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authorLinus Torvalds <torvalds@linux-foundation.org>2013-03-26 17:42:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-26 17:42:55 -0700
commitde55eb1d60d2ed0f1ba5e13226d91b3bfbe1c108 (patch)
tree8f2a62f811562b4008dd1cd50a0ebf5603b13a76 /fs
parentb175293ccc98ab84e93d25472d7422b4a897614b (diff)
parente8cd81693bbbb15db57d3c9aa7dd90eda4842874 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro: "stable fodder; assorted deadlock fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vt: synchronize_rcu() under spinlock is not nice... Nest rename_lock inside vfsmount_lock Don't bother with redoing rw_verify_area() from default_file_splice_from()
Diffstat (limited to 'fs')
-rw-r--r--fs/dcache.c16
-rw-r--r--fs/internal.h5
-rw-r--r--fs/read_write.c25
-rw-r--r--fs/splice.c4
4 files changed, 44 insertions, 6 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index fbfae008ba44..e8bc3420d63e 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2542,7 +2542,6 @@ static int prepend_path(const struct path *path,
bool slash = false;
int error = 0;
- br_read_lock(&vfsmount_lock);
while (dentry != root->dentry || vfsmnt != root->mnt) {
struct dentry * parent;
@@ -2572,8 +2571,6 @@ static int prepend_path(const struct path *path,
if (!error && !slash)
error = prepend(buffer, buflen, "/", 1);
-out:
- br_read_unlock(&vfsmount_lock);
return error;
global_root:
@@ -2590,7 +2587,7 @@ global_root:
error = prepend(buffer, buflen, "/", 1);
if (!error)
error = is_mounted(vfsmnt) ? 1 : 2;
- goto out;
+ return error;
}
/**
@@ -2617,9 +2614,11 @@ char *__d_path(const struct path *path,
int error;
prepend(&res, &buflen, "\0", 1);
+ br_read_lock(&vfsmount_lock);
write_seqlock(&rename_lock);
error = prepend_path(path, root, &res, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error < 0)
return ERR_PTR(error);
@@ -2636,9 +2635,11 @@ char *d_absolute_path(const struct path *path,
int error;
prepend(&res, &buflen, "\0", 1);
+ br_read_lock(&vfsmount_lock);
write_seqlock(&rename_lock);
error = prepend_path(path, &root, &res, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error > 1)
error = -EINVAL;
@@ -2702,11 +2703,13 @@ char *d_path(const struct path *path, char *buf, int buflen)
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
+ br_read_lock(&vfsmount_lock);
write_seqlock(&rename_lock);
error = path_with_deleted(path, &root, &res, &buflen);
+ write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error < 0)
res = ERR_PTR(error);
- write_sequnlock(&rename_lock);
path_put(&root);
return res;
}
@@ -2830,6 +2833,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
get_fs_root_and_pwd(current->fs, &root, &pwd);
error = -ENOENT;
+ br_read_lock(&vfsmount_lock);
write_seqlock(&rename_lock);
if (!d_unlinked(pwd.dentry)) {
unsigned long len;
@@ -2839,6 +2843,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
prepend(&cwd, &buflen, "\0", 1);
error = prepend_path(&pwd, &root, &cwd, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error < 0)
goto out;
@@ -2859,6 +2864,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
}
} else {
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
}
out:
diff --git a/fs/internal.h b/fs/internal.h
index 507141fceb99..4be78237d896 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -125,3 +125,8 @@ extern int invalidate_inodes(struct super_block *, bool);
* dcache.c
*/
extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
+
+/*
+ * read_write.c
+ */
+extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
diff --git a/fs/read_write.c b/fs/read_write.c
index a698eff457fb..f7b5a23b804b 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -17,6 +17,7 @@
#include <linux/splice.h>
#include <linux/compat.h>
#include "read_write.h"
+#include "internal.h"
#include <asm/uaccess.h>
#include <asm/unistd.h>
@@ -417,6 +418,30 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof
EXPORT_SYMBOL(do_sync_write);
+ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
+{
+ mm_segment_t old_fs;
+ const char __user *p;
+ ssize_t ret;
+
+ old_fs = get_fs();
+ set_fs(get_ds());
+ p = (__force const char __user *)buf;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ if (file->f_op->write)
+ ret = file->f_op->write(file, p, count, pos);
+ else
+ ret = do_sync_write(file, p, count, pos);
+ set_fs(old_fs);
+ if (ret > 0) {
+ fsnotify_modify(file);
+ add_wchar(current, ret);
+ }
+ inc_syscw(current);
+ return ret;
+}
+
ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
{
ssize_t ret;
diff --git a/fs/splice.c b/fs/splice.c
index 718bd0056384..29e394e49ddd 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -31,6 +31,7 @@
#include <linux/security.h>
#include <linux/gfp.h>
#include <linux/socket.h>
+#include "internal.h"
/*
* Attempt to steal a page from a pipe buffer. This should perhaps go into
@@ -1048,9 +1049,10 @@ static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
{
int ret;
void *data;
+ loff_t tmp = sd->pos;
data = buf->ops->map(pipe, buf, 0);
- ret = kernel_write(sd->u.file, data + buf->offset, sd->len, sd->pos);
+ ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp);
buf->ops->unmap(pipe, buf, data);
return ret;