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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-23 02:02:39 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-23 02:02:39 (GMT) |
commit | bbd9d6f7fbb0305c9a592bf05a32e87eb364a4ff (patch) | |
tree | 12b2bb4202b05f6ae6a43c6ce830a0472043dbe5 /Documentation | |
parent | 8e204874db000928e37199c2db82b7eb8966cc3c (diff) | |
parent | 5a9a43646cf709312d71eca71cef90ad802f28f9 (diff) | |
download | linux-bbd9d6f7fbb0305c9a592bf05a32e87eb364a4ff.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
isofs: Remove global fs lock
jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
mm/truncate.c: fix build for CONFIG_BLOCK not enabled
fs:update the NOTE of the file_operations structure
Remove dead code in dget_parent()
AFS: Fix silly characters in a comment
switch d_add_ci() to d_splice_alias() in "found negative" case as well
simplify gfs2_lookup()
jfs_lookup(): don't bother with . or ..
get rid of useless dget_parent() in btrfs rename() and link()
get rid of useless dget_parent() in fs/btrfs/ioctl.c
fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
drivers: fix up various ->llseek() implementations
fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
Ext4: handle SEEK_HOLE/SEEK_DATA generically
Btrfs: implement our own ->llseek
fs: add SEEK_HOLE and SEEK_DATA flags
reiserfs: make reiserfs default to barrier=flush
...
Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/filesystems/Locking | 8 | ||||
-rw-r--r-- | Documentation/filesystems/porting | 27 | ||||
-rw-r--r-- | Documentation/filesystems/vfs.txt | 30 |
3 files changed, 53 insertions, 12 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 57d827d6..ca7e252 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -52,7 +52,7 @@ ata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); int (*permission) (struct inode *, int, unsigned int); - int (*check_acl)(struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -412,7 +412,7 @@ prototypes: int (*open) (struct inode *, struct file *); int (*flush) (struct file *); int (*release) (struct inode *, struct file *); - int (*fsync) (struct file *, int datasync); + int (*fsync) (struct file *, loff_t start, loff_t end, int datasync); int (*aio_fsync) (struct kiocb *, int datasync); int (*fasync) (int, struct file *, int); int (*lock) (struct file *, int, struct file_lock *); @@ -438,9 +438,7 @@ prototypes: locking rules: All may block except for ->setlease. - No VFS locks held on entry except for ->fsync and ->setlease. - -->fsync() has i_mutex on inode. + No VFS locks held on entry except for ->setlease. ->setlease has the file_list_lock held and must not sleep. diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 6e29954..7f8861d 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -400,10 +400,31 @@ a file off. -- [mandatory] - --- -[mandatory] ->get_sb() is gone. Switch to use of ->mount(). Typically it's just a matter of switching from calling get_sb_... to mount_... and changing the function type. If you were doing it manually, just switch from setting ->mnt_root to some pointer to returning that pointer. On errors return ERR_PTR(...). + +-- +[mandatory] + ->permission(), generic_permission() and ->check_acl() have lost flags +argument; instead of passing IPERM_FLAG_RCU we add MAY_NOT_BLOCK into mask. + generic_permission() has also lost the check_acl argument; if you want +non-NULL to be used for that inode, put it into ->i_op->check_acl. + +-- +[mandatory] + If you implement your own ->llseek() you must handle SEEK_HOLE and +SEEK_DATA. You can hanle this by returning -EINVAL, but it would be nicer to +support it in some way. The generic handler assumes that the entire file is +data and there is a virtual hole at the end of the file. So if the provided +offset is less than i_size and SEEK_DATA is specified, return the same offset. +If the above is true for the offset and you are given SEEK_HOLE, return the end +of the file. If the offset is i_size or greater return -ENXIO in either case. + +[mandatory] + If you have your own ->fsync() you must make sure to call +filemap_write_and_wait_range() so that all dirty pages are synced out properly. +You must also keep in mind that ->fsync() is not called with i_mutex held +anymore, so if you require i_mutex locking you must make sure to take it and +release it yourself. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 88b9f55..eff6617 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -229,6 +229,8 @@ struct super_operations { ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); + int (*nr_cached_objects)(struct super_block *); + void (*free_cached_objects)(struct super_block *, int); }; All methods are called without any locks being held, unless otherwise @@ -301,6 +303,26 @@ or bottom half). quota_write: called by the VFS to write to filesystem quota file. + nr_cached_objects: called by the sb cache shrinking function for the + filesystem to return the number of freeable cached objects it contains. + Optional. + + free_cache_objects: called by the sb cache shrinking function for the + filesystem to scan the number of objects indicated to try to free them. + Optional, but any filesystem implementing this method needs to also + implement ->nr_cached_objects for it to be called correctly. + + We can't do anything with any errors that the filesystem might + encountered, hence the void return type. This will never be called if + the VM is trying to reclaim under GFP_NOFS conditions, hence this + method does not need to handle that situation itself. + + Implementations must include conditional reschedule calls inside any + scanning loop that is done. This allows the VFS to determine + appropriate scan batch sizes without having to worry about whether + implementations will cause holdoff problems due to large scan batch + sizes. + Whoever sets up the inode is responsible for filling in the "i_op" field. This is a pointer to a "struct inode_operations" which describes the methods that can be performed on individual inodes. @@ -333,8 +355,8 @@ struct inode_operations { void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, unsigned int); - int (*check_acl)(struct inode *, int, unsigned int); + int (*permission) (struct inode *, int); + int (*check_acl)(struct inode *, int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -423,7 +445,7 @@ otherwise noted. permission: called by the VFS to check for access rights on a POSIX-like filesystem. - May be called in rcu-walk mode (flags & IPERM_FLAG_RCU). If in rcu-walk + May be called in rcu-walk mode (mask & MAY_NOT_BLOCK). If in rcu-walk mode, the filesystem must check the permission without blocking or storing to the inode. @@ -755,7 +777,7 @@ struct file_operations { int (*open) (struct inode *, struct file *); int (*flush) (struct file *); int (*release) (struct inode *, struct file *); - int (*fsync) (struct file *, int datasync); + int (*fsync) (struct file *, loff_t, loff_t, int datasync); int (*aio_fsync) (struct kiocb *, int datasync); int (*fasync) (int, struct file *, int); int (*lock) (struct file *, int, struct file_lock *); |