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Diffstat (limited to 'fs/open.c')
-rw-r--r--fs/open.c149
1 files changed, 99 insertions, 50 deletions
diff --git a/fs/open.c b/fs/open.c
index 59071f55bf7f..68354466879f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -30,6 +30,7 @@
#include <linux/fs_struct.h>
#include <linux/ima.h>
#include <linux/dnotify.h>
+#include <linux/compat.h>
#include "internal.h"
@@ -61,33 +62,22 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
return ret;
}
-static long do_sys_truncate(const char __user *pathname, loff_t length)
+long vfs_truncate(struct path *path, loff_t length)
{
- struct path path;
struct inode *inode;
- int error;
+ long error;
- error = -EINVAL;
- if (length < 0) /* sorry, but loff_t says... */
- goto out;
-
- error = user_path(pathname, &path);
- if (error)
- goto out;
- inode = path.dentry->d_inode;
+ inode = path->dentry->d_inode;
/* For directories it's -EISDIR, for other non-regulars - -EINVAL */
- error = -EISDIR;
if (S_ISDIR(inode->i_mode))
- goto dput_and_out;
-
- error = -EINVAL;
+ return -EISDIR;
if (!S_ISREG(inode->i_mode))
- goto dput_and_out;
+ return -EINVAL;
- error = mnt_want_write(path.mnt);
+ error = mnt_want_write(path->mnt);
if (error)
- goto dput_and_out;
+ goto out;
error = inode_permission(inode, MAY_WRITE);
if (error)
@@ -111,25 +101,53 @@ static long do_sys_truncate(const char __user *pathname, loff_t length)
error = locks_verify_truncate(inode, NULL, length);
if (!error)
- error = security_path_truncate(&path);
+ error = security_path_truncate(path);
if (!error)
- error = do_truncate(path.dentry, length, 0, NULL);
+ error = do_truncate(path->dentry, length, 0, NULL);
put_write_and_out:
put_write_access(inode);
mnt_drop_write_and_out:
- mnt_drop_write(path.mnt);
-dput_and_out:
- path_put(&path);
+ mnt_drop_write(path->mnt);
out:
return error;
}
+EXPORT_SYMBOL_GPL(vfs_truncate);
+
+static long do_sys_truncate(const char __user *pathname, loff_t length)
+{
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+ struct path path;
+ int error;
+
+ if (length < 0) /* sorry, but loff_t says... */
+ return -EINVAL;
+
+retry:
+ error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
+ if (!error) {
+ error = vfs_truncate(&path, length);
+ path_put(&path);
+ }
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
+ return error;
+}
SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
{
return do_sys_truncate(path, length);
}
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
+{
+ return do_sys_truncate(path, length);
+}
+#endif
+
static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
{
struct inode *inode;
@@ -185,6 +203,13 @@ SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
return ret;
}
+#ifdef CONFIG_COMPAT
+COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
+{
+ return do_sys_ftruncate(fd, length, 1);
+}
+#endif
+
/* LFS versions of truncate are only needed on 32 bit machines */
#if BITS_PER_LONG == 32
SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length)
@@ -218,7 +243,7 @@ SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64);
int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
{
- struct inode *inode = file->f_path.dentry->d_inode;
+ struct inode *inode = file_inode(file);
long ret;
if (offset < 0 || len <= 0)
@@ -306,6 +331,7 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
struct path path;
struct inode *inode;
int res;
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
return -EINVAL;
@@ -328,8 +354,8 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
}
old_cred = override_creds(override_cred);
-
- res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
+retry:
+ res = user_path_at(dfd, filename, lookup_flags, &path);
if (res)
goto out;
@@ -364,6 +390,10 @@ SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
out_path_release:
path_put(&path);
+ if (retry_estale(res, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
revert_creds(old_cred);
put_cred(override_cred);
@@ -379,8 +409,9 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
{
struct path path;
int error;
-
- error = user_path_dir(filename, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+retry:
+ error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
if (error)
goto out;
@@ -392,6 +423,10 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
dput_and_out:
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
return error;
}
@@ -406,7 +441,7 @@ SYSCALL_DEFINE1(fchdir, unsigned int, fd)
if (!f.file)
goto out;
- inode = f.file->f_path.dentry->d_inode;
+ inode = file_inode(f.file);
error = -ENOTDIR;
if (!S_ISDIR(inode->i_mode))
@@ -425,8 +460,9 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
{
struct path path;
int error;
-
- error = user_path_dir(filename, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
+retry:
+ error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
if (error)
goto out;
@@ -435,7 +471,7 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
goto dput_and_out;
error = -EPERM;
- if (!capable(CAP_SYS_CHROOT))
+ if (!nsown_capable(CAP_SYS_CHROOT))
goto dput_and_out;
error = security_path_chroot(&path);
if (error)
@@ -445,6 +481,10 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
error = 0;
dput_and_out:
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
return error;
}
@@ -489,11 +529,16 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode
{
struct path path;
int error;
-
- error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
+ unsigned int lookup_flags = LOOKUP_FOLLOW;
+retry:
+ error = user_path_at(dfd, filename, lookup_flags, &path);
if (!error) {
error = chmod_common(&path, mode);
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
}
return error;
}
@@ -552,6 +597,7 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
if (flag & AT_EMPTY_PATH)
lookup_flags |= LOOKUP_EMPTY;
+retry:
error = user_path_at(dfd, filename, lookup_flags, &path);
if (error)
goto out;
@@ -562,6 +608,10 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
mnt_drop_write(path.mnt);
out_release:
path_put(&path);
+ if (retry_estale(error, lookup_flags)) {
+ lookup_flags |= LOOKUP_REVAL;
+ goto retry;
+ }
out:
return error;
}
@@ -654,7 +704,7 @@ static int do_dentry_open(struct file *f,
f->f_mode = FMODE_PATH;
path_get(&f->f_path);
- inode = f->f_path.dentry->d_inode;
+ inode = f->f_inode = f->f_path.dentry->d_inode;
if (f->f_mode & FMODE_WRITE) {
error = __get_file_write_access(inode, f->f_path.mnt);
if (error)
@@ -664,7 +714,6 @@ static int do_dentry_open(struct file *f,
}
f->f_mapping = inode->i_mapping;
- f->f_pos = 0;
file_sb_list_add(f, inode->i_sb);
if (unlikely(f->f_mode & FMODE_PATH)) {
@@ -718,6 +767,7 @@ cleanup_file:
path_put(&f->f_path);
f->f_path.mnt = NULL;
f->f_path.dentry = NULL;
+ f->f_inode = NULL;
return error;
}
@@ -775,23 +825,22 @@ struct file *dentry_open(const struct path *path, int flags,
/* We must always pass in a valid mount pointer. */
BUG_ON(!path->mnt);
- error = -ENFILE;
f = get_empty_filp();
- if (f == NULL)
- return ERR_PTR(error);
-
- f->f_flags = flags;
- f->f_path = *path;
- error = do_dentry_open(f, NULL, cred);
- if (!error) {
- error = open_check_o_direct(f);
- if (error) {
- fput(f);
+ if (!IS_ERR(f)) {
+ f->f_flags = flags;
+ f->f_path = *path;
+ error = do_dentry_open(f, NULL, cred);
+ if (!error) {
+ /* from now on we need fput() to dispose of f */
+ error = open_check_o_direct(f);
+ if (error) {
+ fput(f);
+ f = ERR_PTR(error);
+ }
+ } else {
+ put_filp(f);
f = ERR_PTR(error);
}
- } else {
- put_filp(f);
- f = ERR_PTR(error);
}
return f;
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-04 08:18:43 +0000