diff options
Diffstat (limited to 'fs/open.c')
| -rw-r--r-- | fs/open.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/fs/open.c b/fs/open.c index be6a457f4226..a6b054edacba 100644 --- a/fs/open.c +++ b/fs/open.c @@ -26,6 +26,7 @@ #include <linux/syscalls.h> #include <linux/rcupdate.h> #include <linux/audit.h> +#include <linux/falloc.h> int vfs_statfs(struct dentry *dentry, struct kstatfs *buf) { @@ -352,6 +353,64 @@ asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) } #endif +asmlinkage long sys_fallocate(int fd, int mode, loff_t offset, loff_t len) +{ + struct file *file; + struct inode *inode; + long ret = -EINVAL; + + if (offset < 0 || len <= 0) + goto out; + + /* Return error if mode is not supported */ + ret = -EOPNOTSUPP; + if (mode && !(mode & FALLOC_FL_KEEP_SIZE)) + goto out; + + ret = -EBADF; + file = fget(fd); + if (!file) + goto out; + if (!(file->f_mode & FMODE_WRITE)) + goto out_fput; + /* + * Revalidate the write permissions, in case security policy has + * changed since the files were opened. + */ + ret = security_file_permission(file, MAY_WRITE); + if (ret) + goto out_fput; + + inode = file->f_path.dentry->d_inode; + + ret = -ESPIPE; + if (S_ISFIFO(inode->i_mode)) + goto out_fput; + + ret = -ENODEV; + /* + * Let individual file system decide if it supports preallocation + * for directories or not. + */ + if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) + goto out_fput; + + ret = -EFBIG; + /* Check for wrap through zero too */ + if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) + goto out_fput; + + if (inode->i_op && inode->i_op->fallocate) + ret = inode->i_op->fallocate(inode, mode, offset, len); + else + ret = -ENOSYS; + +out_fput: + fput(file); +out: + return ret; +} + /* * access() needs to use the real uid/gid, not the effective uid/gid. * We do this by temporarily clearing all FS-related capabilities and |