diff options
Diffstat (limited to '')
| -rw-r--r-- | fs/open.c | 51 | ||||
| -rw-r--r-- | include/linux/falloc.h | 18 | ||||
| -rw-r--r-- | include/uapi/linux/falloc.h | 1 |
3 files changed, 38 insertions, 32 deletions
diff --git a/fs/open.c b/fs/open.c index 22adbef7ecc2..daf1b55ca818 100644 --- a/fs/open.c +++ b/fs/open.c @@ -252,40 +252,39 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (offset < 0 || len <= 0) return -EINVAL; - /* Return error if mode is not supported */ - if (mode & ~FALLOC_FL_SUPPORTED_MASK) + if (mode & ~(FALLOC_FL_MODE_MASK | FALLOC_FL_KEEP_SIZE)) return -EOPNOTSUPP; - /* Punch hole and zero range are mutually exclusive */ - if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == - (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) - return -EOPNOTSUPP; - - /* Punch hole must have keep size set */ - if ((mode & FALLOC_FL_PUNCH_HOLE) && - !(mode & FALLOC_FL_KEEP_SIZE)) + /* + * Modes are exclusive, even if that is not obvious from the encoding + * as bit masks and the mix with the flag in the same namespace. + * + * To make things even more complicated, FALLOC_FL_ALLOCATE_RANGE is + * encoded as no bit set. + */ + switch (mode & FALLOC_FL_MODE_MASK) { + case FALLOC_FL_ALLOCATE_RANGE: + case FALLOC_FL_UNSHARE_RANGE: + case FALLOC_FL_ZERO_RANGE: + break; + case FALLOC_FL_PUNCH_HOLE: + if (!(mode & FALLOC_FL_KEEP_SIZE)) + return -EOPNOTSUPP; + break; + case FALLOC_FL_COLLAPSE_RANGE: + case FALLOC_FL_INSERT_RANGE: + if (mode & FALLOC_FL_KEEP_SIZE) + return -EOPNOTSUPP; + break; + default: return -EOPNOTSUPP; - - /* Collapse range should only be used exclusively. */ - if ((mode & FALLOC_FL_COLLAPSE_RANGE) && - (mode & ~FALLOC_FL_COLLAPSE_RANGE)) - return -EINVAL; - - /* Insert range should only be used exclusively. */ - if ((mode & FALLOC_FL_INSERT_RANGE) && - (mode & ~FALLOC_FL_INSERT_RANGE)) - return -EINVAL; - - /* Unshare range should only be used with allocate mode. */ - if ((mode & FALLOC_FL_UNSHARE_RANGE) && - (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) - return -EINVAL; + } if (!(file->f_mode & FMODE_WRITE)) return -EBADF; /* - * We can only allow pure fallocate on append only files + * On append-only files only space preallocation is supported. */ if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) return -EPERM; diff --git a/include/linux/falloc.h b/include/linux/falloc.h index f3f0b97b1675..3f49f3df6af5 100644 --- a/include/linux/falloc.h +++ b/include/linux/falloc.h @@ -25,12 +25,18 @@ struct space_resv { #define FS_IOC_UNRESVSP64 _IOW('X', 43, struct space_resv) #define FS_IOC_ZERO_RANGE _IOW('X', 57, struct space_resv) -#define FALLOC_FL_SUPPORTED_MASK (FALLOC_FL_KEEP_SIZE | \ - FALLOC_FL_PUNCH_HOLE | \ - FALLOC_FL_COLLAPSE_RANGE | \ - FALLOC_FL_ZERO_RANGE | \ - FALLOC_FL_INSERT_RANGE | \ - FALLOC_FL_UNSHARE_RANGE) +/* + * Mask of all supported fallocate modes. Only one can be set at a time. + * + * In addition to the mode bit, the mode argument can also encode flags. + * FALLOC_FL_KEEP_SIZE is the only supported flag so far. + */ +#define FALLOC_FL_MODE_MASK (FALLOC_FL_ALLOCATE_RANGE | \ + FALLOC_FL_PUNCH_HOLE | \ + FALLOC_FL_COLLAPSE_RANGE | \ + FALLOC_FL_ZERO_RANGE | \ + FALLOC_FL_INSERT_RANGE | \ + FALLOC_FL_UNSHARE_RANGE) /* on ia32 l_start is on a 32-bit boundary */ #if defined(CONFIG_X86_64) diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h index 51398fa57f6c..5810371ed72b 100644 --- a/include/uapi/linux/falloc.h +++ b/include/uapi/linux/falloc.h @@ -2,6 +2,7 @@ #ifndef _UAPI_FALLOC_H_ #define _UAPI_FALLOC_H_ +#define FALLOC_FL_ALLOCATE_RANGE 0x00 /* allocate range */ #define FALLOC_FL_KEEP_SIZE 0x01 /* default is extend size */ #define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */ #define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */ |