diff options
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 8a59f7ba30e..bcf5d040e32 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2287,9 +2287,22 @@ out: } /* + * Block allocation/map/preallocation routine for extents based files + * + * * Need to be called with * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) + * + * return > 0, number of of blocks already mapped/allocated + * if create == 0 and these are pre-allocated blocks + * buffer head is unmapped + * otherwise blocks are mapped + * + * return = 0, if plain look up failed (blocks have not been allocated) + * buffer head is unmapped + * + * return < 0, error case. */ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, ext4_lblk_t iblock, |