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-rw-r--r--Documentation/filesystems/Locking43
1 files changed, 28 insertions, 15 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 0706d32a61e..fe7afe22538 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -11,10 +11,8 @@ be able to use diff(1).
prototypes:
int (*d_revalidate)(struct dentry *, unsigned int);
int (*d_weak_revalidate)(struct dentry *, unsigned int);
- int (*d_hash)(const struct dentry *, const struct inode *,
- struct qstr *);
- int (*d_compare)(const struct dentry *, const struct inode *,
- const struct dentry *, const struct inode *,
+ int (*d_hash)(const struct dentry *, struct qstr *);
+ int (*d_compare)(const struct dentry *, const struct dentry *,
unsigned int, const char *, const struct qstr *);
int (*d_delete)(struct dentry *);
void (*d_release)(struct dentry *);
@@ -66,6 +64,7 @@ prototypes:
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
+ int (*tmpfile) (struct inode *, struct dentry *, umode_t);
locking rules:
all may block
@@ -93,6 +92,7 @@ removexattr: yes
fiemap: no
update_time: no
atomic_open: yes
+tmpfile: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
@@ -189,7 +189,7 @@ prototypes:
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
sector_t (*bmap)(struct address_space *, sector_t);
- int (*invalidatepage) (struct page *, unsigned long);
+ void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
int (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
@@ -310,8 +310,8 @@ filesystems and by the swapper. The latter will eventually go away. Please,
keep it that way and don't breed new callers.
->invalidatepage() is called when the filesystem must attempt to drop
-some or all of the buffers from the page when it is being truncated. It
-returns zero on success. If ->invalidatepage is zero, the kernel uses
+some or all of the buffers from the page when it is being truncated. It
+returns zero on success. If ->invalidatepage is zero, the kernel uses
block_invalidatepage() instead.
->releasepage() is called when the kernel is about to try to drop the
@@ -344,25 +344,38 @@ prototypes:
locking rules:
- file_lock_lock may block
+ inode->i_lock may block
fl_copy_lock: yes no
fl_release_private: maybe no
----------------------- lock_manager_operations ---------------------------
prototypes:
int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
+ unsigned long (*lm_owner_key)(struct file_lock *);
void (*lm_notify)(struct file_lock *); /* unblock callback */
int (*lm_grant)(struct file_lock *, struct file_lock *, int);
void (*lm_break)(struct file_lock *); /* break_lease callback */
int (*lm_change)(struct file_lock **, int);
locking rules:
- file_lock_lock may block
-lm_compare_owner: yes no
-lm_notify: yes no
-lm_grant: no no
-lm_break: yes no
-lm_change yes no
+
+ inode->i_lock blocked_lock_lock may block
+lm_compare_owner: yes[1] maybe no
+lm_owner_key yes[1] yes no
+lm_notify: yes yes no
+lm_grant: no no no
+lm_break: yes no no
+lm_change yes no no
+
+[1]: ->lm_compare_owner and ->lm_owner_key are generally called with
+*an* inode->i_lock held. It may not be the i_lock of the inode
+associated with either file_lock argument! This is the case with deadlock
+detection, since the code has to chase down the owners of locks that may
+be entirely unrelated to the one on which the lock is being acquired.
+For deadlock detection however, the blocked_lock_lock is also held. The
+fact that these locks are held ensures that the file_locks do not
+disappear out from under you while doing the comparison or generating an
+owner key.
--------------------------- buffer_head -----------------------------------
prototypes:
@@ -414,7 +427,7 @@ prototypes:
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
- int (*readdir) (struct file *, void *, filldir_t);
+ int (*iterate) (struct file *, struct dir_context *);
unsigned int (*poll) (struct file *, struct poll_table_struct *);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);