dmaengine: mmp-pdma support

[firefly-linux-kernel-4.4.55.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 618d3531cf9f7a9221e56e7fa9b6a27556c7d893..1b464390dde85ecd783eb45f64aee1f89f6c3ff1 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2395,7 +2395,7 @@ static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode)
 static int atomic_open(struct nameidata *nd, struct dentry *dentry,
                        struct path *path, struct file *file,
                        const struct open_flags *op,
-                       bool *want_write, bool need_lookup,
+                       bool got_write, bool need_lookup,
                        int *opened)
 {
        struct inode *dir =  nd->path.dentry->d_inode;
@@ -2418,7 +2418,7 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
        if ((open_flag & O_CREAT) && !IS_POSIXACL(dir))
                mode &= ~current_umask();
 
-       if (open_flag & O_EXCL) {
+       if ((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT)) {
                open_flag &= ~O_TRUNC;
                *opened |= FILE_CREATED;
        }
@@ -2432,12 +2432,9 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
         * Another problem is returing the "right" error value (e.g. for an
         * O_EXCL open we want to return EEXIST not EROFS).
         */
-       if ((open_flag & (O_CREAT | O_TRUNC)) ||
-           (open_flag & O_ACCMODE) != O_RDONLY) {
-               error = mnt_want_write(nd->path.mnt);
-               if (!error) {
-                       *want_write = true;
-               } else if (!(open_flag & O_CREAT)) {
+       if (((open_flag & (O_CREAT | O_TRUNC)) ||
+           (open_flag & O_ACCMODE) != O_RDONLY) && unlikely(!got_write)) {
+               if (!(open_flag & O_CREAT)) {
                        /*
                         * No O_CREATE -> atomicity not a requirement -> fall
                         * back to lookup + open
@@ -2445,11 +2442,11 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
                        goto no_open;
                } else if (open_flag & (O_EXCL | O_TRUNC)) {
                        /* Fall back and fail with the right error */
-                       create_error = error;
+                       create_error = -EROFS;
                        goto no_open;
                } else {
                        /* No side effects, safe to clear O_CREAT */
-                       create_error = error;
+                       create_error = -EROFS;
                        open_flag &= ~O_CREAT;
                }
        }
@@ -2556,7 +2553,7 @@ looked_up:
 static int lookup_open(struct nameidata *nd, struct path *path,
                        struct file *file,
                        const struct open_flags *op,
-                       bool *want_write, int *opened)
+                       bool got_write, int *opened)
 {
        struct dentry *dir = nd->path.dentry;
        struct inode *dir_inode = dir->d_inode;
@@ -2574,7 +2571,7 @@ static int lookup_open(struct nameidata *nd, struct path *path,
                goto out_no_open;
 
        if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
-               return atomic_open(nd, dentry, path, file, op, want_write,
+               return atomic_open(nd, dentry, path, file, op, got_write,
                                   need_lookup, opened);
        }
 
@@ -2598,10 +2595,10 @@ static int lookup_open(struct nameidata *nd, struct path *path,
                 * a permanent write count is taken through
                 * the 'struct file' in finish_open().
                 */
-               error = mnt_want_write(nd->path.mnt);
-               if (error)
+               if (!got_write) {
+                       error = -EROFS;
                        goto out_dput;
-               *want_write = true;
+               }
                *opened |= FILE_CREATED;
                error = security_path_mknod(&nd->path, dentry, mode, 0);
                if (error)
@@ -2631,7 +2628,7 @@ static int do_last(struct nameidata *nd, struct path *path,
        struct dentry *dir = nd->path.dentry;
        int open_flag = op->open_flag;
        bool will_truncate = (open_flag & O_TRUNC) != 0;
-       bool want_write = false;
+       bool got_write = false;
        int acc_mode = op->acc_mode;
        struct inode *inode;
        bool symlink_ok = false;
@@ -2700,8 +2697,18 @@ static int do_last(struct nameidata *nd, struct path *path,
        }
 
 retry_lookup:
+       if (op->open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
+               error = mnt_want_write(nd->path.mnt);
+               if (!error)
+                       got_write = true;
+               /*
+                * do _not_ fail yet - we might not need that or fail with
+                * a different error; let lookup_open() decide; we'll be
+                * dropping this one anyway.
+                */
+       }
        mutex_lock(&dir->d_inode->i_mutex);
-       error = lookup_open(nd, path, file, op, &want_write, opened);
+       error = lookup_open(nd, path, file, op, got_write, opened);
        mutex_unlock(&dir->d_inode->i_mutex);
 
        if (error <= 0) {
@@ -2736,13 +2743,13 @@ retry_lookup:
         * possible mount and symlink following (this might be optimized away if
         * necessary...)
         */
-       if (want_write) {
+       if (got_write) {
                mnt_drop_write(nd->path.mnt);
-               want_write = false;
+               got_write = false;
        }
 
        error = -EEXIST;
-       if (open_flag & O_EXCL)
+       if ((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))
                goto exit_dput;
 
        error = follow_managed(path, nd->flags);
@@ -2803,7 +2810,7 @@ finish_open:
                error = mnt_want_write(nd->path.mnt);
                if (error)
                        goto out;
-               want_write = true;
+               got_write = true;
        }
 finish_open_created:
        error = may_open(&nd->path, acc_mode, open_flag);
@@ -2830,7 +2837,7 @@ opened:
                        goto exit_fput;
        }
 out:
-       if (want_write)
+       if (got_write)
                mnt_drop_write(nd->path.mnt);
        path_put(&save_parent);
        terminate_walk(nd);
@@ -2854,9 +2861,9 @@ stale_open:
        nd->inode = dir->d_inode;
        save_parent.mnt = NULL;
        save_parent.dentry = NULL;
-       if (want_write) {
+       if (got_write) {
                mnt_drop_write(nd->path.mnt);
-               want_write = false;
+               got_write = false;
        }
        retried = true;
        goto retry_lookup;
@@ -2968,6 +2975,7 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path
 {
        struct dentry *dentry = ERR_PTR(-EEXIST);
        struct nameidata nd;
+       int err2;
        int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd);
        if (error)
                return ERR_PTR(error);
@@ -2981,6 +2989,8 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path
        nd.flags &= ~LOOKUP_PARENT;
        nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL;
 
+       /* don't fail immediately if it's r/o, at least try to report other errors */
+       err2 = mnt_want_write(nd.path.mnt);
        /*
         * Do the final lookup.
         */
@@ -3002,9 +3012,10 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path
                error = -ENOENT;
                goto fail;
        }
-       error = mnt_want_write(nd.path.mnt);
-       if (error)
+       if (unlikely(err2)) {
+               error = err2;
                goto fail;
+       }
        *path = nd.path;
        return dentry;
 fail:
@@ -3012,6 +3023,8 @@ fail:
        dentry = ERR_PTR(error);
 unlock:
        mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+       if (!err2)
+               mnt_drop_write(nd.path.mnt);
 out:
        path_put(&nd.path);
        return dentry;
@@ -3259,6 +3272,9 @@ 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);
@@ -3269,19 +3285,15 @@ 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);
@@ -3348,6 +3360,9 @@ 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);
@@ -3360,21 +3375,17 @@ 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);
@@ -3746,6 +3757,10 @@ 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;
@@ -3781,23 +3796,19 @@ 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);