bcm2835-v4l2: Fix buffer overflow problem

[mirror_ubuntu-zesty-kernel.git] / fs / xfs / xfs_inode.h

/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_INODE_H__
#define __XFS_INODE_H__

#include "xfs_inode_buf.h"
#include "xfs_inode_fork.h"

/*
 * Kernel only inode definitions
 */
struct xfs_dinode;
struct xfs_inode;
struct xfs_buf;
struct xfs_defer_ops;
struct xfs_bmbt_irec;
struct xfs_inode_log_item;
struct xfs_mount;
struct xfs_trans;
struct xfs_dquot;

typedef struct xfs_inode {
        /* Inode linking and identification information. */
        struct xfs_mount        *i_mount;       /* fs mount struct ptr */
        struct xfs_dquot        *i_udquot;      /* user dquot */
        struct xfs_dquot        *i_gdquot;      /* group dquot */
        struct xfs_dquot        *i_pdquot;      /* project dquot */

        /* Inode location stuff */
        xfs_ino_t               i_ino;          /* inode number (agno/agino)*/
        struct xfs_imap         i_imap;         /* location for xfs_imap() */

        /* Extent information. */
        xfs_ifork_t             *i_afp;         /* attribute fork pointer */
        xfs_ifork_t             *i_cowfp;       /* copy on write extents */
        xfs_ifork_t             i_df;           /* data fork */

        /* operations vectors */
        const struct xfs_dir_ops *d_ops;                /* directory ops vector */

        /* Transaction and locking information. */
        struct xfs_inode_log_item *i_itemp;     /* logging information */
        mrlock_t                i_lock;         /* inode lock */
        mrlock_t                i_mmaplock;     /* inode mmap IO lock */
        atomic_t                i_pincount;     /* inode pin count */
        spinlock_t              i_flags_lock;   /* inode i_flags lock */
        /* Miscellaneous state. */
        unsigned long           i_flags;        /* see defined flags below */
        unsigned int            i_delayed_blks; /* count of delay alloc blks */

        struct xfs_icdinode     i_d;            /* most of ondisk inode */

        xfs_extnum_t            i_cnextents;    /* # of extents in cow fork */
        unsigned int            i_cformat;      /* format of cow fork */

        /* VFS inode */
        struct inode            i_vnode;        /* embedded VFS inode */
} xfs_inode_t;

/* Convert from vfs inode to xfs inode */
static inline struct xfs_inode *XFS_I(struct inode *inode)
{
        return container_of(inode, struct xfs_inode, i_vnode);
}

/* convert from xfs inode to vfs inode */
static inline struct inode *VFS_I(struct xfs_inode *ip)
{
        return &ip->i_vnode;
}

/*
 * For regular files we only update the on-disk filesize when actually
 * writing data back to disk.  Until then only the copy in the VFS inode
 * is uptodate.
 */
static inline xfs_fsize_t XFS_ISIZE(struct xfs_inode *ip)
{
        if (S_ISREG(VFS_I(ip)->i_mode))
                return i_size_read(VFS_I(ip));
        return ip->i_d.di_size;
}

/*
 * If this I/O goes past the on-disk inode size update it unless it would
 * be past the current in-core inode size.
 */
static inline xfs_fsize_t
xfs_new_eof(struct xfs_inode *ip, xfs_fsize_t new_size)
{
        xfs_fsize_t i_size = i_size_read(VFS_I(ip));

        if (new_size > i_size || new_size < 0)
                new_size = i_size;
        return new_size > ip->i_d.di_size ? new_size : 0;
}

/*
 * i_flags helper functions
 */
static inline void
__xfs_iflags_set(xfs_inode_t *ip, unsigned short flags)
{
        ip->i_flags |= flags;
}

static inline void
xfs_iflags_set(xfs_inode_t *ip, unsigned short flags)
{
        spin_lock(&ip->i_flags_lock);
        __xfs_iflags_set(ip, flags);
        spin_unlock(&ip->i_flags_lock);
}

static inline void
xfs_iflags_clear(xfs_inode_t *ip, unsigned short flags)
{
        spin_lock(&ip->i_flags_lock);
        ip->i_flags &= ~flags;
        spin_unlock(&ip->i_flags_lock);
}

static inline int
__xfs_iflags_test(xfs_inode_t *ip, unsigned short flags)
{
        return (ip->i_flags & flags);
}

static inline int
xfs_iflags_test(xfs_inode_t *ip, unsigned short flags)
{
        int ret;
        spin_lock(&ip->i_flags_lock);
        ret = __xfs_iflags_test(ip, flags);
        spin_unlock(&ip->i_flags_lock);
        return ret;
}

static inline int
xfs_iflags_test_and_clear(xfs_inode_t *ip, unsigned short flags)
{
        int ret;

        spin_lock(&ip->i_flags_lock);
        ret = ip->i_flags & flags;
        if (ret)
                ip->i_flags &= ~flags;
        spin_unlock(&ip->i_flags_lock);
        return ret;
}

static inline int
xfs_iflags_test_and_set(xfs_inode_t *ip, unsigned short flags)
{
        int ret;

        spin_lock(&ip->i_flags_lock);
        ret = ip->i_flags & flags;
        if (!ret)
                ip->i_flags |= flags;
        spin_unlock(&ip->i_flags_lock);
        return ret;
}

/*
 * Project quota id helpers (previously projid was 16bit only
 * and using two 16bit values to hold new 32bit projid was chosen
 * to retain compatibility with "old" filesystems).
 */
static inline prid_t
xfs_get_projid(struct xfs_inode *ip)
{
        return (prid_t)ip->i_d.di_projid_hi << 16 | ip->i_d.di_projid_lo;
}

static inline void
xfs_set_projid(struct xfs_inode *ip,
                prid_t projid)
{
        ip->i_d.di_projid_hi = (__uint16_t) (projid >> 16);
        ip->i_d.di_projid_lo = (__uint16_t) (projid & 0xffff);
}

static inline prid_t
xfs_get_initial_prid(struct xfs_inode *dp)
{
        if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
                return xfs_get_projid(dp);

        return XFS_PROJID_DEFAULT;
}

static inline bool xfs_is_reflink_inode(struct xfs_inode *ip)
{
        return ip->i_d.di_flags2 & XFS_DIFLAG2_REFLINK;
}

/*
 * In-core inode flags.
 */
#define XFS_IRECLAIM            (1 << 0) /* started reclaiming this inode */
#define XFS_ISTALE              (1 << 1) /* inode has been staled */
#define XFS_IRECLAIMABLE        (1 << 2) /* inode can be reclaimed */
#define XFS_INEW                (1 << 3) /* inode has just been allocated */
#define XFS_ITRUNCATED          (1 << 5) /* truncated down so flush-on-close */
#define XFS_IDIRTY_RELEASE      (1 << 6) /* dirty release already seen */
#define __XFS_IFLOCK_BIT        7        /* inode is being flushed right now */
#define XFS_IFLOCK              (1 << __XFS_IFLOCK_BIT)
#define __XFS_IPINNED_BIT       8        /* wakeup key for zero pin count */
#define XFS_IPINNED             (1 << __XFS_IPINNED_BIT)
#define XFS_IDONTCACHE          (1 << 9) /* don't cache the inode long term */
#define XFS_IEOFBLOCKS          (1 << 10)/* has the preallocblocks tag set */
/*
 * If this unlinked inode is in the middle of recovery, don't let drop_inode
 * truncate and free the inode.  This can happen if we iget the inode during
 * log recovery to replay a bmap operation on the inode.
 */
#define XFS_IRECOVERY           (1 << 11)

/*
 * Per-lifetime flags need to be reset when re-using a reclaimable inode during
 * inode lookup. This prevents unintended behaviour on the new inode from
 * ocurring.
 */
#define XFS_IRECLAIM_RESET_FLAGS        \
        (XFS_IRECLAIMABLE | XFS_IRECLAIM | \
         XFS_IDIRTY_RELEASE | XFS_ITRUNCATED)

/*
 * Synchronize processes attempting to flush the in-core inode back to disk.
 */

static inline int xfs_isiflocked(struct xfs_inode *ip)
{
        return xfs_iflags_test(ip, XFS_IFLOCK);
}

extern void __xfs_iflock(struct xfs_inode *ip);

static inline int xfs_iflock_nowait(struct xfs_inode *ip)
{
        return !xfs_iflags_test_and_set(ip, XFS_IFLOCK);
}

static inline void xfs_iflock(struct xfs_inode *ip)
{
        if (!xfs_iflock_nowait(ip))
                __xfs_iflock(ip);
}

static inline void xfs_ifunlock(struct xfs_inode *ip)
{
        ASSERT(xfs_isiflocked(ip));
        xfs_iflags_clear(ip, XFS_IFLOCK);
        smp_mb();
        wake_up_bit(&ip->i_flags, __XFS_IFLOCK_BIT);
}

/*
 * Flags for inode locking.
 * Bit ranges:  1<<1  - 1<<16-1 -- iolock/ilock modes (bitfield)
 *              1<<16 - 1<<32-1 -- lockdep annotation (integers)
 */
#define XFS_IOLOCK_EXCL         (1<<0)
#define XFS_IOLOCK_SHARED       (1<<1)
#define XFS_ILOCK_EXCL          (1<<2)
#define XFS_ILOCK_SHARED        (1<<3)
#define XFS_MMAPLOCK_EXCL       (1<<4)
#define XFS_MMAPLOCK_SHARED     (1<<5)

#define XFS_LOCK_MASK           (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED \
                                | XFS_ILOCK_EXCL | XFS_ILOCK_SHARED \
                                | XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED)

#define XFS_LOCK_FLAGS \
        { XFS_IOLOCK_EXCL,      "IOLOCK_EXCL" }, \
        { XFS_IOLOCK_SHARED,    "IOLOCK_SHARED" }, \
        { XFS_ILOCK_EXCL,       "ILOCK_EXCL" }, \
        { XFS_ILOCK_SHARED,     "ILOCK_SHARED" }, \
        { XFS_MMAPLOCK_EXCL,    "MMAPLOCK_EXCL" }, \
        { XFS_MMAPLOCK_SHARED,  "MMAPLOCK_SHARED" }


/*
 * Flags for lockdep annotations.
 *
 * XFS_LOCK_PARENT - for directory operations that require locking a
 * parent directory inode and a child entry inode. IOLOCK requires nesting,
 * MMAPLOCK does not support this class, ILOCK requires a single subclass
 * to differentiate parent from child.
 *
 * XFS_LOCK_RTBITMAP/XFS_LOCK_RTSUM - the realtime device bitmap and summary
 * inodes do not participate in the normal lock order, and thus have their
 * own subclasses.
 *
 * XFS_LOCK_INUMORDER - for locking several inodes at the some time
 * with xfs_lock_inodes().  This flag is used as the starting subclass
 * and each subsequent lock acquired will increment the subclass by one.
 * However, MAX_LOCKDEP_SUBCLASSES == 8, which means we are greatly
 * limited to the subclasses we can represent via nesting. We need at least
 * 5 inodes nest depth for the ILOCK through rename, and we also have to support
 * XFS_ILOCK_PARENT, which gives 6 subclasses. Then we have XFS_ILOCK_RTBITMAP
 * and XFS_ILOCK_RTSUM, which are another 2 unique subclasses, so that's all
 * 8 subclasses supported by lockdep.
 *
 * This also means we have to number the sub-classes in the lowest bits of
 * the mask we keep, and we have to ensure we never exceed 3 bits of lockdep
 * mask and we can't use bit-masking to build the subclasses. What a mess.
 *
 * Bit layout:
 *
 * Bit          Lock Region
 * 16-19        XFS_IOLOCK_SHIFT dependencies
 * 20-23        XFS_MMAPLOCK_SHIFT dependencies
 * 24-31        XFS_ILOCK_SHIFT dependencies
 *
 * IOLOCK values
 *
 * 0-3          subclass value
 * 4-7          unused
 *
 * MMAPLOCK values
 *
 * 0-3          subclass value
 * 4-7          unused
 *
 * ILOCK values
 * 0-4          subclass values
 * 5            PARENT subclass (not nestable)
 * 6            RTBITMAP subclass (not nestable)
 * 7            RTSUM subclass (not nestable)
 * 
 */
#define XFS_IOLOCK_SHIFT                16
#define XFS_IOLOCK_MAX_SUBCLASS         3
#define XFS_IOLOCK_DEP_MASK             0x000f0000

#define XFS_MMAPLOCK_SHIFT              20
#define XFS_MMAPLOCK_NUMORDER           0
#define XFS_MMAPLOCK_MAX_SUBCLASS       3
#define XFS_MMAPLOCK_DEP_MASK           0x00f00000

#define XFS_ILOCK_SHIFT                 24
#define XFS_ILOCK_PARENT_VAL            5
#define XFS_ILOCK_MAX_SUBCLASS          (XFS_ILOCK_PARENT_VAL - 1)
#define XFS_ILOCK_RTBITMAP_VAL          6
#define XFS_ILOCK_RTSUM_VAL             7
#define XFS_ILOCK_DEP_MASK              0xff000000
#define XFS_ILOCK_PARENT                (XFS_ILOCK_PARENT_VAL << XFS_ILOCK_SHIFT)
#define XFS_ILOCK_RTBITMAP              (XFS_ILOCK_RTBITMAP_VAL << XFS_ILOCK_SHIFT)
#define XFS_ILOCK_RTSUM                 (XFS_ILOCK_RTSUM_VAL << XFS_ILOCK_SHIFT)

#define XFS_LOCK_SUBCLASS_MASK  (XFS_IOLOCK_DEP_MASK | \
                                 XFS_MMAPLOCK_DEP_MASK | \
                                 XFS_ILOCK_DEP_MASK)

#define XFS_IOLOCK_DEP(flags)   (((flags) & XFS_IOLOCK_DEP_MASK) \
                                        >> XFS_IOLOCK_SHIFT)
#define XFS_MMAPLOCK_DEP(flags) (((flags) & XFS_MMAPLOCK_DEP_MASK) \
                                        >> XFS_MMAPLOCK_SHIFT)
#define XFS_ILOCK_DEP(flags)    (((flags) & XFS_ILOCK_DEP_MASK) \
                                        >> XFS_ILOCK_SHIFT)

/*
 * For multiple groups support: if S_ISGID bit is set in the parent
 * directory, group of new file is set to that of the parent, and
 * new subdirectory gets S_ISGID bit from parent.
 */
#define XFS_INHERIT_GID(pip)    \
        (((pip)->i_mount->m_flags & XFS_MOUNT_GRPID) || \
         (VFS_I(pip)->i_mode & S_ISGID))

int             xfs_release(struct xfs_inode *ip);
void            xfs_inactive(struct xfs_inode *ip);
int             xfs_lookup(struct xfs_inode *dp, struct xfs_name *name,
                           struct xfs_inode **ipp, struct xfs_name *ci_name);
int             xfs_create(struct xfs_inode *dp, struct xfs_name *name,
                           umode_t mode, xfs_dev_t rdev, struct xfs_inode **ipp);
int             xfs_create_tmpfile(struct xfs_inode *dp, struct dentry *dentry,
                           umode_t mode, struct xfs_inode **ipp);
int             xfs_remove(struct xfs_inode *dp, struct xfs_name *name,
                           struct xfs_inode *ip);
int             xfs_link(struct xfs_inode *tdp, struct xfs_inode *sip,
                         struct xfs_name *target_name);
int             xfs_rename(struct xfs_inode *src_dp, struct xfs_name *src_name,
                           struct xfs_inode *src_ip, struct xfs_inode *target_dp,
                           struct xfs_name *target_name,
                           struct xfs_inode *target_ip, unsigned int flags);

void            xfs_ilock(xfs_inode_t *, uint);
int             xfs_ilock_nowait(xfs_inode_t *, uint);
void            xfs_iunlock(xfs_inode_t *, uint);
void            xfs_ilock_demote(xfs_inode_t *, uint);
int             xfs_isilocked(xfs_inode_t *, uint);
uint            xfs_ilock_data_map_shared(struct xfs_inode *);
uint            xfs_ilock_attr_map_shared(struct xfs_inode *);

uint            xfs_ip2xflags(struct xfs_inode *);
int             xfs_ifree(struct xfs_trans *, xfs_inode_t *,
                           struct xfs_defer_ops *);
int             xfs_itruncate_extents(struct xfs_trans **, struct xfs_inode *,
                                      int, xfs_fsize_t);
void            xfs_iext_realloc(xfs_inode_t *, int, int);

void            xfs_iunpin_wait(xfs_inode_t *);
#define xfs_ipincount(ip)       ((unsigned int) atomic_read(&ip->i_pincount))

int             xfs_iflush(struct xfs_inode *, struct xfs_buf **);
void            xfs_lock_two_inodes(xfs_inode_t *, xfs_inode_t *, uint);

xfs_extlen_t    xfs_get_extsz_hint(struct xfs_inode *ip);
xfs_extlen_t    xfs_get_cowextsz_hint(struct xfs_inode *ip);

int             xfs_dir_ialloc(struct xfs_trans **, struct xfs_inode *, umode_t,
                               xfs_nlink_t, xfs_dev_t, prid_t, int,
                               struct xfs_inode **, int *);

/* from xfs_file.c */
enum xfs_prealloc_flags {
        XFS_PREALLOC_SET        = (1 << 1),
        XFS_PREALLOC_CLEAR      = (1 << 2),
        XFS_PREALLOC_SYNC       = (1 << 3),
        XFS_PREALLOC_INVISIBLE  = (1 << 4),
};

int     xfs_update_prealloc_flags(struct xfs_inode *ip,
                                  enum xfs_prealloc_flags flags);
int     xfs_zero_eof(struct xfs_inode *ip, xfs_off_t offset,
                     xfs_fsize_t isize, bool *did_zeroing);
int     xfs_zero_range(struct xfs_inode *ip, xfs_off_t pos, xfs_off_t count,
                bool *did_zero);
loff_t  __xfs_seek_hole_data(struct inode *inode, loff_t start,
                             loff_t eof, int whence);


/* from xfs_iops.c */
extern void xfs_setup_inode(struct xfs_inode *ip);
extern void xfs_setup_iops(struct xfs_inode *ip);

/*
 * When setting up a newly allocated inode, we need to call
 * xfs_finish_inode_setup() once the inode is fully instantiated at
 * the VFS level to prevent the rest of the world seeing the inode
 * before we've completed instantiation. Otherwise we can do it
 * the moment the inode lookup is complete.
 */
static inline void xfs_finish_inode_setup(struct xfs_inode *ip)
{
        xfs_iflags_clear(ip, XFS_INEW);
        barrier();
        unlock_new_inode(VFS_I(ip));
}

static inline void xfs_setup_existing_inode(struct xfs_inode *ip)
{
        xfs_setup_inode(ip);
        xfs_setup_iops(ip);
        xfs_finish_inode_setup(ip);
}

#define IHOLD(ip) \
do { \
        ASSERT(atomic_read(&VFS_I(ip)->i_count) > 0) ; \
        ihold(VFS_I(ip)); \
        trace_xfs_ihold(ip, _THIS_IP_); \
} while (0)

#define IRELE(ip) \
do { \
        trace_xfs_irele(ip, _THIS_IP_); \
        iput(VFS_I(ip)); \
} while (0)

extern struct kmem_zone *xfs_inode_zone;

/* The default CoW extent size hint. */
#define XFS_DEFAULT_COWEXTSZ_HINT 32

#endif  /* __XFS_INODE_H__ */