Jan Kara
2012-Mar-05 16:01 UTC
[PATCH 04/19] btrfs: Push mnt_want_write() outside of i_mutex
When mnt_want_write() starts to handle freezing it will get a full lock semantics requiring proper lock ordering. So push mnt_want_write() call consistently outside of i_mutex. CC: Chris Mason <chris.mason@oracle.com> CC: linux-btrfs@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> --- fs/btrfs/ioctl.c | 23 +++++++++++------------ 1 files changed, 11 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 03bb62a..c855e55 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -192,6 +192,10 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) if (!inode_owner_or_capable(inode)) return -EACCES; + ret = mnt_want_write_file(file); + if (ret) + return ret; + mutex_lock(&inode->i_mutex); ip_oldflags = ip->flags; @@ -206,10 +210,6 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) } } - ret = mnt_want_write_file(file); - if (ret) - goto out_unlock; - if (flags & FS_SYNC_FL) ip->flags |= BTRFS_INODE_SYNC; else @@ -271,9 +271,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg) inode->i_flags = i_oldflags; } - mnt_drop_write_file(file); out_unlock: mutex_unlock(&inode->i_mutex); + mnt_drop_write_file(file); return ret; } @@ -624,6 +624,10 @@ static noinline int btrfs_mksubvol(struct path *parent, struct dentry *dentry; int error; + error = mnt_want_write(parent->mnt); + if (error) + return error; + mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); dentry = lookup_one_len(name, parent->dentry, namelen); @@ -635,13 +639,9 @@ static noinline int btrfs_mksubvol(struct path *parent, if (dentry->d_inode) goto out_dput; - error = mnt_want_write(parent->mnt); - if (error) - goto out_dput; - error = btrfs_may_create(dir, dentry); if (error) - goto out_drop_write; + goto out_dput; down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); @@ -659,12 +659,11 @@ static noinline int btrfs_mksubvol(struct path *parent, fsnotify_mkdir(dir, dentry); out_up_read: up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem); -out_drop_write: - mnt_drop_write(parent->mnt); out_dput: dput(dentry); out_unlock: mutex_unlock(&dir->i_mutex); + mnt_drop_write(parent->mnt); return error; } -- 1.7.1
We convert btrfs_file_aio_write() to use new freeze check. We also add proper freeze protection to btrfs_page_mkwrite(). Checks in cleaner_kthread() and transaction_kthread() can be safely removed since btrfs_freeze() will lock the mutexes and thus block the threads (and they shouldn''t have anything to do anyway). CC: linux-btrfs@vger.kernel.org CC: Chris Mason <chris.mason@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> --- fs/btrfs/disk-io.c | 3 --- fs/btrfs/file.c | 3 ++- fs/btrfs/inode.c | 6 +++++- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 811d9f9..fc0f74c 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1586,8 +1586,6 @@ static int cleaner_kthread(void *arg) struct btrfs_root *root = arg; do { - vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); - if (!(root->fs_info->sb->s_flags & MS_RDONLY) && mutex_trylock(&root->fs_info->cleaner_mutex)) { btrfs_run_delayed_iputs(root); @@ -1618,7 +1616,6 @@ static int transaction_kthread(void *arg) do { delay = HZ * 30; - vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE); mutex_lock(&root->fs_info->transaction_kthread_mutex); spin_lock(&root->fs_info->trans_lock); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 859ba2d..1aac7ca 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1348,7 +1348,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, ssize_t err = 0; size_t count, ocount; - vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); + sb_start_write(inode->i_sb); mutex_lock(&inode->i_mutex); @@ -1439,6 +1439,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, num_written = err; } out: + sb_end_write(inode->i_sb); current->backing_dev_info = NULL; return num_written ? num_written : err; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 32214fe..63c9006 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6405,6 +6405,7 @@ int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) u64 page_start; u64 page_end; + sb_start_pagefault(inode->i_sb); ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); if (!ret) { ret = btrfs_update_time(vma->vm_file); @@ -6495,12 +6496,15 @@ again: unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_unlock: - if (!ret) + if (!ret) { + sb_end_pagefault(inode->i_sb); return VM_FAULT_LOCKED; + } unlock_page(page); out: btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE); out_noreserve: + sb_end_pagefault(inode->i_sb); return ret; } -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Jan Kara
2012-Mar-05 16:01 UTC
[Ocfs2-devel] [PATCH 02/19] fs: Push mnt_want_write() outside of i_mutex
Currently, mnt_want_write() is sometimes called with i_mutex held and sometimes without it. This isn't really a problem because mnt_want_write() is a non-blocking operation (essentially has a trylock semantics) but when the function starts to handle also frozen filesystems, it will get a full lock semantics and thus proper lock ordering has to be established. So move all mnt_want_write() calls outside of i_mutex. One non-trivial case needing conversion is kern_path_create() / user_path_create() which didn't include mnt_want_write() but now needs to because it acquires i_mutex. Because there are virtual file systems which don't bother with freeze / remount-ro protection we actually provide both versions of the function - one which calls mnt_want_write() and one which does not. CC: ocfs2-devel at oss.oracle.com CC: Mark Fasheh <mfasheh at suse.com> CC: Joel Becker <jlbec at evilplan.org> CC: "David S. Miller" <davem at davemloft.net> Signed-off-by: Jan Kara <jack at suse.cz> --- fs/namei.c | 115 +++++++++++++++++++++++++++-------------------- fs/ocfs2/refcounttree.c | 10 +--- include/linux/namei.h | 2 + net/unix/af_unix.c | 13 ++---- 4 files changed, 74 insertions(+), 66 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index a780ea5..575d3a4 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2383,7 +2383,9 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, return file; } -struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir) +static struct dentry *do_kern_path_create(int dfd, const char *pathname, + struct path *path, int is_dir, + int freeze_protect) { struct dentry *dentry = ERR_PTR(-EEXIST); struct nameidata nd; @@ -2401,6 +2403,14 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL; nd.intent.open.flags = O_EXCL; + if (freeze_protect) { + error = mnt_want_write(nd.path.mnt); + if (error) { + dentry = ERR_PTR(error); + goto out; + } + } + /* * Do the final lookup. */ @@ -2429,24 +2439,49 @@ eexist: dentry = ERR_PTR(-EEXIST); fail: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + if (freeze_protect) + mnt_drop_write(nd.path.mnt); out: path_put(&nd.path); return dentry; } + +struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir) +{ + return do_kern_path_create(dfd, pathname, path, is_dir, 0); +} EXPORT_SYMBOL(kern_path_create); +struct dentry *kern_path_create_thawed(int dfd, const char *pathname, struct path *path, int is_dir) +{ + return do_kern_path_create(dfd, pathname, path, is_dir, 1); +} +EXPORT_SYMBOL(kern_path_create_thawed); + struct dentry *user_path_create(int dfd, const char __user *pathname, struct path *path, int is_dir) { char *tmp = getname(pathname); struct dentry *res; if (IS_ERR(tmp)) return ERR_CAST(tmp); - res = kern_path_create(dfd, tmp, path, is_dir); + res = do_kern_path_create(dfd, tmp, path, is_dir, 0); putname(tmp); return res; } EXPORT_SYMBOL(user_path_create); +struct dentry *user_path_create_thawed(int dfd, const char __user *pathname, struct path *path, int is_dir) +{ + char *tmp = getname(pathname); + struct dentry *res; + if (IS_ERR(tmp)) + return ERR_CAST(tmp); + res = do_kern_path_create(dfd, tmp, path, is_dir, 1); + putname(tmp); + return res; +} +EXPORT_SYMBOL(user_path_create_thawed); + int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { int error = may_create(dir, dentry); @@ -2502,7 +2537,7 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, if (S_ISDIR(mode)) return -EPERM; - dentry = user_path_create(dfd, filename, &path, 0); + dentry = user_path_create_thawed(dfd, filename, &path, 0); if (IS_ERR(dentry)) return PTR_ERR(dentry); @@ -2511,12 +2546,9 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, error = may_mknod(mode); if (error) goto out_dput; - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_mknod(&path, dentry, mode, dev); if (error) - goto out_drop_write; + goto out_dput; switch (mode & S_IFMT) { case 0: case S_IFREG: error = vfs_create(path.dentry->d_inode,dentry,mode,NULL); @@ -2529,11 +2561,10 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, error = vfs_mknod(path.dentry->d_inode,dentry,mode,0); break; } -out_drop_write: - mnt_drop_write(path.mnt); out_dput: dput(dentry); mutex_unlock(&path.dentry->d_inode->i_mutex); + mnt_drop_write(path.mnt); path_put(&path); return error; @@ -2571,24 +2602,20 @@ SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) struct path path; int error; - dentry = user_path_create(dfd, pathname, &path, 1); + dentry = user_path_create_thawed(dfd, pathname, &path, 1); if (IS_ERR(dentry)) return PTR_ERR(dentry); if (!IS_POSIXACL(path.dentry->d_inode)) mode &= ~current_umask(); - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_mkdir(&path, dentry, mode); if (error) - goto out_drop_write; + goto out_dput; error = vfs_mkdir(path.dentry->d_inode, dentry, mode); -out_drop_write: - mnt_drop_write(path.mnt); out_dput: dput(dentry); mutex_unlock(&path.dentry->d_inode->i_mutex); + mnt_drop_write(path.mnt); path_put(&path); return error; } @@ -2683,6 +2710,9 @@ static long do_rmdir(int dfd, const char __user *pathname) } nd.flags &= ~LOOKUP_PARENT; + error = mnt_want_write(nd.path.mnt); + if (error) + goto exit1; mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); @@ -2693,19 +2723,15 @@ static long do_rmdir(int dfd, const char __user *pathname) error = -ENOENT; goto exit3; } - error = mnt_want_write(nd.path.mnt); - if (error) - goto exit3; error = security_path_rmdir(&nd.path, dentry); if (error) - goto exit4; + goto exit3; error = vfs_rmdir(nd.path.dentry->d_inode, dentry); -exit4: - mnt_drop_write(nd.path.mnt); exit3: dput(dentry); exit2: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + mnt_drop_write(nd.path.mnt); exit1: path_put(&nd.path); putname(name); @@ -2772,6 +2798,9 @@ static long do_unlinkat(int dfd, const char __user *pathname) goto exit1; nd.flags &= ~LOOKUP_PARENT; + error = mnt_want_write(nd.path.mnt); + if (error) + goto exit1; mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); @@ -2784,21 +2813,17 @@ static long do_unlinkat(int dfd, const char __user *pathname) if (!inode) goto slashes; ihold(inode); - error = mnt_want_write(nd.path.mnt); - if (error) - goto exit2; error = security_path_unlink(&nd.path, dentry); if (error) - goto exit3; + goto exit2; error = vfs_unlink(nd.path.dentry->d_inode, dentry); -exit3: - mnt_drop_write(nd.path.mnt); - exit2: +exit2: dput(dentry); } mutex_unlock(&nd.path.dentry->d_inode->i_mutex); if (inode) iput(inode); /* truncate the inode here */ + mnt_drop_write(nd.path.mnt); exit1: path_put(&nd.path); putname(name); @@ -2858,23 +2883,19 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, if (IS_ERR(from)) return PTR_ERR(from); - dentry = user_path_create(newdfd, newname, &path, 0); + dentry = user_path_create_thawed(newdfd, newname, &path, 0); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_putname; - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; error = security_path_symlink(&path, dentry, from); if (error) - goto out_drop_write; + goto out_dput; error = vfs_symlink(path.dentry->d_inode, dentry, from); -out_drop_write: - mnt_drop_write(path.mnt); out_dput: dput(dentry); mutex_unlock(&path.dentry->d_inode->i_mutex); + mnt_drop_write(path.mnt); path_put(&path); out_putname: putname(from); @@ -2964,7 +2985,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, if (error) return error; - new_dentry = user_path_create(newdfd, newname, &new_path, 0); + new_dentry = user_path_create_thawed(newdfd, newname, &new_path, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) goto out; @@ -2972,18 +2993,14 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, error = -EXDEV; if (old_path.mnt != new_path.mnt) goto out_dput; - error = mnt_want_write(new_path.mnt); - if (error) - goto out_dput; error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) - goto out_drop_write; + goto out_dput; error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); -out_drop_write: - mnt_drop_write(new_path.mnt); out_dput: dput(new_dentry); mutex_unlock(&new_path.dentry->d_inode->i_mutex); + mnt_drop_write(new_path.mnt); path_put(&new_path); out: path_put(&old_path); @@ -3174,6 +3191,10 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, if (newnd.last_type != LAST_NORM) goto exit2; + error = mnt_want_write(oldnd.path.mnt); + if (error) + goto exit2; + oldnd.flags &= ~LOOKUP_PARENT; newnd.flags &= ~LOOKUP_PARENT; newnd.flags |= LOOKUP_RENAME_TARGET; @@ -3209,23 +3230,19 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, if (new_dentry == trap) goto exit5; - error = mnt_want_write(oldnd.path.mnt); - if (error) - goto exit5; error = security_path_rename(&oldnd.path, old_dentry, &newnd.path, new_dentry); if (error) - goto exit6; + goto exit5; error = vfs_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, new_dentry); -exit6: - mnt_drop_write(oldnd.path.mnt); exit5: dput(new_dentry); exit4: dput(old_dentry); exit3: unlock_rename(new_dir, old_dir); + mnt_drop_write(oldnd.path.mnt); exit2: path_put(&newnd.path); putname(to); diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index cf78233..a99b8e2 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -4453,7 +4453,7 @@ int ocfs2_reflink_ioctl(struct inode *inode, return error; } - new_dentry = user_path_create(AT_FDCWD, newname, &new_path, 0); + new_dentry = user_path_create_thawed(AT_FDCWD, newname, &new_path, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) { mlog_errno(error); @@ -4466,19 +4466,13 @@ int ocfs2_reflink_ioctl(struct inode *inode, goto out_dput; } - error = mnt_want_write(new_path.mnt); - if (error) { - mlog_errno(error); - goto out_dput; - } - error = ocfs2_vfs_reflink(old_path.dentry, new_path.dentry->d_inode, new_dentry, preserve); - mnt_drop_write(new_path.mnt); out_dput: dput(new_dentry); mutex_unlock(&new_path.dentry->d_inode->i_mutex); + mnt_drop_write(new_path.mnt); path_put(&new_path); out: path_put(&old_path); diff --git a/include/linux/namei.h b/include/linux/namei.h index ffc0213..432f6bb 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -77,7 +77,9 @@ extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, extern int kern_path(const char *, unsigned, struct path *); extern struct dentry *kern_path_create(int, const char *, struct path *, int); +extern struct dentry *kern_path_create_thawed(int, const char *, struct path *, int); extern struct dentry *user_path_create(int, const char __user *, struct path *, int); +extern struct dentry *user_path_create_thawed(int, const char __user *, struct path *, int); extern int kern_path_parent(const char *, struct nameidata *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 85d3bb7..7888b09 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -856,7 +856,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) * Get the parent directory, calculate the hash for last * component. */ - dentry = kern_path_create(AT_FDCWD, sun_path, &path, 0); + dentry = kern_path_create_thawed(AT_FDCWD, sun_path, &path, 0); err = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_mknod_parent; @@ -866,19 +866,13 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) */ mode = S_IFSOCK | (SOCK_INODE(sock)->i_mode & ~current_umask()); - err = mnt_want_write(path.mnt); - if (err) - goto out_mknod_dput; err = security_path_mknod(&path, dentry, mode, 0); if (err) - goto out_mknod_drop_write; - err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); -out_mknod_drop_write: - mnt_drop_write(path.mnt); - if (err) goto out_mknod_dput; + err = vfs_mknod(path.dentry->d_inode, dentry, mode, 0); mutex_unlock(&path.dentry->d_inode->i_mutex); dput(path.dentry); + mnt_drop_write(path.mnt); path.dentry = dentry; addr->hash = UNIX_HASH_SIZE; @@ -916,6 +910,7 @@ out: out_mknod_dput: dput(dentry); mutex_unlock(&path.dentry->d_inode->i_mutex); + mnt_drop_write(path.mnt); path_put(&path); out_mknod_parent: if (err == -EEXIST) -- 1.7.1
Jan Kara
2012-Mar-05 16:01 UTC
[Ocfs2-devel] [PATCH 12/19] ocfs2: Convert to new freezing mechanism
Protect ocfs2_page_mkwrite() and ocfs2_file_aio_write() using the new freeze protection. We also protect several ioctl entry points which were missing the protection. CC: Mark Fasheh <mfasheh at suse.com> CC: Joel Becker <jlbec at evilplan.org> CC: ocfs2-devel at oss.oracle.com Signed-off-by: Jan Kara <jack at suse.cz> --- fs/ocfs2/file.c | 11 +++++++++-- fs/ocfs2/ioctl.c | 14 ++++++++++++-- fs/ocfs2/mmap.c | 2 ++ 3 files changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 061591a..9b1e3d4 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1971,6 +1971,7 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd, { struct inode *inode = file->f_path.dentry->d_inode; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + int ret; if ((cmd == OCFS2_IOC_RESVSP || cmd == OCFS2_IOC_RESVSP64) && !ocfs2_writes_unwritten_extents(osb)) @@ -1985,7 +1986,12 @@ int ocfs2_change_file_space(struct file *file, unsigned int cmd, if (!(file->f_mode & FMODE_WRITE)) return -EBADF; - return __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0); + ret = mnt_want_write_file(file); + if (ret) + return ret; + ret = __ocfs2_change_file_space(file, inode, file->f_pos, cmd, sr, 0); + mnt_drop_write_file(file); + return ret; } static long ocfs2_fallocate(struct file *file, int mode, loff_t offset, @@ -2261,7 +2267,7 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb, if (iocb->ki_left == 0) return 0; - vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); + sb_start_write(inode->i_sb); appending = file->f_flags & O_APPEND ? 1 : 0; direct_io = file->f_flags & O_DIRECT ? 1 : 0; @@ -2434,6 +2440,7 @@ out_sems: ocfs2_iocb_clear_sem_locked(iocb); mutex_unlock(&inode->i_mutex); + sb_end_write(inode->i_sb); if (written) ret = written; diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c index a6fda3c..59de312 100644 --- a/fs/ocfs2/ioctl.c +++ b/fs/ocfs2/ioctl.c @@ -928,7 +928,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (get_user(new_clusters, (int __user *)arg)) return -EFAULT; - return ocfs2_group_extend(inode, new_clusters); + status = mnt_want_write_file(filp); + if (status) + return status; + status = ocfs2_group_extend(inode, new_clusters); + mnt_drop_write_file(filp); + return status; case OCFS2_IOC_GROUP_ADD: case OCFS2_IOC_GROUP_ADD64: if (!capable(CAP_SYS_RESOURCE)) @@ -937,7 +942,12 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (copy_from_user(&input, (int __user *) arg, sizeof(input))) return -EFAULT; - return ocfs2_group_add(inode, &input); + status = mnt_want_write_file(filp); + if (status) + return status; + status = ocfs2_group_add(inode, &input); + mnt_drop_write_file(filp); + return status; case OCFS2_IOC_REFLINK: if (copy_from_user(&args, (struct reflink_arguments *)arg, sizeof(args))) diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c index 9cd4108..d150372 100644 --- a/fs/ocfs2/mmap.c +++ b/fs/ocfs2/mmap.c @@ -136,6 +136,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) sigset_t oldset; int ret; + sb_start_pagefault(inode->i_sb); ocfs2_block_signals(&oldset); /* @@ -165,6 +166,7 @@ static int ocfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) out: ocfs2_unblock_signals(&oldset); + sb_end_pagefault(inode->i_sb); return ret; } -- 1.7.1
Jan Kara
2012-Mar-05 16:01 UTC
[Ocfs2-devel] [PATCH 00/19] Fix filesystem freezing deadlocks
Hallelujah, after a couple of weeks and several rewrites, here comes the third iteration of my patches to improve filesystem freezing. Filesystem freezing is currently racy and thus we can end up with dirty data on frozen filesystem (see changelog patch 06 for detailed race description). This patch series aims at fixing this. To be able to block all places where inodes get dirtied, I've moved filesystem freeze handling in mnt_want_write() / mnt_drop_write(). This however required some code shuffling and changes to kern_path_create() (see patches 02-05). I think the result is OK but opinions may differ ;). The advantage of this change also is that all filesystems get freeze protection almost for free - even ext2 can handle freezing well now. Another potential contention point might be patch 19. In that patch we make freeze_super() refuse to freeze the filesystem when there are open but unlinked files which may be impractical in some cases. The main reason for this is the problem with handling of file deletion from fput() called with mmap_sem held (e.g. from munmap(2)), and then there's the fact that we cannot really force such filesystem into a consistent state... But if people think that freezing with open but unlinked files should happen, then I have some possible solutions in mind (maybe as a separate patchset since this is large enough). I'm not able to hit any deadlocks, lockdep warnings, or dirty data on frozen filesystem despite beating it with fsstress and bash-shared-mapping while freezing and unfreezing for several hours (using ext4 and xfs) so I'm reasonably confident this could finally be the right solution. And for people wanting to test - this patchset is based on patch series "Push file_update_time() into .page_mkwrite" so you'll need to pull that one in as well. Changes since v2: * completely rewritten * freezing is now blocked at VFS entry points * two stage freezing to handle both mmapped writes and other IO The biggest changes since v1: * have two counters to provide safe state transitions for SB_FREEZE_WRITE and SB_FREEZE_TRANS states * use percpu counters instead of own percpu structure * added documentation fixes from the old fs freezing series * converted XFS to use SB_FREEZE_TRANS counter instead of its private m_active_trans counter Honza CC: Alex Elder <elder at kernel.org> CC: Anton Altaparmakov <anton at tuxera.com> CC: Ben Myers <bpm at sgi.com> CC: Chris Mason <chris.mason at oracle.com> CC: cluster-devel at redhat.com CC: "David S. Miller" <davem at davemloft.net> CC: fuse-devel at lists.sourceforge.net CC: "J. Bruce Fields" <bfields at fieldses.org> CC: Joel Becker <jlbec at evilplan.org> CC: KONISHI Ryusuke <konishi.ryusuke at lab.ntt.co.jp> CC: linux-btrfs at vger.kernel.org CC: linux-ext4 at vger.kernel.org CC: linux-nfs at vger.kernel.org CC: linux-nilfs at vger.kernel.org CC: linux-ntfs-dev at lists.sourceforge.net CC: Mark Fasheh <mfasheh at suse.com> CC: Miklos Szeredi <miklos at szeredi.hu> CC: ocfs2-devel at oss.oracle.com CC: OGAWA Hirofumi <hirofumi at mail.parknet.co.jp> CC: Steven Whitehouse <swhiteho at redhat.com> CC: "Theodore Ts'o" <tytso at mit.edu> CC: xfs at oss.sgi.com
Kamal Mostafa
2012-Mar-11 20:23 UTC
[Ocfs2-devel] [PATCH 00/19] Fix filesystem freezing deadlocks
On Mon, 2012-03-05 at 17:00 +0100, Jan Kara wrote:> Hallelujah, > > after a couple of weeks and several rewrites, here comes the third iteration > of my patches to improve filesystem freezing. [...]We've been testing this patch set at Canonical on the multipath failover SAN configuration where we originally encountered the freeze deadlock. We are happy to report that it does appear to fix the problem. Thanks Jan! Please add the following endorsements for these patches (those actually exercised by our test case): 01, 02, 03, 06, 07, 08, 09, 10, 14, 18, 19 BugLink: https://bugs.launchpad.net/bugs/897421 Tested-by: Kamal Mostafa <kamal at canonical.com> Tested-by: Peter M. Petrakis <peter.petrakis at canonical.com> Tested-by: Dann Frazier <dann.frazier at canonical.com> Tested-by: Massimo Morana <massimo.morana at canonical.com> -Kamal -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: This is a digitally signed message part Url : http://oss.oracle.com/pipermail/ocfs2-devel/attachments/20120311/9f92c086/attachment-0001.bin