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2011-07-23ext4: correct comment for ext4_ext_check_cacheRobin Dong
The comment for ext4_ext_check_cache has a litte mistake. Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-23ext4: correct the debug message in ext4_ext_insert_extentRobin Dong
The debug message in ext4_ext_insert_extent before moving extent is incorrect (the "from xx to xx"). Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-23ext4: remove unused argument in ext4_ext_next_leaf_blockRobin Dong
The argument "inode" in function ext4_ext_next_allocated_block looks useless, so clean it. Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-23ext4: remove ac_repeats from ext4_allocation_contextTao Ma
ac_repeats isn't referenced in the mballoc code. So remove it. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-23ext4: don't increment s_mb_buddies_generated in ext4_mb_releaseTao Ma
In ext4_mb_release, we use s_mb_buddies_generated++. Although the output is OK, but I don't think we need this extra ++. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-23ext4: remove unnecessary ext4_get_group_info in ext4_mb_load_buddyTao Ma
ext4_mb_load_buddy() calls ext4_get_group_info() for setting both "grp" and "e4b->bd_info", but it could do "e4b->bd_info = grp". Reported-by: Andreas Dilger <adilger@whamcloud.com> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-20fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlersJosef Bacik
Btrfs needs to be able to control how filemap_write_and_wait_range() is called in fsync to make it less of a painful operation, so push down taking i_mutex and the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some file systems can drop taking the i_mutex altogether it seems, like ext3 and ocfs2. For correctness sake I just pushed everything down in all cases to make sure that we keep the current behavior the same for everybody, and then each individual fs maintainer can make up their mind about what to do from there. Thanks, Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20Ext4: handle SEEK_HOLE/SEEK_DATA genericallyJosef Bacik
Since Ext4 has its own lseek we need to make sure it handles SEEK_HOLE/SEEK_DATA. For now just do the same thing that is done in the generic case, somebody else can come along and make it do fancy things later. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: move inode_dio_done to the end_io handlerChristoph Hellwig
For filesystems that delay their end_io processing we should keep our i_dio_count until the the processing is done. Enable this by moving the inode_dio_done call to the end_io handler if one exist. Note that the actual move to the workqueue for ext4 and XFS is not done in this patch yet, but left to the filesystem maintainers. At least for XFS it's not needed yet either as XFS has an internal equivalent to i_dio_count. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: simplify the blockdev_direct_IO prototypeChristoph Hellwig
Simple filesystems always pass inode->i_sb_bdev as the block device argument, and never need a end_io handler. Let's simply things for them and for my grepping activity by dropping these arguments. The only thing not falling into that scheme is ext4, which passes and end_io handler without needing special flags (yet), but given how messy the direct I/O code there is use of __blockdev_direct_IO in one instead of two out of three cases isn't going to make a large difference anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20fs: move inode_dio_wait calls into ->setattrChristoph Hellwig
Let filesystems handle waiting for direct I/O requests themselves instead of doing it beforehand. This means filesystem-specific locks to prevent new dio referenes from appearing can be held. This is important to allow generalizing i_dio_count to non-DIO_LOCKING filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20ext4: Rewrite ext4_page_mkwrite() to use generic helpersJan Kara
Rewrite ext4_page_mkwrite() to use __block_page_mkwrite() helper. This removes the need of using i_alloc_sem to avoid races with truncate which seems to be the wrong locking order according to lock ordering documented in mm/rmap.c. Also calling ext4_da_write_begin() as used by the old code seems to be problematic because we can decide to flush delay-allocated blocks which will acquire s_umount semaphore - again creating unpleasant lock dependency if not directly a deadlock. Also add a check for frozen filesystem so that we don't busyloop in page fault when the filesystem is frozen. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20make d_splice_alias(ERR_PTR(err), dentry) = ERR_PTR(err)Al Viro
... and simplify the living hell out of callers Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20->permission() sanitizing: don't pass flags to ->check_acl()Al Viro
not used in the instances anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20->permission() sanitizing: pass MAY_NOT_BLOCK to ->check_acl()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-18security: new security_inode_init_security API adds function callbackMimi Zohar
This patch changes the security_inode_init_security API by adding a filesystem specific callback to write security extended attributes. This change is in preparation for supporting the initialization of multiple LSM xattrs and the EVM xattr. Initially the callback function walks an array of xattrs, writing each xattr separately, but could be optimized to write multiple xattrs at once. For existing security_inode_init_security() calls, which have not yet been converted to use the new callback function, such as those in reiserfs and ocfs2, this patch defines security_old_inode_init_security(). Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-17ext4: avoid eh_entries overflow before insert extent_idxRobin Dong
If eh_entries is equal to (or greater than) eh_max, the operation of inserting new extent_idx will make number of entries overflow. So check eh_entries before inserting the new extent_idx. Although there is no bug case according the code (function ext4_ext_insert_index is called by ext4_ext_split and ext4_ext_split is called only if the index block has free space), the right logic should be "lookup the capacity before insertion". Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-17ext4: avoid wasted extent cache lookup if !PUNCH_OUT_EXTRobin Dong
This patch avoids an extraneous lookup of the extent cache in ext4_ext_map_blocks() when the flag EXT4_GET_BLOCKS_PUNCH_OUT_EXT is absent. The existing logic was performing the lookup but not making use of the result. The patch simply reverses the order of evaluation in the condition. Since ext4_ext_in_cache() does not initialize newex on misses, bypassing its invocation does not introduce any new issue in this regard. Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Eric Gouriou <egouriou@google.com>
2011-07-17ext4: remove unneeded parameter to ext4_ext_remove_space()Allison Henderson
This patch removes the extra parameter in ext4_ext_remove_space() which is no longer needed. Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-17ext4: punch hole optimizations: skip un-needed extent lookupAllison Henderson
This patch optimizes the punch hole operation by skipping the tree walking code that is used by truncate. Since punch hole is done through map blocks, the path to the extent is already known in this function, so we do not need to look it up again. Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-17ext4: ignore a stripe width of 1Dan Ehrenberg
If the stripe width was set to 1, then this patch will ignore that stripe width and ext4 will act as if the stripe width were 0 with respect to optimizing allocations. Signed-off-by: Dan Ehrenberg <dehrenberg@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-17ext4: make the preallocation size be a multiple of stripe sizeDan Ehrenberg
Previously, if a stripe width was provided, then it would be used as the preallocation granularity, with no santiy checking and no way to override this. Now, mb_prealloc_size defaults to the smallest multiple of stripe size that is greater than or equal to the old default mb_prealloc_size, and this can be overridden with the sysfs interface. Signed-off-by: Dan Ehrenberg <dehrenberg@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-16ext4: fix compilation with -DDX_DEBUGBernd Schubert
Compilation of ext4/namei.c brought up an error and warning messages when compiled with -DDX_DEBUG Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: remove unnecessary comments in ext4_orphan_add()Lukas Czerner
The comment from Al Viro about possible race in the ext4_orphan_add() is not justified. There is no race possible as we always have either i_mutex locked, or the inode can not be referenced from outside hence the J_ASSERS should not be hit from the reason described in comment. This commit replaces it with notion that we are holding i_mutex so it should not be possible for i_nlink to be changed while waiting for s_orphan_lock. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: Fix a double free of sbi->s_group_info in ext4_mb_init_backendTao Ma
If we meet with an error in ext4_mb_add_groupinfo, we kfree sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)], but fail to reset it to NULL. So the caller ext4_mb_init_backend will try to kfree it again and causes a double free. So fix it by resetting it to NULL. Some typo in comments of mballoc.c are also changed. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: fix a race which could leak memory in ext4_groupinfo_create_slab()Tao Ma
In ext4_groupinfo_create_slab, we create ext4_groupinfo_caches within ext4_grpinfo_slab_create_mutex, but set it outside the lock, and there does exist some case that we may create it twice and causes a memory leak. So set it before we call mutex_unlock. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: avoid unneeded ext4_ext_next_leaf_block() while inserting extentsRobin Dong
Optimize ext4_ext_insert_extent() by avoiding ext4_ext_next_leaf_block() when the result is not used/needed. Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: remove redundant goto in ext4_ext_insert_extent()Robin Dong
If eh->eh_entries is smaller than eh->eh_max, the routine will go to the "repeat" and then go to "has_space" directlly , since argument "depth" and "eh" are not even changed. Therefore, goto "has_space" directly and remove redundant "repeat" tag. Signed-off-by: Robin Dong <sanbai@taobao.com>
2011-07-11ext4: Change the wrong param comment for ext4_trim_all_freeTao Ma
at ext4_trim_all_free() comment, there is no longer an @e4b parameter, instead it is @group. Reported-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: Speed up FITRIM by recording flags in ext4_group_infoTao Ma
In ext4, when FITRIM is called every time, we iterate all the groups and do trim one by one. It is a bit time wasting if the group has been trimmed and there is no change since the last trim. So this patch adds a new flag in ext4_group_info->bb_state to indicate that the group has been trimmed, and it will be cleared if some blocks is freed(in release_blocks_on_commit). Another trim_minlen is added in ext4_sb_info to record the last minlen we use to trim the volume, so that if the caller provide a small one, we will go on the trim regardless of the bb_state. A simple test with my intel x25m ssd: df -h shows: /dev/sdb1 40G 21G 17G 56% /mnt/ext4 Block size: 4096 run the FITRIM with the following parameter: range.start = 0; range.len = UINT64_MAX; range.minlen = 1048576; without the patch: [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m5.505s user 0m0.000s sys 0m1.224s [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m5.359s user 0m0.000s sys 0m1.178s [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m5.228s user 0m0.000s sys 0m1.151s with the patch: [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m5.625s user 0m0.000s sys 0m1.269s [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m0.002s user 0m0.000s sys 0m0.001s [root@boyu-tm linux-2.6]# time ./ftrim /mnt/ext4/a real 0m0.002s user 0m0.000s sys 0m0.001s A big improvement for the 2nd and 3rd run. Even after I delete some big image files, it is still much faster than iterating the whole disk. [root@boyu-tm test]# time ./ftrim /mnt/ext4/a real 0m1.217s user 0m0.000s sys 0m0.196s Cc: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Andreas Dilger <adilger.kernel@dilger.ca> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: Add new ext4 trim tracepointsTao Ma
Add ext4_trim_extent and ext4_trim_all_free. Reviewed-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-11ext4: speed up group trim with the right free block countTao Ma
When we trim some free blocks in a group of ext4, we need to calculate the free blocks properly and check whether there are enough freed blocks left for us to trim. Current solution will only calculate free spaces if they are large for a trim which isn't appropriate. Let us see a small example: a group has 1.5M free which are 300k, 300k, 300k, 300k, 300k. And minblocks is 1M. With current solution, we have to iterate the whole group since these 300k will never be subtracted from 1.5M. But actually we should exit after we find the first 2 free spaces since the left 3 chunks only sum up to 900K if we subtract the first 600K although they can't be trimed. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-10ext4: fix trim length underflow with small trim lengthTao Ma
In 0f0a25b, we adjust 'len' with s_first_data_block - start, but it could underflow in case blocksize=1K, fstrim_range.len=512 and fstrim_range.start = 0. In this case, when we run the code: len -= first_data_blk - start; len will be underflow to -1ULL. In the end, although we are safe that last_group check later will limit the trim to the whole volume, but that isn't what the user really want. So this patch fix it. It also adds the check for 'start' like ext3 so that we can break immediately if the start is invalid. Cc: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-10ext4: add tracepoint for ext4_journal_startTheodore Ts'o
This will help debug who is responsible for starting a jbd2 transaction. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-10ext4: free allocated and pre-allocated blocks when check_eofblocks_fl failsJiaying Zhang
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> Cc: stable@kernel.org
2011-07-10ext4: fix i_blocks/quota accounting when extent insertion failsMaxim Patlasov
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> Cc: stable@kernel.org
2011-06-29ext4: remove loop around bio_alloc()Theodore Ts'o
These days, bio_alloc() is guaranteed to never fail (as long as nvecs is less than BIO_MAX_PAGES), so we don't need the loop around the struct bio allocation. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-28ext4: quiet 'unused variables' compile warningsYongqiang Yang
Unused variables was deleted. Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-28ext4: refactor duplicated block placement codeEric Sandeen
I found that ext4_ext_find_goal() and ext4_find_near() share the same code for returning a coloured start block based on i_block_group. We can refactor this into a common function so that they don't diverge in the future. Thanks to adilger for suggesting the new function name. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: move ext4_ind_* functions from inode.c to indirect.cAmir Goldstein
This patch moves functions from inode.c to indirect.c. The moved functions are ext4_ind_* functions and their helpers. Functions called from inode.c are declared extern. Signed-off-by: Amir Goldstein <amir73il@users.sf.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: move common truncate functions to header fileTheodore Ts'o
Move two functions that will be needed by the indirect functions to be moved to indirect.c as well as inode.c to truncate.h as inline functions, so that we can avoid having duplicate copies of the function (which can be a maintenance problem) without having to expose them as globally functions. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: move __ext4_check_blockref to block_validity.cTheodore Ts'o
In preparation for moving the indirect functions to a separate file, move __ext4_check_blockref() to block_validity.c and rename it to ext4_check_blockref() which is exported as globally visible function. Also, rename the cpp macro ext4_check_inode_blockref() to ext4_ind_check_inode(), to make it clear that it is only valid for use with non-extent mapped inodes. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: rename ext4_indirect_* funcs to ext4_ind_*Amir Goldstein
We are going to move all ext4_ind_* functions to indirect.c. Before we do that, let's rename 2 functions called ext4_indirect_* to ext4_ind_*, to keep to the naming convention. Signed-off-by: Amir Goldstein <amir73il@users.sf.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: split ext4_ind_truncate from ext4_truncateAmir Goldstein
We are about to move all indirect inode functions to a new file. Before we do that, let's split ext4_ind_truncate() out of ext4_truncate() leaving only generic code in the latter, so we will be able to move ext4_ind_truncate() to the new file. Signed-off-by: Amir Goldstein <amir73il@users.sf.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27ext4: fix incorrect error msg in ext4_ext_insert_indexRobin Dong
In function ext4_ext_insert_index when eh_entries of curp is bigger than eh_max, error messages will be printed out, but the content is about logical and ei_block, that's incorret. Signed-off-by: Robin Dong <sanbai@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-08writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stageWu Fengguang
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>
2011-06-06ext4: fixed tracepoints cleanupLukas Czerner
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>
2011-06-06ext4: use FIEMAP_EXTENT_LAST flag for last extent in fiemap Lukas Czerner
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>
2011-06-06ext4: Fix max file size and logical block counting of extent format fileLukas Czerner
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>
2011-06-05ext4: correct comments for ext4_free_blocks()Yongqiang Yang
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>