I have not implemented FA_FL_FREE_ENOSPC and FA_ZERO_SPACE flags yet, as *suggested* by Andreas in http://lkml.org/lkml/2007/6/14/323 post. If it is decided that these flags are also needed, I will update this patch. Thanks! On Mon, Jun 25, 2007 at 07:15:00PM +0530, Amit K. Arora wrote: > Implement new flags and values for mode argument. > > This patch implements the new flags and values for the "mode" argument > of the fallocate system call. It is based on the discussion between > Andreas Dilger and David Chinner on the man page proposed (by the later) > on fallocate. > > Signed-off-by: Amit Arora <aarora@xxxxxxxxxx> > > Index: linux-2.6.22-rc4/include/linux/fs.h > =================================================================== > --- linux-2.6.22-rc4.orig/include/linux/fs.h > +++ linux-2.6.22-rc4/include/linux/fs.h > @@ -267,15 +267,16 @@ extern int dir_notify_enable; > #define SYNC_FILE_RANGE_WAIT_AFTER 4 > > /* > - * sys_fallocate modes > - * Currently sys_fallocate supports two modes: > - * FA_ALLOCATE : This is the preallocate mode, using which an application/user > - * may request (pre)allocation of blocks. > - * FA_DEALLOCATE: This is the deallocate mode, which can be used to free > - * the preallocated blocks. > + * sys_fallocate mode flags and values > */ > -#define FA_ALLOCATE 0x1 > -#define FA_DEALLOCATE 0x2 > +#define FA_FL_DEALLOC 0x01 /* default is allocate */ > +#define FA_FL_KEEP_SIZE 0x02 /* default is extend/shrink size */ > +#define FA_FL_DEL_DATA 0x04 /* default is keep written data on DEALLOC */ > + > +#define FA_ALLOCATE 0 > +#define FA_DEALLOCATE FA_FL_DEALLOC > +#define FA_RESV_SPACE FA_FL_KEEP_SIZE > +#define FA_UNRESV_SPACE (FA_FL_DEALLOC | FA_FL_KEEP_SIZE | FA_FL_DEL_DATA) > > #ifdef __KERNEL__ > > Index: linux-2.6.22-rc4/fs/open.c > =================================================================== > --- linux-2.6.22-rc4.orig/fs/open.c > +++ linux-2.6.22-rc4/fs/open.c > @@ -356,23 +356,26 @@ asmlinkage long sys_ftruncate64(unsigned > * sys_fallocate - preallocate blocks or free preallocated blocks > * @fd: the file descriptor > * @mode: mode specifies if fallocate should preallocate blocks OR free > - * (unallocate) preallocated blocks. Currently only FA_ALLOCATE and > - * FA_DEALLOCATE modes are supported. > + * (unallocate) preallocated blocks. > * @offset: The offset within file, from where (un)allocation is being > * requested. It should not have a negative value. > * @len: The amount (in bytes) of space to be (un)allocated, from the offset. > * > * This system call, depending on the mode, preallocates or unallocates blocks > * for a file. The range of blocks depends on the value of offset and len > - * arguments provided by the user/application. For FA_ALLOCATE mode, if this > + * arguments provided by the user/application. For FA_ALLOCATE and > + * FA_RESV_SPACE modes, if the sys_fallocate() > * system call succeeds, subsequent writes to the file in the given range > * (specified by offset & len) should not fail - even if the file system > * later becomes full. Hence the preallocation done is persistent (valid > - * even after reopen of the file and remount/reboot). > + * even after reopen of the file and remount/reboot). If FA_RESV_SPACE mode > + * is passed, the file size will not be changed even if the preallocation > + * is beyond EOF. > * > * It is expected that the ->fallocate() inode operation implemented by the > * individual file systems will update the file size and/or ctime/mtime > - * depending on the mode and also on the success of the operation. > + * depending on the mode (change is visible to user or not - say file size) > + * and obviously, on the success of the operation. > * > * Note: Incase the file system does not support preallocation, > * posix_fallocate() should fall back to the library implementation (i.e. > @@ -398,7 +401,8 @@ asmlinkage long sys_fallocate(int fd, in > > /* Return error if mode is not supported */ > ret = -EOPNOTSUPP; > - if (mode != FA_ALLOCATE && mode != FA_DEALLOCATE) > + if (!(mode == FA_ALLOCATE || mode == FA_DEALLOCATE || > + mode == FA_RESV_SPACE || mode == FA_UNRESV_SPACE)) > goto out; > > ret = -EBADF; > - > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
