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2013-03-03fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman
Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-02-27more file_inode() open-coded instancesAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...
2013-02-22new helper: file_inode(file)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-12f2fs: avoid build warningJaegeuk Kim
This patch removes the following build warning: fs/f2fs/node.c: warning: 'nofs' may be used uninitialized in this function [-Wuninitialized]: => 738:8 Note that this is a false alarm. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12Merge branch 'f2fs' of ↵Jaegeuk Kim
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into dev Pull f2fs cleanup patches from Al Viro: f2fs: get rid of fake on-stack dentries f2fs: switch init_inode_metadata() to passing parent and name separately f2fs: switch new_inode_page() from dentry to qstr f2fs: init_dent_inode() should take qstr Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Conflicts: fs/f2fs/recovery.c
2013-02-12f2fs: add compat_ioctl to provide backward compatabilityNamjae Jeon
adding compat_ioctl to provide support for backward comptability - 32bit binary execution on 64bit kernel. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: fix calculation of max. gc cost in the SSR caseJaegeuk Kim
In the SSR case, the max gc cost should be the number of pages in a segment. Otherwise, f2fs is able to fail getting dirty segments frequently for SSR. In get_victim_by_default() previously, while(1) { ... cost = get_gc_cost(); <- cost is between 0 ~ 512. ... if (cost == get_max_cost(sbi, &p)) <- max cost is UINT_MAX due to GC_CB type continue; if (nsearched++ >= MAX_VICTIM_SEARCH) break; } So, if there are a number of fully valid segments in series, f2fs cannot skip those segments by comparing the cost and max cost of each segment. Note that, the cost is the number of valid blocks at the time of the last checkpoint. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: clarify and enhance the f2fs_gc flowJaegeuk Kim
This patch makes clearer the ambiguous f2fs_gc flow as follows. 1. Remove intermediate checkpoint condition during f2fs_gc (i.e., should_do_checkpoint() and GC_BLOCKED) 2. Remove unnecessary return values of f2fs_gc because of #1. (i.e., GC_NODE, GC_OK, etc) 3. Simplify write_checkpoint() because of #2. 4. Clarify the main f2fs_gc flow. o monitor how many freed sections during one iteration of do_garbage_collect(). o do GC more without checkpoints if we can't get enough free sections. o do checkpoint once we've got enough free sections through forground GCs. 5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data log types. See. get_ssr_segement() Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: optimize the return condition for has_not_enough_free_secsNamjae Jeon
Instead of evaluating the free_sections and then deciding to return true/false from that path. We can directly use the evaluation condition for returning proper value. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: make an accessor to get sections for particular block typeNamjae Jeon
Introduce accessor to get the sections based upon the block type (node,dents...) and modify the functions : should_do_checkpoint, has_not_enough_free_secs to use this accessor function to get the node sections and dent sections. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: mark gc_thread as NULL when thread creation is failedNamjae Jeon
When gc thread creation is failed, mark gc_thread as NULL to avoid crash while trying to stop invalid thread in stop_gc_thread->kthread_stop. Instead make it return from: if (!gc_th) return; Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: name gc task as per the block deviceNamjae Jeon
Currently GC task is started for each f2fs formatted/mounted device. But, when we check the task list, using 'ps', there is no distinguishing factor between the tasks. So, name the task as per the block device just like the flusher threads. Also, remove the macro GC_THREAD_NAME and instead use the name: f2fs_gc to avoid name length truncation, as the command length is 16 -> TASK_COMM_LEN 16 and example name like: f2fs_gc_task:8:16 -> this exceeds name length Before Patch for 2 F2FS formatted partitions: root 28061 0.0 0.0 0 0 ? S 10:31 0:00 [f2fs_gc_task] root 28087 0.0 0.0 0 0 ? S 10:32 0:00 [f2fs_gc_task] After Patch: root 16756 0.0 0.0 0 0 ? S 14:57 0:00 [f2fs_gc-8:18] root 16765 0.0 0.0 0 0 ? S 14:57 0:00 [f2fs_gc-8:19] Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: remove unnecessary gc option check and balance_fsChangman Lee
1. If f2fs is mounted with background_gc_off option, checking BG_GC is not redundant. 2. f2fs_balance_fs is checked in f2fs_gc, so this is also redundant. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: remove repeated F2FS_SET_SB_DIRT callChangman Lee
F2FS_SET_SB_DIRT is called in inc_page_count and it is directly called one more time in the next line. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: when check superblock failed, try to check another superblockmajianpeng
In f2fs, there are two superblocks. So when the first superblock was invalidate, it should try to check another. By Jaegeuk Kim: o Remove a white space for coding style o Clean up for code readability o Fix a typo Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: use F2FS_BLKSIZE to judge bloksize and page_cache_sizemajianpeng
In some system PAGE_CACHE_SIZE isn't 4K. So using F2FS_BLKSIZE to judge. By Jaegeuk Kim: o f2fs does not support no other 4KB page cache size. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: add device name in debugfsmajianpeng
In file status, it can't distinguish between different devices. So add device name to do this function. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: stop repeated checking if cp is neededChangman Lee
If it is decided that f2fs should do checkpoint, skip next comparison. Signed-off-by: Changman Lee <cm224.lee@samsung.com>
2013-02-12f2fs: avoid balanc_fs during evict_inodeJaegeuk Kim
1. Background Previously, if f2fs tries to move data blocks of an *evicting* inode during the cleaning process, it stops the process incompletely and then restarts the whole process, since it needs a locked inode to grab victim data pages in its address space. In order to get a locked inode, iget_locked() by f2fs_iget() is normally used, but, it waits if the inode is on freeing. So, here is a deadlock scenario. 1. f2fs_evict_inode() <- inode "A" 2. f2fs_balance_fs() 3. f2fs_gc() 4. gc_data_segment() 5. f2fs_iget() <- inode "A" too! If step #1 and #5 treat a same inode "A", step #5 would fall into deadlock since the inode "A" is on freeing. In order to resolve this, f2fs_iget_nowait() which skips __wait_on_freeing_inode() was introduced in step #5, and stops f2fs_gc() to complete f2fs_evict_inode(). 1. f2fs_evict_inode() <- inode "A" 2. f2fs_balance_fs() 3. f2fs_gc() 4. gc_data_segment() 5. f2fs_iget_nowait() <- inode "A", then stop f2fs_gc() w/ -ENOENT 2. Problem and Solution In the above scenario, however, f2fs cannot finish f2fs_evict_inode() only if: o there are not enough free sections, and o f2fs_gc() tries to move data blocks of the *evicting* inode repeatedly. So, the final solution is to use f2fs_iget() and remove f2fs_balance_fs() in f2fs_evict_inode(). The f2fs_evict_inode() actually truncates all the data and node blocks, which means that it doesn't produce any dirty node pages accordingly. So, we don't need to do f2fs_balance_fs() in practical. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: remove the use of page_cache_releaseJaegeuk Kim
Let's remove the use of page_cache_release() in f2fs, and instead, use f2fs_put_page(page, 0) which is exactly same but for code readability. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: fix typo mistake for data_version descriptionNamjae Jeon
In f2fs_inode_info structure, the description for data_version has a typo mistake. It should be latest instead of lastes. So, correcting that. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: reorganize code for ra_node_pageNamjae Jeon
We can remove unneeded label unlock_out, avoid unnecessary jump and reorganize the returning conditions in this function. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: avoid redundant call to has_not_enough_free_secs in f2fs_gcNamjae Jeon
After doing a write_checkpoint from garbage collection path if there is still need to do more garbage collection, gc_more label is used to jump and start the process again. And in that process, first step before getting victim is to check if there are not enough free sections, which is already done before doing a jump to gc_more. We can avoid the redundant call to check free sections, by checking the gc_type flag which will remain FG_GC(value 1) under this condition. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: add un/freeze_fs into super_operationsChangman Lee
This patch supports ioctl FIFREEZE and FITHAW to snapshot filesystem. Before calling f2fs_freeze, all writers would be suspended and sync_fs would be completed. So no f2fs has to do something. Just background gc operation should be skipped due to generate dirty nodes and data until unfreeze. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: clean up the add_orphan_inode funcmajianpeng
For the code > prev = list_entry(orphan->list.prev, typeof(*prev), list); if orphan->list.prev == head, it can't get the right prev. And we can use the parameter 'this' to add. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: fix disable_ext_identify option spellingAlejandro Martinez Ruiz
There is a typo in the ->show_options function for disable_ext_identify. Fix it to match the spelling from the documentation. Signed-off-by: Alejandro Martinez Ruiz <alex@nowcomputing.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: cover global locks for reserve_new_blockJaegeuk Kim
The fill_zero() from fallocate() calls get_new_data_page() in which calls reserve_new_block(). The reserve_new_block() should be covered by *DATA_NEW*, one of global locks. And also, before getting the lock, we should check free sections by calling f2fs_balance_fs(). If we break this rule, f2fs is able to face with out-of-control free space management and fall into infinite loop like the following scenario as well. [f2fs_sync_fs()] [fallocate()] - write_checkpoint() - fill_zero() - block_operations() - get_new_data_page() : grab NODE_NEW - get_dnode_of_data() : get locked dirty node page - sync_node_pages() : try to grab NODE_NEW for data allocation : trylock and skip the dirty node page : call sync_node_pages() repeatedly in order to flush all the dirty node pages! In order to avoid this, we should grab another global lock such as DATA_NEW before calling get_new_data_page() in fill_zero(). Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: prevent checkpoint once any IO failure is detectedJaegeuk Kim
This patch enhances the checkpoint routine to cope with IO errors. Basically f2fs detects IO errors from end_io_write, and the errors are able to be occurred during one of data, node, and meta page writes. In the previous code, when an IO error is occurred during writes, f2fs sets a flag, CP_ERROR_FLAG, in the raw ckeckpoint buffer which will be written to disk. Afterwards, write_checkpoint() will check the flag and remount f2fs as a read-only (ro) mode. However, even once f2fs is remounted as a ro mode, dirty checkpoint pages are freely able to be written to disk by flusher or kswapd in background. In such a case, after cold reboot, f2fs would restore the checkpoint data having CP_ERROR_FLAG, resulting in disabling write_checkpoint and remounting f2fs as a ro mode again. Therefore, let's prevent any checkpoint page (meta) writes once an IO error is occurred, and remount f2fs as a ro mode right away at that moment. Reported-by: Oliver Winker <oliver@oli1170.net> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-02-12f2fs: save device node number into f2fs_inodeChangman Lee
This patch stores inode->i_rdev into on-disk inode structure. Alun reported that: aspire tmp # mount -t f2fs /dev/sdb mnt aspire tmp # mknod mnt/sda1 b 8 1 aspire tmp # mknod mnt/null c 1 3 aspire tmp # mknod mnt/console c 5 1 aspire tmp # ls -l mnt total 2 crw-r--r-- 1 root root 5, 1 Jan 22 18:44 console crw-r--r-- 1 root root 1, 3 Jan 22 18:44 null brw-r--r-- 1 root root 8, 1 Jan 22 18:44 sda1 aspire tmp # umount mnt aspire tmp # mount -t f2fs /dev/sdb mnt aspire tmp # ls -l mnt total 2 crw-r--r-- 1 root root 0, 0 Jan 22 18:44 console crw-r--r-- 1 root root 0, 0 Jan 22 18:44 null brw-r--r-- 1 root root 0, 0 Jan 22 18:44 sda1 In this report, f2fs lost the major/minor numbers of device files after umount. The reason was revealed that f2fs does not store the inode->i_rdev to the on-disk inode data structure. So, as the other file systems do, f2fs also stores i_rdev into the i_addr fields in on-disk inode structure without any on-disk layout changes. Note that, this bug is limited to device files made by mknod(). Reported-and-Tested-by: Alun Jones <alun.linux@ty-penguin.org.uk> Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-08f2fs: get rid of fake on-stack dentriesAl Viro
those should never be used for a lot of reasons... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08f2fs: switch init_inode_metadata() to passing parent and name separatelyAl Viro
... sure, it's tempting to just pass dentry. Except that we don't _have_ anything resembling a real dentry on one of the paths to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08f2fs: switch new_inode_page() from dentry to qstrAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-08f2fs: init_dent_inode() should take qstrAl Viro
for one thing, it doesn't (and shouldn't) use anything else from dentry; for another, on some call chains the dentry is fake and should be eliminated completely. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-01-22f2fs: use _safe() version of list_for_eachDan Carpenter
This is calling list_del() inside a loop which is a problem when we try move to the next item on the list. I've converted it to use the _safe version. And also, as a cleanup, I've converted it to use list_for_each_entry instead of list_for_each. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22f2fs: add comments of start_bidx_of_nodeJaegeuk Kim
The caller of start_bidx_of_node() should give proper node offsets which point only direct node blocks. Otherwise, it is a caller's bug. This patch adds comments to make it clear. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22f2fs: avoid issuing small bios due to several dirty node pagesJaegeuk Kim
If some small bios of dirty node pages are supposed to be issued during the sequential data writes, there-in well-produced consecutive data bios are able to be split by the small node bios, resulting in performance degradation. So, let's collect a number of dirty node pages until reaching a threshold. And, by default, I set the threshold as 2MB, a segment size. This improves sequential write performance on i5, 512GB SSD (830 w/ SATA2) as follows. Before: 231 MB/s -> After: 255 MB/s Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-01-22f2fs: support swapfileJaegeuk Kim
This patch adds f2fs_bmap operation to the data address space. This enables f2fs to support swapfile. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22f2fs: add remap_pages as generic_file_remap_pagesJaegeuk Kim
This was added for all the file systems before. See the following commit. commit id: 0b173bc4daa8f8ec03a85abf5e47b23502ff80af [PATCH] mm: kill vma flag VM_CAN_NONLINEAR This patch moves actual ptes filling for non-linear file mappings into special vma operation: ->remap_pages(). File system must implement this method to get non-linear mappings support, if it uses filemap_fault() then generic_file_remap_pages() can be used. Now device drivers can implement this method and obtain nonlinear vma support." Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-22f2fs: add __init to functions in init_f2fs_fsNamjae Jeon
Add __init to functions in init_f2fs_fs for code consistency. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-15f2fs: fix the debugfs entry creation pathNamjae Jeon
As the "status" debugfs entry will be maintained for entire F2FS filesystem irrespective of the number of partitions. So, we can move the initialization to the init part of the f2fs and destroy will be done from exit part. After making changes, for individual partition mount - entry creation code will not be executed. Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-15f2fs: add global mutex_lock to protect f2fs_stat_listmajianpeng
There is an race condition between umounting f2fs and reading f2fs/status, which results in oops. Fox example: Thread A Thread B umount f2fs cat f2fs/status f2fs_destroy_stats() { stat_show() { list_for_each_entry_safe(&f2fs_stat_list) list_del(&si->stat_list); mutex_lock(&si->stat_lock); si->sbi = NULL; mutex_unlock(&si->stat_lock); kfree(sbi->stat_info); } mutex_lock(&si->stat_lock) <- si is gone. ... } Solution with a global lock: f2fs_stat_mutex: Thread A Thread B umount f2fs cat f2fs/status f2fs_destroy_stats() { stat_show() { mutex_lock(&f2fs_stat_mutex); list_del(&si->stat_list); mutex_unlock(&f2fs_stat_mutex); kfree(sbi->stat_info); mutex_lock(&f2fs_stat_mutex); } list_for_each_entry_safe(&f2fs_stat_list) ... mutex_unlock(&f2fs_stat_mutex); } Signed-off-by: Jianpeng Ma <majianpeng@gmail.com> [jaegeuk.kim@samsung.com: fix typos, description, and remove the existing lock] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-15f2fs: remove the blk_plug usage in f2fs_write_data_pagesNamjae Jeon
Let's consider the usage of blk_plug in f2fs_write_data_pages(). We can come up with the two issues: lock contention and task awareness. 1. Merging bios prior to grabing "queue lock" The f2fs merges consecutive IOs in the file system level before submitting any bios, which is similar with the back merge by the plugging mechanism in attempt_plug_merge(). Both of them need to acquire no queue lock. 2. Merging policy with respect to tasks The f2fs merges IOs as much as possible regardless of tasks, while blk-plugging is conducted on a basis of tasks. As we can understand there are trade-offs, f2fs tries to maximize the write performance with well-merged bios. As a result, if f2fs produces many consecutive but separated bios in writepages(), it would be good to use blk-plugging since f2fs would be able to avoid queue lock contention in the block layer by merging them. But, f2fs merges IOs and submit one bio, which means that there are not much chances to merge bios by attempt_plug_merge(). However, f2fs has already been used blk_plug by triggering generic_writepages() in f2fs_write_data_pages(). So to make the overall code consistency, I'd like to remove blk_plug there. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-14f2fs: avoid redundant time update for parent directory in f2fs_delete_entryNamjae Jeon
In call to f2fs_delete_entry, 'dir' time modification code is put at two places. So, remove the redundant code for timing update. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-14f2fs: remove redundant call to set_blocksize in f2fs_fill_superNamjae Jeon
Since, f2fs supports only 4KB blocksize, which is set at the beginning in f2fs_fill_super. So, we do not need to again check this blocksize setting in such case. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-11f2fs: move f2fs_balance_fs to punch_holeJaegeuk Kim
The f2fs_fallocate() has two operations: punch_hole and expand_size. Only in the case of punch_hole, dirty node pages can be produced, so let's trigger f2fs_balance_fs() in this case only. Furthermore, let's trigger it at every data truncation routine. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-11f2fs: add f2fs_balance_fs in several interfacesJaegeuk Kim
The f2fs_balance_fs() is to check the number of free sections and decide whether it needs to conduct cleaning or not. If there are not enough free sections, the cleaning job should be started. In order to control an amount of free sections even under high utilization, f2fs should call f2fs_balance_fs at all the VFS interfaces that are able to produce dirty pages. This patch adds the function calls in the missing interfaces as follows. 1. f2fs_setxattr() The f2fs_setxattr() produces dirty node pages so that we should call f2fs_balance_fs() either likewise doing in other VFS interfaces such as f2fs_lookup(), f2fs_mkdir(), and so on. 2. f2fs_sync_file() We should guarantee serving free sections for syncing metadata during fsync. Previously, there is no space check before triggering checkpoint and sync_node_pages. Therefore, if a bunch of fsync calls are triggered under 100% of FS utilization, f2fs is able to be faced with no free sections, resulting in BUG_ON(). 3. f2fs_sync_fs() Before calling write_checkpoint(), we should guarantee that there are minimum free sections. 4. f2fs_write_inode() f2fs_write_inode() is also able to produce dirty node pages. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-10f2fs: revisit the f2fs_gc flowJaegeuk Kim
I'd like to revisit the f2fs_gc flow and rewrite as follows. 1. In practical, the nGC parameter of f2fs_gc is meaningless. So, let's remove it. 2. Background GC marks victim blocks as dirty one at a time. 3. Foreground GC should do cleaning job until acquiring enough free sections. Afterwards, it needs to do checkpoint. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-04f2fs: check return value during recoveryJaegeuk Kim
This patch resolves Coverity #753102: >>> No check of the return value of "f2fs_add_link(&dent, inode)". Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-01-04f2fs: avoid null dereference in f2fs_acl_from_diskJaegeuk Kim
This patch resolves Coverity #751303: >>> CID 753103: Explicit null dereferenced (FORWARD_NULL) Passing null >>> pointer "value" to function "f2fs_acl_from_disk(char const *, size_t)", which dereferences it. [Error path] - value = NULL; - retval = 0 by f2fs_getxattr(); - f2fs_acl_from_disk(value:NULL, ...); Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>