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authorDavid Howells <dhowells@redhat.com>2008-02-07 00:15:52 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:29 -0800
commit12debc4248a4a7f1873e47cda2cdd7faca80b099 (patch)
tree1ad80b77d213ea09cb746d6e4d50c4316462a452 /Documentation/filesystems/Locking
parent755aedc15900ff7d83dd046f632af9a680b0c28f (diff)
iget: remove iget() and the read_inode() super op as being obsolete
Remove the old iget() call and the read_inode() superblock operation it uses as these are really obsolete, and the use of read_inode() does not produce proper error handling (no distinction between ENOMEM and EIO when marking an inode bad). Furthermore, this removes the temptation to use iget() to find an inode by number in a filesystem from code outside that filesystem. iget_locked() should be used instead. A new function is added in an earlier patch (iget_failed) that is to be called to mark an inode as bad, unlock it and release it should the get routine fail. Mark iget() and read_inode() as being obsolete and remove references to them from the documentation. Typically a filesystem will be modified such that the read_inode function becomes an internal iget function, for example the following: void thingyfs_read_inode(struct inode *inode) { ... } would be changed into something like: struct inode *thingyfs_iget(struct super_block *sp, unsigned long ino) { struct inode *inode; int ret; inode = iget_locked(sb, ino); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; ... unlock_new_inode(inode); return inode; error: iget_failed(inode); return ERR_PTR(ret); } and then thingyfs_iget() would be called rather than iget(), for example: ret = -EINVAL; inode = iget(sb, ino); if (!inode || is_bad_inode(inode)) goto error; becomes: inode = thingyfs_iget(sb, ino); if (IS_ERR(inode)) { ret = PTR_ERR(inode); goto error; } Note that is_bad_inode() does not need to be called. The error returned by thingyfs_iget() should render it unnecessary. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems/Locking')
-rw-r--r--Documentation/filesystems/Locking3
1 files changed, 0 insertions, 3 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 37c10cba717..42d4b30b104 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -90,7 +90,6 @@ of the locking scheme for directory operations.
prototypes:
struct inode *(*alloc_inode)(struct super_block *sb);
void (*destroy_inode)(struct inode *);
- void (*read_inode) (struct inode *);
void (*dirty_inode) (struct inode *);
int (*write_inode) (struct inode *, int);
void (*put_inode) (struct inode *);
@@ -114,7 +113,6 @@ locking rules:
BKL s_lock s_umount
alloc_inode: no no no
destroy_inode: no
-read_inode: no (see below)
dirty_inode: no (must not sleep)
write_inode: no
put_inode: no
@@ -133,7 +131,6 @@ show_options: no (vfsmount->sem)
quota_read: no no no (see below)
quota_write: no no no (see below)
-->read_inode() is not a method - it's a callback used in iget().
->remount_fs() will have the s_umount lock if it's already mounted.
When called from get_sb_single, it does NOT have the s_umount lock.
->quota_read() and ->quota_write() functions are both guaranteed to