@@ -26,7 +26,7 @@
#include "xfs_rtalloc.h"
/* Convert an xfs_fsmap to an fsmap. */
-void
+static void
xfs_fsmap_from_internal(
struct fsmap *dest,
struct xfs_fsmap *src)
@@ -155,8 +155,7 @@ xfs_fsmap_owner_from_rmap(
/* getfsmap query state */
struct xfs_getfsmap_info {
struct xfs_fsmap_head *head;
- xfs_fsmap_format_t formatter; /* formatting fn */
- void *format_arg; /* format buffer */
+ struct fsmap *fsmap_recs; /* mapping records */
struct xfs_buf *agf_bp; /* AGF, for refcount queries */
xfs_daddr_t next_daddr; /* next daddr we expect */
u64 missing_owner; /* owner of holes */
@@ -224,6 +223,20 @@ xfs_getfsmap_is_shared(
return 0;
}
+static inline void
+xfs_getfsmap_format(
+ struct xfs_mount *mp,
+ struct xfs_fsmap *xfm,
+ struct xfs_getfsmap_info *info)
+{
+ struct fsmap *rec;
+
+ trace_xfs_getfsmap_mapping(mp, xfm);
+
+ rec = &info->fsmap_recs[info->head->fmh_entries++];
+ xfs_fsmap_from_internal(rec, xfm);
+}
+
/*
* Format a reverse mapping for getfsmap, having translated rm_startblock
* into the appropriate daddr units.
@@ -288,10 +301,7 @@ xfs_getfsmap_helper(
fmr.fmr_offset = 0;
fmr.fmr_length = rec_daddr - info->next_daddr;
fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
- error = info->formatter(&fmr, info->format_arg);
- if (error)
- return error;
- info->head->fmh_entries++;
+ xfs_getfsmap_format(mp, &fmr, info);
}
if (info->last)
@@ -323,11 +333,8 @@ xfs_getfsmap_helper(
if (shared)
fmr.fmr_flags |= FMR_OF_SHARED;
}
- error = info->formatter(&fmr, info->format_arg);
- if (error)
- return error;
- info->head->fmh_entries++;
+ xfs_getfsmap_format(mp, &fmr, info);
out:
rec_daddr += XFS_FSB_TO_BB(mp, rec->rm_blockcount);
if (info->next_daddr < rec_daddr)
@@ -795,11 +802,11 @@ xfs_getfsmap_check_keys(
#endif /* CONFIG_XFS_RT */
/*
- * Get filesystem's extents as described in head, and format for
- * output. Calls formatter to fill the user's buffer until all
- * extents are mapped, until the passed-in head->fmh_count slots have
- * been filled, or until the formatter short-circuits the loop, if it
- * is tracking filled-in extents on its own.
+ * Get filesystem's extents as described in head, and format for output. Fills
+ * in the supplied records array until there are no more reverse mappings to
+ * return or head.fmh_entries == head.fmh_count. In the second case, this
+ * function returns -ECANCELED to indicate that more records would have been
+ * returned.
*
* Key to Confusion
* ----------------
@@ -819,8 +826,7 @@ int
xfs_getfsmap(
struct xfs_mount *mp,
struct xfs_fsmap_head *head,
- xfs_fsmap_format_t formatter,
- void *arg)
+ struct fsmap *fsmap_recs)
{
struct xfs_trans *tp = NULL;
struct xfs_fsmap dkeys[2]; /* per-dev keys */
@@ -895,8 +901,7 @@ xfs_getfsmap(
info.next_daddr = head->fmh_keys[0].fmr_physical +
head->fmh_keys[0].fmr_length;
- info.formatter = formatter;
- info.format_arg = arg;
+ info.fsmap_recs = fsmap_recs;
info.head = head;
/*
@@ -27,13 +27,9 @@ struct xfs_fsmap_head {
struct xfs_fsmap fmh_keys[2]; /* low and high keys */
};
-void xfs_fsmap_from_internal(struct fsmap *dest, struct xfs_fsmap *src);
void xfs_fsmap_to_internal(struct xfs_fsmap *dest, struct fsmap *src);
-/* fsmap to userspace formatter - copy to user & advance pointer */
-typedef int (*xfs_fsmap_format_t)(struct xfs_fsmap *, void *);
-
int xfs_getfsmap(struct xfs_mount *mp, struct xfs_fsmap_head *head,
- xfs_fsmap_format_t formatter, void *arg);
+ struct fsmap *out_recs);
#endif /* __XFS_FSMAP_H__ */
@@ -1716,39 +1716,17 @@ xfs_ioc_getbmap(
return error;
}
-struct getfsmap_info {
- struct xfs_mount *mp;
- struct fsmap_head __user *data;
- unsigned int idx;
- __u32 last_flags;
-};
-
-STATIC int
-xfs_getfsmap_format(struct xfs_fsmap *xfm, void *priv)
-{
- struct getfsmap_info *info = priv;
- struct fsmap fm;
-
- trace_xfs_getfsmap_mapping(info->mp, xfm);
-
- info->last_flags = xfm->fmr_flags;
- xfs_fsmap_from_internal(&fm, xfm);
- if (copy_to_user(&info->data->fmh_recs[info->idx++], &fm,
- sizeof(struct fsmap)))
- return -EFAULT;
-
- return 0;
-}
-
STATIC int
xfs_ioc_getfsmap(
struct xfs_inode *ip,
struct fsmap_head __user *arg)
{
- struct getfsmap_info info = { NULL };
struct xfs_fsmap_head xhead = {0};
struct fsmap_head head;
- bool aborted = false;
+ struct fsmap *recs;
+ unsigned int count;
+ __u32 last_flags = 0;
+ bool done = false;
int error;
if (copy_from_user(&head, arg, sizeof(struct fsmap_head)))
@@ -1760,38 +1738,113 @@ xfs_ioc_getfsmap(
sizeof(head.fmh_keys[1].fmr_reserved)))
return -EINVAL;
+ /*
+ * Use an internal memory buffer so that we don't have to copy fsmap
+ * data to userspace while holding locks. Start by trying to allocate
+ * up to 16 pages for the buffer, but fall back to a single page if we
+ * have to.
+ */
+ count = min_t(unsigned int, head.fmh_count,
+ (16 * PAGE_SIZE) / sizeof(struct fsmap));
+ recs = kvzalloc(count * sizeof(struct fsmap), GFP_KERNEL);
+ if (!recs) {
+ count = min_t(unsigned int, head.fmh_count,
+ PAGE_SIZE / sizeof(struct fsmap));
+ recs = kvzalloc(count * sizeof(struct fsmap), GFP_KERNEL);
+ if (!recs)
+ return -ENOMEM;
+ }
+
xhead.fmh_iflags = head.fmh_iflags;
- xhead.fmh_count = head.fmh_count;
xfs_fsmap_to_internal(&xhead.fmh_keys[0], &head.fmh_keys[0]);
xfs_fsmap_to_internal(&xhead.fmh_keys[1], &head.fmh_keys[1]);
trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]);
trace_xfs_getfsmap_high_key(ip->i_mount, &xhead.fmh_keys[1]);
- info.mp = ip->i_mount;
- info.data = arg;
- error = xfs_getfsmap(ip->i_mount, &xhead, xfs_getfsmap_format, &info);
- if (error == -ECANCELED) {
- error = 0;
- aborted = true;
- } else if (error)
- return error;
-
- /* If we didn't abort, set the "last" flag in the last fmx */
- if (!aborted && info.idx) {
- info.last_flags |= FMR_OF_LAST;
- if (copy_to_user(&info.data->fmh_recs[info.idx - 1].fmr_flags,
- &info.last_flags, sizeof(info.last_flags)))
- return -EFAULT;
+ head.fmh_entries = 0;
+ do {
+ struct fsmap __user *user_recs;
+ struct fsmap *last_rec;
+
+ user_recs = &arg->fmh_recs[head.fmh_entries];
+ xhead.fmh_entries = 0;
+ xhead.fmh_count = min_t(unsigned int, count,
+ head.fmh_count - head.fmh_entries);
+
+ /* Run query, record how many entries we got. */
+ error = xfs_getfsmap(ip->i_mount, &xhead, recs);
+ switch (error) {
+ case 0:
+ /*
+ * There are no more records in the result set. Copy
+ * whatever we got to userspace and break out.
+ */
+ done = true;
+ break;
+ case -ECANCELED:
+ /*
+ * The internal memory buffer is full. Copy whatever
+ * records we got to userspace and go again if we have
+ * not yet filled the userspace buffer.
+ */
+ error = 0;
+ break;
+ default:
+ goto out_free;
+ }
+ head.fmh_entries += xhead.fmh_entries;
+ head.fmh_oflags = xhead.fmh_oflags;
+
+ /*
+ * If the caller wanted a record count or there aren't any
+ * new records to return, we're done.
+ */
+ if (head.fmh_count == 0 || xhead.fmh_entries == 0)
+ break;
+
+ /* Copy all the records we got out to userspace. */
+ if (copy_to_user(user_recs, recs,
+ xhead.fmh_entries * sizeof(struct fsmap))) {
+ error = -EFAULT;
+ goto out_free;
+ }
+
+ /* Remember the last record flags we copied to userspace. */
+ last_rec = &recs[xhead.fmh_entries - 1];
+ last_flags = last_rec->fmr_flags;
+
+ /* Set up the low key for the next iteration. */
+ xfs_fsmap_to_internal(&xhead.fmh_keys[0], last_rec);
+ trace_xfs_getfsmap_low_key(ip->i_mount, &xhead.fmh_keys[0]);
+ } while (!done && head.fmh_entries < head.fmh_count);
+
+ /*
+ * If there are no more records in the query result set and we're not
+ * in counting mode, mark the last record returned with the LAST flag.
+ */
+ if (done && head.fmh_count > 0 && head.fmh_entries > 0) {
+ struct fsmap __user *user_rec;
+
+ last_flags |= FMR_OF_LAST;
+ user_rec = &arg->fmh_recs[head.fmh_entries - 1];
+
+ if (copy_to_user(&user_rec->fmr_flags, &last_flags,
+ sizeof(last_flags))) {
+ error = -EFAULT;
+ goto out_free;
+ }
}
/* copy back header */
- head.fmh_entries = xhead.fmh_entries;
- head.fmh_oflags = xhead.fmh_oflags;
- if (copy_to_user(arg, &head, sizeof(struct fsmap_head)))
- return -EFAULT;
+ if (copy_to_user(arg, &head, sizeof(struct fsmap_head))) {
+ error = -EFAULT;
+ goto out_free;
+ }
- return 0;
+out_free:
+ kmem_free(recs);
+ return error;
}
STATIC int