linux/fs/xfs/libxfs/xfs_attr.c
Dave Chinner 51b495eba8 xfs: rename xfs_has_attr()
xfs_has_attr() is poorly named. It has global scope as it is defined
in a header file, but it has no namespace scope that tells us what
it is checking has attributes. It's not even clear what "has_attr"
means, because what it is actually doing is an attribute fork lookup
to see if the attribute exists.

Upcoming patches use this "xfs_has_<foo>" namespace for global
filesystem features, which conflicts with this function.

Rename xfs_has_attr() to xfs_attr_lookup() and make it a static
function, freeing up the "xfs_has_" namespace for global scope
usage.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-19 10:07:11 -07:00

1685 lines
42 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_attr_sf.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_bmap_btree.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_quota.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
/*
* xfs_attr.c
*
* Provide the external interfaces to manage attribute lists.
*/
/*========================================================================
* Function prototypes for the kernel.
*========================================================================*/
/*
* Internal routines when attribute list fits inside the inode.
*/
STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args);
/*
* Internal routines when attribute list is one block.
*/
STATIC int xfs_attr_leaf_get(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args);
STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp);
STATIC int xfs_attr_leaf_try_add(struct xfs_da_args *args, struct xfs_buf *bp);
/*
* Internal routines when attribute list is more than one block.
*/
STATIC int xfs_attr_node_get(xfs_da_args_t *args);
STATIC void xfs_attr_restore_rmt_blk(struct xfs_da_args *args);
STATIC int xfs_attr_node_addname(struct xfs_delattr_context *dac);
STATIC int xfs_attr_node_addname_find_attr(struct xfs_delattr_context *dac);
STATIC int xfs_attr_node_addname_clear_incomplete(
struct xfs_delattr_context *dac);
STATIC int xfs_attr_node_hasname(xfs_da_args_t *args,
struct xfs_da_state **state);
STATIC int xfs_attr_fillstate(xfs_da_state_t *state);
STATIC int xfs_attr_refillstate(xfs_da_state_t *state);
STATIC int xfs_attr_set_iter(struct xfs_delattr_context *dac,
struct xfs_buf **leaf_bp);
STATIC int xfs_attr_node_removename(struct xfs_da_args *args,
struct xfs_da_state *state);
int
xfs_inode_hasattr(
struct xfs_inode *ip)
{
if (!XFS_IFORK_Q(ip) ||
(ip->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
ip->i_afp->if_nextents == 0))
return 0;
return 1;
}
/*
* Returns true if the there is exactly only block in the attr fork, in which
* case the attribute fork consists of a single leaf block entry.
*/
bool
xfs_attr_is_leaf(
struct xfs_inode *ip)
{
struct xfs_ifork *ifp = ip->i_afp;
struct xfs_iext_cursor icur;
struct xfs_bmbt_irec imap;
if (ifp->if_nextents != 1 || ifp->if_format != XFS_DINODE_FMT_EXTENTS)
return false;
xfs_iext_first(ifp, &icur);
xfs_iext_get_extent(ifp, &icur, &imap);
return imap.br_startoff == 0 && imap.br_blockcount == 1;
}
/*========================================================================
* Overall external interface routines.
*========================================================================*/
/*
* Retrieve an extended attribute and its value. Must have ilock.
* Returns 0 on successful retrieval, otherwise an error.
*/
int
xfs_attr_get_ilocked(
struct xfs_da_args *args)
{
ASSERT(xfs_isilocked(args->dp, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
if (!xfs_inode_hasattr(args->dp))
return -ENOATTR;
if (args->dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
return xfs_attr_shortform_getvalue(args);
if (xfs_attr_is_leaf(args->dp))
return xfs_attr_leaf_get(args);
return xfs_attr_node_get(args);
}
/*
* Retrieve an extended attribute by name, and its value if requested.
*
* If args->valuelen is zero, then the caller does not want the value, just an
* indication whether the attribute exists and the size of the value if it
* exists. The size is returned in args.valuelen.
*
* If args->value is NULL but args->valuelen is non-zero, allocate the buffer
* for the value after existence of the attribute has been determined. The
* caller always has to free args->value if it is set, no matter if this
* function was successful or not.
*
* If the attribute is found, but exceeds the size limit set by the caller in
* args->valuelen, return -ERANGE with the size of the attribute that was found
* in args->valuelen.
*/
int
xfs_attr_get(
struct xfs_da_args *args)
{
uint lock_mode;
int error;
XFS_STATS_INC(args->dp->i_mount, xs_attr_get);
if (XFS_FORCED_SHUTDOWN(args->dp->i_mount))
return -EIO;
args->geo = args->dp->i_mount->m_attr_geo;
args->whichfork = XFS_ATTR_FORK;
args->hashval = xfs_da_hashname(args->name, args->namelen);
/* Entirely possible to look up a name which doesn't exist */
args->op_flags = XFS_DA_OP_OKNOENT;
lock_mode = xfs_ilock_attr_map_shared(args->dp);
error = xfs_attr_get_ilocked(args);
xfs_iunlock(args->dp, lock_mode);
return error;
}
/*
* Calculate how many blocks we need for the new attribute,
*/
STATIC int
xfs_attr_calc_size(
struct xfs_da_args *args,
int *local)
{
struct xfs_mount *mp = args->dp->i_mount;
int size;
int nblks;
/*
* Determine space new attribute will use, and if it would be
* "local" or "remote" (note: local != inline).
*/
size = xfs_attr_leaf_newentsize(args, local);
nblks = XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK);
if (*local) {
if (size > (args->geo->blksize / 2)) {
/* Double split possible */
nblks *= 2;
}
} else {
/*
* Out of line attribute, cannot double split, but
* make room for the attribute value itself.
*/
uint dblocks = xfs_attr3_rmt_blocks(mp, args->valuelen);
nblks += dblocks;
nblks += XFS_NEXTENTADD_SPACE_RES(mp, dblocks, XFS_ATTR_FORK);
}
return nblks;
}
STATIC int
xfs_attr_try_sf_addname(
struct xfs_inode *dp,
struct xfs_da_args *args)
{
int error;
/*
* Build initial attribute list (if required).
*/
if (dp->i_afp->if_format == XFS_DINODE_FMT_EXTENTS)
xfs_attr_shortform_create(args);
error = xfs_attr_shortform_addname(args);
if (error == -ENOSPC)
return error;
/*
* Commit the shortform mods, and we're done.
* NOTE: this is also the error path (EEXIST, etc).
*/
if (!error && !(args->op_flags & XFS_DA_OP_NOTIME))
xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
if (dp->i_mount->m_flags & XFS_MOUNT_WSYNC)
xfs_trans_set_sync(args->trans);
return error;
}
/*
* Check to see if the attr should be upgraded from non-existent or shortform to
* single-leaf-block attribute list.
*/
static inline bool
xfs_attr_is_shortform(
struct xfs_inode *ip)
{
return ip->i_afp->if_format == XFS_DINODE_FMT_LOCAL ||
(ip->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
ip->i_afp->if_nextents == 0);
}
/*
* Checks to see if a delayed attribute transaction should be rolled. If so,
* transaction is finished or rolled as needed.
*/
STATIC int
xfs_attr_trans_roll(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
int error;
if (dac->flags & XFS_DAC_DEFER_FINISH) {
/*
* The caller wants us to finish all the deferred ops so that we
* avoid pinning the log tail with a large number of deferred
* ops.
*/
dac->flags &= ~XFS_DAC_DEFER_FINISH;
error = xfs_defer_finish(&args->trans);
} else
error = xfs_trans_roll_inode(&args->trans, args->dp);
return error;
}
/*
* Set the attribute specified in @args.
*/
int
xfs_attr_set_args(
struct xfs_da_args *args)
{
struct xfs_buf *leaf_bp = NULL;
int error = 0;
struct xfs_delattr_context dac = {
.da_args = args,
};
do {
error = xfs_attr_set_iter(&dac, &leaf_bp);
if (error != -EAGAIN)
break;
error = xfs_attr_trans_roll(&dac);
if (error) {
if (leaf_bp)
xfs_trans_brelse(args->trans, leaf_bp);
return error;
}
} while (true);
return error;
}
STATIC int
xfs_attr_sf_addname(
struct xfs_delattr_context *dac,
struct xfs_buf **leaf_bp)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_inode *dp = args->dp;
int error = 0;
/*
* Try to add the attr to the attribute list in the inode.
*/
error = xfs_attr_try_sf_addname(dp, args);
/* Should only be 0, -EEXIST or -ENOSPC */
if (error != -ENOSPC)
return error;
/*
* It won't fit in the shortform, transform to a leaf block. GROT:
* another possible req'mt for a double-split btree op.
*/
error = xfs_attr_shortform_to_leaf(args, leaf_bp);
if (error)
return error;
/*
* Prevent the leaf buffer from being unlocked so that a concurrent AIL
* push cannot grab the half-baked leaf buffer and run into problems
* with the write verifier.
*/
xfs_trans_bhold(args->trans, *leaf_bp);
/*
* We're still in XFS_DAS_UNINIT state here. We've converted
* the attr fork to leaf format and will restart with the leaf
* add.
*/
trace_xfs_attr_sf_addname_return(XFS_DAS_UNINIT, args->dp);
dac->flags |= XFS_DAC_DEFER_FINISH;
return -EAGAIN;
}
/*
* Set the attribute specified in @args.
* This routine is meant to function as a delayed operation, and may return
* -EAGAIN when the transaction needs to be rolled. Calling functions will need
* to handle this, and recall the function until a successful error code is
* returned.
*/
int
xfs_attr_set_iter(
struct xfs_delattr_context *dac,
struct xfs_buf **leaf_bp)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_inode *dp = args->dp;
struct xfs_buf *bp = NULL;
int forkoff, error = 0;
/* State machine switch */
switch (dac->dela_state) {
case XFS_DAS_UNINIT:
/*
* If the fork is shortform, attempt to add the attr. If there
* is no space, this converts to leaf format and returns
* -EAGAIN with the leaf buffer held across the roll. The caller
* will deal with a transaction roll error, but otherwise
* release the hold once we return with a clean transaction.
*/
if (xfs_attr_is_shortform(dp))
return xfs_attr_sf_addname(dac, leaf_bp);
if (*leaf_bp != NULL) {
xfs_trans_bhold_release(args->trans, *leaf_bp);
*leaf_bp = NULL;
}
if (xfs_attr_is_leaf(dp)) {
error = xfs_attr_leaf_try_add(args, *leaf_bp);
if (error == -ENOSPC) {
error = xfs_attr3_leaf_to_node(args);
if (error)
return error;
/*
* Finish any deferred work items and roll the
* transaction once more. The goal here is to
* call node_addname with the inode and
* transaction in the same state (inode locked
* and joined, transaction clean) no matter how
* we got to this step.
*
* At this point, we are still in
* XFS_DAS_UNINIT, but when we come back, we'll
* be a node, so we'll fall down into the node
* handling code below
*/
dac->flags |= XFS_DAC_DEFER_FINISH;
trace_xfs_attr_set_iter_return(
dac->dela_state, args->dp);
return -EAGAIN;
} else if (error) {
return error;
}
dac->dela_state = XFS_DAS_FOUND_LBLK;
} else {
error = xfs_attr_node_addname_find_attr(dac);
if (error)
return error;
error = xfs_attr_node_addname(dac);
if (error)
return error;
dac->dela_state = XFS_DAS_FOUND_NBLK;
}
trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
case XFS_DAS_FOUND_LBLK:
/*
* If there was an out-of-line value, allocate the blocks we
* identified for its storage and copy the value. This is done
* after we create the attribute so that we don't overflow the
* maximum size of a transaction and/or hit a deadlock.
*/
/* Open coded xfs_attr_rmtval_set without trans handling */
if ((dac->flags & XFS_DAC_LEAF_ADDNAME_INIT) == 0) {
dac->flags |= XFS_DAC_LEAF_ADDNAME_INIT;
if (args->rmtblkno > 0) {
error = xfs_attr_rmtval_find_space(dac);
if (error)
return error;
}
}
/*
* Repeat allocating remote blocks for the attr value until
* blkcnt drops to zero.
*/
if (dac->blkcnt > 0) {
error = xfs_attr_rmtval_set_blk(dac);
if (error)
return error;
trace_xfs_attr_set_iter_return(dac->dela_state,
args->dp);
return -EAGAIN;
}
error = xfs_attr_rmtval_set_value(args);
if (error)
return error;
/*
* If this is not a rename, clear the incomplete flag and we're
* done.
*/
if (!(args->op_flags & XFS_DA_OP_RENAME)) {
if (args->rmtblkno > 0)
error = xfs_attr3_leaf_clearflag(args);
return error;
}
/*
* If this is an atomic rename operation, we must "flip" the
* incomplete flags on the "new" and "old" attribute/value pairs
* so that one disappears and one appears atomically. Then we
* must remove the "old" attribute/value pair.
*
* In a separate transaction, set the incomplete flag on the
* "old" attr and clear the incomplete flag on the "new" attr.
*/
error = xfs_attr3_leaf_flipflags(args);
if (error)
return error;
/*
* Commit the flag value change and start the next trans in
* series.
*/
dac->dela_state = XFS_DAS_FLIP_LFLAG;
trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
case XFS_DAS_FLIP_LFLAG:
/*
* Dismantle the "old" attribute/value pair by removing a
* "remote" value (if it exists).
*/
xfs_attr_restore_rmt_blk(args);
error = xfs_attr_rmtval_invalidate(args);
if (error)
return error;
fallthrough;
case XFS_DAS_RM_LBLK:
/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
dac->dela_state = XFS_DAS_RM_LBLK;
if (args->rmtblkno) {
error = xfs_attr_rmtval_remove(dac);
if (error == -EAGAIN)
trace_xfs_attr_set_iter_return(
dac->dela_state, args->dp);
if (error)
return error;
dac->dela_state = XFS_DAS_RD_LEAF;
trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
}
fallthrough;
case XFS_DAS_RD_LEAF:
/*
* This is the last step for leaf format. Read the block with
* the old attr, remove the old attr, check for shortform
* conversion and return.
*/
error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno,
&bp);
if (error)
return error;
xfs_attr3_leaf_remove(bp, args);
forkoff = xfs_attr_shortform_allfit(bp, dp);
if (forkoff)
error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
/* bp is gone due to xfs_da_shrink_inode */
return error;
case XFS_DAS_FOUND_NBLK:
/*
* Find space for remote blocks and fall into the allocation
* state.
*/
if (args->rmtblkno > 0) {
error = xfs_attr_rmtval_find_space(dac);
if (error)
return error;
}
fallthrough;
case XFS_DAS_ALLOC_NODE:
/*
* If there was an out-of-line value, allocate the blocks we
* identified for its storage and copy the value. This is done
* after we create the attribute so that we don't overflow the
* maximum size of a transaction and/or hit a deadlock.
*/
dac->dela_state = XFS_DAS_ALLOC_NODE;
if (args->rmtblkno > 0) {
if (dac->blkcnt > 0) {
error = xfs_attr_rmtval_set_blk(dac);
if (error)
return error;
trace_xfs_attr_set_iter_return(
dac->dela_state, args->dp);
return -EAGAIN;
}
error = xfs_attr_rmtval_set_value(args);
if (error)
return error;
}
/*
* If this was not a rename, clear the incomplete flag and we're
* done.
*/
if (!(args->op_flags & XFS_DA_OP_RENAME)) {
if (args->rmtblkno > 0)
error = xfs_attr3_leaf_clearflag(args);
goto out;
}
/*
* If this is an atomic rename operation, we must "flip" the
* incomplete flags on the "new" and "old" attribute/value pairs
* so that one disappears and one appears atomically. Then we
* must remove the "old" attribute/value pair.
*
* In a separate transaction, set the incomplete flag on the
* "old" attr and clear the incomplete flag on the "new" attr.
*/
error = xfs_attr3_leaf_flipflags(args);
if (error)
goto out;
/*
* Commit the flag value change and start the next trans in
* series
*/
dac->dela_state = XFS_DAS_FLIP_NFLAG;
trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
case XFS_DAS_FLIP_NFLAG:
/*
* Dismantle the "old" attribute/value pair by removing a
* "remote" value (if it exists).
*/
xfs_attr_restore_rmt_blk(args);
error = xfs_attr_rmtval_invalidate(args);
if (error)
return error;
fallthrough;
case XFS_DAS_RM_NBLK:
/* Set state in case xfs_attr_rmtval_remove returns -EAGAIN */
dac->dela_state = XFS_DAS_RM_NBLK;
if (args->rmtblkno) {
error = xfs_attr_rmtval_remove(dac);
if (error == -EAGAIN)
trace_xfs_attr_set_iter_return(
dac->dela_state, args->dp);
if (error)
return error;
dac->dela_state = XFS_DAS_CLR_FLAG;
trace_xfs_attr_set_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
}
fallthrough;
case XFS_DAS_CLR_FLAG:
/*
* The last state for node format. Look up the old attr and
* remove it.
*/
error = xfs_attr_node_addname_clear_incomplete(dac);
break;
default:
ASSERT(0);
break;
}
out:
return error;
}
/*
* Return EEXIST if attr is found, or ENOATTR if not
*/
static int
xfs_attr_lookup(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_buf *bp = NULL;
int error;
if (!xfs_inode_hasattr(dp))
return -ENOATTR;
if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
return xfs_attr_sf_findname(args, NULL, NULL);
if (xfs_attr_is_leaf(dp)) {
error = xfs_attr_leaf_hasname(args, &bp);
if (bp)
xfs_trans_brelse(args->trans, bp);
return error;
}
return xfs_attr_node_hasname(args, NULL);
}
/*
* Remove the attribute specified in @args.
*/
int
xfs_attr_remove_args(
struct xfs_da_args *args)
{
int error;
struct xfs_delattr_context dac = {
.da_args = args,
};
do {
error = xfs_attr_remove_iter(&dac);
if (error != -EAGAIN)
break;
error = xfs_attr_trans_roll(&dac);
if (error)
return error;
} while (true);
return error;
}
/*
* Note: If args->value is NULL the attribute will be removed, just like the
* Linux ->setattr API.
*/
int
xfs_attr_set(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
struct xfs_trans_res tres;
bool rsvd = (args->attr_filter & XFS_ATTR_ROOT);
int error, local;
int rmt_blks = 0;
unsigned int total;
if (XFS_FORCED_SHUTDOWN(dp->i_mount))
return -EIO;
error = xfs_qm_dqattach(dp);
if (error)
return error;
args->geo = mp->m_attr_geo;
args->whichfork = XFS_ATTR_FORK;
args->hashval = xfs_da_hashname(args->name, args->namelen);
/*
* We have no control over the attribute names that userspace passes us
* to remove, so we have to allow the name lookup prior to attribute
* removal to fail as well.
*/
args->op_flags = XFS_DA_OP_OKNOENT;
if (args->value) {
XFS_STATS_INC(mp, xs_attr_set);
args->op_flags |= XFS_DA_OP_ADDNAME;
args->total = xfs_attr_calc_size(args, &local);
/*
* If the inode doesn't have an attribute fork, add one.
* (inode must not be locked when we call this routine)
*/
if (XFS_IFORK_Q(dp) == 0) {
int sf_size = sizeof(struct xfs_attr_sf_hdr) +
xfs_attr_sf_entsize_byname(args->namelen,
args->valuelen);
error = xfs_bmap_add_attrfork(dp, sf_size, rsvd);
if (error)
return error;
}
tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
M_RES(mp)->tr_attrsetrt.tr_logres *
args->total;
tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
total = args->total;
if (!local)
rmt_blks = xfs_attr3_rmt_blocks(mp, args->valuelen);
} else {
XFS_STATS_INC(mp, xs_attr_remove);
tres = M_RES(mp)->tr_attrrm;
total = XFS_ATTRRM_SPACE_RES(mp);
rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);
}
/*
* Root fork attributes can use reserved data blocks for this
* operation if necessary
*/
error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
if (error)
return error;
if (args->value || xfs_inode_hasattr(dp)) {
error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
if (error)
goto out_trans_cancel;
}
error = xfs_attr_lookup(args);
if (args->value) {
if (error == -EEXIST && (args->attr_flags & XATTR_CREATE))
goto out_trans_cancel;
if (error == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
goto out_trans_cancel;
if (error != -ENOATTR && error != -EEXIST)
goto out_trans_cancel;
error = xfs_attr_set_args(args);
if (error)
goto out_trans_cancel;
/* shortform attribute has already been committed */
if (!args->trans)
goto out_unlock;
} else {
if (error != -EEXIST)
goto out_trans_cancel;
error = xfs_attr_remove_args(args);
if (error)
goto out_trans_cancel;
}
/*
* If this is a synchronous mount, make sure that the
* transaction goes to disk before returning to the user.
*/
if (mp->m_flags & XFS_MOUNT_WSYNC)
xfs_trans_set_sync(args->trans);
if (!(args->op_flags & XFS_DA_OP_NOTIME))
xfs_trans_ichgtime(args->trans, dp, XFS_ICHGTIME_CHG);
/*
* Commit the last in the sequence of transactions.
*/
xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
error = xfs_trans_commit(args->trans);
out_unlock:
xfs_iunlock(dp, XFS_ILOCK_EXCL);
return error;
out_trans_cancel:
if (args->trans)
xfs_trans_cancel(args->trans);
goto out_unlock;
}
/*========================================================================
* External routines when attribute list is inside the inode
*========================================================================*/
static inline int xfs_attr_sf_totsize(struct xfs_inode *dp)
{
struct xfs_attr_shortform *sf;
sf = (struct xfs_attr_shortform *)dp->i_afp->if_u1.if_data;
return be16_to_cpu(sf->hdr.totsize);
}
/*
* Add a name to the shortform attribute list structure
* This is the external routine.
*/
STATIC int
xfs_attr_shortform_addname(xfs_da_args_t *args)
{
int newsize, forkoff, retval;
trace_xfs_attr_sf_addname(args);
retval = xfs_attr_shortform_lookup(args);
if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
return retval;
if (retval == -EEXIST) {
if (args->attr_flags & XATTR_CREATE)
return retval;
retval = xfs_attr_sf_removename(args);
if (retval)
return retval;
/*
* Since we have removed the old attr, clear ATTR_REPLACE so
* that the leaf format add routine won't trip over the attr
* not being around.
*/
args->attr_flags &= ~XATTR_REPLACE;
}
if (args->namelen >= XFS_ATTR_SF_ENTSIZE_MAX ||
args->valuelen >= XFS_ATTR_SF_ENTSIZE_MAX)
return -ENOSPC;
newsize = xfs_attr_sf_totsize(args->dp);
newsize += xfs_attr_sf_entsize_byname(args->namelen, args->valuelen);
forkoff = xfs_attr_shortform_bytesfit(args->dp, newsize);
if (!forkoff)
return -ENOSPC;
xfs_attr_shortform_add(args, forkoff);
return 0;
}
/*========================================================================
* External routines when attribute list is one block
*========================================================================*/
/* Store info about a remote block */
STATIC void
xfs_attr_save_rmt_blk(
struct xfs_da_args *args)
{
args->blkno2 = args->blkno;
args->index2 = args->index;
args->rmtblkno2 = args->rmtblkno;
args->rmtblkcnt2 = args->rmtblkcnt;
args->rmtvaluelen2 = args->rmtvaluelen;
}
/* Set stored info about a remote block */
STATIC void
xfs_attr_restore_rmt_blk(
struct xfs_da_args *args)
{
args->blkno = args->blkno2;
args->index = args->index2;
args->rmtblkno = args->rmtblkno2;
args->rmtblkcnt = args->rmtblkcnt2;
args->rmtvaluelen = args->rmtvaluelen2;
}
/*
* Tries to add an attribute to an inode in leaf form
*
* This function is meant to execute as part of a delayed operation and leaves
* the transaction handling to the caller. On success the attribute is added
* and the inode and transaction are left dirty. If there is not enough space,
* the attr data is converted to node format and -ENOSPC is returned. Caller is
* responsible for handling the dirty inode and transaction or adding the attr
* in node format.
*/
STATIC int
xfs_attr_leaf_try_add(
struct xfs_da_args *args,
struct xfs_buf *bp)
{
int retval;
/*
* Look up the given attribute in the leaf block. Figure out if
* the given flags produce an error or call for an atomic rename.
*/
retval = xfs_attr_leaf_hasname(args, &bp);
if (retval != -ENOATTR && retval != -EEXIST)
return retval;
if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
goto out_brelse;
if (retval == -EEXIST) {
if (args->attr_flags & XATTR_CREATE)
goto out_brelse;
trace_xfs_attr_leaf_replace(args);
/* save the attribute state for later removal*/
args->op_flags |= XFS_DA_OP_RENAME; /* an atomic rename */
xfs_attr_save_rmt_blk(args);
/*
* clear the remote attr state now that it is saved so that the
* values reflect the state of the attribute we are about to
* add, not the attribute we just found and will remove later.
*/
args->rmtblkno = 0;
args->rmtblkcnt = 0;
args->rmtvaluelen = 0;
}
/*
* Add the attribute to the leaf block
*/
return xfs_attr3_leaf_add(bp, args);
out_brelse:
xfs_trans_brelse(args->trans, bp);
return retval;
}
/*
* Return EEXIST if attr is found, or ENOATTR if not
*/
STATIC int
xfs_attr_leaf_hasname(
struct xfs_da_args *args,
struct xfs_buf **bp)
{
int error = 0;
error = xfs_attr3_leaf_read(args->trans, args->dp, 0, bp);
if (error)
return error;
error = xfs_attr3_leaf_lookup_int(*bp, args);
if (error != -ENOATTR && error != -EEXIST)
xfs_trans_brelse(args->trans, *bp);
return error;
}
/*
* Remove a name from the leaf attribute list structure
*
* This leaf block cannot have a "remote" value, we only call this routine
* if bmap_one_block() says there is only one block (ie: no remote blks).
*/
STATIC int
xfs_attr_leaf_removename(
struct xfs_da_args *args)
{
struct xfs_inode *dp;
struct xfs_buf *bp;
int error, forkoff;
trace_xfs_attr_leaf_removename(args);
/*
* Remove the attribute.
*/
dp = args->dp;
error = xfs_attr_leaf_hasname(args, &bp);
if (error == -ENOATTR) {
xfs_trans_brelse(args->trans, bp);
return error;
} else if (error != -EEXIST)
return error;
xfs_attr3_leaf_remove(bp, args);
/*
* If the result is small enough, shrink it all into the inode.
*/
forkoff = xfs_attr_shortform_allfit(bp, dp);
if (forkoff)
return xfs_attr3_leaf_to_shortform(bp, args, forkoff);
/* bp is gone due to xfs_da_shrink_inode */
return 0;
}
/*
* Look up a name in a leaf attribute list structure.
*
* This leaf block cannot have a "remote" value, we only call this routine
* if bmap_one_block() says there is only one block (ie: no remote blks).
*
* Returns 0 on successful retrieval, otherwise an error.
*/
STATIC int
xfs_attr_leaf_get(xfs_da_args_t *args)
{
struct xfs_buf *bp;
int error;
trace_xfs_attr_leaf_get(args);
error = xfs_attr_leaf_hasname(args, &bp);
if (error == -ENOATTR) {
xfs_trans_brelse(args->trans, bp);
return error;
} else if (error != -EEXIST)
return error;
error = xfs_attr3_leaf_getvalue(bp, args);
xfs_trans_brelse(args->trans, bp);
return error;
}
/*
* Return EEXIST if attr is found, or ENOATTR if not
* statep: If not null is set to point at the found state. Caller will
* be responsible for freeing the state in this case.
*/
STATIC int
xfs_attr_node_hasname(
struct xfs_da_args *args,
struct xfs_da_state **statep)
{
struct xfs_da_state *state;
int retval, error;
state = xfs_da_state_alloc(args);
if (statep != NULL)
*statep = NULL;
/*
* Search to see if name exists, and get back a pointer to it.
*/
error = xfs_da3_node_lookup_int(state, &retval);
if (error) {
xfs_da_state_free(state);
return error;
}
if (statep != NULL)
*statep = state;
else
xfs_da_state_free(state);
return retval;
}
/*========================================================================
* External routines when attribute list size > geo->blksize
*========================================================================*/
STATIC int
xfs_attr_node_addname_find_attr(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
int retval;
/*
* Search to see if name already exists, and get back a pointer
* to where it should go.
*/
retval = xfs_attr_node_hasname(args, &dac->da_state);
if (retval != -ENOATTR && retval != -EEXIST)
return retval;
if (retval == -ENOATTR && (args->attr_flags & XATTR_REPLACE))
goto error;
if (retval == -EEXIST) {
if (args->attr_flags & XATTR_CREATE)
goto error;
trace_xfs_attr_node_replace(args);
/* save the attribute state for later removal*/
args->op_flags |= XFS_DA_OP_RENAME; /* atomic rename op */
xfs_attr_save_rmt_blk(args);
/*
* clear the remote attr state now that it is saved so that the
* values reflect the state of the attribute we are about to
* add, not the attribute we just found and will remove later.
*/
args->rmtblkno = 0;
args->rmtblkcnt = 0;
args->rmtvaluelen = 0;
}
return 0;
error:
if (dac->da_state)
xfs_da_state_free(dac->da_state);
return retval;
}
/*
* Add a name to a Btree-format attribute list.
*
* This will involve walking down the Btree, and may involve splitting
* leaf nodes and even splitting intermediate nodes up to and including
* the root node (a special case of an intermediate node).
*
* "Remote" attribute values confuse the issue and atomic rename operations
* add a whole extra layer of confusion on top of that.
*
* This routine is meant to function as a delayed operation, and may return
* -EAGAIN when the transaction needs to be rolled. Calling functions will need
* to handle this, and recall the function until a successful error code is
*returned.
*/
STATIC int
xfs_attr_node_addname(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_da_state *state = dac->da_state;
struct xfs_da_state_blk *blk;
int error;
trace_xfs_attr_node_addname(args);
blk = &state->path.blk[state->path.active-1];
ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
error = xfs_attr3_leaf_add(blk->bp, state->args);
if (error == -ENOSPC) {
if (state->path.active == 1) {
/*
* Its really a single leaf node, but it had
* out-of-line values so it looked like it *might*
* have been a b-tree.
*/
xfs_da_state_free(state);
state = NULL;
error = xfs_attr3_leaf_to_node(args);
if (error)
goto out;
/*
* Now that we have converted the leaf to a node, we can
* roll the transaction, and try xfs_attr3_leaf_add
* again on re-entry. No need to set dela_state to do
* this. dela_state is still unset by this function at
* this point.
*/
dac->flags |= XFS_DAC_DEFER_FINISH;
trace_xfs_attr_node_addname_return(
dac->dela_state, args->dp);
return -EAGAIN;
}
/*
* Split as many Btree elements as required.
* This code tracks the new and old attr's location
* in the index/blkno/rmtblkno/rmtblkcnt fields and
* in the index2/blkno2/rmtblkno2/rmtblkcnt2 fields.
*/
error = xfs_da3_split(state);
if (error)
goto out;
dac->flags |= XFS_DAC_DEFER_FINISH;
} else {
/*
* Addition succeeded, update Btree hashvals.
*/
xfs_da3_fixhashpath(state, &state->path);
}
out:
if (state)
xfs_da_state_free(state);
return error;
}
STATIC int
xfs_attr_node_addname_clear_incomplete(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_da_state *state = NULL;
int retval = 0;
int error = 0;
/*
* Re-find the "old" attribute entry after any split ops. The INCOMPLETE
* flag means that we will find the "old" attr, not the "new" one.
*/
args->attr_filter |= XFS_ATTR_INCOMPLETE;
state = xfs_da_state_alloc(args);
state->inleaf = 0;
error = xfs_da3_node_lookup_int(state, &retval);
if (error)
goto out;
error = xfs_attr_node_removename(args, state);
/*
* Check to see if the tree needs to be collapsed.
*/
if (retval && (state->path.active > 1)) {
error = xfs_da3_join(state);
if (error)
goto out;
}
retval = error = 0;
out:
if (state)
xfs_da_state_free(state);
if (error)
return error;
return retval;
}
/*
* Shrink an attribute from leaf to shortform
*/
STATIC int
xfs_attr_node_shrink(
struct xfs_da_args *args,
struct xfs_da_state *state)
{
struct xfs_inode *dp = args->dp;
int error, forkoff;
struct xfs_buf *bp;
/*
* Have to get rid of the copy of this dabuf in the state.
*/
ASSERT(state->path.active == 1);
ASSERT(state->path.blk[0].bp);
state->path.blk[0].bp = NULL;
error = xfs_attr3_leaf_read(args->trans, args->dp, 0, &bp);
if (error)
return error;
forkoff = xfs_attr_shortform_allfit(bp, dp);
if (forkoff) {
error = xfs_attr3_leaf_to_shortform(bp, args, forkoff);
/* bp is gone due to xfs_da_shrink_inode */
} else
xfs_trans_brelse(args->trans, bp);
return error;
}
/*
* Mark an attribute entry INCOMPLETE and save pointers to the relevant buffers
* for later deletion of the entry.
*/
STATIC int
xfs_attr_leaf_mark_incomplete(
struct xfs_da_args *args,
struct xfs_da_state *state)
{
int error;
/*
* Fill in disk block numbers in the state structure
* so that we can get the buffers back after we commit
* several transactions in the following calls.
*/
error = xfs_attr_fillstate(state);
if (error)
return error;
/*
* Mark the attribute as INCOMPLETE
*/
return xfs_attr3_leaf_setflag(args);
}
/*
* Initial setup for xfs_attr_node_removename. Make sure the attr is there and
* the blocks are valid. Attr keys with remote blocks will be marked
* incomplete.
*/
STATIC
int xfs_attr_node_removename_setup(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_da_state **state = &dac->da_state;
int error;
error = xfs_attr_node_hasname(args, state);
if (error != -EEXIST)
return error;
error = 0;
ASSERT((*state)->path.blk[(*state)->path.active - 1].bp != NULL);
ASSERT((*state)->path.blk[(*state)->path.active - 1].magic ==
XFS_ATTR_LEAF_MAGIC);
if (args->rmtblkno > 0) {
error = xfs_attr_leaf_mark_incomplete(args, *state);
if (error)
goto out;
error = xfs_attr_rmtval_invalidate(args);
}
out:
if (error)
xfs_da_state_free(*state);
return error;
}
STATIC int
xfs_attr_node_removename(
struct xfs_da_args *args,
struct xfs_da_state *state)
{
struct xfs_da_state_blk *blk;
int retval;
/*
* Remove the name and update the hashvals in the tree.
*/
blk = &state->path.blk[state->path.active-1];
ASSERT(blk->magic == XFS_ATTR_LEAF_MAGIC);
retval = xfs_attr3_leaf_remove(blk->bp, args);
xfs_da3_fixhashpath(state, &state->path);
return retval;
}
/*
* Remove the attribute specified in @args.
*
* This will involve walking down the Btree, and may involve joining
* leaf nodes and even joining intermediate nodes up to and including
* the root node (a special case of an intermediate node).
*
* This routine is meant to function as either an in-line or delayed operation,
* and may return -EAGAIN when the transaction needs to be rolled. Calling
* functions will need to handle this, and call the function until a
* successful error code is returned.
*/
int
xfs_attr_remove_iter(
struct xfs_delattr_context *dac)
{
struct xfs_da_args *args = dac->da_args;
struct xfs_da_state *state = dac->da_state;
int retval, error = 0;
struct xfs_inode *dp = args->dp;
trace_xfs_attr_node_removename(args);
switch (dac->dela_state) {
case XFS_DAS_UNINIT:
if (!xfs_inode_hasattr(dp))
return -ENOATTR;
/*
* Shortform or leaf formats don't require transaction rolls and
* thus state transitions. Call the right helper and return.
*/
if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL)
return xfs_attr_sf_removename(args);
if (xfs_attr_is_leaf(dp))
return xfs_attr_leaf_removename(args);
/*
* Node format may require transaction rolls. Set up the
* state context and fall into the state machine.
*/
if (!dac->da_state) {
error = xfs_attr_node_removename_setup(dac);
if (error)
return error;
state = dac->da_state;
}
fallthrough;
case XFS_DAS_RMTBLK:
dac->dela_state = XFS_DAS_RMTBLK;
/*
* If there is an out-of-line value, de-allocate the blocks.
* This is done before we remove the attribute so that we don't
* overflow the maximum size of a transaction and/or hit a
* deadlock.
*/
if (args->rmtblkno > 0) {
/*
* May return -EAGAIN. Roll and repeat until all remote
* blocks are removed.
*/
error = xfs_attr_rmtval_remove(dac);
if (error == -EAGAIN) {
trace_xfs_attr_remove_iter_return(
dac->dela_state, args->dp);
return error;
} else if (error) {
goto out;
}
/*
* Refill the state structure with buffers (the prior
* calls released our buffers) and close out this
* transaction before proceeding.
*/
ASSERT(args->rmtblkno == 0);
error = xfs_attr_refillstate(state);
if (error)
goto out;
dac->dela_state = XFS_DAS_RM_NAME;
dac->flags |= XFS_DAC_DEFER_FINISH;
trace_xfs_attr_remove_iter_return(dac->dela_state, args->dp);
return -EAGAIN;
}
fallthrough;
case XFS_DAS_RM_NAME:
/*
* If we came here fresh from a transaction roll, reattach all
* the buffers to the current transaction.
*/
if (dac->dela_state == XFS_DAS_RM_NAME) {
error = xfs_attr_refillstate(state);
if (error)
goto out;
}
retval = xfs_attr_node_removename(args, state);
/*
* Check to see if the tree needs to be collapsed. If so, roll
* the transacton and fall into the shrink state.
*/
if (retval && (state->path.active > 1)) {
error = xfs_da3_join(state);
if (error)
goto out;
dac->flags |= XFS_DAC_DEFER_FINISH;
dac->dela_state = XFS_DAS_RM_SHRINK;
trace_xfs_attr_remove_iter_return(
dac->dela_state, args->dp);
return -EAGAIN;
}
fallthrough;
case XFS_DAS_RM_SHRINK:
/*
* If the result is small enough, push it all into the inode.
* This is our final state so it's safe to return a dirty
* transaction.
*/
if (xfs_attr_is_leaf(dp))
error = xfs_attr_node_shrink(args, state);
ASSERT(error != -EAGAIN);
break;
default:
ASSERT(0);
error = -EINVAL;
goto out;
}
out:
if (state)
xfs_da_state_free(state);
return error;
}
/*
* Fill in the disk block numbers in the state structure for the buffers
* that are attached to the state structure.
* This is done so that we can quickly reattach ourselves to those buffers
* after some set of transaction commits have released these buffers.
*/
STATIC int
xfs_attr_fillstate(xfs_da_state_t *state)
{
xfs_da_state_path_t *path;
xfs_da_state_blk_t *blk;
int level;
trace_xfs_attr_fillstate(state->args);
/*
* Roll down the "path" in the state structure, storing the on-disk
* block number for those buffers in the "path".
*/
path = &state->path;
ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
if (blk->bp) {
blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
blk->bp = NULL;
} else {
blk->disk_blkno = 0;
}
}
/*
* Roll down the "altpath" in the state structure, storing the on-disk
* block number for those buffers in the "altpath".
*/
path = &state->altpath;
ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
if (blk->bp) {
blk->disk_blkno = XFS_BUF_ADDR(blk->bp);
blk->bp = NULL;
} else {
blk->disk_blkno = 0;
}
}
return 0;
}
/*
* Reattach the buffers to the state structure based on the disk block
* numbers stored in the state structure.
* This is done after some set of transaction commits have released those
* buffers from our grip.
*/
STATIC int
xfs_attr_refillstate(xfs_da_state_t *state)
{
xfs_da_state_path_t *path;
xfs_da_state_blk_t *blk;
int level, error;
trace_xfs_attr_refillstate(state->args);
/*
* Roll down the "path" in the state structure, storing the on-disk
* block number for those buffers in the "path".
*/
path = &state->path;
ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
if (blk->disk_blkno) {
error = xfs_da3_node_read_mapped(state->args->trans,
state->args->dp, blk->disk_blkno,
&blk->bp, XFS_ATTR_FORK);
if (error)
return error;
} else {
blk->bp = NULL;
}
}
/*
* Roll down the "altpath" in the state structure, storing the on-disk
* block number for those buffers in the "altpath".
*/
path = &state->altpath;
ASSERT((path->active >= 0) && (path->active < XFS_DA_NODE_MAXDEPTH));
for (blk = path->blk, level = 0; level < path->active; blk++, level++) {
if (blk->disk_blkno) {
error = xfs_da3_node_read_mapped(state->args->trans,
state->args->dp, blk->disk_blkno,
&blk->bp, XFS_ATTR_FORK);
if (error)
return error;
} else {
blk->bp = NULL;
}
}
return 0;
}
/*
* Retrieve the attribute data from a node attribute list.
*
* This routine gets called for any attribute fork that has more than one
* block, ie: both true Btree attr lists and for single-leaf-blocks with
* "remote" values taking up more blocks.
*
* Returns 0 on successful retrieval, otherwise an error.
*/
STATIC int
xfs_attr_node_get(
struct xfs_da_args *args)
{
struct xfs_da_state *state;
struct xfs_da_state_blk *blk;
int i;
int error;
trace_xfs_attr_node_get(args);
/*
* Search to see if name exists, and get back a pointer to it.
*/
error = xfs_attr_node_hasname(args, &state);
if (error != -EEXIST)
goto out_release;
/*
* Get the value, local or "remote"
*/
blk = &state->path.blk[state->path.active - 1];
error = xfs_attr3_leaf_getvalue(blk->bp, args);
/*
* If not in a transaction, we have to release all the buffers.
*/
out_release:
for (i = 0; state != NULL && i < state->path.active; i++) {
xfs_trans_brelse(args->trans, state->path.blk[i].bp);
state->path.blk[i].bp = NULL;
}
if (state)
xfs_da_state_free(state);
return error;
}
/* Returns true if the attribute entry name is valid. */
bool
xfs_attr_namecheck(
const void *name,
size_t length)
{
/*
* MAXNAMELEN includes the trailing null, but (name/length) leave it
* out, so use >= for the length check.
*/
if (length >= MAXNAMELEN)
return false;
/* There shouldn't be any nulls here */
return !memchr(name, 0, length);
}