diff options
Diffstat (limited to 'Documentation/filesystems/porting')
| -rw-r--r-- | Documentation/filesystems/porting | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 0f33c77bc14b..92b888d540a6 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -34,8 +34,8 @@ FOO_I(inode) (see in-tree filesystems for examples). Make them ->alloc_inode and ->destroy_inode in your super_operations. -Keep in mind that now you need explicit initialization of private data - -typically in ->read_inode() and after getting an inode from new_inode(). +Keep in mind that now you need explicit initialization of private data +typically between calling iget_locked() and unlocking the inode. At some point that will become mandatory. @@ -173,10 +173,10 @@ should be a non-blocking function that initializes those parts of a newly created inode to allow the test function to succeed. 'data' is passed as an opaque value to both test and set functions. -When the inode has been created by iget5_locked(), it will be returned with -the I_NEW flag set and will still be locked. read_inode has not been -called so the file system still has to finalize the initialization. Once -the inode is initialized it must be unlocked by calling unlock_new_inode(). +When the inode has been created by iget5_locked(), it will be returned with the +I_NEW flag set and will still be locked. The filesystem then needs to finalize +the initialization. Once the inode is initialized it must be unlocked by +calling unlock_new_inode(). The filesystem is responsible for setting (and possibly testing) i_ino when appropriate. There is also a simpler iget_locked function that @@ -184,11 +184,19 @@ just takes the superblock and inode number as arguments and does the test and set for you. e.g. - inode = iget_locked(sb, ino); - if (inode->i_state & I_NEW) { - read_inode_from_disk(inode); - unlock_new_inode(inode); - } + inode = iget_locked(sb, ino); + if (inode->i_state & I_NEW) { + err = read_inode_from_disk(inode); + if (err < 0) { + iget_failed(inode); + return err; + } + unlock_new_inode(inode); + } + +Note that if the process of setting up a new inode fails, then iget_failed() +should be called on the inode to render it dead, and an appropriate error +should be passed back to the caller. --- [recommended] |