From 8033426e6bdb2690d302872ac1e1fadaec1a5581 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 26 Jul 2013 06:23:25 -0400 Subject: vfs: allow umount to handle mountpoints without revalidating them Christopher reported a regression where he was unable to unmount a NFS filesystem where the root had gone stale. The problem is that d_revalidate handles the root of the filesystem differently from other dentries, but d_weak_revalidate does not. We could simply fix this by making d_weak_revalidate return success on IS_ROOT dentries, but there are cases where we do want to revalidate the root of the fs. A umount is really a special case. We generally aren't interested in anything but the dentry and vfsmount that's attached at that point. If the inode turns out to be stale we just don't care since the intent is to stop using it anyway. Try to handle this situation better by treating umount as a special case in the lookup code. Have it resolve the parent using normal means, and then do a lookup of the final dentry without revalidating it. In most cases, the final lookup will come out of the dcache, but the case where there's a trailing symlink or !LAST_NORM entry on the end complicates things a bit. Cc: Neil Brown Reported-by: Christopher T Vogan Signed-off-by: Jeff Layton Signed-off-by: Al Viro --- include/linux/namei.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/namei.h b/include/linux/namei.h index 5a5ff57ceed4..cd09751c71a0 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -58,6 +58,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; extern int user_path_at(int, const char __user *, unsigned, struct path *); extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty); +extern int user_path_umountat(int, const char __user *, unsigned int, struct path *); #define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path) #define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path) -- cgit v1.2.3 From badcf2b7b816130a60152d9f5a06705176596925 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 16 Jul 2013 18:15:46 +0400 Subject: constify touch_atime() Signed-off-by: Al Viro --- include/linux/fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index 981874773e85..65c9929cd340 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1804,7 +1804,7 @@ enum file_time_flags { S_VERSION = 8, }; -extern void touch_atime(struct path *); +extern void touch_atime(const struct path *); static inline void file_accessed(struct file *file) { if (!(file->f_flags & O_NOATIME)) -- cgit v1.2.3 From ef7bca1456e7f65e66b9466c3b149601fe32eec0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 19 Jul 2013 15:52:42 +0400 Subject: oprofile: don't bother with passing superblock to ->create_files() Signed-off-by: Al Viro --- include/linux/oprofile.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index a4c562453f6b..8a906b4034a7 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -51,7 +51,7 @@ struct pt_regs; struct oprofile_operations { /* create any necessary configuration files in the oprofile fs. * Optional. */ - int (*create_files)(struct super_block * sb, struct dentry * root); + int (*create_files)(struct dentry * root); /* Do any necessary interrupt setup. Optional. */ int (*setup)(void); /* Do any necessary interrupt shutdown. Optional. */ -- cgit v1.2.3 From ecde28237e10de3750a97579f42bc2ec65b8a0e1 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 19 Jul 2013 15:58:27 +0400 Subject: oprofilefs_mkdir() doesn't need superblock argument it's always equal to ->d_sb of the second argument (parent dentry), due to either being literally that, or ->d_sb of parent's parent. Signed-off-by: Al Viro --- include/linux/oprofile.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index 8a906b4034a7..957877e7a408 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -144,8 +144,7 @@ int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root, char const * name, atomic_t * val); /** create a directory */ -struct dentry * oprofilefs_mkdir(struct super_block * sb, struct dentry * root, - char const * name); +struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name); /** * Write the given asciz string to the given user buffer @buf, updating *offset -- cgit v1.2.3 From 6af4ea0ba708172be8caf1ba5047b2b8a9d2fea3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 19 Jul 2013 16:10:36 +0400 Subject: oprofilefs_create_...() do not need superblock argument same story as with oprofilefs_mkdir() Signed-off-by: Al Viro --- include/linux/oprofile.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'include') diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index 957877e7a408..166ef4fb4b5c 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -125,22 +125,22 @@ void oprofile_add_trace(unsigned long eip); * Create a file of the given name as a child of the given root, with * the specified file operations. */ -int oprofilefs_create_file(struct super_block * sb, struct dentry * root, +int oprofilefs_create_file(struct dentry * root, char const * name, const struct file_operations * fops); -int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root, +int oprofilefs_create_file_perm(struct dentry * root, char const * name, const struct file_operations * fops, int perm); /** Create a file for read/write access to an unsigned long. */ -int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root, +int oprofilefs_create_ulong(struct dentry * root, char const * name, ulong * val); /** Create a file for read-only access to an unsigned long. */ -int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root, +int oprofilefs_create_ro_ulong(struct dentry * root, char const * name, ulong * val); /** Create a file for read-only access to an atomic_t. */ -int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root, +int oprofilefs_create_ro_atomic(struct dentry * root, char const * name, atomic_t * val); /** create a directory */ -- cgit v1.2.3 From 2b2fee80a7058959a6a9ba8706b3af5589b286d3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 19 Jul 2013 16:13:30 +0400 Subject: oprofile: get rid of pointless forward declarations of struct super_block Signed-off-by: Al Viro --- include/linux/oprofile.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include') diff --git a/include/linux/oprofile.h b/include/linux/oprofile.h index 166ef4fb4b5c..b2a0f15f11fe 100644 --- a/include/linux/oprofile.h +++ b/include/linux/oprofile.h @@ -42,7 +42,6 @@ #define IBS_FETCH_CODE 13 #define IBS_OP_CODE 14 -struct super_block; struct dentry; struct file_operations; struct pt_regs; -- cgit v1.2.3 From 7b7a8665edd8db733980389b098530f9e4f630b2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 4 Sep 2013 15:04:39 +0200 Subject: direct-io: Implement generic deferred AIO completions Add support to the core direct-io code to defer AIO completions to user context using a workqueue. This replaces opencoded and less efficient code in XFS and ext4 (we save a memory allocation for each direct IO) and will be needed to properly support O_(D)SYNC for AIO. The communication between the filesystem and the direct I/O code requires a new buffer head flag, which is a bit ugly but not avoidable until the direct I/O code stops abusing the buffer_head structure for communicating with the filesystems. Currently this creates a per-superblock unbound workqueue for these completions, which is taken from an earlier patch by Jan Kara. I'm not really convinced about this use and would prefer a "normal" global workqueue with a high concurrency limit, but this needs further discussion. JK: Fixed ext4 part, dynamic allocation of the workqueue. Signed-off-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Al Viro --- include/linux/buffer_head.h | 2 ++ include/linux/fs.h | 7 +++++-- 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 91fa9a94ae92..d77797a52b7b 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -36,6 +36,7 @@ enum bh_state_bits { BH_Quiet, /* Buffer Error Prinks to be quiet */ BH_Meta, /* Buffer contains metadata */ BH_Prio, /* Buffer should be submitted with REQ_PRIO */ + BH_Defer_Completion, /* Defer AIO completion to workqueue */ BH_PrivateStart,/* not a state bit, but the first bit available * for private allocation by other entities @@ -128,6 +129,7 @@ BUFFER_FNS(Write_EIO, write_io_error) BUFFER_FNS(Unwritten, unwritten) BUFFER_FNS(Meta, meta) BUFFER_FNS(Prio, prio) +BUFFER_FNS(Defer_Completion, defer_completion) #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK) diff --git a/include/linux/fs.h b/include/linux/fs.h index 65c9929cd340..c9013876eb29 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -46,6 +46,7 @@ struct vfsmount; struct cred; struct swap_info_struct; struct seq_file; +struct workqueue_struct; extern void __init inode_init(void); extern void __init inode_init_early(void); @@ -63,8 +64,7 @@ struct buffer_head; typedef int (get_block_t)(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create); typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, - ssize_t bytes, void *private, int ret, - bool is_async); + ssize_t bytes, void *private); #define MAY_EXEC 0x00000001 #define MAY_WRITE 0x00000002 @@ -1328,6 +1328,9 @@ struct super_block { /* Being remounted read-only */ int s_readonly_remount; + + /* AIO completions deferred from interrupt context */ + struct workqueue_struct *s_dio_done_wq; }; /* superblock cache pruning functions */ -- cgit v1.2.3