to ext4_ext_in_cache except it accepts a ext4_ext_cache parameter instead of a ext4_extent parameter. This routine is used by ext4_ext_punch_hole to check and see if a block in a hole that has been cached. The ext4_ext_cache parameter is necessary because the members ext4_extent structure are not large enough to hold a 32 bit value. The existing ext4_ext_in_cache routine has become a wrapper to this new function. [ext4 punch hole patch series 5/5 v7] Signed-off-by: Allison Henderson <achender@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Mingming Cao <cmm@us.ibm.com>
* | ext4: add "punch hole" flag to ext4_map_blocks()Allison Henderson2011-05-251-11/+87
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new flag to ext4_map_blocks() that specifies the given range of blocks should be punched out. Extents are first converted to uninitialized extents before they are punched out. Because punching a hole may require that the extent be split, it is possible that the splitting may need more blocks than are available. To deal with this, use of reserved blocks are enabled to allow the split to proceed. The routine then returns the number of blocks successfully punched out. [ext4 punch hole patch series 4/5 v7] Signed-off-by: Allison Henderson <achender@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Mingming Cao <cmm@us.ibm.com>
* | ext4: punch out extentsAllison Henderson2011-05-251-19/+141
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch modifies the truncate routines to support hole punching Below is a brief summary of the patches changes: - Added end param to ext_ext4_rm_leaf This function has been modified to accept an end parameter which enables it to punch holes in leafs instead of just truncating them. - Implemented the "remove head" case in the ext_remove_blocks routine This routine is used by ext_ext4_rm_leaf to remove the tail of an extent during a truncate. The new ext_ext4_rm_leaf routine will now also use it to remove the head of an extent in the case that the hole covers a region of blocks at the beginning of an extent. - Added "end" param to ext4_ext_remove_space routine This function has been modified to accept a stop parameter, which is passed through to ext4_ext_rm_leaf. [ext4 punch hole patch series 3/5 v6] Signed-off-by: Allison Henderson <achender@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>